Intestinal immunity is finely regulated by several concomitant and overlapping mechanisms, in order to efficiently sense external stimuli and mount an adequate response of either tolerance or defense. In this context, a complex interplay between immune and nonimmune cells is responsible for the maintenance of normal homeostasis. However, in certain conditions, the disruption of such an intricate network may result in intestinal inflammation, including inflammatory bowel disease (IBD). IBD is believed to result from a combination of genetic and environmental factors acting in concert with an inappropriate immune response, which in turn interacts with nonimmune cells, including nervous system components. Currently, evidence shows that the interaction between the immune and the nervous system is bidirectional and plays a critical role in the regulation of intestinal inflammation. Recently, the maintenance of intestinal homeostasis has been shown to be under the reciprocal control of the microbiota by immune mechanisms, whereas intestinal microorganisms can modulate mucosal immunity. Therefore, in addition to presenting the mechanisms underlying the interaction between immune and nervous systems in the gut, here we discuss the role of the microbiota also in the regulation of neuroimmune crosstalk involved in intestinal homeostasis and inflammation, with potential implications to IBD pathogenesis. The enteric nervous system (ENS) constitutes a major autonomic division of the nervous system that provides the intrinsic innervation of the gut, capable of controlling different functions, such as motility, mucosal secretion and absorption, mucosal growth, local blood flow, and the immune function . The ENSNerve cells located within the mucosa are in close proximity to immune cells, where they produce and respond to several common mediators , 6. UponThe ENS, commonly called “the little brain of the gut,” is a constituent of the peripheral nervous system which is composed by an intrinsic network containing enteric neurons cell bodies, intestinal cells of Cajal (ICC), interneurons and motor neurons, and enteric glial cells (EGC). The latter have been extensively studied in recent years and consist of small cells with stellate shape that is associated with neuron cell bodies and nerve fibers in intraganglionic connections. Evidence supports that EGC are very similar to astrocytes, not only morphologically, but also functionally . All theThe myenteric plexus extends from the upper esophageal to the external anal sphincter, situated between the longitudinal and the circular muscle layer. The submucosal plexus is restricted to the submucosa of the small and large intestines. In human, for instance, two ganglionated submucosal plexuses can be distinguished. Thereby, there is an internal submucosal plexus, which lies in the inner half of the submucosa, and also an external submucosal plexus, this one situated close to the inner border of the circular muscle layer  Figure .In the present review, the current knowledge and the clinical implication of ENS in IBD will be discussed.Neurotransmitters are molecules produced by neurons that play a role in the transmission of information cell to cell, in maintaining stimulus of impulses, and act in the neuromuscular junction. When an action potential reaches the terminal button of a presynaptic neuron, a voltage-dependent calcium channel opens, resulting in the release of neurotransmitters in the synaptic cleft , 13. TheAcetylcholine (ACh) plays a role in both CNS and in ENS upon ligation with ACh receptors, ligand-dependent cation channels, of which the two major classes are the muscarinic and the nicotinic receptors , 16. TheAnother neurotransmitter, abundant in intestinal neuroendocrine cells, is serotonin . About 95% of 5-HT in the human body is found in GI tract and its action influences luminal contents and secretions . The mosSubstance P (SP) is localized in enteric nerves distributed throughout the gut and present in myenteric and submucosal plexuses , 26. TheNitric oxide (NO) is regarded as a cellular signaling molecule, which can play different roles in the GI tract, such as participating in the maintenance of mucosal integrity and also regulating vascular tone and the mucosal blood flow . NO is cDuring the course of IBD, the marked immune cell infiltration and the activation of mechanisms that modulate cell turnover within the intestinal epithelium can lead to permeability changes with potential disruption of the intestinal barrier –57. ThisIn the context of experimental colitis, enteric nervous abnormalities have also been reported in animal models. For example, results from a study using trinitrobenzene sulfonic acid- (TNBS-) induced colitis have shown that, in the beginning of inflammation, 20% of myenteric neurons are rapidly lost , and neuThe presence of neuropeptides and neurotransmitter receptors on immune cells represents a strong indication of the integration between the ENS and the immune system.In normal conditions, mucosal T cells respond to different environmental challenges orchestrating the immune response in an adaptable fashion . In IBD,Another interesting example of this integration is the evidence of hypothalamic-pituitary-adrenal axis regulation of intestinal inflammation , throughIn the intestinal mucosa, resident macrophages are usually present in the lamina propria where they preferentially locate in the subepithelial area to constitute the first line of defense against potentially harmful external stimuli . NeverthIn the gut, vagus nerve stimulation has anti-inflammatory properties, also known as cholinergic anti-inflammatory pathway, with influence on diverse immune-mediated disorders . For exaα7nAChR) is essential in acetylcholine inhibition of TNF-alpha production by macrophages [α7nAChR would probably be the ultimate intestinal target of such anti-inflammatory pathway [TNF-alpha, a prototypical Th-1-type of proinflammatory cytokine, associated with IBD and particularly with CD , can be rophages , reveali pathway . Like T cells, neutrophils are rarely observed in submucosal and myenteric plexuses in normal conditions, but during chronic active IBD these inflammatory cells accumulate and infiltrate the mucosa, contributing to the tissue injury  and possIn experimental colitis in rats, induced by dinitrobenzene sulfonic acid (DNBS) administration, Sanovic et al. demonstrated a significant neuronal reduction in the inflamed segments in the first 24 hours, with less than half of neurons remaining by days 4 to 6 and thereafter, when inflammation had diminished. The neuronal damage was associated with the early accumulation of neutrophils and eosinophils within the ganglia, an effect more prominent in the submucosal ganglia . In anotIn the past three decades, relevant evidences point to an important role of eosinophils in IBD –94. SmytMast cells play an important role in innate and adaptive immune responses by regulating the allergic reaction and defense against pathogens. Their growth and proliferation are regulated by cKit ligand stem cell factor (SCF), nerve growth factor (NGF), IL-3, IL-4, IL-9, and IL-10 . Under pIncreased mast cell numbers are observed in the proximity of mucosal enteric nerve fibers in a model of visceral hypersensitivity in rats . In a moPurinergic receptors, also known as purinoceptors, are transmembrane receptors including the P1 and P2 subtypes. P2 is composed of two subforms, namely, P2Y and P2X. P2Y, and its variants, is a G-protein coupled receptor, while P2X, and its variants, is a ligand gate ion channel . P2X7 isUnder physiologic conditions, intestinal barrier is relatively impermeable, but during pathologic conditions, barrier disruption has been associated with the development of GI diseases, including inflammatory disorders . RegardiThe genetic ablation of enteric glial cells using transgenic mice expressing herpes simplex virus thymidine kinase from the mouse glial fibrillary acidic protein (GFAP) promoter, performed by Bush et al., showed that when the animals were treated with ganciclovir, an increased inflammatory response ensued and led to death with an underlying severe jejunoileitis . In anotTrillions of bacteria colonize the gut, with hundreds of different species unevenly distributed throughout the GI tract, basically shaped by diet and immune and genetic factors of the host . In humaIn virtue of the potential ability of microorganisms to deregulate the physiological equilibrium, innate immune system is the first to respond to microbiota antigens through the recognition of microbial associated molecular patterns (MAMPs) at the transmembrane or cytosolic receptors, known as pattern recognition receptors (PRRs) , 136. ThUsing animal models, Brun et al. found that the absence of TLR2 determines changes in the architecture of the myenteric and submucosal plexuses, leading to bowel dysmotility and increased susceptibility to intestinal inflammation . In anotThe colonization of the gut by microorganisms starts early in life and is critically important in several functions of the normal GI physiology , 146 and E. faecalis proteins, namely, gelatinase, induced permeability in the colonic epithelia of mice, which was absent in PAR2-deficient animals [Another set of important receptors able to interact with the ENS and modulate neurally mediated intestinal functions is the proteinase-activated receptors (PARs), expressed in different cell types in the gut. PARs belong to a group of G protein-coupled receptors that are activated by proteolytic cleavage , 154. Bo animals . TogetheFinally, the accumulating evidence of multidirectional signaling involving the multiple components of the gastrointestinal system, including the bidirectional interplay by which the nervous system modulates the immune response, suggests that these neuronal circuits and neuromediators could be used for novel therapeutic strategies. In addition to gastrointestinal motility, sensitivity, and pain, such therapeutic approach should also provide the possibility of reestablishing immune tolerance and effective controlling chronic intestinal inflammation, for example, through the activation of the vagal anti-inflammatory pathway or the development of new pharmacological agents to control the afferent neuronal signaling.The CNS interacts dynamically with the immune system to modulate inflammation through humoral and neural pathways. Neuroimmune interactions within ENS can modulate gut functions, such as motility, ion transport, and mucosal permeability, contributing to the pathophysiology of several intestinal diseases, including IBD. Intestinal inflammation has been implicated in neuroplasticity, degeneration of the ENS, and alterations in the enteric glia, with an important contribution attributed to oxidative stress. The microbiota also plays a critical role in the intestinal homeostasis and neurogenic inflammation, as it drives postnatal development of the ENS, and affects the intrinsic and extrinsic nerve function and gut-brain signaling. Further investigation of these counterregulatory mechanisms will provide additional insights into neuroimmunomodulation, potentially leading to the identification of novel therapeutic targets for the treatment of inflammatory bowel disorders.


Working memory (WM) is one of key concepts to understand functions of the prefrontal cortex. Delay-period activity is an important neural correlate to understand the role of WM in prefrontal functions. The importance of delay-period activity is that this activity can encode not only visuospatial information but also a variety of information including non-spatial visual features, auditory and tactile stimuli, task rules, expected reward, and numerical quantity. This activity also participates in a variety of information processing including sensory-to-motor information transformation. These mnemonic features of delay-period activity enable to perform various important operations that the prefrontal cortex participates in, such as executive controls, and therefore, support the notion that WM is an important function to understand prefrontal functions. On the other hand, although experiments using manual versions of the delayed-response task had revealed many important findings, an oculomotor version of this task enabled us to use multiple cue positions, exclude postural orientation during the delay period, and further prove the importance of mnemonic functions of the prefrontal cortex. In addition, monkeys with unilateral lesions exhibited specific impairment only in the performance of memory-guided saccades directed toward visual cues in the visual field contralateral to the lesioned hemisphere. This result indicates that memories for visuospatial coordinates in each hemifield are processed primarily in the contralateral prefrontal cortex. This result further strengthened the idea of mnemonic functions of the prefrontal cortex. Thus, the mnemonic functions of the prefrontal cortex and delay-period activity may not need to be reconsidered, but should be emphasized. Since Jacobsen’s Tsujimoto and Postle  publisheHowever, WM is an important concept to understand functions of the prefrontal cortex. To understand the role of WM in prefrontal functions, delay-period activity is an important neural correlate. In this article, I emphasize an importance of delay-period activity to understand prefrontal functions based on characteristics of and information encoded by this activity. The importance of delay-period activity is that this activity can encode a variety of information and could participate in a variety of information processing. In addition, since spatial information affects the representation of various other kinds of information and since most of delay-period activity exhibits directional selectivity and contralateral bias, mnemonic hemianopia or scotoma must also be an important feature to understand prefrontal functions. Therefore, I emphasize mnemonic functions of the prefrontal cortex and delay-period activity in this article. Neither the concept of mnemonic scotoma nor the functional interpretation of delay-period activity need to be reconsidered.Since Jacobsen’s In the delayed-response task , baited position changes randomly  between right and left. Therefore, the subjects need to hold information of the baited position (right or left) during the delay period to perform the task correctly. If delay-period activity is a neural correlate of mnemonic processes holding the baited position, this activity should exhibit differential nature depending on the difference of the baited positions. Fuster and Alexander , Kubota Correct performance of the delayed-response task requires not only retaining spatial information regarding where the visual cue was presented, but also retaining information regarding where the response behavior will be directed. Which information does differential delay-period activity represent, information for the visual cues or response behavior? Niki and Watanabe  directlySince then, directionally selective delay-period activity has been reported in several studies while monkeys performed manual delayed-response tasks and manual delayed alternation tasks Niki, . AlthougFinding of differential delay-period activity was an important result for understanding mnemonic functions of the prefrontal cortex. However, the results described above had some weakness for interpreting delay-period activity as a neural correlate of spatial mnemonic processes in the prefrontal cortex. For example, all these studies used only two cues, which were usually located at right and left positions. Although it had been shown that prefrontal neurons encoded not absolute but relative spatial positions Niki, , examinaIn addition, although monkey’s hand and arm movements were controlled, monkey’s eye movements were not monitored and controlled. Eye movements and the direction of the gaze have been shown to strongly affect the magnitude of prefrontal activity. For example, many prefrontal neurons have been shown to exhibit eye movement-related activities  of delay-period activity was directionally selective, such that delay-period activity was observed only when the visual cues were presented at a particular area in the visual field. To describe directional characteristics of delay-period activity quantitatively, Funahashi et al.  construcNiki and Watanabe  found thAlthough Niki and Watanabe  and FunaThe results showing that more prefrontal neurons having delay-period activity encode sensory attribute than motor attribute were also obtained by the experiments using other tasks . Since spatial information of the object does not always need to hold during these task performances, these tasks are classified as non-spatial tasks. Lesions of the dorsolateral prefrontal cortex had shown to produce deficits in performing these non-spatial delay tasks  information, whereas accelerating type of the activity encodes motor intention or the expectation of the target stimulus (prospective information). Interestingly, Takeda and Funahashi  had alsoInformation encoded by delay-period activity in non-spatial delay tasks has been examined using rather simple visual stimuli  as sample and target stimuli. Freedman et al. , 2002 exWilson et al.  examinedIf the behavioral task includes a delay period imposed between the presentation of the sensory cue and the behavioral response, characteristic activities such as tonic and sustained excitation, or gradually increasing or decreasing activity are often observed during the delay period. A simple definition of delay-period activity is the activity observed during the delay period. Therefore, delay-period activity can be observed in any task condition if the task includes the delay period. And, delay-period activity can be observed in any brain areas. In fact, delay-period activity had been observed not only in the prefrontal cortex but also in the parietal cortex  when the visual cues are used for the task. However, the importance of delay-period activity is that this activity can encode a variety of information. Delay-period activity in the prefrontal cortex not only encodes visual information but also encodes tactile information  was limited. In addition, since the monkey’s behavior was not restrained in the cage, the monkey could freely move around during the task period as well as during the inter-trial interval, view the food wells from a variety of angles, and sit anywhere in the cage during the delay and response periods. Therefore, the experimenter could not control the activity of the monkey during the delay period. Thus, the WGTA used to examine this task and the unrestrained nature of the monkeys’ behavior made it difficult to interpret the psychological processes that were tapped by the delayed-response task and to assess the source of the difficulty observed in lesioned monkeys  has been proposed as “a cognitive system that temporarily holds a limited amount of information in an active state so that it may be quickly accessed, integrated with other information, or otherwise manipulated” (Drew and Vogel, Tsujimoto and Postle  claimed Wajima and Sawaguchi  also obsTsujimoto and Postle  also claThe author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Corynebacterium, more than a dozen oligotypes were detectable in each individual, of which a different subset reached high abundance in any given person. This pattern suggests that each mouth contains a subtly different community of organisms. We also compared the Chinese plaque community characterized here to previously characterized Western plaque communities, as represented by analyses of data emerging from the Human Microbiome Project, and found no major differences between Chinese and Western supragingival plaque. In conclusion, we found the plaque microbiome to be highly individualized at the oligotype level and characterized by stability of community membership, with variability in the relative abundance of community members between individuals and over time.Dental plaque is a bacterial biofilm composed of a characteristic set of organisms. Relatively little information from cultivation-independent, high-throughput analyses has been published on the temporal dynamics of the dental plaque microbiome. We used Minimum Entropy Decomposition, an information theory-based approach similar to oligotyping that provides single-nucleotide resolution, to analyze a previously published time series data set and investigate the dynamics of the plaque microbiome at various analytic and taxonomic levels. At both the genus and 97% Operational Taxonomic Unit (OTU) levels of resolution, the range of variation within each individual overlapped that of other individuals in the data set. When analyzed at the oligotype level, however, the overlap largely disappeared, showing that single-nucleotide resolution enables differentiation of individuals from one another without ambiguity. The overwhelming majority of the plaque community in all samples was made up of bacteria from a moderate number of plaque-typical genera, indicating that the overall community framework is shared among individuals. Each of these genera fluctuated in abundance around a stable mean that varied between individuals, with some genera having higher inter-individual variability than others. Thus, at the genus level, differences between individuals lay not in the identity of the major genera but in consistently differing proportions of these genera from mouth to mouth. However, at the oligotype level, we detected oligotype “fingerprints,” a highly individual-specific set of persistently abundant oligotypes fluctuating around a stable mean over time. For example, within the genus  This and other 16S rRNA gene-based studies used high throughput, large-scale cross-sectional sampling and documented a tremendous range of compositional variability between individuals and even between oral sites  classification at the genus level or phylotypes defined at the operational taxonomic unit (OTU) level of >97% sequence identity. These analyses provide a useful overview and allow comparison of complex data sets, but do not address the stability or variability of microbial communities at lower taxonomic levels, even when there is signal in the sequenced region of the marker gene to distinguish closely related but distinct members.Most studies of stability have drawn primarily upon summary community metrics, typically involving diversity metrics and/or distance metrics to quantify and relate communities over time. One popular analytic tool, UniFrac, provides a phylogeny-based distance metric for comparison of community composition . The HMP, in addition to gut, skin and vaginal sites, included sampling of 9 different sites in the oral cavity. Initial analysis at the genus level characterized some of the similarities and differences among the oral microbial communities . To eliminate the artificial length variation among reads introduced by the original quality trimming, we re-trimmed each read to 336 nucleotides and removed the reads that were shorter, which reduced the size of the data set by less than 10%. These reads were then aligned against the GreenGenes reference alignment  using PyNAST version 0.1 (biocore.github.io/pynast/) .We used R  in contrast to the variability of Prevotella (maroon) and Neisseria (dark blue). The distinction is also evident in the coefficient of variation. Five relatively constant genera, Streptococcus, Corynebacterium, Capnocytophaga, Fusobacterium, and Actinomyces, each had a coefficient of variation between 58 and 68% over all 64 samples  in any individual. As in the genus-level analysis, the abundance of taxa fluctuated about a mean that was stable for each individual. A stable mean within an individual, but sharp differences between individuals, was confirmed by examination of the coefficient of variation: for the 8 Corynebacterium oligotypes of high relative abundance, the mean within-mouth coefficient of variation was 45% in mouths in which that oligotype was >10% of the Corynebacterium but was much higher, 173%, across all samples from all individuals, reflecting the consistent abundance of these oligotypes in some mouths and their near-absence in others  clusters of filaments, providing the structural framework for the consortium. Streptococcus binds in abundance to the distal ends of these filaments, forming an outer shell of “corncob” structures. We hypothesize that this shell of Streptococcus alters the local biochemical environment by consuming oxygen and secreting lactate, acetate, carbon dioxide, and peroxide  and oligotypes identified sub-species-level groups, such as within the genera Corynebacterium and Capnocytophaga.The relationship of oligotypes to species-level groupings is not straightforward. Species-level taxonomy itself is not static, but is continually subject to refinement. Enterobacter. Takeshita et al. (Neisseria to be significantly more abundant in Koreans and Prevotella, Fusobacterium, and Veillonella more abundant in Japanese. A study of the oral mucosa of uncontacted Amerindians showed similar overall diversity to the oral microbiomes of developed Americans, but higher proportions of certain taxa including Prevotella, Fusobacterium, and Gemella (Clemente et al., Halomonas hamiltonii, to be abundant in subgingival plaque from healthy Korean volunteers. It may be that the presence of ethnic or cultural signatures varies by oral site with certain locations such as saliva and subgingival plaque being more sensitive to ethnic differences than others. Any such signatures, however, were undetectable in this study of the healthy supragingival plaque community.Our comparison of plaque 16S rRNA gene sequencing data from China and the United States showed that the plaque microbial community contains the same major genera and spans a similar range of variation in individuals from both cultures. Our results suggest that any systematic differences between Chinese and Western plaque, should they exist, lie in shifts of species composition within abundant genera, or in the presence and abundance of rare genera. In contrast to the lack of ethnic differences we found in the supragingival plaque community, previous studies have reported ethnic distinctions in other oral microbiomes. Mason et al.  studied a et al.  comparedRegardless of the question of ethnic signatures, our application of oligotype analysis to supragingival plaque highlights the importance of single-nucleotide analysis of microbial communities. Understanding of the individuality, stability and variability, the habitat and community dynamics, and the physiological or ecological meaning of microbial communities all would be deepened by analysis of sequence data at the highest level of resolution possible.JMW and GB conceived and designed the work; DU and JMW analyzed the data; and DU, JMW, and GB wrote the paper.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Mozambique suffers from a critical shortage of healthcare workers. Mid-level healthcare workers, ), in Mozambique require less money and time to train than physicians. From 2009–2010, the Mozambique Ministry of Health (MoH) and the International Training and Education Center for Health (I-TECH), University of Washington, Seattle, revised the TMG curriculum. To evaluate the effect of the curriculum revision, we used mixed methods to determine: 1) if TMGs meet the MoH's basic standards of clinical competency; and 2) do scores on measurements of clinical knowledge, physical exam, and clinical case scenarios differ by curriculum?T-tests of differences in means examined differences in continuous score variables between curriculum groups. Univariate and multivariate linear regression models assess curriculum-related and demographic factors associated with assessment scores on each of the three evaluation methods at the p<0.05 level. Qualitative interviews and focus groups inform interpretation.We found no significant differences in sex, marital status and age between the 112 and 189 TMGs in initial and revised curriculum, respectively. Mean scores at graduation of initial curriculum TMGs were 56.7%, 63.5%, and 49.1% on the clinical cases, knowledge test, and physical exam, respectively. Scores did not differ significantly from TMGs in the revised curriculum. Results from linear regression models find that training institute was the most significant predictor of TMG scores on both the clinical cases and physical exam.TMGs trained in either curriculum may be inadequately prepared to provide quality care. Curriculum changes are a necessary, but insufficient, part of improving TMG knowledge and skills overall. A more comprehensive, multi-level approach to improving TMG training that includes post-graduation mentoring, strengthening the pre-service internship training, and greater resources for training institute faculty may result in improvements in TMG capacity and patient care over time. The introduction and rapid scale up of Mozambique's Tecnico de Medicina Geral (TMGs) healthcare cadre, analogous to Clinical Officers in other settings, was driven by a persistent shortage and uneven distribution of medical doctors (MDs). In 2007, approximately 550 doctors served Mozambique's population of over 18 million, a ratio of 3 physicians per 100,000 people The need to generate more TMGs and to provide them with better professional training is a priority for the Mozambique MoH. Therefore, from 2009–2010, the Training Directorate of the MoH with the assistance of the International Training and Education Center for Health (I-TECH), University of Washington, Seattle, completely overhauled the TMG curriculum. The overarching goal of the curriculum revision was to strengthen the clinical competencies of these mid-level clinicians with the ultimate goal of improving healthcare for the people of Mozambique. The process of developing the new curriculum included a review and revision of the TMG Terms of Reference (including skill and knowledge competencies) to more closely align with the epidemiological profile of the country; the resulting curriculum increased emphasis on malaria, malnutrition, HIV, and TB. The collaborative effort also resulted in a change from the initial curriculum that was subject- and classroom-based to a revised curriculum organized around body systems that places increased emphasis on hands-on practice and mastery of clinical skills. Health Training Institute (HTI) faculty was involved in reviewing initial drafts of the curriculum, and their feedback was incorporated into the revision process. Faculty development and implementation of the revised curriculum began in July 2010 including a multiple-day training of faculty and administrators to help ensure consistent and confident implementation of the revised curriculum at each HTI.All training, initial and revised, was implemented at the HTIs of the MoH. Although HTIs vary in size and scope, all HTIs are located in urban or peri-urban centers in the provinces with campuses that include administration buildings, classrooms, practice laboratories, library and housing facilities. HTIs educate all health professionals other than MDs, including nurses, health agents, and non-medical specialties such as laboratory technicians. In either nationally-standardized curriculum, a mixture of full, part-time, and adjunct faculty implement courses at each HTI. The final class graduating under the initial curriculum was December, 2012. All eight HTIs that educate TMGs across the country now employ only the revised curriculum. Additional details on the processes of curriculum development and program implementation is detailed in a separate paper To evaluate the effect of the curriculum revision on the skills and capacities of the TMGs, we use mixed methods to determine: 1) to what extent did TMG graduates meet the MoH's basic standards of patient care, measured by their clinical competency? and 2) did cohorts trained in the revised curriculum score higher on measurements of clinical knowledge, physical exam procedures and solving clinical case scenarios, than those trained in the initial curricula? We compare clinical decision-making, clinical knowledge, and ability to perform a physical exam among 112 TMGs trained under the initial curriculum to 189 TMGs trained under the revised curriculum at two measurement periods: 1) immediately prior to graduation; and 2) ten months after graduation. For both curriculum groups at graduation only, qualitative interviews were conducted with key informants from the training institutions and with focus groups of TMGs to gage their perception of the strengths and weaknesses of their curriculum and to better understand factors that facilitate or hinder clinical competency. The results presented here use data from TMGs at baseline, immediately before graduation.It is expected that the results of the study will inform the MoH in the development of practical, relevant ways to improve the quality of pre-service training for non-physician health cadres in Mozambique and could be used to inform policies and decisions regarding pre-service education for all mid-level health workers. If shown to be effective, this curriculum design could be applicable to pre-service curricula for other health worker cadres in Mozambique and in the region.The study was approved by both the Centers for Disease Control in Atlanta, Georgia, USA and Mozambique's National Committee for Health Bioethics . The internal review board of the University of Washington determined that this evaluation was not human subjects research but a routine program evaluation, granting a non-research determination. A part of the approved protocol, a comprehensive study consent form was read to all potential TMG participants, and participation was voluntary. Students could complete their training without participating in the study. Each voluntary participant signed the informed consent for all quantitative and qualitative measurements prior to participation. Consent documentation was retained by the INS and stored in a locked cabinet.This post-test only comparison group evaluation will compare clinical knowledge and reasoning, ability to perform a physical exam, as well as the degree to which specific standards of clinical care are met by 112 TMGs trained under the initial curriculum with 189 TMGs trained under the revised curriculum at two measurement periods: immediately prior to graduation; and after ten months of clinical experience. The study design, outlined in TMG students eligible to graduate from all Health Training Institutes (HTIs) between September 2011 and July 2013 were recruited for voluntary enrollment in the study. Measurement at graduation took place in December 2011 in four HTIs that implemented the initial curriculum. Three HTIs graduated students in the revised curriculum in 2012, and an additional four HTIs graduated revised TMGs in July 2013. TMG students only took courses in their specific curriculum, minimizing opportunities for contamination.The sample size was calculated based on an expected 18% difference in mean scores between the initial and revised curriculum groups, increasing from a hypothesized 75% to 88.5%. Using G*power sample size calculator Facilitators and barriers to clinical competency were gathered through semi-structured interviews and focus groups following the clinical competency assessment at graduation. Interviews were conducted with HTI administrators or faculty; focus groups were conducted with 8–16 graduating TMGs per HTI. Weaknesses in the quality of the qualitative data identified in the first two rounds of data collection led to changes in the focus group guide for the final round of data collection for the revised curriculum group. Key informant and focus group questions are listed in To improve the assessment and overcome flaws in any one evaluation method Clinical simulation through case scenarios (vignettes) was chosen as a principle mean to obtain standardized, objective measurements of both clinical competence and reasoning skills of TMGs In addition to case simulation, a multiple-choice test was implemented to test a broader range of knowledge Lastly, physical examination skills were tested through a standardized checklist administered during a mock physical exam, excluding genital and rectal exams. The use of task-based methodology to assess skill demonstration and variation has been demonstrated in the context of both clinical performance and curriculum evaluation Outcome variables include: 1) continuous variable of average score across the 5 clinical case scenarios used to assess competency in specific clinical standards; 2) continuous score on the written, multiple choice exam to assess clinical knowledge and reasoning leading to decision-making on patient care for various conditions common to resource-poor countries; and 3) continuous score on the checklist used to assess physical exam skills.Independent variables include: 1) curriculum type ; 2) training institution; 3) demographic variables including age, marital status and gender.To reduce possible bias in the evaluation, I-TECH subcontracted with Mozambique's National Institute of Health , an autonomous technical and scientific institution subordinated to the Ministry of Health. INS responsibilities included collaboration on protocol development; assessment tool drafting and pre-testing; field team recruitment; quantitative and qualitative data collection; field logistics; data entry; data transcription, and first-line data quality assurance. I-TECH responsibilities included data quality assurance, data coding, and data analysis. A senior researcher from I-TECH and a senior clinician from INS were responsible for training the clinical evaluators who conducted the quantitative evaluations. MoH retains ownership of data.The INS led a five-day training prior to each implementation round that included study ethics, study design overview, preparation of field materials, field protocols, and evaluation task training. Medical doctors from provinces where HTIs are located were selected by the local health authority to serve as clinical evaluators and were rigorously trained on all assessment types prior to each study round. Two or three evaluators were selected to participate in the training and evaluation per HTI site. Practice evaluations and inter-rater exercises were performed during the five day training to reach standardization among the evaluators. Study coordinators reviewed logistic preparation and assisted with the training. At graduation, an INS team comprised of a coordinator, study assistant, and 2–3 evaluators was dispatched to each HTI. INS teams in each location explained the study, administered the written informed consent, filled demographic information, and solicited both immediate and follow-up contact information. Participants were assigned a study number for all evaluation materials to reduce potential for bias or data tampering. Names and study numbers were not linked during field implementation or analysis. A staff member from I-TECH observed the first week of field implementation.All data was collected, entered, and analyzed in Portuguese. Quantitative data from the clinical case scenarios, physical exam, and knowledge tests were analyzed using STATA 11.0 Demographics of 112 and 189 TMGs trained in the initial and revised curriculum, respectively, are presented in Results from linear regression models of factors that influence continuous scores on all three assessment types are presented in The same key informant interview and focus group guides were used for the initial curriculum group and for the first round of data collection among the revised group. Guides were changed for the second group of students under the revised curriculum group to better explore themes exposed by the initial quantitative findings. Among the initial curriculum school, in 2011, seven key informants and four focus groups were conducted; eight key informant and six focus groups were conducted in 2012; and additional twelve interviews and seven focus groups were conducted with the revised group in 2013. There were forty-five interviews and focus groups, combined. Of themes reported in more than half of all combined discussions, administrators and students noted three major weaknesses in the internship component of the training: the internship was too short; the tutoring received during the internship was of poor quality; and, overcrowding at the internship sites limited practice opportunities. Comments on how the rapid pace of the revised curriculum was detrimental for students or faculty was commonly noted, and discussions of weaknesses among HTI faculty and lack of hands-on practice time at the HTI often followed. On the positive side, both students and administrators frequently noted their appreciation of uniformity of the new curriculum within all HTIs, the provision of the course packets, and the organization of the training materials. However, both administrators and students complained that the number of course packets provided were insufficient, leading students to share learning materials between several students.Although the revised curriculum was intended to improve TMG training and lead to improvements in both knowledge and practice in this low resource setting, the evaluation results found no difference between initial and revised curriculum groups across evaluation types: case studies, knowledge test, or physical examination. We also found that overall scores of TMGs trained by both the initial and revised curriculum were not as high as we initially expected in any assessment type. On average, TMGs of both groups scored below 50% on the physical exam, and scored only marginally higher on the clinical case scenarios with an average score of 57%. Students fared better on the knowledge exam, with an average score of 63%. Although some students did exceptionally well on one or more of the assessment types, few TMGs in the initial or revised curriculum scored near the expected 75% or 88% achievement, respectively, hypothesized at study onset. These results suggest that TMGs from either curriculum may not have sufficient training to provide high quality clinical services upon graduation and that the revision of the pre-service curriculum, alone, did not improve TMG knowledge or skills. Qualitative results help illuminate these findings and shed light on some of the potential causes for the lack of change of between curriculum groups.Primarily, although the curriculum revision was intended to be implemented in the same way in all schools, significant HTI-based differences in clinical case and physical exam scores suggest that the facility-based differences may affect student achievement more than course content. Post hoc analysis of school-based differences  further In further exploration of HTI-based differences, the qualitative interviews reveal several key constraints which may have affected curriculum implementation. First, in order to meet national TMG training targets and more quickly address critical shortages in the healthcare workforce, the TMG training schedule was reduced from 36 months for the initial curriculum to 30 months for the revised program while maintaining the same competency expectations. Both administrators and student note that the quick pace of the revised curriculum puts teachers and students at a disadvantage. Administrators mentioned that some teachers have a hard time getting through the courses on the intended schedule while other faculty have little flexibility to make up classes if they were absent, leaving students with gaps in classroom or practice-based learning. For students, some TMGs may be unprepared for rigor of the new course having entered with poor secondary school preparation and insufficient study skills. Students and administrators both noted that the expectation of studying or teaching on nights, weekends, and holidays was detrimental to their ability to help students synthesize and retain information. Moreover, although many administrators and students spoke positively about the initial provision of course materials for all teachers and students by I-TECH, later semesters required that the HTI copy and provide these materials for their students using MoH funds. As most HTIs and students have few resources, five or six students often shared one course packet, severely curtailing learning. Furthermore, both administrators and students noted deficits in teacher quality and quantity including that the number of dedicated HTI teachers are few, many are tasked with training multiple cadres, some teachers do not have course-specific or appropriate levels of expertise, and existing expert teachers may be called away for other duties leaving vacancies. Lastly, although both administrators and students approved of the increased emphasis on practical versus classroom learning in the revised curriculum, many noted that there were too many students and too little time for the limited practice lab space at the HTI and that the laboratories, themselves, often lacked the basic materials such as stethoscopes or functional mannequins to practice.Outside of the HTI environment, factors associated with the quality of the internship component of the training present clear challenges to TMG skill acquisition. As part of both curricula, TMGs complete several standardized internships of various lengths at local health facilities or hospitals. However, administrators and students in both curriculum groups agree that there were several critical weaknesses of this training component. First, the internship sites are currently pre-selected by the MoH and are located in major population centers in the same province as the associated HTI. Students in TMG, nursing, and medicine programs often share practice sites with a limited number of on-site tutors and patients from whom to learn and practice. The overcrowding at practice sites strains tutor availability to teach and student ability to practice key skills. Second, both students and administrators noted the limited time that students spend at internship sites, both in hours per day and in days or weeks per topic rotation. Students are often expected to complete internship activities in the morning and return to the HTI for discussion in the afternoon, a scheduling decision that further limits TMG flexibility to observe, practice, and perfect the knowledge and skills needed to correctly manage patients from diagnosis through treatment. Third, the poor quality of the internship tutoring was noted commonly by students and administrators. Students suggested that tutor absences, limited teaching time, overcrowding at practice sites, and tutor reluctance to teach according to TMG-required competencies decreased the value of their internships. Administrators pointed out problems with the arrival of MoH-provided incentives for tutors as an explanation for why some medical doctors, clinical officers, and nurses tasked with mentoring TMG students may lack the motivation or desire to train TMGs. Overall, these gaps in experiential learning may leave some TMGs poorly prepared to assume their duties after graduation, reducing the quality of patient care.There are several limitations that affected the evaluation implementation and application of the results for policy or practice. Several deviations from the field implementation protocol may compromise the quality of the findings. First, the treatment section of the case studies (one of 5 sections) were updated between initial curriculum and revised curriculum to reflect guideline changes; therefore study instruments were not identical between curriculum groups. However, analysis of differences in scores (not shown) between groups on this section, alone, showed no significant variation and no further adjustment was made. Some challenges in the quality of study implementation at the field sites resulted in deviations from the initial randomization of students. As noted previously, the level of clinical cases varied significantly within topic groups. Although randomization meant that each student had an equal likelihood of getting a hard or easy case, the variation may have put some TMGs at a disadvantage. Second, the materials available to the TMGs to conduct the mock physical exam differed between and within schools . This may have caused bias in the scores of TMGs, but we are unable to determine the direction. Moreover, the evaluation was not designed to examine inter-HTI differences quantitatively. Further research that explores differences among the training institutes might better inform an HTI-specific, tailored intervention. Lastly, it is possible that the lack of effect between curriculum groups may be explained by Type III error, or failure to implement the program as intended. Examples from process evaluations conducted as part of the implementation and reviewed as part of background research suggest that components of the curriculum and its intended support structures were not implemented. Without the specified course materials, hands-on training practice, and trained faculty required by the curriculum, it is possible that students did not receive the full benefits of implementation. Despite these limitations, we believe that the findings from this field study provide insights on the realities of implementing, and evaluating, a revision of healthcare worker pre-service training in a low resource setting.This evaluation has several strengths. Primarily, to the best of our knowledge, this is the first standardized evaluation of this cadre of healthcare worker training in Mozambique. Also, the process of developing and implementing the evaluation was conducted in partnership with, instead of for, the MoH, which may help translate the findings more rapidly into policy changes at the national or HTI level. Moreover, the three-part assessment utilized for the evaluation provided a mechanism to triangulate responses, affording a more robust measure of performance. Additionally, the implementation of the study helped increase local capacity, improving the skills of the INS research team to conduct rigorous assessments of healthcare worker competency. Lastly, there is often a bias in the literature towards positive results. We believe that sharing the results of this study widely will help others learn from the possible weaknesses in the implementation of the curriculum revision program, contribute positively to discussions on how to improve health workers training, and help others avoid similar pitfalls in the future. Sharing the limitations of the design of our evaluation may also help others further strengthen evaluation of health training programs in the future.These results suggest that TMGs may be inadequately prepared to provide quality care immediately after graduation and that curriculum changes are a necessary, but insufficient, part of improving TMG knowledge and skills overall. Weaknesses at the HTIs and in TMG internship opportunities compromise the training of the TMGs, limiting the potential effectiveness of the curriculum revision, alone. We present several recommendations for administrators, faculty, and TMGs that may be helpful in further strengthening the TMG training. First, at the national level, recent reviews of task shifting efforts


Malaria disease shifts to older ages when interventions are applied only to the youngest children, and incidence will resurge in endemic settings when intervention coverage decreases. This has consequences for the deployment of long-lasting insecticide treated nets or infection blocking vaccines (e.g. pre-erythrocytic vaccines). These delay acquisition of immunity, with the result that previously protected individuals may experience pathology later in life due to undeveloped or waning immunity.Here we use a mathematical model to investigate the long-term population impact and cost-effectiveness of new interventions and address the reasons rebounds are observed in models when interventions are not renewed and relate to observations from field trials.Plasmodium falciparum dynamics, with varied assumptions about immunity decay, transmission heterogeneity, and access to treatment. The impact of transmission intensity, levels of access to malaria treatment and primary levels of intervention coverage and intervention profile are also considered. The main drivers of shifts in incidence are determined, examining model assumptions of age incidence, immunity, and initial exposure. The likely onset and duration of excess events in a treated cohort compared to a control is also examined for specific intervention profiles.The age and magnitude of age- and time-shifting of incidence is investigated using an ensemble of individual-based stochastic simulation models of In the absence of new interventions, or the redistribution of current interventions, we find that the underlying absence or loss of immunity resulting from previous lack of exposure is a primary driver of shifting of disease burden to older age groups. The simulations suggest that with short half-life interventions (~1 year), excess cases in the intervened cohort may be seen as soon as 3-4 years after intervention cessation. An excess of severe disease occurs sooner than one of uncomplicated disease, and sooner in high transmission areas than in low transmission areas. Because of slow build-up of natural immunity, excess incidence may be distributed over a long period after intervention cessation, making it unlikely that this will be detectable in field studies.This has important consequences for the design of transient interventions, in terms of both duration and demographics of deployment. Effective interventions will lead to initial decreases in malaria cases in a population, but these can be lost - or worse, redistributed in time and magnified in number and impact, without sustained efforts to decrease transmission.


Work-related health inequalities are determined to some extent by an unequal exposure to chemical and biological risk factors of disease. Although their potential economic burden in the European Union (EU-25) might be substantial, comprehensive reviews focusing on the distribution of these risks across occupational groups are limited. Thus, the main objective of this review is to provide a synopsis of the exposure to chemical and biological hazards across occupational groups. In addition, main industrial applications of hazardous substances are identified and some epidemiological evidence is discussed regarding societal costs and incidence rates of work-related diseases.Available lists of carcinogens, sensitisers, mutagens, reprotoxic substances and biological hazards were consulted. For each work-related hazard the main industrial application was identified in order to assess which ISCO occupational groups may be associated with direct exposure. Where available, information on annual tonnage production, risk assessment of the substances and pathogens, and other relevant data were collected and reported.Altogether 308 chemical and biological hazards were identified which may account to at least 693 direct exposures. These hazards concentrate on the following major occupational groups: technicians (ISCO 3), operators (ISCO 8), agricultural workers (ISCO 6) and workers in elementary occupations (ISCO 9). Common industrial applications associated with increased exposure rates relate among others to: (1) production or application of pigments, resins, cutting fluids, adhesives, pesticides and cleaning products, (2) production of rubber, plastics, textiles, pharmaceuticals and cosmetics, and (3) in agriculture, metallurgy and food processing industry, Societal costs of the unequal distribution of chemical and biological hazards across occupations depend on the corresponding work-related diseases and may range from 2900 EUR to 126000 EUR per case/year.Risk of exposure to chemical and biological risks and work-related disease incidence are highly concentrated on four occupational groups. The unequal burden of exposure across occupations is an important contributing factor leading to health inequalities in society. The bulk of societal costs, however, are actually being borne by the workers themselves. There is an urgent need of taking into account the health impact of production processes and services on workers’ health. Physical, chemical and biological risks still account for a substantial proportion of work-related diseases and fatalities in Europe . FrequenWhat is known is that despite great advances in occupational health surveillance in European countries in the last decades, adverse health outcomes are still more frequently observed among workers in hazardous occupations . MoreoveFurthermore it is clear that a proportion of diseases and corresponding economic costs is due to the unequal burden of exposure to chemical and biological hazards across occupations. For this reason, it is necessary not only to update and expand our knowledge on the etiological mechanisms associated with those hazards but also to identify the distribution of exposure across occupations in order to reduce more effectively the resulting work-related health inequalities . AlthougIn this context, the purpose of this review is to provide a synopsis of the distribution of specific chemical and biological risks across occupations. Besides other factors such as education, living conditions and income, these risks may contribute substantially to the causal mechanisms leading to work-related health inequalities. In order to fulfil the main objective the following tasks were undertaken: (1) identification of the occupational groups that may be at higher risk of exposure to specific carcinogens, sensitisers, mutagenic, reprotoxic and biological hazards, (2) identification of common occupational settings and industrial applications of hazardous substances, and (3) synthesis of some epidemiological evidence regarding the societal costs, assessment, incidence or methodological problems associated with those hazards.The identification of carcinogenic agents was based on the IARC classification and corresponding IARC-Monographs -12. OnlyThe identification of sensitising substances was based on the list of compounds published in 2013 by the German Commission for the Investigation of Health Hazards of Chemical Compounds (MAK-Commission) ,16. SensGroup A: damage to the embryo or foetus in humans has been unequivocally demonstrated and is to be expected even when occupational exposure limits are observed; (ii) Group B: damage to the embryo or foetus cannot be excluded after exposure to concentrations at occupational exposure limits, (iii) Group C: there is no reason to fear damage to the embryo or foetus when occupational exposure limits are observed, and (iv) Group D: either there are no data for assessment of damage or the currently available data are insufficient for classification in one of the groups A to C. In this review reprotoxic substances belonging to group B only are included.Most of the mutagenic (M) and reprotoxic substances (R) (i.e. toxic to reproduction) were taken from the German Technical Rules for Hazardous Substances 905 (TRGS 905) updated May 2008 . In ordeActinomyces spp., mycotoxins (low-molecular toxic metabolites of molds such as gliotoxin), and high-molecular toxic constituents of the cell membrane of fungi released once the fungus is dissolved  [The identification of biological hazards across ISCO categories was based on the systematic review published by J. Haagsma and collaborators . The assglucans) ,24.All information regarding use and manufacture of chemical substances and compounds related to carcinogenic, mutagenic, reprotoxic and sensitising agents was based primarily on Ullmann’s Encyclopedia of Industrial Chemistry, the Toxicology Data Network, PubChem Compound and Haz-Map databases developed by the US National Library of Medicine, the GESTIS-database on hazardous substances provided by the German Social Accident Insurance (IFA), and the eChemPortal provided by various international organisations -29. InfoSince a detailed cross-tabulation of occupational titles and exposure to each carcinogen, sensitiser, mutagen and reprotoxic agent is lacking, major ISCO groups were assigned to each substance. Only the first digit of the ISCO classification was used which forms the basis of the ISCO versions 1988 and 2008. This assignment was performed by taking into account, on the one hand, the major production processes and occupational settings implied in the use and/or manufacture of the agent, and on the other hand, those occupations for which a direct exposure can be assumed. The construction of a detailed job-exposure matrix was not pursued. Instead, the assignment serves only descriptive purposes. The major and sub-major occupational ISCO groups are listed in Table The procedure for assigning the ISCO categories to each hazard can be illustrated with two examples. The carcinogen benzene 71-43-2) is used in the production of plastics, resins, nylon fibres, dyes, detergents, and gasoline. According to the CAREX database most of the workers exposed to benzene are employed in the manufacturing, transport, wholesale and retail trade sectors. The corresponding major ISCO categories would correspond roughly to 3, 5, 8, and 9 respectively. The allergen methyl vinyl ketone (78-94-4) is used as a starting material for plastics and as an intermediate in the synthesis of steroids and vitamin A. Exposure may be expected among workers involved directly with this substance during manufacturing processes. Consequently, workers at risk are expected to be employed in occupations covered by ISCO categories 3 (technicians) and 8 (operators). The assignment of ISCO categories to the pathogens included in Section D of the Additional file -43-2 is The list of carcinogenic substances is reproduced in Section A of the Additional file As a consequence, exposures are concentrated in the ISCO groups associated with tasks usually performed in the craft, manufacturing, construction and mining sectors. From Table Epidemiological studies suggest that cancer incidence follows the distribution pattern of exposure to carcinogens. The results of a large census-based study on cancer incidence by occupational category in the Nordic countries indicate high standardised incidence rates (SIR) of all malignant neoplasms among men for occupations such as waiters, beverage, tobacco and metal workers, seamen, plumbers, packers, chimney sweeps, sales agents, miners and drivers. Among women high SIRs were observed for occupations such as journalists, clerical workers, construction workers, printers, tobacco workers, transport workers and waiters. In contrast, occupations with a low exposure to industrial agents such as farmers, gardeners and fishermen had the lowest SIRs for all malignant neoplasms (for details see Table eighty in ). RushtoKogevinas and colleagues  confirmeUnfortunately, economic analyses of the societal costs of work-related cancer in Europe are limited and difficult to perform given serious methodological difficulties regarding the estimation of attributable fractions and the lack of appropriate data. Nonetheless, Binazzi and colleagues  estimateThe list of sensitising substances is reproduced in Section B of Additional file A large body of epidemiological evidence on skin diseases in some European countries indicates that most of all occupational skin diseases (OSD) are due to irritant or allergic contact dermatitis  localised mostly on the hands and face . ICD is The incidence of OSD across occupational groups is rather consistent and corresponds to the increased exposure risks of specific occupational groups. Hairdressers and barbers show the largest incidence of OSD both in Germany and the UK with 97.4 and 11.6 cases per 10000 workers, respectively, followed by bakers and printers ,41. OtheAlthough research on societal costs of occupational skin diseases is rather limited, the direct and indirect costs of occupational hand eczema in Germany have been estimated in a study conducted in 2013 by Diepgen and colleagues . The annFrom the 143 sensitisers in Section B of the Additional file Respiratory sensitisers are associated with several respiratory diseases including irritation of mucous membranes, asthma, chronic bronchitis, chronic obstructive pulmonary disease and rhinitis ,47. AsthIncidence rates estimates of occupational asthma from several European countries report an unequal distribution of cases across occupational groups. Assuming that genetic susceptibility is randomly distributed across occupational groups, the unequal distribution of occupational asthma cases is related primarily to (i) the presence or absence of a latency period of airway obstruction associated mostly with allergic (IgE mediated) or irritant-induced asthma, respectively, (ii) the agent to which workers are exposed (low- vs. high-molecular-weight > 5 kDa), (iii) the duration of exposure and the agent concentration ,58.α-amylase) [In France, the United Kingdom, Sweden and Finland bakers and painters show the largest incidence rates per 10000 workers ranging from 6.8 in France to 44.8 for male bakers in Finland, and from 3.3 in France to 22.3 for male painters and lacquerers in Finland -56,59. Tamylase) . The excThuja plicata) are the main exposure for sawmill workers, carpenters and related wood processing workers showing relatively large incidence rates [In general, workers in the chemical, plastic and metallurgic industries are exposed primarily to low-molecular-weight agents such as metal compounds  and reactive chemicals (e.g. diisocyanates and anhydrides) which have extensive applications as resins, dyes, production of polyurethanes, adhesives, insulating foams, lacquers and metal alloys for welding. The risk for healthcare workers and cleaners is related to increased exposure to biocides  and cleaning products (e.g. quaternary ammonium compounds ), antiobce rates . The facce rates .A further complication of exposure to airway sensitisers is the fact that the majority of workers diagnosed with occupational asthma also suffer from occupational rhinitis, an inflammatory disease of the nose characterised by nasal congestion, variable airflow limitation and/or hypersecretion after exposure to sensitisers at the workplace . EpidemiOccupational asthma has a poor prognosis; once a worker develops occupational asthma after a latency period the chances of recovery are small . It has The list of some mutagenic and reprotoxic substances across occupational groups is reproduced in Section C of the Additional file Regarding occupational exposure to mutagenic substances of category 2, technicians (ISCO 3) and operators (ISCO 8) each are exposed to at least 5 substances, whereas professionals (ISCO 2), agricultural workers (ISCO 6), and workers in elementary occupations (ISCO 9) each to at least 1 substance  a total of 26 substances were identified. The most frequent industrial applications are in the manufacture and/or use of adhesives, lacquerers, cements, pesticides, leather, resins, rubber, solvents and plastics. Hence, occupational exposure is expected to occur mostly in technicians and operators (26 substances each), workers in elementary occupations (19 substances), and agricultural and craft workers (8 substances each).The risk assessment of mutagenic substances poses unique problems in comparison with carcinogens and sensitisers. First, conclusive epidemiological evidence of a causal association between exposure to chemicals or radiations and heritable gene mutations is lacking . This exNew developments in mutagenicity research are expected with the introduction of genomics technologies such as high-throughput sequencing analysis . In addiRegarding the associations between chemical substances and impaired fertility there are also several challenges for assessing potential hazards. These challenges encompass above all (i) validity issues affecting different endpoints of fertility including time to conception, infertility, and standardised birth ratio, (ii) the ability to control for major confounders of fertility such as drug and alcohol consumption, sexually transmitted infections, etc. (iii) methodological deficiencies of the studies  ,76.However, pooled estimates of the association between occupational exposure to pesticides and fecundability among fruit and greenhouse workers resulted in a substantial reduction of fecundability, especially when considering studies with improved assessment of occupational pesticide exposure . ConcernThe list of biological hazards across occupational groups are reproduced in Section D of the Additional file Some factors explaining the high concentration of biological hazards in the healthcare and biotechnology sectors and agriculture are related to the nature of work tasks , the environmental and the social context in which work is performed , and several characteristics of biological agents such as the routes of exposure, the pathogenicity, the mechanisms of transmission , the mechanisms of dissemination , the natural habitat of the biological agents, the particular characteristics of pathogen hosts and/or pathogen vectors and the clinical picture of the disease . From anThe excess risk of infectious diseases among healthcare workers is related to a large extent to the intense contact with body fluids and tissues, the exposure to airborne agents and percutaneous injuries. Even though great improvements have been achieved in industrialised countries concerning the risk of infection for major diseases such as tuberculosis, hepatitis and influenza in workers and the general population ,83, healIn contrast to workers in the healthcare and biotechnology sector, the exposure of veterinarians, farmers and agricultural labourers to biological agents are related to zoonoses, bacterial and parasitic infections and hypersensitivity reactions due to bioaerosols . FarmersBorrelia burgdorferi), tick-born encephalitis virus and human granulocytic anaplasmosis (caused by Anaplasma phagocytophilum), Q fever (caused by infection with Coxiella burnetii), and leptospirosis (caused by Leptospira spp.) are associated with outdoor activities in agricultural, forestry and veterinarian settings [Zoonoses, diseases transmitted between animals and humans, account also for a substantial excess risk of disease among veterinarians, agricultural and forestry workers. Among others, tick-borne diseases such as Lyme borreliosis  and mutidrug-resistant Gram-negative enteric pathogens (GNEP). Whereas the prevalence of MRSA in the general population has been estimated to be about 5%, prevalence among equine veterinarians and workers in small-animal hospitals has been estimated to be 10% and 18%, respectively [The emergence of antimicrobial-resistant bacteria in mass animal husbandry has raised further concern regarding occupational exposure and its possible public health consequences. Particular attention has been paid to methicilin-resistant ectively .In this review the distribution of work-related chemical and biological risks across major ISCO occupational groups was summarised. In particular, the following tasks were undertaken: (1) identification of the occupational groups that may be at higher risk of exposure, (2) identification of common occupational settings and industrial applications of hazardous substances, and (3) synthesis of some epidemiological evidence regarding the societal costs, assessment, incidence or methodological problems associated with chemical and biological occupational hazards.Altogether 308 chemical and biological hazards were identified which may account to at least 693 direct exposures. These hazards, however, concentrate on specific major occupational groups depending on the type of hazard under consideration. The majority of direct exposures are expected among technicians and associate professionals (ISCO 3), operators and assemblers (ISCO 8), agricultural workers (ISCO 6) and workers in elementary occupations (ISCO 9)  and the indirect costs . Estimates for some important outcomes such as cancer, occupational contact dermatitis and occupational asthma range from 2900 EUR to 126000 EUR per case/year  the ubiquity of hazardous chemicals in a huge variety of production processes and industrial sectors, (2) the number and production amounts of commonly used chemicals , (3) thThese challenges point to the urgent need of re-thinking the production process by taking into account the health impact on workers from the very beginning. This is particularly important in case of innovative production processes. The possibilities of eliminating or substituting chemical hazards, and the provision of a health-conducive organisation of work should be given high priority.This review suffers from several limitations. First, the exposure of managers and clerks has been underestimated . However, the epidemiological evidence summarised in the previous sections suggest that the exposure of managers and clerks is very low in comparison to other occupational groups. On the contrary, since exposure to one or more substances for single occupational titles in the rest of ISCO groups is not an uncommon phenomenon , it is possible that in fact the inequality of exposures might be even larger. Second, the assignment of ISCO groups is subjected to some extent to misclassification bias since the exact titles of exposed workers are not available for each single chemical and biological hazard. However, the complete lists provided in the Additional file Risk of exposure to chemical and biological risks and work-related disease incidence are highly concentrated on four occupational groups . The unequal burden of exposure across occupations is an important contributing factor leading to health inequalities in society. The bulk of societal costs, however, are actually being borne by the workers themselves. There is an urgent need of re-thinking the production process by taking into account the health impact on workers from the very beginning.The author declares that he does not have competing interests.Lists of occupational hazards. Supplementary tables of carcinogens, sensitisers, mutagens, reprotoxic substances and biological agents by ISCO-2008 major occupational groups.Click here for file


Lutzomyia longipalpis by Lutz and Neivamore than 100 years ago, much has been written in the scientific literature aboutthis phlebotomine species. Soares and Turco (2003) and Lainson and Rangel (2005) havewritten extensive reviews focused on vector-host-parasite interactions and Americanvisceral leishmaniasis ecology. However, during the last two decades, the success ofLu. longipalpis in colonising urban environments and itssimultaneous geographical spreading have led to new theoretical and operationalquestions. Therefore, this review updates the general information about this speciesand notes the more challenging topics regarding the new scenario ofurbanisation-spreading and its control in America. Here, we summarise the literatureon these issues and the remaining unsolved questions, which pose recommendations foroperational research.Since the description of  Lu. longipalpissuccessfully established itself and spread. In Brazil, since the first report in thecities of Teresina, state of Piauí, and São Luís, state of Maranhão (MA)  , AVL hashão (MA) . This sihão (MA) . TherefoThis same trend of AVL spreading with urbanisation has been observed in Paraguay since1998, when the first infected dogs and the Lu. longipalpis occurred on theborder with Paraguay, close to Asunción , a massive migration of poor families occurred and a rural settlement wasestablished. Between 1998-2000, eight cases of AVL were reported. In a long-term study(May 1999-May 2000), natural infection with the subgenusLeishmania sppwas found in 1.93% of cases  "first" AVL autochthonous urban or atypicalcases , (ii) urLu. longipalpis spread are discussed, the actualevidence from recent events should be taken into account, such as the lack of previousknowledge of cases or the presence of vector. New reports could appear due to theincrease in the awareness of AVL, acquired availability of diagnosis tools at the locallevel and "filling the gap" designs between two known endemic areas. In addition, somecases require in-depth studies to confirm or discard autochthony , land use and theintegrated energy supply networks that involved massive migrations of populations withtheir pets from endemic areas, the progressive deforestation (from "fishbone" tocrop-extensive cultures), changes in the value of the land and thus unplanned urbangrowth in poor socioeconomic conditions  and likely local climate changes due to regional human interventions . The AVL in the municipality of Rio deJaneiro was related to deforestation in a reserve to install high-voltage power lines, toSalto, Uruguay, in 10 years -9-methylgermacrene-B (S)-9-methylgermacrene/Lu.longipalpis populations were associated with the spread to the west, whilethe sibling cembrene-1/Lu. longipalpis populations were restricted toplaces with historical rural records , the temperature seasonalityand annual mean precipitation in MS . The criteria usedto define high abundance in the literature is usually an operational one, as naturalbreaks or quartiles, because there are no data about estimated thresholds oftransmission, especially as this could also differ between foci according to the supplyof parasites and availability of hosts. In Posadas, the changes in the vectordistribution between 2007 (3 human AVL cases) and 2009 (24 cumulated AVL cases) showedlimited growth, expansion and change of position for the sandfly patches of abundance, apattern consistent with metapopulation dynamics where the high-abundance hot spots couldact as source populations  and normalised difference water index with extremevalues , while the abundance was better associatedwith variables at both the micro and macro-habitat levels, such as peridomiciles withaccumulated unused material and greater number of plan-pots and number of tree species or human treatment have been reviewed by Lu.longipalpis in the environment. In this sense, an effective strategy forreducing disease would be vector control, especially in dwellings and peridomesticenvironments.The activities aimed to vector control depend upon the AVL transmission characteristicsat each locality . For theLu. longipalpisto reduce the man-vector contact. We do not include works on the use of dog-collars asthis method is actually intended to reduce canine visceral leishmaniasis, reducing thevector-reservoir contact, but it is neither expected nor has been demonstrated to haveany effect on the reduction of the vector population.In this review, we have gathered methods and results that were obtained only throughstudies aiming to control the population abundance of Indoor residual spraying (IRS) - The main strategy of chemical vectorcontrol is based on the use of insecticides, with residual action as the main step inthe collective protection. There are several classes of insecticides with residualaction: organochlorines (DDT), organophosphates , carbamates and syntheticpyrethroids  ( others) .Among the methods used to control sandfly vectors at the beginning of the 2000s,In countries where this method has been used in sustained Malaria Control Programs, asin Brazil and Venezuela, IRS is generally well accepted by householders because of theadditional protection against other vectors and annoying arthropods.Lu. longipalpis . Undoubtedly, in many situations the procedures are not adequatelymonitored.From the point of view of society, another point to be considered is the culture ofpopular groups; communities that are not informed about the diseases, to which they areusually exposed, have resistance or even refuse to accept practices that compromisetheir daily conditions of life.2). Kennels, hen-houses and stacks of adobe were also treated in thesame way. Sandfly captures previous to the intervention were compared with those after.As a result of the treatment, Lu. longipalpis disappeared from thehouses and animal shelters after nine and 10 months, respectively.On the other hand, because of the complaint of ecologists worldwide about environmentalcontamination by the indiscriminate use of DDT and because of human health hazards,attention was given to synthetic pyrethroids. One of the first field trials of thesecompounds was by Lu.longipalpis in the rural municipality of Santa Rita, Paraíba (PB), Brazil,was obtained by 2, 25 mg/m2 and 12.5 mg/m2, in comparison withthose collected in control houses sprayed with kerosene in water (1:100), with extremeirregularity in the captures.Conversely, a limited reduction (2-4 weeks) in the population of 2) wasapplied twice a year onto the internal and external walls of 10 houses, includingappended rooms and animal shelters  in Caxitu,municipality of Conde, on the south coast of PB. The results showed that the insecticidesignificantly reduced the indoor Lu. longipalpispopulations during thetwo months after the spraying and then they started to recover. The rates of mortalitywere variable depending on the kind of wall, but the residual effect after the fourthmonth was similar for the three types of walls in the area. No effect of the insecticidespraying on the occurrence of Lu. longipalpis was observed in theperidomestic habitat (Cypermethrin pyrethroid 31.2% wettable powder (WP)  of fenitrothion around the houses at 30 g/ha was applied in three cycles inthe village Santa Ana. The densities of the indoor Lu. longipalpisweresignificantly reduced in the target locality in comparison with the densities in thecontrol village Las Cabreras, while no significant reduction was achieved outdoors withSF. Wall bioassays showed that the residual effect of the insecticide lasted forapproximately three months. It was concluded that SF should only be used in epidemicsituations, while by moderately increasing the dose of the insecticide in IRS, theindoor population of Lu. longipalpis might be kept controlled,therefore also reducing the indoor transmission  at 25 mg/msmission .2 only on the external walls of threehouses, peridomestic dwellings and tree trunks up to 200 m from the houses. Three houseswithout spraying (control) and three houses not sprayed located just at the border ofthe intervention area (control of dispersion due to the insecticide) were also monitoredby Centers for Disease Control and Prevention (CDC) traps forLu.longipalpis abundance. The results showed a significant reduction in thesandfly captures up to seven days post-intervention in the target group, but, due to thehigh deviation of the data, it was not considered significantly different from thecontrols. Observations on human behaviour, resting outdoors during the summer at thehours of major peak of Lu. longipalpisfemales (09:30 pm-00:30 am) andLu. longipalpis behaviour  strengthened the need for a multidisciplinary approach forprevention strategies based both on biological and anthropological studies.2) in 10 districts of Montes Claros in thenorthern state of Minas Gerais, Brazil, in two cycles: November/2005 and May/2006. Theinsecticide was applied to the internal and external walls of 10 houses (1 per district)selected for the trial and their annexes  and inall neighbourhood houses. Two traps were placed in each residence for three consecutivedays a month, one inside the house and another in the peridomicile, totalling 20 traps.Lu. longipalpis was the predominant species, of which 85.8% of thetotal was collected outdoors. The two months prior to each spraying campaign(September-October/2005 and March-April/2006) were compared with the subsequent periods.The results showed that, two months after spraying, a significant reduction occurredonly outdoors. In the second spraying period, the differences between the pre andpost-spraying were significant at two months and four months after spraying, with theresidual effect lasting from two-four months.To conclude, it is worth noting that, regardless of the formulation used (EC or WP), inall of the trials mentioned above, it was confirmed that the residual effect ofpyrethroids does not exceed four months .Lu. longipalpis is a"species complex" whose populations could have different responses to the actions ofinsecticides, including vectorial competence  - It was thought thatITNs, a cheaper method than IRS, might represent the most suitable and sustainablemethod of reducing intradomiciliary transmission  (PermaNet®2.0). However, this was not significant in comparison to controls (number of sandfliescollected in homes with untreated nets as well as in homes with no nets), which led tothe thought that the use of the bednets was not regular, probably because the knowledgeaimed at the community before implementing this control measure was not entirelyappropriate .The same conclusion was reached after a field trial in San Mateo, state of Aragua,Venezuela, where the obtained results showed a reduction of the sandfly density in homeswith LLINs pre-treated with deltamethrin in a rural area in the district of Salvatierra, Marajó Island. The interventions were:(i) the spraying of all animal pens (blanket coverage), (ii) treating a subset of animalpens, using the same method, or (iii) by the installation oflambda-cyhalothrin-impregnated 1 m2 cotton sheets as "targets" . Following blanket intervention, catches at untreated dining huts increased,possibly because the blanket coverage diverted Lu. longipalpis awayfrom the major aggregation sites at animal pens and so the reduction in the abundance ofLu. longipalpis in CDC traps was not significant. Conversely, a 90%reduction in the Lu. longipalpisabundance of the sprayed sheds of thefocal intervention was detected. This differential impact was attributed to thedisruption of male pheromone production. It was recommended to treat all potentialaggregation sites to avoid an increase in the biting rate on dogs and humans and toapply an integrated control based on: (i) treatment of houses and dining-huts with anexcito-repellent insecticide, (ii) children sleeping under insecticide-treated bednetsand (iii) dogs being protected by the use of some sandfly repellent, like collars.With the aim to investigate the effect of insecticides on the abundance and distributionof peridomestic L. infantum and (iii) their zooprophylactic effect.Environmental, physiologic, socioeconomic and cultural factors related to raisingchickens in urban areas that might affect the transmission of L. infantumand whether this practice affects the risk to acquire AVL in Brazilian citieswere discussed. It was suggested that the perspective would be to explore, throughsocioeconomic surveys, the feasibility to apply inexpensive and sustainable preventivemeasures that are based on the communities' willingness to participate in the controlprogram, e.g., in the removal of chicken houses.The burden of urban AVL in Brazil led Lu. longipalpis and could be used to improve the effectiveness ofresidual insecticide attracting sandflies to insecticide-treated animal houses, as itwas tested in experimental chicken sheds  is usually the product of choice and has been used world-widefor over 50 years .More reEnvironmental management - Environmental management aims to reduceman-vector contact through interventions in an ecological niche where theepidemiological chain has been occurring. Essential measures such as street cleaning,removal and disposal of organic solid waste, eliminating sources of moisture andremoving domestic animals outside houses and animals shelters are procedures that canchange the conditions of the environment or eliminate substrates that favour theestablishment of the breeding of immature stages of vector, which impacts the populationcurve. Environmental management appears to be an effective tool for controlling AVL,considering that the expansion process of the disease is mainly associated with thepresence and distribution of the vector Lu. longipalpis, especiallywith its ability to easily adapt to domestic habitats and its remarkable feedingplasticity  of the populations at risk. Additionally,this tool may be useful to evaluate the impact of a control program (García & Borges2010).Lu.longipalpis involves an educational process that aims to encourage suchparticipation in a way that enhances and integrates popular knowledge in theirpractices.The creation of a healthy environment, focusing on eliminating or reducing thetransmission of AVL, depends upon practices that involve the community in a partnershipwith health services. Therefore, community participation in the control of Lu. longipalpis has crepuscular and nocturnal activity divulging to the community information about the occurrence of the disease in theregion, with warnings about the signs and clinical services for diagnosis and treatment,and (ii) training teams and developing practices in the community, through health andeducation services, with a wide spread of strategies and educational materials informingabout the disease and its transmission, in accordance with the attitudes, practices andliving conditions of the local groups .In Brazil, a KAP study was conducted in the endemic areas of MA amongst the ruralpopulation of the Codó township and in peripheral urban areas  andVila Nova/Bom Viver, Paço do Lumiar township (with recent establishment and occurrenceof cases). Although people were in general aware of the disease and they knew the vectorand the reservoir, they did not know how to control the disease. It was concluded thatthe knowledge about several aspects of AVL were poor in both the rural and theperipheral urban areas .To evaluate the impact of the AVL control program implemented during the years from1998-2000, in which a health education program was one of the measures applied inVenezuela, a KAP study was carried out in two communities, La Pista and La Guardia, onthe Margarita Island. The main differences between the two foci were the incidence ofAVL, the socioeconomic level and the time of residence in the endemic area. Throughinterviews, it was found that people living in La Pista, the community with longerresidence in the area, knew more about the disease. However, knowledge about preventionand control was very poor in both localities. It was stressed that KAP studies previousto the control actions are necessary to obtain a baseline for the management andsustainability of educational programs about the prevention and control of VL (García& Borges 2010).Furthermore, KAP studies are required as baseline data or input for the design ofintervention strategies, as health education programs should not be isolated or "topdown" unidirectional measures. Research on the social determination of AVL risk and theactual agency of the individuals to accomplish the heath system recommendations, inaddition to the social construction and perception of risk by each social groupinvolved, also contribute to contextualising the problem and the solutions. Therefore,the transdisciplinary systemic perspective, joining the biological and socialcontextualisation, is an essential approach to promote community participation beyondjust community collaboration. This participation implies thinking together with thecommunity about the more appropriate measures for environment and animal management andpersonal protection as applied in the actual territory where the people are living.Multisectorial involvement is also necessary for sustainable programs, defining theactivities and responsibilities of the public and private sectors and consolidating acommon frame of risk .Lu. longipalpisrequires us to discriminate between both issues according to spatial and temporalscales. The actual mechanism of dispersion of the vector at each scale by field andgenetic research should be addressed to contribute to design control strategies.The analysis of the spread of AVL and urbanisation of ex-ante eventual outbreaks.At the macro-scale, to think in the frame of macro-economic trends, the consequentenvironmental/climatic changes and social determination of health would allow us todefine prevention policies and control strategies at the country-continental level. Inactual or potential risk areas, the main projects that imply environmental intervention and human movements should include leishmaniasesin the assessment of risk and an appropriate monitoring design and responsibilitydefinitions to act Lu.longipalpis will improve the resource allocation and prevention measuresperformance at the programmatic and county level. The local environmental disturbancesand changes in land use with the growth of peripheral neighbourhoods (deforestation) anddisorganised urbanisation with poor sociosanitary conditions  should also be monitored for leishmaniasis risk.In the meso-scale, to understand the factors that drive the deforestation-urbanisationprocess, the distribution and the metapopulation dynamics of the urban At the micro-scale, the factors that determine the presence and abundance of the vectorsare better known, allowing us to work together with the community and the county todesign sustainable control strategies adapted to the local level and focused on theprivate and public environments, domestic animal management and the actual capacity ofagency of the families to afford the programmatic recommendations.Lu. longipalpis indicatesthat it is required to be part of an integrated control program that involvestransdisciplinary teams at least at the country level, with experts from thebio-medical, bio-ecological and social sciences in the frame of the ecohealth systemicperspective. Such a program would thus include chemical focus control, environmentalmanagement, health education and community participation. This program should includethe periodic training of agents of health, zoonosis control, education and environmentalprotection agencies  and entomological studies . The control program agentscould perform these studies together with researchers by intersectoral collaboration.The analysed information, when shared and discussed with decision-makers, relevantstakeholders and the involved community, will allow us to translate the research resultsinto actual, feasible and effective measures  and the contents ofhealth education programs for empowering the actors. In this sense, health promoters andcommunity leaders could follow and evaluate the proposed measures, providing furthersustainability. The use of LLINs is recommended, especially in youngsters, but itrequires prior work to solve issues about acceptability, affordability, equity andcorrect use. On the other hand, entomological surveillance at the local level in a ruralfocus of low steady endemicity should be performed as a "continuous observation andassessment of information"  withquaLu. longipalpis control should requirestandardised protocols for the impact assessment of integrated actions, both in theshort and long term. Networks are also needed for monitoring resistance to insecticidein wild and domestic populations of Lu. longipalpis, in addition tostudies on sibling and other species vectorial capacity, such as Lutzomyiacruzi . Socialstudies should be aware of the social determination and consequent spatial segregationof risk as well as the different accessibility to the health system and basic urbansanitary services between different social groups. The practices and actors associatedwith the transit, traffic and management of dogs should be taken into account, asownership practices have individual, corporative  and public sector (dog population programs andpublic areas) responsibilities. Therefore, the intersectoral teams in urban scenarioshave a broader composition, including the media and agents from different countyservices . Regarding programmatic surveillance, it shouldbe designed according to the intensity of transmission in the locality and thespace-time distribution of vector abundance inside the locality. Due to the lack ofstronger evidence for residual effectivity, chemical control with IRS is not a generallyrecommended measure in urban foci. Additionally, indoor insecticide cycles could berejected by urban householders. Otherwise, IRS requires eco-epidemiological scenariosthat are fairly characterised and must be performed with a supervised protocol ofapplication and a rigorous design of evaluation . Furthermore, theoperational research on AVL and cruzi de  andMigonmigonei .