Surveillance and sociodemographic risk profiling of human soil-transmitted helminth infections in Gabon, Central Africa.

BACKGROUND

Sub-Saharan Africa bears the highest global burden of soil-transmitted helminth (STH) infections. In Gabon, community-level epidemiological data remain limited and no molecular surveillance of STHs has been conducted to date.

METHODS

In July 2023, a community-based cross-sectional survey was conducted in rural and urban areas of Ngounié Province, Gabon. Stool samples from 233 participants were analysed using formalin-ethyl acetate sedimentation microscopy and the Allplex GI-Helminth(I) quantitative polymerase chain reaction (qPCR) assay.

RESULTS

Overall, 70.0% (95% CI 63.6 to 75.8) of participants tested positive for at least one STH by microscopy or qPCR. Trichuris spp. was the most prevalent helminth (59.2% [95% CI 52.6 to 65.6]), followed by Ascaris spp. (48.1% [95% CI 41.5 to 54.7%]), hookworms (18.5% [95% CI 13.7 to 24.0]) and Strongyloides spp. (12.0% [95% CI 8.1 to 16.9]). Microscopy identified Strongyloides fuelleborni in 2.7% of samples. qPCR detected Necator americanus in 16.7% and Ancylostoma spp. in 0.4%. Rural residence was independently associated with Ascaris spp. (adjusted odds ratio [AOR] 2.50; p=0.007) and Trichuris spp. (AOR 2.45; p=0.008) infections. Male sex (AOR 3.83; p=0.010) and age 18-40 y (AOR 4.90; p=0.011) were associated with Strongyloides spp. infection.

CONCLUSIONS

STH infections remain endemic in certain Gabonese communities. The findings highlight the need for species-specific surveillance using sensitive molecular diagnostics to inform targeted control strategies.