Background: Our aim was to analyze the association of self-reported mentally-passive and mentally-active sedentary behaviors with different patterns (bouts and breaks) of device-measured sedentary time in adolescents. Methods: This was a cross-sectional study conducted among 375 adolescents (177 boys) aged 1015 years. Total time, bouts and breaks of sedentary time were measured through accelerometers. Self-reported sedentary behavior in different activities was summed and divided into mentally-active  and mentally-passive . Bayesian linear regression models were used for association analyses. Results: Only mentally-passive sedentary behaviors were positively associated with longer bouts  and lower number of breaks [-0.138 (-0.228 to -0.044)] of device-measured sedentary time. Conclusion: Self-reported mentally-passive sedentary behaviors are associated with longer bouts and lower breaks of device-measured sedentary time. Here, we propose that different types of sedentary behavior  can be accumulated in different patterns. Sedentary behaviors that require minimal cognitive efforts  can be accumulated in higher bouts, while mentally-active behavior can be accumulated with fewer or higher number of breaks. However, these assumptions have not tested in previous studies among adolescents. Previous studies among older adults found that passive sedentary behaviors as TV-viewing and computer use during leisure-time were associated with prolonged bouts of sedentary time.13 This type of investigation is particularly important among adolescents as it could inform specific strategies and interventions on the type of activity and pattern of behavior. Therefore, our aim was to analyze the association of self-reported mentally-active and mentally-passive sedentary behavior with different patterns of device-measured sedentary time (bouts and breaks) among adolescents.Given the potential association between sedentary behavior patterns (length of bouts or number of breaks) and cardiovascular risk factors such as metabolic risk and obesity,th year of elementary school, 2) Willing to wear accelerometer for at least seven consecutive days and 3) Delivery of the signed informed consent form by the legal guardian. Adolescents were excluded from the sample if they reported using prescribed medicines or were being treated for a disease. The sample size was estimated considering eight participants per correlate plus 50 participants.14 As the initial aim of the project was to estimate correlates of sedentary time, 47 correlates were included, resulting in a minimal sample of 426 adolescents. However, only 375 adolescents presented valid accelerometer data. From 680 initial participants, 286 did not present valid accelerometer data  and five adolescents presented missing data on the covariates and, therefore, were excluded from final sample.This was a school-based cross-sectional study, conducted between October 2015 and May 2017, in primary public schools in Londrina, Paraná, Brazil, involving adolescents of both sexes, aged between 10 and 14 years old. Regarding the sample process, all the public schools of the city were first divided into regions , and two schools were randomly selected from each region. Classes were then randomly selected from schools and all the students in these classes were invited to participate in the study. The inclusion criteria were 1) Be regularly enrolled in the 615 The criterion of 60 minutes of consecutive zeros was utilized to determine the non-wear time.15 Sedentary behavior was classified using cut-points developed for ActiGraph vector magnitude counts (180 counts.15s-1) in Brazilian adolescents.16 Bouts are defined as uninterrupted periods in sedentary behavior17 (drop time = 0) with durations of 1-4 minutes, 5-14 minutes and ≥15 minutes. Breaks were defined as the non-sedentary period between two sedentary bouts.17 For analytic purposes, total sedentary time and time accumulated in bouts were expressed as percentage values , while breaks were expressed as mean frequency by hour (breaks.hour-1).ActiGraph  GT3X and GT3X-Plus models were used to assess device-measured sedentary time patterns. Participants were asked to wear the accelerometer on the right side of the hip for seven consecutive days; only to be removed during shower, aquatic activities and sleep time. For the present study, 15 s epochs were used . Adolescents with at least four valid days  registered by the accelerometer were included in the analyses.6 and two continuous indicators were created. The reproducibility was tested using a sample of 25 adolescents with similar characteristics, which were not included in the final sample. We found the following reproducibility, with a one-week interval, for the questions (in intra-class correlation coefficients - ICC): watching TV = ICC: 0.90, watching DVD = ICC: 0.33, using computer for leisure = ICC: 0.72, playing electronic games = ICC: 0.54, studying = ICC: 0.87 and reading = ICC: 0.79.Domains of self-reported sedentary behavior were assessed through general questions about different sedentary behaviors: “Considering a typical weekday (Monday to Friday), how much time do you spend… (e.g. watch TV)” and “Considering a typical weekend day (Saturday and Sunday), how much time do you spend… (e.g. watch TV)”. These questions were asked for watching tv, watching DVD, using computer for leisure, playing electronic games, studying and reading, with 6 possible answers: (a) none, (b) less than 1 hour, (c) between 1 and 2 hours, (d) between 2.01 and 3 hours, (e) between 3.01 and 4 hours, (f) more than 4 hours. Mean time spent in each behavior was computed (e.g. less than 1 hour was transformed to 0.5 hours) and behaviors were divided into mentally-passive  and mentally-active  according to the expected cognitive demand. The mean time in each categories of sedentary behavior was summed,18), cardiorespiratory fitness (Léger 20-m shuttle run test), and body mass index (through measures of stature and height), were adopted as covariates. Socioeconomic status was assessed through the ABEP questionnaire.19Sex, chronological age, somatic maturation  with different bouts  and breaks of device-measured sedentary time (treated as outcomes). Mean posterior distribution and the respective 95% credible intervals were used. All analyses were performed using the software Stata 15.1 .Our final sample was composed of 375 adolescents (177 boys), aged between 10.3 and 14.5 years. Characteristics of sample are presented in The association between different types of self-reported sedentary behavior and bouts and breaks of sedentary time is shown in Our aim was to analyze the association of mentally-passive and mentally-active self-reported sedentary behavior with device-measured sedentary time patterns. Our main findings were that self-reported mentally-passive sedentary behavior was associated with longer bouts and lower number of breaks in sedentary time. Self-reported mentally-active sedentary behavior was consistently not associated with patterns of device-measured sedentary time. To our knowledge, this was the first study to investigate the associations of types of self-reported sedentary behavior and patterns of device-measured sedentary time among adolescents.4 metabolic syndrome risk,2 lower cognition8 and depressive symptoms.3 However, previous findings also reported that different types of sedentary behaviors can have different roles in the association with mental health,5 given that mentally-passive behaviors such as TV-viewing have been especially associated with poorer indicators of mental health. Recently, studies found that mentally-passive sedentary behavior was associated with higher rates of depression among adults, while mentally-active sedentary behavior was not consistently associated or even protective of depression.7 The cognitive demands and occupational pathways have been used to explain these findings between different type of sedentary behavior and mental health outcomes.20Sedentary behavior, among adolescents, is associated with several negative health outcomes such as obesity,21 Thus, our finding could be an alternative potential mechanism that can be used to explain and understand the nexus between sedentary behaviors and health outcome. The present finding suggests that breaks and bouts of sedentary time might be potential variables that can be explored in future studies as the mediators of the association between self-reported mentally-passive sedentary behaviors and health outcomes.Beyond the total time and type of activity, the pattern of sedentary behavior is associated with health outcomes.22 In this pathway, elevated inflammatory cytokines levels are associated with poorer mental health indicators.23 Also, longer bouts are associated with greater levels of adiposity,4 which is also associated with poorer mental health.24 Current findings should be considered for further studies on the association between sedentary behavior and health outcomes. Possibly, the negative impact of sedentary behavior, especially on mental health, could be better explained when the patterns and cognitive demand of sedentary behaviors or even their interactions are taken into consideration in future studies.Higher uninterrupted time in sedentary behavior is associated with several alterations on metabolism, including the elevation of inflammatory levels, especially due to lack of muscle contraction and consequently release of anti-inflammatory hormones.25 For example, computer use is higher among older adolescents, while TV-viewing is similar among younger and older adolescents.26 Also, there are several social  and environmental (e.g. availability of electronic devices as television inside the bedroom) determinants associated with longer mentally-passive sedentary behavior.28Our findings highlight that future interventions should be focused on reducing mentally-passive sedentary behavior activities, such as TV-viewing, computer using for leisure and DVD viewing. To achieve the reduction of sedentary behavior, interventions should explore the potential determinants of the specific behaviors aiming to create different strategies and priority groups to focus on different types and manifestations of sedentary behavior.Our results should be interpreted in the light of the potential limitations. First, due to a limitation from the questionnaire, the maximum amount of time answer for each type of sedentary behavior was 4 h/d, which can be a potential bias. However, the prevalence of the highest category was low. Second, we were not able to adjust the analyses for other potential mediators/confounders as inflammation and cognition. However, this is the first study to explore this new pathway between device-measured and self-reported measures of sedentary behavior.Thus, self-reported mentally-passive sedentary behavior was associated with longer periods of uninterrupted sedentary time, while self-reported mentally-active sedentary behavior was not associated with device-measured sedentary time among adolescents. The relationship between pattern and cognitive demand of sedentary time should be confirmed in other population groups in order to guide the interpretation of the studies linking sedentary behavior and health outcomes.We gratefully acknowledge the contributions of all participants of the present research as well as the staff for the data collection. André O. Werneck is supported by the São Paulo Research Foundation (FAPESP) with a PhD scholarship (FAPESP process: 2019/24124-7). Enio RV Ronque is funded by National Council for Scientific and Technological Development - Brazil (CNPq) with a research productivity grant (CNPq process: 309731/2018-6).This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.The authors report no conflicts of interest.All procedures performed in the original studies involving human participants were approved by Londrina State University Ethics Committee (process: 1.281.324) in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Additionally, informed consent was obtained from all individual participants as well as the parents of included participants.AOW: Concept and study design, data analysis, interpretation of the data and drafted the initial manuscript. MR, MROB and ERVR: Conceptualization, study design, collection of data, supervision and critical revision. DRS and ALO: Critical revision and approval of the manuscript with important intellectual content. All authors have read and approved the final version of the manuscript and agree with the order of presentation of the authors.


The COVID-19 pandemic and public health “lockdown” responses in sub-Saharan Africa, including Uganda, are now widely reported. Although the impact of COVID-19 on African populations has been relatively light, it is feared that redirecting focus and prioritization of health systems to fight COVID-19 may have an impact on access to non–COVID-19 diseases. We applied age-based COVID-19 mortality data from China to the population structures of Uganda and non-African countries with previously established outbreaks, comparing theoretical mortality and disability-adjusted life years (DALYs) lost. We then predicted the impact of possible scenarios of the COVID-19 public health response on morbidity and mortality for HIV/AIDS, malaria, and maternal health in Uganda. Based on population age structure alone, Uganda is predicted to have a relatively low COVID-19 burden compared with an equivalent transmission in comparison countries, with 12% of the mortality and 19% of the lost DALYs predicted for an equivalent transmission in Italy. By contrast, scenarios of the impact of the public health response on malaria and HIV/AIDS predict additional disease burdens outweighing that predicted from extensive SARS-CoV-2 transmission. Emerging disease data from Uganda suggest that such deterioration may already be occurring. The results predict a relatively low COVID-19 impact on Uganda associated with its young population, with a high risk of negative impact on non–COVID-19 disease burden from a prolonged lockdown response. This may reverse hard-won gains in addressing fundamental vulnerabilities in women and children’s health, and underlines the importance of tailoring COVID-19 responses according to population structure and local disease vulnerabilities. Public health responses have been dominated by enforced social distancing and stay-at-home interventions, characterized as “lockdowns,” advocated by the World Health Organization (WHO).4 However, sub-Saharan Africa is considered particularly vulnerable to COVID-19 because of the relatively weak health service infrastructure and low clinician–population ratios,5 relatively limited laboratory capacity,6 and a higher rate of underlying conditions including malnutrition and anemia, HIV/AIDs, and chronic respiratory conditions due to tuberculosis and air pollution.7 There is paucity of data on interactions between SARS-CoV-2 infection and other acute febrile disease, such as malaria.8 Although these conditions could exacerbate or ameliorate COVID-19, they increase the population’s dependence on health service access and the commodity supply lines that support it, including access to long-term medication and care in acute illness. Access to health services is also essential for reducing poor antenatal and birthing outcomes.Relatively few cases of COVID-19 have been recorded to date in sub-Saharan African countries.9 Closure of logistics-related workplaces and transport services interrupts supply lines.10 Travel bans and reduction in public transportation limit access, and public perceptions of increased risk of SARS-CoV-2 infection near health facilities dissuade attendance, whereas clinic activities considered “non-urgent,” such as antenatal care, may be postponed.11Health services are at risk in the COVID-19 outbreak through various mechanisms. Clinicians and direct care givers of COVID-19 patients have a disproportionately higher mortality than the general age-adjusted population.13 Countries with far higher ratios of children to older adults are expected to have lower overall mortality and higher rates of asymptomatic infection.14 Age comparisons are of particular importance to public health, as disability-adjusted life years (DALYs), fundamental to assessing relative burden, are highly influenced by age of death or onset of long-term disability.15In contradistinction to potential health vulnerabilities, sub-Saharan African countries could be “protected” from COVID-19 mortality by an age structure differing significantly from countries where mortality has been particularly high—such as Italy, Spain, the United States, and in Hubei Province in China.16 Total incidence and mortality from malaria  and tuberculosis  in 2018 imparted a significant burden on its 41 million people.18 Maternal mortality ratio was 368 per 100,000 live births in 2016,19 whereas 100,000 HIV-positive women were dependent on antiretroviral therapy (ART) to prevent mother-to-child transmission in 2018.20 Success of the HIV/AIDS program has reduced AIDS-related mortality from 43,000 in 1990 to 23,500 in 2018,20 resulting in a growing number of people living with HIV  and dependent on frequent monitoring, ART, and treatment of coinfections.20 With low ratios of physicians to population  and hospital beds ,21 Uganda has a relatively fragile health system with limited capacity to expand critical care services.Uganda typifies many of the characteristics of sub-Saharan countries. With a fertility rate greater than 5, 50% of the population are estimated to be younger than 17 years, and only 1.6% are ≥ 70 years in 2020.22 The neighboring country of Kenya has reported higher community transmission with five-hold higher numbers of COVID-19 cases.23 A significant proportion of the Uganda cases are among transborder cargo truck drivers, underlining the threat of continued cross-border introduction.22In view of this, we hypothesize that mortality in Uganda accrued from COVID-19 and from interruptions to other disease programs resulting from the response will differ greatly from those of outbreak countries in Europe, North America, and East Asia. As of June 22, 2020, Uganda had conducted 166,917 tests for COVID-19 and of these, 770 (0.5%) tested positive, whereas 492 persons have recovered, and no deaths have been registered.15 We then predicted the potential for impact of a COVID-19 lockdown response on the burden of selected diseases in Uganda, where restrictions on travel and workplace attendance have been implemented by the government of Uganda since March 12, 2020. We grounded this against limited publicly available data on changes in health burden in Uganda over recent months.We therefore predicted the potential burden of COVID-19 in Uganda based on its population age structure in comparison to an equivalent outbreak in other countries with established COVID-19 transmission. We calculated mortality and DALYs lost, a summary measure of lifetime impact combining time lost through premature death and time lived in states of less than optimal health.4Data collection was conducted in Uganda, which has a sporadic transmission of COVID-19 and conditions generalizable across several sub-Saharan countries.Supplemental Table S1).24Information on the Ugandan population structure was obtained from the Uganda Bureau of Statistics census report, whereas data on comparison countries were obtained from UN data  weekly surge reports generated from data across 13 PEPFAR Uganda implementing partners,28 Maternal mortality data including deliveries from January 2019 to March 2020 inclusive were similarly obtained from the Uganda HMIS quarterly reporting.28Age-stratified malaria incidence for 2019–2020 was obtained from the Uganda Health Management Information System (HMIS) quarterly reporting.29 This involved defining life years lost by age as the difference between actual age of death and the life expectancy in a standard life table reflecting the highest life expectancy in the world today and a set of disability weights to reflect the relative severity of diseases. The unequal age-weighting function and discounting of future life years applied in earlier DALY versions were excluded.15Calculations of DALYs lost followed broadly the methods outlined for the most recent WHO global burden of disease estimates.30 where testing rates have been relatively high.23 For the sake of comparison, a 20% total detectable infection rate was applied across all age-groups, this being assumed to be a worst case for comparison with deterioration in non-COVID disease burden.COVID-19 disease burden and excess HIV, malaria, and maternal mortality were calculated by multiplying the DALYs lost for a single health event by the population incidence and deaths by age-group. Disability-adjusted life years for COVID-19 are based on age-related mortality reported by Verity et al. from the China outbreak, applied to age structures of comparison countries with relatively high COVID-19 burden  and Iceland,25The details of assumptions involved in DALY calculations are provided in the supplementary file. Potential impact of reduced health service access in Uganda through the COVID-19 response was predicted for HIV/AIDS, malaria, and maternal mortality. HIV/AIDS predictions assumed an arbitrarily low (20%) loss to follow-up (no medication) for current infections extending for 6 months, with mortality returning to 1990 levels . Reduced detection of new HIV infections and initiation of management is based on first quarter 2020 data.31 Relative malaria mortality and incidence rates by age for Uganda were derived from the Institute of Health Metrics data,32 with the 2018 baseline mortality reported by the WHO.18Excess malaria burden was estimated based on 6 months of incidence and mortality rate changes recently predicted by the WHO for three scenarios of minor, moderate, and major reductions in services .Maternal mortality was based on Uganda data from 2019 to 2020 and the data include only mortality, not persisting injury (see Results section).The study used publicly available secondary aggregate-level data. No individual person-identifying information was used.As social-distancing policies were only instituted in Uganda in March 12, 2020, data accruing from the mandatory lockdown policy are limited, although prior knowledge of COVID-19 may have influenced prior health-seeking behavior.25 These dips were similar to a temporary decline over the 2019–2020 Christmas–New year period that subsequently recovered .New HIV case declined by 75% in the first 2 weeks of April, with a similar 75% reduction in the initiation of isoniazid-preventive therapy to prevent secondary tuberculosis.Supplemental Table S3). This is difficult to interpret without a longer 2020 recording period, as it is consistent both with a larger seasonal decline in 2020 and with reduced health service and facility access .Malaria showed a reduction in case detection in the first quarter of 2020, consistent with a seasonal decline but more persistent and of greater magnitude than 2019 . Admissions and inpatient deaths declined by similar proportions .A 29%  reduction in facility deliveries is recorded in the Ministry of Health Uganda data in March compared with January 2020, 28% less than the 12-month average for 2019. Over the same period, an 82% increase in maternal mortality was recorded (from 92 to 167 women), an increase of 87% over the 12-month 2019 average of 89.5 . The burden from undiagnosed new HIV cases, based on the 55% decline in new ART initiation in April 2020 and using standard assigned HIV DALYs, predicts 41,757 excess cases failing to commence therapy over 6 months, with 12,151 DALYs lost . Combined, this predicts 475,319 DALYs lost  for this population, and assuming an equal mortality across age-groups, 463,168 excess DALYs are predicted to be lost .The Ugandan population is predicted to be significantly impacted if the WHO scenarios are realized, reflecting the low age at which most mortality occurs: mortality and total DALYs lost for WHO scenarios being 3,209 and 257,780 (WS1), 6,533 and 509,394 (WS4), and 31,046 and 2,427,769 (WS9), respectively . Non-fatal morbidity has not been taken into account.Based on the observed increase in maternal mortality in early March 2020 compared with the preceding 2019–2020 average, an excess 486 deaths are predicted for a 6-month period, incurring 31,343 DALYs lost  is predicted to impart a lower burden than potential lockdown impacts in HIV/AIDs and malaria programs alone. Early data showing rising maternal mortality and reduced facility-based deliveries, reduced case finding for HIV/AIDS, and possibly malaria indicate deterioration in essential health service access associated with the COVID-19 pandemic and risk the reversal of hard-won gains in addressing fundamental vulnerabilities in women’s and children’s health.35 are generally less prevalent in sub-Saharan populations.36 In Uganda, a recent national survey reported the prevalence of diabetes at 1.4%.36 It is difficult to predict whether the population at a given age will be more or less susceptible. Lower access to intensive care, and particularly to oxygen, may reduce recovery rates for severe cases in Uganda and more broadly in this region in DALYs lost and mortality.38 We also make no adjustments for the impact of age structure on underlying transmission, but compare the age-based predicted mortality for a hypothetical equivalent transmission uniformly across each age-group.A significant assumption here is that age-related mortality in Uganda would be similar to that in China. The effects of undernutrition, anemia, intestinal parasite infestation, and infectious disease such as tuberculosis and HIV are unknown. They are widely assumed to increase susceptibility, as may chronic lung conditions from indoor and outdoor air pollution. However, major risk factors recorded for COVID-19, such as obesity, diabetes, hypertension, and other cardiovascular diseases,39 the COVID-19 burden predicted here would reflect a population infection rate considerably higher than 20%. It is noted that countries with major established outbreaks have far lower levels of detectable infection overall.23 The predictions for COVID-19 disease burden used here in comparison to other disease burdens are intended as a worst-case scenario for COVID-19, and probably greatly overestimate the COVID-19 impact.To address these uncertainties, this article has taken a conservative approach to comparing COVID-19 impact with that of lockdown-related program deterioration, assuming a very high transmission of COVID-19 (a 20% detectable infection rate) across Uganda. As “detectable infection” here is based on early China data when testing was scaling up, and subsequent data suggest that asymptomatic SARS-CoV-2 infection is relatively frequent,40The fragility of the Uganda HIV/AIDS burden is reflected in the high predicted DALYs lost with moderate reductions in health service access, similar to that predicted with a widespread SARS-COV-2 transmission producing 20% detectable infection across the population. This prediction here may be conservative regarding long-term burden as HIV/AIDS high infant mortality might be expected through increased maternal–infant transmission, whereas adult-to-adult transmission will also increase if access to ART and condoms is reduced. The reduction in HIV/AIDS case finding is early and may not be sustained, whereas impact on mortality will also take time to accrue. We have used a lower rate of loss to follow-up than shown in the PEPFAR data (20%) to account for this, but this is an area where further data are needed. Later data from June 7 (week 23) show both HIV case finding and treatment initiation remaining 37% less than the 26-week average end of March, suggesting the estimates are indeed conservative.35 each death imparts a far lower burden than is commonly accrued from HIV/AIDs, malaria, or a maternal death. Maternal and HIV deaths not only remove many years of a parent’s life but also frequently leave children orphaned, with further resultant costs. The predictions in this article, although based on fairly modest assumptions of program deterioration from only three disease areas, indicate a considerable risk of collateral damage to other disease programs compared with the COVID-19 burden from an extensive outbreak predicted here (41 The impact of interruption of vaccination programs will increase the longer health service interruptions persist, with outbreaks including measles in neighboring Democratic Republic of Congo as a growing threat.42 An expected 2.1–5.1% reduction in gross domestic product across sub-Saharan Africa will impede the ability of health systems and populations to recover,43 whereas reduction in support from donor countries is a risk as they deal with economic downturn at home.The use of DALYs lost, rather than reliance solely on incidence and mortality, seems essential to understand COVID-19 burden. With the burden of COVID-19 heavily concentrated in older age-groups,ted here . IncreasUnderstanding the extent of spread in the community through better testing will be important to understand whether the relatively low COVID-19 numbers recorded in African countries to date are due to late introduction, are an artifact of low testing, or are due to the low rate of severe presentations predicted here. The consequences of getting the equation wrong are dire. Ramping up testing capacity, prioritizing the building of an evidence base on COVID-19 epidemiology in African populations, is urgent if the risks raised in this study are to be minimized.A broader modeling approach to COVID-19 is needed, incorporating accepted measures of disease burden rather than solely mortality, and including comparisons for collateral damage due to the public health response based on emerging health system data. Sentinels for deterioration such as facility-based delivery, maternal mortality, and case finding for HIV and tuberculosis should provide bases for this modeling. Uganda’s relatively strong surveillance and monitoring networks provide a strong basis for this across a range of diseases.Our predictions strongly suggest that on the basis of DALYs lost, the impact of the COVID-19 public health response on non–COVID-19 diseases could outweigh the direct impact of an extensive COVID-19 outbreak. Although public health responses to COVID-19 should be prioritized, prior morbidities should not be de-prioritized. COVID-19 is predicted here to cause considerably less direct impact than predicted elsewhere, and the response in Uganda, and by extension elsewhere where population age structure is similar, should be strongly tailored to local context.Supplemental materials


To prevent the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), strict control of person-to-person transmission is essential. Family transmission is the most common route of transmission; however, family transmission patterns and outcomes are not well understood.We enrolled confirmed cases discharged from Wuhan Zhuankou Fangcang Shelter Hospital from February 17, 2020 to March 8, 2020 along with the family members they had contact with, to evaluate baseline characteristics, family transmission patterns and outcomes. The follow-up period lasted until May 8, 2020.2 vs 41.0 ± 19.70 cm2, respectively, P = 0.037), and the per capita area was negatively associated with the number of infected family members . Of the 190 confirmed cases, the 113 mild or moderate cases were monitored in fangcang (including Wuhan Zhuankou Fangcang and other fangcang), and the 59 severe cases were treated at designated hospitals. By the end of follow-up, 185 patients recovered and returned home after completing at least 14 days of isolation at the community quarantine center, four died in hospitals, and one died at home before hospitalization. Interestingly, four patients had positive nucleic acid test results after previous negative results, though none of these patients were re-hospitalized, and none of their close contacts reported an infection.This study evaluated 369 participants, which included 100 patients admitted to the shelter hospital and the family members they had contact with. Family transmission occurred in 62% of household, with 190 cases confirmed to have SARS-CoV-2 infection. There were eight patterns of family transmission, and spousal transmission  was the most common pattern, especially in the middle-age generation group . The homes of the families in which all members were infected had a smaller per capita area than those of other families (29.1 ± 11.89 cmOur data found eight family transmission patterns, of which spousal transmission was the most common. Some patients were also found to have positive test results during follow-up. On December 29, 2019, several cases of pneumonia caused by a novel coronavirus, recognized as severe acute respiratory syndrome virus 2 (SARS-CoV-2), were reported in Wuhan, Hubei Province, China . The escAs previous investigations have shown, cluster cases and community transmission of COVID-19 have been common, with family clusters being one of the most common patterns of transmission ,5. HowevWuhan Zhuankou Fangcang Shelter Hospital was set up as a temporary quarantine location with limited medical resources from February 17, 2020 to March 8, 2020 . During o2/FiO2  less than 300 mm Hg; lung infiltrates greater than 50% within 24-48h; severe co-existing conditions; respiratory failure requiring mechanical ventilation; septic shock; or multiple organ dysfunction or failure. Recovery referred to patients meeting all the following criteria: normal temperature for more than three days; marked improvement in respiratory symptoms; decrease in inflammation on pulmonary imaging; and two consecutive negative nucleic acid tests from respiratory tract samples .During the clinical assessment, information including symptoms, coexisting conditions, RT-PCR for SARS-CoV-2 and chest computed tomography (CT) results, and the disease severity of confirmed cases were recorded. Mild or moderate cases were defined as patients presenting with mild symptoms without any severe comorbidities. Severe cases referred to patients with any of the following: breathing rate greater than 30 breaths per min; oxygen saturation level less than 93% at rest; PaFamily transmission was defined as at least two members having confirmed SARS-Cov-2 infections in one family. Family transmission was determined by examining the relationship between index cases and other infected family members. According to age and marriage status, family members were divided into the young-age generation, middle-age generation and old-age generation group. Considering that some family members presented with an onset of illness at the same time, we could not identify the index cases and therefore used the house effect rate rather than the second infection rate. The household effect rate was calculated as the ratio of infected family members to total family members. The index case was the family member who presented with symptoms at the earliest time and had a final confirmed diagnosis. When two or more cases showed symptoms at the same time, the index case could not be confirmed.All patients admitted to Wuhan Zhuankou Fangcang Shelter Hospital were asked to complete a questionnaire  to obtain basic information and family transmission data (Supplement). Paper of photo images of all laboratory and imaging tests performed before admission were provided, including those of the family members.Follow-up continued for two months after discharge, with the last follow-up performed on May 15, 2020. Telephone or WeChat was used for communication between physicians and patients to acquire the latest follow-up information, including repeated RT-PCR and CT results, immunoglobulin (Ig) M and IgG for SARS-CoV-2, rehospitalizations and reinfections. All confirmed cases of COVID-19 discharged from Wuhan Zhuankou Fangcang Shelter Hospital were followed up. Any repeated test results (if available) of the patients and the family members in contact with them were provided to physicians through WeChat in the form of photos.Data were collected independently by two physicians. All data were extracted manually for quality assurance and validity. When there was a discrepancy between the two physicians, they reviewed the original records to ensure the data were accurate. Statistical analyses were performed by a third person who was not involved in the data-entry process. All patients provided consent to participate in the survey. The Inner Mongolia Health Committee, which dispatched health staff to Wuhan Zhuankou Fangcang Shelter Hospital, approved this study.2 or Fisher exact test as appropriate. Correlation coefficients were calculated for living conditions and family transmission, using the Spearman or Pearson correlation as appropriate. The kappa coefficient was used to test for consistency of the RT-PCR tests and CT scans. A 2-tailed P < 0.05 was established as the level of statistical significance for all tests. All analyses were performed using SPSS version 24.0 software .Continuous variables were expressed as the mean or median and compared using the Student's t or Mann-Whitney U test as appropriate. Categorical variables were described as frequency rates and percentages and analyzed using the χP < 0.001). The proportion of children younger than 14 years in infected group was significantly lower than that in the uninfected group . Compared with patients in the uninfected group, those in the infected group also had a higher incidence of hypertension , diabetes , cardiovascular disease  and chronic pulmonary disease    = 13.0-49.8) and 46 (IQR = 38.8-56.0) years in the uninfected group and infected group, respectively (P < 0.001). Nineteen patients presented with positive RT-PCR test results and normal CT imaging, whereas 17 patients had abnormal CT results and no RT-PCR confirmation. Moreover, two patients with normal CT and RT-PCR results were confirmed by antibody testing to have SARS-CoV-2 infection. Among the 100 patients discharged from Wuhan Zhuankou Fangcang Shelter Hospital, 98 provided CT reports. Ground glass opacities and fibrous stripes were the most common features of SARS-CoV-2 infection on CT. Nearly 70% of the patients had bilateral infiltration  were asymptomatic. The most common symptoms found in the symptomatic patients at onset of illness were fever (67.4%), cough (42.6%), and dyspnea (15.8%). Less common symptoms included fatigue and pharyngalgia. In total, 152 patients had positive results on both CT and RT-PCR, showing high consistency between them  or per capita area  between the family transmission and no family transmission groups. However, families with all members infected had a smaller per capita area  compared to other families, and per capita area was negatively related to the number of infected family members .We also investigated the relationship between living conditions and family transmission. There were no significant differences in home size  patients had return home from the community quarantine center and RT-PCR and viral serology were reevaluated during home quarantine. Four patients had nasopharyngeal swabs for RT-PCR that were positive after previously negative results, and three presented with persistent positive results of IgM and IgG for SARS-CoV-2 . None of these patients were re-hospitalized, and no infections of close contacts were reported. Furthermore, of the 17 patients with CT-confirmed features but without a positive nucleic acid or viral serology test, 8 had negative IgG and IgM results for SARS-CoV-2, indicating that those patients might have had a false positive diagnosis of COVID-19.To our knowledge, this is the first study to explore transmission patterns of family clusters and outcomes for COVID-19. The study showed that: (1) children have less potential to be infected, whereas individuals with chronic diseases such as hypertension, diabetes, and cardiovascular disease are more likely to be infected by family members; (2) common transmission occurs in more than 60% of families and spousal transmission is the most common; (3) individuals with smaller per capita living areas are more prone to be infected; (4) the Wuhan Zhuankou Fangcang Shelter Hospital supported mild or moderate confirmed cases by providing basic medical resources; and (5) some patients may present with positive RT-PCR results after recovery.Previous studies have reported that family members can be infected with COVID-19 after close contact  with confirmed-positive family members, demonstrating a person-to-person transmission of the virus within the family and providing evidence for asymptomatic carriers as potential sources of SARS-CoV-2 transmission ,5,9. SARHowever, strict home quarantine is still effective in protecting some family members from family transmission, especially during periods of insufficient medical capacity . SuspectOur study also showed that children had a lower risk of infection, which contrasts with the results of a recent study from Shenzhen, China . The reaIn our study, one patient died before hospitalization at an early stage of the epidemic due to medical care shortage. After several Fangcang shelter hospitals started admitting patients with mild or moderate symptoms, the number of newly confirmed cases decreased steadily ,16. The Our study describes triage and quarantine measures for suspected or confirmed COVID-19 cases, which reflected the full picture of Wuhan (This study has some limitations. First, this is a single-center study with a limited sample size. We only enrolled patients discharged from Wuhan Zhuankou Fangcang Shelter Hospital and tracked their contacted family members, meaning that confirmed cases at a very early stage of the epidemic were not included. Second, information on the distribution of the virus in patients' home was not available, which limited knowledge of the exact routes of family transmission.In conclusion, in this study, children had a lower risk of infection, and individuals with multiple comorbidities were more susceptible. Our study described family transmission patterns, showing that although strict home quarantine prevents SARS-Cov-2 transmission in some families, family transmission was evident in nearly two-thirds of the families, and spousal transmission was the most common pattern. In addition, some patients had recurrent positive RT-PCR results, which requires further investigation.


The burden of congestive heart failure (CHF) is the greatest among older adults. Cognition is important for carrying out self-care tasks such as monitoring sodium intake, but little is known about how cognition affects self-care in acutely ill CHF patients. We aimed to assess the association between cognition and self-care in CHF patients from an outpatient diuresis clinic. Cognitive function was measured using the Mini-Mental State Exam (MMSE) and other tests representing 5 cognitive domains. The Self-Care of Heart Failure Index (SCHFI), given to a subset of participants, consisted of 22 questions each scored on an ordinal scale of 1-4 with a total score ranging from 22-88; higher scores indicated better self-care. SCHFI questions were further categorized into maintenance, management and confidence sub-scores. Multiple linear regressions were used to analyze the association between neuropsychological test scores and SCHFI scores. A total of 68 CHF patients had complete SCHFI data, with a mean age of 65.6 years and a mean total SCHFI score of 70.9 points. Nine (13.2%) patients were cognitively impaired (MMSE<24). Older age, lower education and history of stroke were associated with cognitive impairment. After adjusting for age, education, diabetes, and depressive symptoms, no associations were observed between the other neuropsychological test scores and any of the SCHFI scores. Though findings suggest that cognition is not associated with self-care, the analysis may have been underpowered. Further evaluation of a greater number of CHF patients is needed to understand the implications of cognition on self-care and provide guidance for interventions.


To compare the macular interdigitation zone (IZ) of normal eyes with eyes showing different normal-tension glaucoma (NTG) stages.Forty-two normal eyes , 45 pre-perimetric eyes , 51 mild-to-moderate glaucoma eyes , and 50 severe glaucoma eyes  were enrolled. All of the subjects underwent high-resolution spectral-domain optical coherence tomography (SD-OCT) to obtain 19 horizontal and 19 vertical macular B-scans 9 mm in length. The en face image of the scan area was divided into 589 rectangular boxes (side length of 375 µm). The IZ locations were marked on the corresponding image boxes. The IZ area was then quantified according to the number of boxes showing IZs among the 589 total boxes.2 vs. 40.79 ± 7.46 mm2; P < 0.001), was smaller in the mild-to-moderate glaucoma eyes than in the pre-perimetric glaucoma eyes , and was smaller still in the pre-perimetric glaucoma eyes than in the normal eyes . In the 146 NTG eyes, a statistically significant correlation was found between IZ area and MD .The IZ area in the severe glaucoma eyes was significantly smaller than in the mild-to-moderate glaucoma eyes (28.99 ± 7.88 mmSD-OCT revealed a reduction in IZ area in NTG eyes, and the extent of the reduction was positively associated with glaucoma severity. These findings suggest, though tentatively, that changes in the outer retinal layer can occur in the course of glaucoma progression. High-resolution spectral-domain optical coherence tomography (SD-OCT) was employed to examine retinal microstructures in greater detail. SD-OCT indicated that the single, highly reflective, outer retinal band observed using original OCT devices can be resolved as four separate bands that correspond to the external limiting membrane (ELM), the photoreceptor ellipsoid zone (EZ), the interdigitation zone (IZ), and the retinal pigment epithelium (RPE)–Bruch membrane complex.The third band, the IZ, has been determined to be the covering by apical processes of the RPE of the cone outer segments within a structure known as the contact cylinder.,Glaucoma manifests in the form of pathological changes in the retinal ganglion cells (RGCs) of the inner retina.Recently, we published findings indicating that in mild-to-moderate and severe glaucoma eyes a relative reduction in EZ intensity occurs and the extent of the reduction is positively associated with glaucoma severity.The Seoul National University Hospital Institutional Review Board approved this cross-sectional study, which adhered faithfully to the tenets of the Declaration of Helsinki. Informed consent was waived due to the retrospective nature of the study.All of the subjects were examined at the Seoul National University Hospital Glaucoma Clinic in Seoul, Korea, between January 2015 and February 2019. Eligible participants were enrolled, consecutively, based on a retrospective medical records review. All underwent a complete ophthalmic examination, which included a best-corrected visual acuity assessment, refraction, slit-lamp biomicroscopy, gonioscopy, Goldmann applanation tonometry , and dilated stereoscopic optic disc examination. Additionally, the subjects underwent central corneal thickness measurement , axial length measurement , stereo disc photography (SDP), red-free retinal nerve fiber layer (RNFL) photography, and optical coherence tomography  for macular ganglion cell-inner plexiform layer (GCIPL) thickness measurement, as well as central 24-2 threshold testing of the Humphrey visual field (HVF) .The subjects included in the study were between 40 and 65 years of age, had a best-corrected visual acuity of ≥20/40 , spherical refraction between –6 and 3 diopters (D), untreated intraocular pressure (IOP) of 21 mm Hg or less, an open anterior chamber angle, and reliable visual field (VF) test results. The exclusion criteria were as follows: (1) history of intraocular surgery (except uncomplicated cataract surgery) or retinal laser photocoagulation, or (2) any neurological or systemic diseases potentially affecting the retinal structure and/or function and the VF results. Also excluded were cases of suspicious retinal lesions potentially affecting the outer retinal layer, such as inflammatory conditions or hereditary and degenerative retinal diseases. An experienced ophthalmologist (YSH) reviewed both red-free RNFL photographs and OCT images. Cases with any retinal pathologies including epiretinal membranes, macular holes, macular edema, hard exudate, cotton wool spots, or drusen, as well as changes in the RPE, were excluded. Patients with underlying diabetes but without diabetic retinopathy were not excluded.Glaucomatous eyes were diagnosed based on the characteristic optic disc appearance  on SDP and on RNFL defect presence in the corresponding region (based on red-free fundus imaging), irrespective of the presence or absence of glaucomatous VF defect. Cases of optic nerve pits or other congenital anomalous discs were not included. Optic disc signs on SDP and RNFL signs on red-free imaging were evaluated independently by two glaucoma specialists  who were masked to all clinical data. Discrepancies were resolved by consensus. Among the glaucomatous eyes, a diagnosis of pre-perimetric glaucoma was made in cases of normal VFs using conventional HVF analysis. Normal HVF results were defined as follows: mean deviation (MD) and pattern standard deviation within the 95% confidence interval (CI) and glaucoma hemifield test results within normal limits.Glaucomatous VF defects were defined as (1) a cluster of three points having probabilities of less than 5% in at least one hemifield on the pattern deviation map, including at least one point having a probability of less than 1% or a cluster of two points having a probability of less than 1%; (2) Glaucomatous Hemifield Test results outside the normal limits; and (3) pattern standard deviation beyond 95% of normal limits, as confirmed by no fewer than two reliable examinations .For the control group, patients regularly examined due to a family history of glaucoma or cataract were enrolled consecutively. The normal controls showed an IOP ≤ 21 mm Hg, no history of IOP elevation, no glaucomatous optic disc appearance, no RNFL/GCIPL defect, and normal HVF results. If both eyes were found to be eligible, one was randomly selected.,SD-OCT confocal scanning laser ophthalmoscopy scanning  was performed in all of the subjects using the eye-tracking feature . All of the images were obtained through dilated pupils by one experienced examiner. The 19 horizontal and 19 vertical and consecutive parallel lines of the 9-mm-length macular scans were obtained in the high-resolution setting, and 128 images were averaged. The presence of foveal bulge, foveal depression, or inner-retinal-layer thinning  was considered to represent confirmation of foveal area. For inclusion, all of the images were reviewed to confirm centered scans, a lack of artifacts,,It is known that the IZ becomes less distinct with eccentricity due to the fact that the EZ and IZ approach one another and become indistinguishable at the periphery.2 , and the analyzed area was assumed to be a two-dimensional flat-plane area; therefore, the total scan area encompassing 589 boxes was 82.828 mm2. As an example, if a given eye had 375 red boxes (intact IZs) with 214 blue boxes (absent IZs), the macular IZ area was quantified as 52.73 mm2 (= 82.828 mm2 × 375/589).In Cumulative maps of intact IZ frequency were visualized for the four groups. Topographic information for all of the left eyes was mirrored horizontally. If all of the subjects of a group showed an intact IZ in a box at a specific location, this box was colored red . Meanwhile, if all of the subjects of a group showed no intact IZ in a box, this box was colored blue . In this manner, the cumulative frequency maps showed red and blue coloring according to the frequency of intact IZs.2 test using Bonferroni correction for multiple comparisons. For glaucomatous eyes, Pearson correlation analysis was performed on the macular IZ area for VF MD or average GCIPL thickness. In each analysis, parametric or nonparametric tests were employed based on the results of a normality test, and the 95% CI was calculated. The statistical analyses were performed using SPSS Statistics 22.0 ; a two-sided P value less than 0.05 was considered to represent statistical significance.Comparison of normally distributed demographic data and macular IZ area among the four groups was performed by one-way ANOVA with Tukey's post hoc test. The categorical data were analyzed by χA total of 219 eyes (219 subjects) that met the entry criteria underwent SD-OCT. Thirty-one eyes (31 subjects) were excluded based on poor-quality OCT scans. A total of 42 normal eyes (42 subjects), 45 pre-perimetric glaucomatous eyes (45 subjects), and 101 glaucomatous eyes with VF defect on HVF (101 subjects) were included. Most of the enrolled patients underwent both Spectralis and Cirrus OCT scans for routine screening of ophthalmic diseases in their first visit to our outpatient clinic. A total of eight (4.26%) glaucoma patients who had a Spectralis OCT examination for retinal evaluation but were found to have no retinal pathologies were included. The normal-tension glaucoma (NTG) eyes with VF defect were categorized as follows based on a reliable HVF result that had been obtained within 3 months of SD-OCT imaging: (1) 51 eyes, mild-to-moderate glaucoma (VF MD ≥ –12 dB), and (2) 50 eyes, severe glaucoma (VF MD < –12 dB). See 2; range, 32.22–65.21; CI, 54.38–59.33 vs. 49.92 ± 8.10 mm2; range, 25.64–66.64; CI, 47.49–52.34; P < 0.001). In glaucomatous eyes with VF defect, the IZ areas were further reduced for both mild-to-moderate glaucoma  and severe glaucoma  groups compared with the normal subjects. In the severe glaucoma group, the IZ area was lower than in the mild-to-moderate glaucoma group (P < 0.001)  . See Supr = 0.64; P < 0.001).The IZ areas of 146 glaucomatous eyes were plotted against their respective VF MD results A. A signr = 0.73; P < 0.001).The IZ area and average macular GCIPL thickness were compared for all of the subjects B. A signWe used SD-OCT to perform in vivo evaluations of the outer retina with regard to the various stages of glaucoma. We observed that a reduction in IZ area occurred in glaucoma and that its extent was positively associated with glaucoma severity. To the best of our knowledge, ours is the first study to have examined IZ change relative to advancing glaucoma stage.,The data gathered in previous studies suggest that the IZ is consistently aligned with the contact cylinder that joins the RPE apical processes to the external portion of the outer cone segment.–Although the microscopic structures of the IZ have not yet been fully determined, IZ integrity has been considered to be an important clinical marker of photoreceptor damage and recovery in various retinal diseases. In fact, IZ restoration is a predictor of visual acuity outcome following surgeries for epiretinal membranes, retinal detachment, diabetic macular edema, or macular hole.–It has been suggested that this reduction in IZ area and its mechanism in glaucoma are related to increased oxidative stress caused by mitochondrial dysfunction. Indeed, there is supporting evidence from both animal and human studies that have assessed reactive oxygen species production, antioxidant levels, and markers of oxidative damage to macromolecules under conditions prevailing in glaucoma.,Another possible cause of the reduction in IZ area is trans-synaptic degeneration in glaucomatous eyes. Neurons can affect, either directly or indirectly, other synapsed neurons by retrograde or anterograde degeneration.,In the current study, we found that a decrease in IZ area occurred not only in perimetric NTG eyes but also in pre-perimetric NTG eyes. Interestingly, in our previous report (with an independent patient group), EZ intensity reduction was observed only in glaucomatous eyes with VF defect, not at the pre-perimetric stage.In our opinion, for better monitoring, intervention, and therapy, it is important to understand the alterations associated with glaucomatous optic neuropathy that arise in the outer retinal layer. In the clinical setting, patients showing the same apparent degree of glaucomatous optic nerve damage can manifest different degrees of VF loss.The findings of this study must be interpreted in light of its limitations. First, although we found excellent inter-reader agreement for IZ intact/absent status, determining IZ margins can be subjective. Also, we calculated the IZ area under the assumption that the analyzed area is a two-dimensional flat plane; however, the analyzed area is actually a curved plane with different curvature in each patient. These factors could have introduced a degree of variability regarding the final resultsSecond, our results were drawn from patients who turned out to be representative of a relatively narrow age range. Also, given that our patients had NTG, our results might not be directly applicable to primary open-angle glaucoma (POAG) patients with higher baseline IOP. It has been reported that VF defects are deeper and closer to fixation in NTG as compared with glaucoma eyes with high pressure.,Third, although we excluded cases with optic nerve pits or other congenital anomalous discs, there is a possibility that optic disc changes due to other causes were included in the pre-perimetric NTG group. In addition, the control group included subjects with a family history of glaucoma. Even though they did not show any signs of glaucoma at the time of their inclusion in our study, they still had an increased risk of developing the disease relative to those without any such family history. Fourth, as also seen in our results in In conclusion, the mean IZ decrease in glaucomatous eyes was determined using SD-OCT imaging, and the decrease was positively associated with glaucoma severity. These findings suggest, tentatively, that outer retinal layer changes might occur in the course of glaucoma progression; they also serve to identify new directions of research that can lead to better understanding of photoreceptor changes during the progression of glaucoma. Further investigation is called for to determine the clinical significance of this reduction in IZ area in glaucoma.


Existing research on marginal bone stability around hydroxyapatite (HA)-coated implants often lacks adequate long-term follow-up. The purpose of this randomized prospective study was to evaluate the 7-year outcome of patients with immediate and early loaded single-tooth restorations supported by implants with plasma-sprayed, partially HA-coated surfaces. Forty-two patients in need of 50 single implants were treated in in the Postgraduate Periodontics Clinic of Louisiana State University School of Dentistry. Implants were randomly divided into 2 groups: Group A was immediately loaded, and Group B was early loaded. Continuous follow-up with periodic maintenance care and radiographic evaluations was performed. The primary outcome of interest was implant survival, characterized using the Kaplan–Meier method. Secondary study outcome consisted of peri-implant crestal bone level changes. Data on age, sex, bone quality, implant location, length and diameter, and prior augmentation of the site were collected. Multiple regression analyses were conducted to determine whether the independent variables were associated with bone loss.One implant failed to maintain stability and was removed at 3 weeks. Thirty-four patients  completed the 7-year follow-up visit. Average age of evaluable patients was 52 in Group A and 55 in Group B. No significant difference was observed regarding sex and age distribution between the 2 groups. No significant difference was detected in the distribution of implant locations, types of bone, implant length, implant diameter, and augmentation status of the bone between the 2 groups. After 7 years of functioning for the 42 implants examined, implant survival rate was 100% for Group A and 95.5% for Group B. The results from this study of 50 implants showed that HA-coated Zimmer Tapered Screw-Vent Implants were clinically effective, with an overall cumulative 7-year survival rate of 98.0%. When comparing radiographic bone levels between 2-year and 7-year follow-ups, no significant differences in bone loss were found between Group A and Group B.After 7 years in function, implants partially coated with plasma-sprayed and hydrothermally treated HA were clinically predictable when restored in occlusion immediately after or 3 weeks after implant placement. Endosseous dental implants are currently a widely accepted treatment option for the replacement of missing teeth. The original protocol for treatment with implants proposed by Branemark advocates a waiting period of at least 3 months for osseointegration before loading the implant . HoweverEsposito et al. defined 3 protocols for implant load timing: immediate implant loading, within 1 week from implant placement; early implant loading, between 1 week and 2 months; and conventional implant loading, after 2 months from implant placement –8.The clinical success of immediate loading is dependent on many factors such as bone quality and quantity, implant number and design, implant primary stability, occlusal loading, and clinician’s surgical ability. Among these, implant primary stability is considered the most important .Osstell®  is an electronic instrument designed to measure implant vibrations in response to resonance frequency analysis (RFA). This device measures the resonance frequency of a transductor attached to the implant body . The resThe determinant and most accessible parameter to assess the primary stability is thought to be the implant insertion torque value. However, research has shown strong correlations among primary implant stability, insertion torque (IT) values, and RFA’s proprietary ISQ (Osstell®) . CertainFactors such as implant surface characteristics and diameter have also been shown to influence primary stability: rough implant surfaces create more surface area for implant–bone contact . TherefoIn the human body, hydroxyapatite (HA) forms 98% of the enamel, 77% of the dentin, 70% of the cementum, and 60–70% of bone by weight , 16. SynLongitudinal research is required on the clinical efficacy of plasma-sprayed HA-coated implants with different loading times. The purpose of this prospective study was to evaluate the 7-year outcome of patients with immediate and early loaded single-tooth restorations supported by implants with plasma-sprayed, partially HA-coated surfaces.Forty-two patients in need for 50 single implants were treated in in the Postgraduate Periodontics Clinic of Louisiana State University School of Dentistry. The 2-year results of this prospective randomized clinical study were published previously . The curInclusion criteria are males or females; at least 18 years old; healthy enough to undergo routine implant surgery and subsequent dental treatment; partially edentulous requiring single implants in either jaw; adequate bone volume to accommodate implants at least 10-mm long; no active infections; physically, emotionally, and financially able to undergo planned implant procedures; and adequately compliant to meet study requirements and necessary appointments.Exclusion criteria are those with medical need for antibiotic premedication for infective endocarditis; artificial joints or any other medication; uncontrolled hypertension; uncontrolled diabetes; serological human immunodeficiency virus (HIV) positive; history of significant heart, stomach, liver, kidney, blood, immune system or other organ impairment or systemic disease that would prevent undergoing the proposed treatment; smoke cigarettes or other tobacco products; use of investigational drugs during the previous month; unresolved dental conditions likely to require exiting the study for treatment, such as deep cavities, abscesses or moderate to severe periodontal disease; history of radiation therapy to the head and neck; unwilling or inability to sign the informed consent form; failure to demonstrate willingness to return for a required number of visits; and need immediate dental implant placement following tooth extraction.Dental implants were randomly divided into 2 groups by the study coordinator: in Group A, immediately loaded (implants to be loaded at the day of placement) and in Group B, early loaded (implants to be loaded 3 weeks after placement). Randomization was implemented using assignments in sealed envelopes; these envelopes were opened just prior to each implant surgery, and the patient was assigned to either treatment group based on the information provided in the envelope.All implants  were placed in healed extraction sites with or without prior augmentation by periodontal residents . ImplantPatients in Group A received a provisional restoration the day of surgery, loading the implant. Patients in Group B received a healing abutment the day of surgery and returned in 3 weeks. At this time, a provisional restoration was placed, and the implant was loaded. Definitive prosthesis RFA was conducted at 6 months and 12 months of provisionalized loading. After 1 year of provisionalized function, a final impression was made for a computer-aided designed and computer-aided manufactured custom abutment, which was delivered with a definitive, cement-retained crown. Provisional and final restorations were placed by an implant restorative fellow in training.Continuous follow-up with periodic maintenance care was performed every 6 months for 2 years following implant placement. During these periodic follow-up appointments, clinical and radiographic evaluation was performed along with oral hygiene prophylaxis. At every appointment, oral hygiene was reinforced. If patients presented with any problems, they were advised on, and issues were assessed. Periodontal parameters were assessed by clinical evaluation and standardized bitewing digital radiographs , which were performed using a prefabricated template made for each patient. After this point, patients continued their visits in the periodontics department if any other ongoing treatments existed. Patients with no additional dental treatments at LSUHSC dental clinic were guided to continue receiving oral hygiene prophylaxes elsewhere.Seven years after the initiation of the study, all participants were contacted and followed up for a 7-year evaluation of the implants. At this follow-up appointment, clinical parameters and restorative complications were assessed by clinical exams and radiographic imaging. The originally made radiographic standardization stents were not reusable anymore due to distortion of the material over the years. Therefore, bitewing radiographs were taken with efforts made to mimic the previous angulations as much as possible for each radiograph image. Clinical and prosthetic evaluations were done at this appointment. All patients were educated with tailored oral hygiene instructions at the end of follow-up visits.Radiographs were taken at 3 different time points: immediately after (baseline) and 2 and 7 years after implant placement. The radiographic images were imported into the ImageJ image processing software. ImageJ is an open source image processing program designed to analyze scientific multidimensional images . Using It test and Fisher’s exact test.Implant survival was summarized through the characterization of failure over time, using the Kaplan–Meier method. Cumulative survival of the implants was estimated at each time of assessment, with corresponding 95% confidence intervals. The secondary study outcome consisted of peri-implant crestal bone level changes (measured from a fixed point on the implant to the area of first bone contact with the implant surface). Peri-implant crestal bone change was measured at the 2- and 7-year follow-up visits. Data on age, sex, bone quality  , implantA bivariate analysis was performed to show the distribution of the outcome in different groups. A multivariate regression analysis was conducted to determine whether the independent variables were associated with bone loss at 2 and 7 years. Predictors that, based on the available literature, are potentially associated to bone loss were considered in the full regression model. The predictors included in the full models were (a) type of bone , (b) location (mandible or maxilla), (c) implant diameter, (d) implant length, (e) load time (immediate or early), (f) augmented or non-augmented bone, (g) ISQ values, (h) participant age (years), and (i) participant sex. A separate regression model was fit for each outcome variable. Participant confidentiality was protected at all stages of the study. Participants’ unique identifiers were used for the analysis.To estimate the sample size needed for the study, a confidence interval for the sample size of 50 was generated using the expected rate of implant success of 94%. A 95% interval for this rate with a sample size of 50 was 87.4 to 100.0%.A total of 42 subjects with 50 dental implants were initially enrolled in this study. One implant failed to maintain stability and was removed at 3 weeks. Thirty-four patients  completed the 7-year follow-up visit  and age  distribution between the 2 groups . However, such a correlation was not detected at 7 years. Placing an 11.5-mm implant was negatively correlated to bone loss at 2 years (close to significance at p = 0.07), indicating that 11.5-mm length might be a predictor for lesser bone loss. However, this was not detected in the 7-year bone loss analysis. Furthermore, having a 4.1-mm diameter implant was significantly correlated to bone loss at 2 years (p = 0.04), compared with a smaller diameter (3.7 mm). The same finding was detected in the 7-year bone loss analysis, with at least half a millimeter greater bone loss in 4.1-mm diameter implants (close to significance at p = 0.09).Multivariate regression analysis Table  was applTo the authors’ knowledge, this study was the first comparing HA-coated Zimmer Tapered Screw-Vent Implant survival rates and marginal bone stability, when loaded immediately versus when loaded early in 3 weeks. There has been a reluctance to manipulate implants in 3 weeks due to fear of disrupting osseointegration. By using RFA, we were able to dispel this myth. With this implant after 7 years in function, we found no significant loss of stability and with survival of 100% in Group A and 95.5% in Group B. The results from this study of 50 implants showed that HA-coated Zimmer Tapered Screw-Vent Implants were clinically effective, with an overall cumulative 7-year survival rate of 98.0%.This was equal or better than other immediate loading studies , 26, 27.n = 1725) and uncoated (n = 1070) implants placed in participants and monitored for 36–71 months of clinical follow-up [During the 1990s, the US government conducted a prospective, randomized, multicenter study of HA-coated  of the present study at the 7-year follow-up period were consistent with earlier outcomes of the same highly crystalline HA-coated surface used on cylindrical rather than threaded implant designs .The current study has limitations. The original sample size was 50 implants, and 8 of these implants were lost to follow-up prior to the study end, decreasing the evaluable sample size and with unknown outcomes for the censored implants. Additionally, the study was conducted at a single center, so operator (surgeon) influence, either positive or negative, could not be considered as a covariate in the analyses. Lastly, this study did not include smokers or those with significant comorbidities, so it is unknown if the implant performance that was noted in this study is generalizable to a larger and heterogenous population.After 7 years in function, implants partially coated with plasma-sprayed and hydrothermally treated HA were favorable when restored in occlusion immediately after or after 3 weeks of implant placement. Overall, within the limitations of our study, the outcomes of this particular implant system were favorable with clinically predictable results at 7 years for both immediate and early loaded implants.


COVID-19 may predispose pregnant women to higher risks of severe disease and poorer neonatal outcome. Psychological sequalae of this pandemic may pose a greater conundrum than its clinical aspects. It is currently unknown that how pregnant women cope with this global pandemic and its ramifications. The aims of the study are to understand the attitudes and precaution practices of non-infected pregnant women towards the COVID-19 outbreak in Singapore.An online cross-sectional survey of COVID-19 awareness among pregnant women attending antenatal clinics in Singapore was conducted. An internet link was provided to complete an online electronic survey on Google platform using a quick response (QR) code on mobile devices. The online survey consists of 34 questions that were categorized into 4 main sections, namely 1) social demographics 2) attitude on safe distancing measures 3) precaution practices and 4) perceptions of COVID-19. Multiple linear regression analysis was performed to examine women’s precaution practices among six independent socio-demographic variables, including age, ethnicity, education, front-line jobs, history of miscarriage and type of antenatal clinic .n = 127), were of Chinese ethnicity , attained tertiary education  and were not working as frontline staff (70%). Using multiple linear regression models, Malay ethnicity  was associated with higher frequency of practicing social distancing. Malay women  and those who worked as frontline staff  sanitized their hands at higher frequencies. Age of ≥36 years , Malay  and Indian ethnicity , and attendance at high-risk clinic  were associated with higher frequency of staying-at-home.A total of 167 survey responses were obtained over 8 weeks from April to June 2020. The majority of women were aged ≤35 years (76%, Social demographical factors including age > 36 years old, Malay ethnicity, employment in front line jobs and attendance at high-risk clinics are likely to influence the attitudes and precaution practices among pregnant women towards COVID-19 in Singapore. Knowledge gained from our cross-sectional online survey can better guide clinicians to communicate better with pregnant women. Hence, it is important for clinicians to render appropriate counselling and focused clarification on the effect of COVID-19 among pregnant women for psychological support and mental well being.The online version contains supplementary material available at 10.1186/s12884-020-03378-w. Coronavirus disease COVID-19) is an infectious disease caused by a newly discovered severe acute respiratory syndrome coronavirus SARS-CoV-2) first identified in Wuhan City, China, in December 2019 [9 is an i first idThe effects of SARS-CoV-2 in pregnancy were initially based upon previous experience with SARS-CoV-1 and Middle East Respiratory Syndrome-related coronavirus (MERS) , 9. HoweThe physiological and immunological changes in pregnancy make women more susceptible to severe illness from respiratory infections , 15. A rPregnancy itself poses logistical challenges and conundrums for obstetricians managing pregnant women with suspected or diagnosed with COVID-19. The RCOG suggests that the COVID-19 pandemic increases the risk of perinatal anxiety, depression, and domestic violence in pregnant women . Hence, Social media and information access in Singapore are readily available via the internet with majority owning mobile devices. Thus, establishing public awareness of COVID-19 using an online survey is easily achieved in a developed country like Singapore using information technology for disseminating and receiving information on social media. We reported the results from a rapid online cross-sectional survey related to COVID-19 among pregnant women attending antenatal clinics in Singapore. The survey aimed to 1) establish the baseline attitudes of pregnant women towards COVID-19 and 2) correlate socio-demographics with women’s precaution practices towards COVID-19 in Singapore. This online survey will help identify various characteristics of pregnant women who are more likely to be vulnerable towards the effects of COVID and enable clinicians to reflect on the insecurities and worries of pregnant women for more focused counselling.We conducted an online cross-sectional survey for pregnant women attending antenatal clinics in two large tertiary-referral hospitals in Singapore, namely KK Womens’ Childrens’ Hospital and Singapore General Hospital from April to June 2020. These two hospital have approximately twelve-thousand and two-thousand pregnancies and deliveries respectively per year, accounting for more than 50% of the total number of pregnancies and deliveries per year in Singapore , 20. EthPregnant women attending antenatal clinics were provided with an internet link to complete an online electronic survey on Google platform using a quick response (QR) code on any mobile device with internet access. The survey was anonymous and could be completed in about 10 min. The online electronic survey was created using CHERRIES (Checklist for Reporting Results of Internet E-Surveys)  and the The online survey consisted of 34 questions that were categorized into 4 main sections, namely 1) social demographics (Q1-Q10), 2) attitude on safe distancing measures (Q11–17), 3) precaution practices towards COVID-19 (Q18–21) and 4) perceptions of COVID-19 in the antepartum period (Q22-Q27), intra-partum care (Q28-Q30) and post-partum care. (Q31-Q34).  Yes, No, Not Sure, or 2) Not often, Occasionally, Often, Very often, or 3) Never, Rarely, Sometimes, Usually, Always. The different types of response scales were determined based on the forms and appropriateness of questions asked. Respondents did not receive any incentive to complete the survey and standard of care was not affected if they did not participate in the online survey. Respondents had to provide a response to every question to complete the survey. The electronic data were compiled and saved on a secured website that was password protected to access the data with no identifiable patient information available.Women’s characteristics and distributions of their attitudes, practices and perceptions towards COVID-19 were presented in frequencies and percentages. Multiple linear regression analysis was performed to examine the main factors associated with women’s precaution practices among the six-independent socio-demographic variables, including age , ethnicity , education , front-line jobs , history of miscarriage  and type of antenatal clinic . The scales of the dependent variables were treated in continuous form based on the design of rating in a continuum sequence of values, which could also help to increase the power of analysis. Data were presented as β coefficients and 95% confidence interval (CIs). Statistical analysis was performed using the IBM SPSS Statistic Package, version 20.0 .n = 127), were of Chinese ethnicity , attained tertiary education  and were not working as frontline staff (70%). This was representative of the social-demographics in the Singapore study population. In terms of obstetric history, most women conceived naturally , were primiparous  and at their third trimester of pregnancy , had no history of miscarriage  and were currently followed up in general clinics .A total of 167 survey responses were obtained over 8 weeks from April to June 2020. The clinical characteristics and demographics are presented in Table Table Table To the best of our knowledge, our study is hitherto the first study performed in a South East Asian population of pregnant women. Factors like race, religion, education background and employment status can influence women’s attitude, practice and perception especially in an affluent country like Singapore. Our survey showed that Malay pregnant women are likely to practice safe distancing and sanitise their hands at a higher frequency compared to Chinese to minimise the spread of COVID-19. In addition, women attending ‘high-risk’ clinics are more likely to stay at home compared to women attending ‘general clinics’. A plausible explanation suggests that women with high risk pregnancies are more likely to stay at home to minimize themselves or their foetuses from being infected with COVID-19 when compared to women with low risk pregnancies.Employed individuals who worked in front line services such as healthcare, hospitality have a lower tendency to stay home for social distancing, possibly driven by their more sociable or out-going characteristics when compared to those do not work in front line. Conversely, our study also showed that employed individuals with front line jobs are more likely to practice hand hygiene compared to those who do not to reduce the risk of infection. It is possible to attribute this to the nature characteristics of front-line jobs and these women are likely to have a high tendency to wash their hands more often compared to those who do not work in front-line jobs. In our study, women with previous history of miscarriage had a lower tendency to stay home for maintaining social distancing  suggesting that obstetric experience did not make women more cautious to practice social distancing to protect themselves. The same inverse associations were observed for Q18,Q20, Q21 with no significance.There are currently limited cross-sectional studies addressing the attitude and perception of COVID-19 among pregnant women. Anikwe et al. showed that majority of pregnant women in their third trimester in Nigeria demonstrated good attitude and preventative practices of COVID-19  by practPregnant women should be appropriately educated on preventative measures to reduce the severity of COVID-19 associated illness. Pregnant women should also avoid missing prenatal appointments if well and limit interactions with others to reduce the risk of transmission. Symptomatic women should be urged to be tested early for COVID-19 by nasopharyngeal or oropharyngeal swabs and practice self-isolation to reduce the risk of vertical transmission , 25.Yassa et al. focused on Turkish pregnant women in attitude, concerns and knowledge towards COVID-19 from 30 weeks gestation onwards  where TuIn our study, 46% of pregnant women believed they are more likely to go into pre-term labour when infected with COVID-19. Di Mascio et al. showed that 41.1% of pregnant women with COVID-19 had preterm birth before 37 weeks gestation, however that study did not distinguish between spontaneous and iatrogenic preterm birth . A systeIn our study, 46% of pregnant women also believed they are more likely to miscarry when infected with COVID-19. A systematic review by Zaigham et al. did not report any adverse outcomes relating to perinatal outcomes . AlthougIn our study, almost three in four (74%) of women were worried and very worried about being infected with COVID-19 in pregnancy. Durankus et al. showed that pregnant women scored higher on the Edinburgh Postpartum Depression Scale (EPDS) when compared to the control group . It is uMost cases of COVID-19 have evidence of human-to-human transmission where the virus appears to spread through respiratory, fomite or faecal methods , 34. TheA case series published by Chen et al. a tested amniotic fluid, cord blood, neonatal throat swabs and breast milk samples from COVID-19 infected mothers and all samples tested negative for the virus . ConversThe mode of delivery should be discussed adequately with pregnant women taking into consideration their preferences and any obstetric indications. In our study, 53% of women would choose to have a caesarean section over a vaginal delivery if they were diagnosed with COVID-19. A. Khalil et al. showed that nearly half of pregnant women infected with COVID-19 had caesarean deliveries . As therIn our study, only 35% of pregnant women will choose to breast feed if they were diagnosed with COVID-19. There is also limited data to guide the postnatal management of babies of mothers who tested positive for COVID-19 in the third trimester of pregnancy. Currently, possibility of infection from breast milk remain uncertain although there is recent evidence to suggest a small risk of transmission through breast feeding –45. As bWe chose to perform an online survey as this is a rapid and convenient mode of administration. Furthermore, we used CHERRIES to ensure the quality of our web-based survey . LimitatEver-since the WHO declared COVID-19 a global pandemic, the world has seen an exponential number of rising cases and unprecedented death rates. Until a vaccine is found, herculean efforts rests on containing community spread of COVID-19 through means like testing for suspected cases, practising social distancing and maintaining good personal hygiene –49.As much of COVID-19 remains hitherto unknown, current opinions regarding management of COVID-19 positive women may change with input of new knowledge. The physical burden of pregnancy makes it psychologically and emotional challenging in vulnerable pregnant women. Social demographical factors including age > 36 years old, Malay ethnicity, employment in front line jobs and attendance at high-risk clinics are likely to influence the attitude and precaution measures among pregnant women towards COVID-19 in Singapore. Knowledge gained from our cross-sectional online survey can better guide clinicians to communicate better with pregnant women. Our study highlights the importance for clinicians to render appropriate counselling and focused clarification on the effect of COVID-19 among pregnant women for psychological support and mental wellbeing.Additional file 1.