Seroprevalence and risk factors for Taenia spp infection in pigs in Kongwa and Songwe districts, Tanzania: A cross-sectional study

Christina Wilson; Robinson Hammerthon Mdegela; Hezron Emmanuel Nonga; George Makingi; Ayubu Jacob Churi; Dominik Stelzle; Ernatus Martin Mkupasi; Veronika Schmidt; Hélène Carabin; Andrea Sylvia Winkler; Helena Aminiel Ngowi

doi:10.1016/j.fawpar.2023.e00215

Seroprevalence and risk factors for Taenia spp infection in pigs in Kongwa and Songwe districts, Tanzania: A cross-sectional study

Food Waterborne Parasitol. 2023 Nov 28:33:e00215. doi: 10.1016/j.fawpar.2023.e00215. eCollection 2023 Dec.

Authors

Affiliations

¹ Department of Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania.
² Department of Veterinary Medicine and Public Health, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania.
³ Department of Informatics and Information Technology, Sokoine University of Agriculture, Morogoro, Tanzania.
⁴ Center for Global Health, Department of Neurology, Technical University of Munich, Munich, Germany.
⁵ Department of Pathology and Microbiology, University of Montreal, Canada.
⁶ Department of Social and Preventive Medicine, University of Montreal, Canada.
⁷ Center de Recherche en Santé Publique (CReSP), Canada.
⁸ Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique (GREZOSP), Canada.
⁹ Center for Global Health, Institute of Health and Society, University of Oslo, Norway.

Abstract

Taenia solium porcine cysticercosis (PCC) is widespread in many low- and middle-income countries (LMICs) where free-range pig rearing is common and hygienic standards are subpar. A cross-sectional survey was conducted in 42 villages between June and September 2019 (14 in Songwe district, southwest Tanzania, and 28 in Kongwa district, central Tanzania). Using a commercial Ag-ELISA kit (apDia, Belgium), circulating antigens of Taenia spp in pig serum were identified and used to calculate the PCC seroprevalence. The study recruited 692 randomly selected households, sampling one pig per household. The relationship between each risk factor and the seroprevalence of PCC at the household and village levels was analysed using mixed logistic regression models. The findings showed that approximately 28% of the pigs were reared in free-range settings, the proportion of households with latrines across the districts was 92%. Twenty-seven percent of households with latrines had water and soap available for hand washing. Sixty-seven (9.7%) tested positive for PCC based on Ag-ELISA. The overall seroprevalence in Kongwa and Songwe districts was 7.3% and 14.0% respectively. In addition, the overall village Ag-ELISA positivity was 9.3%, with an interquartile range (IQR) of 4.6% - 14.1%. Increasing the age of the pig (OR = 3.13 95% CI = 1.48 - 6.60; p = 0.003), pig originating from outside the household (OR = 0.5 95% CI = 0.25 - 0.99; p = 0.05), and pigs kept in a household that practised deworming (OR = 2.23 95% CI = 1.08 - 4.61; p = 0.03) were important risk factors associated with PCC positivity. Therefore, the high seroprevalence of PCC, up to 14%, calls for rapid and effective control actions such as vaccination and treatment of pigs against PCC, and public health education emphasises on indoor pig rearing, hygienic practices and regular use of latrines. Our findings also point to a potential danger of Taenia. spp infection indicating the possibility of people carrying the adult parasite Taenia solium not only in the rural communities of Kongwa and Songwe districts but also in the urban areas of Tanzania, where pigs from these areas are transported for consumption. To develop effective management measures, further research on taeniasis and cysticercosis in the human population is required.

Keywords: Ag-ELISA; Foodborne disease; Mixed logistic regression models - fixed and random effects; Risk factor; Taenia solium; Tanzania.