Epidemiology of epizootic lymphangitis of carthorses in northern Ethiopia using conventional diagnostic methods and nested polymerase chain reaction.
BACKGROUND
Epizootic lymphangitis (EL), caused by Histoplasma capsulatum variety farciminosum (HCF) is a contagious, chronic disease of equines, characterized by development of nodular lesions in the lymph nodes, lymphatic vessels and skin. It is one of the most important diseases of equines in Ethiopia, causing significant economic loss, particularly in the livelihood of carthorse owners. To date there is neither effective diagnostic nor control measure implemented in the country. Furthermore, there is a shortage of data on the epidemiology of the disease in different regions of this country. The aim of this study was to investigate epidemiology of EL in northern Ethiopia, using the conventional methods as well as nested polymerase chain reaction (PCR).


RESULTS
The presence of HCF genetic material was confirmed in 44% (84/191) of the carthorses. Subclinical infection was observed in 18.2% (22/121) of the apparently healthy carthorses. Considering the nested PCR as a gold standard, sensitivity and specificity of clinical examination were 74% and 92.5%, respectively, while the area under the ROC curve (AUR) was 0.83 (95% confidence interval, 0.77, 0.896). Moreover, a moderate (k = 0.675) agreement observed between the nested PCR and clinical examination.


CONCLUSIONS
This study demonstrated widespread occurrence of EL in northern Ethiopia, and the advantage of the nested PCR in detecting infection of HCF, even before the clinical symptoms became apparent.
['Hadush|Birhanu|B|', 'Michaelay|Molla|M|', 'Menghistu|Habtamu Taddele|HT|', 'Abebe|Nigus|N|', 'Genzebu|Abreha Tesfaye|AT|', 'Bitsue|Habtom Kiros|HK|', 'Afera|Berihun|B|', 'Duguma|Bojia E|BE|', 'Gugsa|Getachew|G|', 'Ameni|Gobena|G|']
D000818:Animals D003430:Cross-Sectional Studies D005002:Ethiopia D006658:Histoplasma D006660:Histoplasmosis D006734:Horse Diseases D006736:Horses D008205:Lymphangitis D016133:Polymerase Chain Reaction
Epizootic lymphangitis PCR Gram stain Histoplasma capsulatum var farciminosum