Prevalence and Sociodemographic Risk Factors of Soil-Transmitted Helminths in Rural Communities Living in Endemic Foci of Onchocerciasis in Southern Gabon.

Abstract

This prospective survey determined the prevalence and intensity of infections due to geohelminths and the associated risk factors in five onchocerciasis-endemic communities in Gabon between January and February 2020. Onchocerciasis endemicity was confirmed by Ov16 IgG testing. STHs were detected using the Kato-Katz techniques. Prevalence and parasite density were analyzed according to age, sex, and onchocerciasis endemicity. STHs were found in 64.8% of participants and were more common in hypoendemic (80.9%) and hyperendemic (63.9%) onchocerciasis communities (p < 0.01). Ascaris lumbricoides (65.5%), Trichuris trichiura (57.1%), and hookworms (17.3%) were prevalent in areas hypoendemic for onchocerciasis (p = 0.04). Male participants were more often infected by hookworms. Adults were more frequently infected by STHs (75.9%) than elders, who were the least infected (39.3%) (p < 0.01). Participants living in sporadic onchocerciasis areas frequently but not significantly harbored a moderate ascariasis load (6960.0 (1068.0-9492.0) eggs per gram) (p = 0.4). The highest parasite density was observed among participants aged 20-45 years (15,336.0 (3888.0-35,028.0)). A low T. trichiuria prevalence was found in all communities. STHs are highly prevalent in hypoendemic and hyperendemic areas and adults. An integrated combined approach of STH and onchocerciasis elimination through efficacious mass drug administration targeting all age groups should be considered.