Transmission of Soil Transmitted Helminthiasis in the Mifi Health District (West Region, Cameroon): Low Endemicity but Still Prevailing Risk

Abstract

The control of soil-transmitted helminthiasis (STH) in Cameroon is focused on large-scale deworming through annual mass drug administration (MDA) of albendazole or mebendazole to at-risk groups, principally pre-school and school-age children. After a decade of intervention, prevalence and intensity of infection have been significantly lowered, encouraging the paradigm shift from control to elimination. However, STH eggs are extremely resistant to environmental stressors and may survive for years in soils. It therefore appeared important to assess whether the risk of transmission was still prevailing, especially in a context where transmission of soil-transmitted helminths in the human population had almost been interrupted. A retrospective and a prospective cross-sectional surveys were conducted in five Health Areas of the Mifi Health District (West Region, Cameroon) to: (i) assess the trends in infestation rates over three-years (2018–2020) using health facility registers, and (ii) investigate, in 2020, the contamination rates of the environment by dissemination stages of soil-transmitted helminths using the sucrose centrifugal flotation method. The overall soil-transmitted helminth infestation rate was 4.9% (95% CI: 4.3–5.6), significantly lower than the overall soil contamination rate (12.0%; 95% CI: 8.2–17.2). These results are supportive of the low endemicity level of STHs in the Mifi Health District, but environmental pollution by dissemination stages of the parasites outlines that the risk of transmission is still persistent. It therefore appears compulsory to account for the environment when considering policy/recommendations for transmission interruption and stopping MDA, as it is in the case with vector-borne diseases.

Assessment of environmental contamination with soil-transmitted helminths life stages at school compounds, households and open markets in Jimma Town, Ethiopia

“…The contamination at households was comparable to that observed in a study in Bangladesh (78.0% [ 24 ]) but higher that of a study in Kenya 26.8% [ 25 ]. The contamination level in the present study was higher than that previously reported (15% in Cameron [ 80 ]).…”

Prevalence of Soil Transmitted Helminths Among School Children in Aliade, Gwer- East Local Government Area, Benue State, Nigeria

“…Soil-transmitted helminths (STHs) are a group of neglected tropical diseases that causes the most common infections worldwide and primarily affect marginalized populations in low-and middle-income countries. The three main species that infect people are Ascaris lumbricoides, Trichuris trichiura and hookworms 1 (STH) infections are tagged as one of the most common and neglected infections globally 2 Parasitic worms are referred to as helminthes because they live and feed on living hosts. They receive both nourishment and protection by disrupting the host's ability to absorb nutrients, resulting in weakness and disease of the host.…”