Prevalence and species distribution of caprine trypanosomosis in Sinazongwe and Kalomo districts of Zambia

摘要

African animal trypanosomosis is one of the key livestock diseases hindering full exploitation of livestock production potential covering 37 countries across sub-Saharan Africa. Many studies have been carried out to investigate the prevalence of the disease in cattle and humans in many tropical African countries but very little attention has been directed towards generating the disease prevalence rates in goats. The current study was conducted between December 2013 and January 2014 to establish the prevalence of caprine trypanosomosis in Sinazongwe and Kalomo districts, southern Zambia. It involved 422 goats which were first examined by palpation for possible enlargement of superficial lymph nodes. Blood samples were then collected from the goats and subjected to laboratory diagnosis using the microscope and Loop Mediated Isothermal Amplification (LAMP). None of the examined goats displayed enlargement of superficial lymph nodes. On microscopy only one goat was found to be positive. The results of investigation using the LAMP method showed that 100 goats were infected with trypanosomes giving an overall prevalence rate of 23.7%. The prevalence of infection in Sinazongwe was 22.4% (n=183) while in Kalomo it was 24.7% (n=239); and the difference between the two districts was statistically significant at 95% CL (x(2) = 4.4, df = 1, p 0.05). Ttypanosoma brucei, Trypanasoma vivax and Trypanasoma congolense were detected in 82.0%, 31.0% and 23.0% of the infected goats, respectively. Mixed infections were detected among 33.0% of the positive samples. The high prevalence rate of trypanosomes detected in the study area confirms the earlier reports that trypanosomosis is re-emerging in the areas previously aerial sprayed by Government. The detection of trypanosomes in naturally infected goats outlines the important role goats play in the epidemiology of African animal trypanosomosis. (C) 2015 Elsevier B.V. All rights reserved.