An investigation of prevalence and risk factors of Porcine Cysticercosis and human Taeniosis in Teso district, Kenya
Cysticercosis due to Taenia solium is a disease of both public health and economic importance, which has been reported in developing countries of Africa, Asia and America. Infection in humans and pigs is a disease of the poor, mostly affecting the rural small-scale farmers. In this study, the prevalence of porcine cysticercosis and the potential risk factors of infection among the free-range pigs in Teso District were assessed. Information on T. solium infection in humans in the district was obtained from hospital records. A cross-sectional study was conducted in which a sample of small-scale pig keepers was randomly selected and pigs examined for the presence of T. solium larval cysts using the lingual palpation method. A total of 505 pigs from 316 survey households were examined for the larval cysts. Information on potential risk factors for porcine cysticercosis was obtained by means of standardized questionnaires administered via personal interviews. Out of the cross-sectional sample of 316 households, a case-control sample of 31 case and 93 control-households was selected. A case household was defined as one with allcast one pig testing positive for the T. solium larval cysts and a control household as one where no pig tested positive for the cysts. The household prevalence of porcine cysticercosis was estimated at 9.8 7c with a 95 % confidence interval (Cl) of 6.5 - 13.1 7c. The total number of pigs testing positive was 33, converting to a pig prevalence of 6.5 7c, and a 95 % Cl of 2 7c - 10.7 7c. Out of the 124 survey households, 11 7c did not keep any other type of livestock except pigs. Thirty-eight percent of the farmers kept only one pig and 12 7c had more than five pigs. Pigs in Teso District were kept as a source of income (98 7c) and for home consumption (2 7c). Major sources of pigs included purchases from within the district (94 %) and purchases from Uganda (6 %). Two methods of raising pigs were identified, namely, free-ranging and total confinement. Most (95 %) of the pig farmers allowed their pigs to roam freely in the villages and 71 % of these practiced a mixture of free-range and tethering. A total of six (5 %) households reportedly confined their pigs, either by tethering (67 %) or by housing (33 %). Pork was consumed in 110 (89 %) of the surveyed households. The meat was sourced from local butcheries (85 %) and home-slaughtering (15 %). Fifty-six percent of study households practicing home-slaughter had their meat inspected at “home”. This “inspection” was done by household friends (56 %), the owners themselves (11%) and government meat inspectors (33 %). The most commonly (94 %) practiced method of pork preparation before eating was frying. Epilepsy was identified as a common disease in the villages, 56 % of the respondents reported presence of epileptics in their villages while 19 % had observed epileptics in their families. The taeniosis / cysticcrcosis complex was poorly understood by both the public and even the medical personnel in the district. Most of the potential risk factors considered in the study were equally distributed in both case and control households. The only variable which was significantly more in the case households (42 %) than in the control households (19 %) was absence of latrines (p< 0.05; OR=3.2). The prevalence of tapeworm infections in humans in the District was 0.18 %. Other intestinal infections reported in humans were: hookworm (17.5 %); Entamoeba histolytica (10.1 %); Giardia lamblia (2.4 %); Ascaris lumbricoides (2.5 %); Strongyloides stercolaris (2.7 7c) and Schistosoma mansoni (0.18%). It was concluded that porcine cysticercosis is prevalent in the locally-raised pigs of Teso District. This strongly suggests presence of human T. solium carriers who, due to non-use of toilet facilities, contaminate the environment with T. solium eggs infective to both humans and pigs, and thus maintaining the life cycle of the parasite. Appropriate and sustainable control strategies based on the scientific data collected should be devised in collaboration with the affected local populations to effectively address this emerging problem. Education of the public should be an integral component of any envisaged control programme of the taeniosis / cysticercosjs complex in the district.