Heterogeneity in the prevalence and intensity of bovine trypanosomiasis in the districts of Amuru and Nwoya, Northern Uganda

Abstract

BackgroundLivestock trypanosomiasis, transmitted mainly by tsetse flies of the genus Glossina is a major constraint to livestock health and productivity in the sub-Saharan Africa. Knowledge of the prevalence and intensity of trypanosomiasis is important in understanding the epidemiology of the disease. The objectives of this study were to (a) assess the prevalence and intensity of trypanosome infections in cattle, and (b) to investigate the reasons for the heterogeneity of the disease in the tsetse infested districts of Amuru and Nwoya, northern Uganda.MethodsA cross-sectional study was conducted from September, 2011 to January, 2012. Blood samples were collected from 816 cattle following jugular vein puncture, and screened for trypanosomes by HCT and ITS-PCR. A Pearson chi-squared test and logistic regression analyses were performed to determine the association between location, age, sex, and prevalence of trypanosome infections.ResultsOut of the 816 blood samples examined, 178 (22 %) and 338 (41 %) tested positive for trypanosomiasis by HCT and ITS-PCR, respectively. Trypanosoma vivax infection accounted for 77 % of infections detected by ITS-PCR, T. congolense (16 %), T. brucei s.l (4 %) and mixed (T. vivax/ T. congolense/T.brucei) infections (3 %). The risk of trypanosome infection was significantly associated with cattle age (χ2 = 220.4, df = 3, P < 0.001). The highest proportions of infected animals were adult males (26.7 %) and the least infected were the less than one year old calves (2.0 %). In addition, the risk of trypanosome infection was significantly associated with sex (χ2 = 16.64, df = 1, P < 0.001), and males had a significantly higher prevalence of infections (26.8 %) than females (14.6 %).ConclusionOur results indicate that the prevalence and intensity of trypanosome infections are highly heterogeneous being associated with cattle age, location and sex.

Apparent density, trypanosome infection rates and host preference of tsetse flies in the sleeping sickness endemic focus of Northwestern Uganda

“…Trypanosoma vivax is also known to have a shorter developmental life cycle and can be mechanically transmitted by haematopahgous insects, which may explain its predominance in the surveyed samples [51]. An earlier study by Angwech et al [52] in Amuru and Nwoya districts, which border the study area in the present study, found that T. vivax was also the most predominant trypanosome species in cattle. Our results are also consistent with several other previous studies on tsetse and trypanosomes ecology in Uganda [39,53,54].…”

Apparent Density, Trypanosome Infection Rates and Host Preference of Tsetse Flies in the Sleeping Sickness Endemic Focus of North-Western Uganda

“…In addition, T. vivax is known to have a shorter developmental life cycle which is entirely completed in the 10 days in the proboscis, which may explain its predominance in the surveyed samples [50]. An earlier study by Angwech et al [51] in Amuru and Nwoya districts, which border the study area in the present study, found that T. vivax was also the most predominant trypanosome species in cattle. Our results are also consistent with several other previous studies on tsetse and trypanosomes ecology in Uganda [39,52,53].…”

Distribution Of Tsetse Flies And Significance To The Control Of African Trypanosomiasis In Busia County, Kenya

“…An approach that severely reduced tsetse densities by over 95% within the 1999-2004 program period. A number of follow up control initiatives by the Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) maintained the success gained for a longer period of time(16,30). This survey was conducted to assess if the tsetse populations had rebounded in this region.…”

“…The infections with T. congolense were disproportionately lower (2.0%) in the sampled areas. Previous research has shown that G. fuscipes fuscipes is a better vector for T. vivax leading higher infection rates among animals in this region(16,30,33,36). The numerous tsetse and trypanosomiasis control activities implemented in Busia County over the past decade have immensely contributed to lowering tsetse densities and infection rates.…”