Dept. of Public Health and Preventive Medicine
Oregon Health & Science University
Background: Neurocysticercosis (NCC), caused by Taenia solium larval infection, is a leading cause of acquired epilepsy in developing countries. Case reports of NCC are increasing among refugees resettled to non-endemic countries including the United States, but little is known about T. solium infection within refugee camps. Heavily-infected pigs can indicate areas where the risk of T. solium taeniasis is elevated so identifying these pigs could guide treatment and screening programs in areas with limited resources such as refugee camps. We sought to examine factors associated with being a tapeworm carrier in the Ban Mai Nai Soi refugee camp, including owning a heavily-infected pig. Methods: We carried out a random sample and a targeted sample of households within the camp. All participants were asked to submit a fecal sample and to complete an interview. Fecal samples were analyzed for presence of Taenia sp. antigens using ELISA or for presence of Taenia sp. eggs or proglottids using light microscopy. A pig was determined to be heavily-infected by tongue examination for characteristic cysts. Generalized estimating equations (GEE) models were used to characterize the association between owning a heavily-infected pig and taeniasis as well as the association between other demographic measures and meat consumption practices and taeniasis in the camp. Results: Among the random sample, 3% (18/552) were positive for taeniasis. After accounting for household clustering and sampling weight, the prevalence of taeniasis in the random sample was 2.8% (95% CI: 1.4, 4.2%). Among pigs sampled in all households, 2.5% (18/722) were tongue-positive. After accounting for household clustering and sampling weight, the prevalence of tongue-positive pigs was 2.5% (95% CI: 0.8, 4.2%). Owning a tongue-positive pig was not significantly associated with taeniasis upon univariate (OR = 2.43; 95% CI: 0.60, 9.76) or multivariate (OR = 2.30; 95% CI: 0.62, 8.46) GEE analysis. Multivariate GEE analyses indicated that the number of household residents, self-report of worm passage, and eating pork outside of camp more than 5 times per month were significantly associated with taeniasis while having a latrine within the yard had a protective association with taeniasis. Conclusion: The prevalence of human taeniasis in this population is comparable to estimates from other Taenia spp. endemic regions. However, owning a heavily-infected pig, as measured by tongue palpitation, did not accurately predict taeniasis infection. The association between eating pork outside of the camp more than 5 times a month and taeniasis suggests that pigs within the camp may be protected from T. solium infection. Furthermore, self-report of worm passage may be a useful initial screening for determining taeniasis-negative status.
School of Medicine
McCleery, Ellen J., "Taeniasis among refugees on the Thailand-Burma border" (2013). Scholar Archive. 984.