A survey of human Taeniosis/Bovine cysticercosis in Northern Turkana District,Kenya

Abstract

Bovine cysticercosis IS a zoonosis of socioeconomic and public health importance. A survey was carried out in northern Turkana District to: 1) estimate the prevalence of bovine cysticercosis using serology and meat inspection, and to determine the prevalence of human taeniosis; 2) To determine the risk factors for bovine cysticercosis; and 3) To translate the prevalence information into thematic maps using Geographical Information Systems (GIS). This information will be used to estimate losses arising from refrigeration, downgrading and condemnation of carcasses with the disease. The study area was northern Turkana District and it was stratified into the three livestock grazing regions of Oropoi to the south, Lokichoggio-Mogilla centrally and Kibish in the north. This was done for the purposes of the serological (n=792) and questionnaire (n=75) data collection. Five adakaars (grazing units) were visited and, 34, 63, 49, 75, and 571 serum samples were obtained. The slaughter slabs of Lokichoggio and Kakuma were visited and 188 serum samples were obtained so as to determine the relation between serology and meat inspection, however only a fraction (441188) of those slaughtered came from northern Turkana, the rest were sourced across the border in Uganda and Sudan. Human stool samples were collected in at least one location of the three strata; a total of 241 stool samples were obtained. Meat inspection data were obtained from records of the Public Health Officer (PHO) and District Veterinary Officer (DVO) in Turkana District during the study period and for the previous year. Secondary data regarding human taeniosis was obtained from the AMREF community based healthcare (CBHC) project reports. The prevalence of cysticercosis was estimated at 18% (95% Cl, 15.4% - 20.9%) using a secretory-excretory antigen detection ELISA. There was poor agreement between meat inspection and serology (k = 0.025). The prevalence of human taeniosis was estimated at 2% (95% Cr,0.8%-5.6%) by microscopy. A backwards elimination logistic regression analysis indicated that grazing unit tAdakaar}, deworming history and distance of grazing fields from the homestead were significant explanatory variables for bovine cysticercosis seropositivity. However, confounding was established between grazing unit and the distance of grazing fields from homesteads. An intra-cluster correlation coefficient (lCC) of 0.07 (95%CI, 0.02 - 0.12); p<O.OOO1 was calculated for bovine cysticercosis in this area. A standard questionnaire to assess the inhabitant's knowledge of bovine cysticercosis indicates that a majority of them did not know about this condition or how it appears and how it is transmitted. It is therefore suggested that an awareness campaign be carried out in this community in addition to instituting a program to improve the quality of meat inspectors.