Detection of Echinococcus granulosus sensu lato in Environmental Samples from Ibadan, Oyo State, South West Nigeria

SIMPLE SUMMARY: The presence of parasite eggs in the environment represents an alarming threat for human health. In particular, the accidental ingestion of tapeworm eggs can cause severe and disabling illness in humans. Cystic Echinococcosis (CE), caused by infection from the tapeworm Echinococcus granulosus, gives rise to great concern for its medical and economic burden. CE transmission to humans mostly occurs through the consumption of water or food contaminated by feces of infected dogs. In the present study, we collected soil, fecal and water samples in the city of Ibadan, Oyo State, Nigeria, to detect parasite contamination in the environment. We evidenced that the urban and semi-urban areas of Ibadan are highly contaminated with E. granulosus s.l. eggs, emphasising the need for appropriate measures to control CE. These findings suggest that prevention strategies should consider the control of stray dogs, the establishment of deworming programs and the promotion of public education. ABSTRACT: Environmental contamination with parasite eggs poses a serious risk to public health. This study aimed to assess the presence of taeniid eggs and, in particular, E. granulosus s.l., in environmental samples in the city of Ibadan, South West Nigeria. To this purpose, soil (n = 200), fecal (n = 200) and water samples (n = 50) were examined by microscopic observation and the multiplex PCR method. The influence of specific environmental factors on E. granulosus s.l. egg dispersion was also evaluated. Taeniid eggs were microscopically found in 11.5%, 25.5% and 8.0% of soil, fecal and water samples, respectively. PCR analyses evidenced the presence of E. granulosus s.l. in 8.0%, 24.0% and 2.0% of soil, fecal and water samples, respectively. The proximity to slaughterhouses, the level of urbanisation and the local government area of belonging did not seem to affect E. granulosus s.l. egg dissemination patterns. Our results have clearly demonstrated that both urban and semi-urban areas of the city of Ibadan in Nigeria are highly contaminated by taeniid eggs and we recommend the adoption of appropriate measures to control E. granulosus s.l.