Prevalence and risk factors associated with Trypanosomosis in Cattle Herds in Kilwa District of Lindi Region of Tanzania

African Animal trypanosomosis (AAT) or Nagana and Human African Trypanosomosis (HAT) or Sleeping Sickness are complex chronic, debilitating, emaciating and often fatal diseases of animals and humans, respectively. This cross-sectional study was conducted to determine the prevalence and risk factors associated with bovine trypanosomosis in tsetse-infested Kilwa district, Lindi region, Southern Tanzania. Blood samples were collected from 420 cattle randomly selected from 86 herds from ten villages. A maximum of ten herds per village and at maximum six animals from each herd were selected for sampling. At the same time a questionnaire was administered. Individual animal samples were analysed using microscopy and pooled sample at herd level were analysed by loop mediated isothermal amplification (LAMP). A herd was considered positive if at least one animal in the herd was positive for AAT.
A herd prevalence of 9.3 % (95% CI: 2.9-14.9) was recorded for AAT by microscopy, mainly caused by Trypanosoma congolense 5.8% (95% CI = 0.9-10.7), Trypanosoma brucei species 5.8% (95%, CI = 0.9-10.7) and Trypanosoma vivax 3.5% (95% CI = 0-7.4). Loop mediated isothermal amplification (LAMP) recorded a heard prevalence of 41.9% (95% CI: 30.0-51.4%), mainly caused by T. congolense 30.2% (95% CI: 20.5-39.9), T. brucei species 25.6% (95% CI: 16.4-34.8) and T. vivax 20.9% (95% CI: 12.3-29.7). Most of the cattle herds had mixed infections of these parasites. According to LAMP, Miteja and Matandu villages both had the highest AAT prevalence of 57% (95% CI: 20.3-93.7) while Mavuji had the lowest prevalence of 14% (95% CI: 0-39.7). Data from the present study suggest that district of origin, grazing in Game Reserve, season of increased vector, form of watering point, and affordability of the anti-trypanosomal drugs are risk factors associated with AAT in Kilwa district, southern Tanzania. Use of tsetse trapes and targets, continuous surveillance and monitoring of AAT using more sensitive and specific molecular tests, discouraging settlement and graing in the game reserve are recommended.