Situation Analysis of Ticks and Seroprevalence of Theileria Parva in Two Farming Systems in Two Districts of Uganda.
Authors: Kwesiga Stephen , Okello-Onen Joseph , Byenek Simon Ogwal , Otim-Nape William 
Published: August 2020

Background: In Uganda, livestock supports the livelihoods of poor people, fulfilling multiple-economic, social, and risk management functions. However, its productivity is constrained by ticks and tick-borne diseases (TTBDs), more importantly, East Cost Fever (ECF) whose epidemiology is not well known and understood in the cattle corridor. Methodology: A cross-sectional study was carried out in pastoral and mixed crop-livestock farming systems in Nakaseke and Nakasongola districts to understand the; local composition of ticks, the prevalence of Theileria parva and management of ECF and ticks. A structured closed-ended questionnaire was administered in (189) pastoral and (197) mixed-crop livestock households which were randomly selected, and a total of 384 calves were sampled. The tick challenge was assessed in situ on one side of the animal body considering different predilection sites. The prevalence of ECF was assessed by collecting whole blood in Ethylene Diamine Tetra acetic Acid (EDTA) tubes following veni-puncture. Thin and thick blood smears were made and serum samples were collected for determination of seroprevalence of ECF, using Enzyme-Linked Immunosorbent Assay (ELISA). Results/Discussion: From a sample of 384 cattle surveyed, 316 (82.3%) were found to be infested with ticks of different species at their preferential predilection sites. Rhipicephalus. appendiculatus was the most abundant tick species (88.2%), followed by Ambryomma. variegatum (7.5%) and lastly Rhipicephalus. evertsi evertsi (4.3%). 80.7% of respondents believe that there was a tick infestation problem severe and ticks were managed on regular basis mainly by using acaricides (65.3%). In the pastoral farming system, no ticks were found on calves below 6 months old. The seroprevalence of T. parva was below 20% percentage positivity (pp)in calves below 4 months old, thereafter rising to 65% at 5 months, and then dropping to 20% from the age of 6 to 9 months. In mixed crop-livestock farming system, all age groups of cattle were exposed to tick challenge. The prevalence of T. parva increased from 1-month old calf reaching a peak in 2-3 months old calves but drastically dropped in calves 4 months old. Thereafter, it gradually built up to 70% in animals 7 months old. There was a moderate correlation between the mean number of R. appendiculatus ticks and seroprevalence of T. parva (r =0.47) and there was no significant difference between age category and percentage positivity of T. parva (p = 0.969). However, there was a relationship between mean number of ticks and farming system (p = 0.019) as well as percentage positivity of T. parva and farming system (p = 0.007)Conclusion: ECF was prevalent in the two farming systems albeit frequent application of acaricides on animals as reported by most of the respondents. Further longitudinal studies required to assess seasonal variations of TTBDs, prevalence of other tick-borne diseases and acaricide resistance status.