Prevalence of Kala-azar in Pokot County, Nakapiripirit District

Abstract

Background: Kala-azar is the only clinical manifestation of leishmaniasis so far recently reported in Uganda and has been largely confined in Pokot County. Here it is caused by Leishmania donovani and transmitted by the sand fly Phlebotomus martini. Amudat hospital in-patient records (April 1998-March 1999) indicate that KA accounted for about 17% of hospital in-patients. But the actual prevalence of KA is not known in Pokot County, yet this is vital epidemiological information for its control. Objective: To determine the prevalence of KA in Pokot County using Direct Agglutination Test and to determine some of the factors associated with KA in Pokot County. Methods: A cross-sectional study was conducted in Pokot County Nakapirirpirit district in February to March 2010. The study participants were ≥5years randomly selected from the various strata in the selected clusters (Manyatta), the number of clusters were got using Bennett’s formula. A questionnaire that elicits demographic profile of the participant was used for data collection. Standard procedure for DAT using blood samples collected from participants on blotting papers was performed at Amudat Hospital laboratory. Data entered in EPIINFO and exported to STATA was used to produce frequencies and cross tabulation of DAT outcome and independent variables. Multivariable logistic regression was used to show how DAT outcome was related to risk factors. Results: Overall prevalence of KA in Pokot County is 17.2% (49/285) but the prevalence of clinical KA in the community is 2.5%. The ratio of clinical to sub-clinical KA is 1:6. Kala-azar prevalence is higher amongst males 19.9% (28/141) compared to females 14.6% (21/144). DAT positive participants were more in sub-counties with more clinical cases. Loroo Sub County had the highest prevalence of KA followed by Karita and Amudat at 31.9%, 14.6% and 5.3% respectively. Conclusion: Kala-azar is common in Pokot County with the highest prevalence in Loroo sub-county. Therefore there are many infectious persons in the community who are continuously spreading the infection. The prevalence is higher in males compared to females and infection is common amongst individuals who report a previous case of KA in their household. Given the high prevalence and recent reports of cases from neighbouring districts there is need to institute appropriate control program.