Animal African trypanosomaisis and associated cytokine profiles in naturally infected cattle in Paicho and Lakwana Subcounties, Gulu District

Abstract

Trypanosomes are the causative agents of Animal African Trypanosomiasis (AAT) and Human African Trypanosomiasis (HAT), the former affecting domestic animals prevalent in the sub Saharan Africa. The main species causing AAT in cattle are T. congolense, T. vivax and T. b. brucei. Northern Uganda has been politically unstable with no form of vector control in place. The return of displaced inhabitants led to restocking of cattle from AAT endemic areas. It was thus paramount to estimate the burden of trypanosomiasis in the region. The current understanding of cytokine profiles during trypanosome natural infections is limited. Most studies on cytokine profiles in trypanosome infections have been carried out on experimental infections using T. congolense. There was a need to investigate cytokine profiles in natural field conditions where animals encounter different species of varying pathogenicity including mixed infections. The major aim of this study was to assess the prevalence of trypanosome infections in cattle and the associated cytokine profiles in Paicho and Lakwana sub counties. In this study, prevalence of trypanosomiasis in cattle was determined using Hematocrit Centrifugation Technique (HCT) that was used to detect trypanosome infections in cattle while Polymerase Chain Reaction (PCR) was used to identify the infecting species and also confirm the infection status of some apparent negative samples by microscopy. To compare differences in the plasma levels of IFN-g, TNF- , IL-10 and TGF- in infected and non infected cattle sandwich ELISA was then carried out. Out of the 1329 cattle screened, the microscopy prevalence of trypanosomes was 8.1% respectively. The IFN-g and IL-10 were up regulated in infected than non-infected cattle regardless of pathogenicity of infecting species. The results indicated that up regulation of IL-10 and IFN- g cytokine levels is not dependant on pathogenicity of species and whether it was single or mixed infections. It is thus recommended that appropriate control efforts should be put in place to prevent escalation of trypanosomiasis in the area and detailed study on possible use of IL-10 & IFN- g as targets for supportive therapy in favor of the host.