Soil transmitted helminths infections

Dear Editor,

“Soil-transmitted” helminthiases (STHs) are among the world's leading tropical diseases, representing a challenging public health problem that affects school-age children in low-income areas. In many countries, there is a lack of data on environmental contamination by STHs.^[1-4] Therefore, the recent article published in this Journal by Aliyu FO and colleagues increased our interest in this important public health matter, and additional literature data are included.^[2-4] Those Nigerian authors reported results of a cross-sectional descriptive study performed from June to August 2023, focusing on soil-transmitted helminth infections in a rural community.^[1] Among the 500 participants, the individuals aged between 18 and 23 years had the highest response rate (32.2%), a higher prevalence was observed among males (51.0%), and the prevalence of STHs was 13.2%. The most frequent species were hookworm (40.91%), while S. stercoralis was the least (12.12%); risk factors for STH infection were: the 12-17 years age range, not wearing shoes, lack of hand washing, and improper sources of drinking water. The cited Nigerian study also reported E. histolytica among detected intestinal parasites; however, it should not be categorized as a soil-transmitted helminth.^[1] An Ethiopian study conducted between May 2024 and March 2025 included 277 schoolchildren; of the infected, 31 were males, and 14 were females; the prevalence was 18.7% among males and 12.6% among females. Ascaris lumbricoides, Trichuris trichiura, and hookworms were more often found.^[2] STHs were more common in children under 10 years of age, and the predisposing factors included large families, dirty fingernails, and a lack of handwashing after using the toilet.^[2] The prevalence of STHs was lower than 20%, with no relation to nutritional status; the authors highlighted the major role of access to clean toilets and hand-washing facilities in schools.^[2] The study conducted in Tanzania from May to June 2022 involved a two-stage random sampling in which one neighborhood out of ten, and four primary schools out of five were selected.^[3] Questionnaires were utilized to collect information about socio-demographic data and risk factors for STHs from each participant; stool samples were evaluated to search for helminth eggs. The prevalence of STHs was 26.6%, higher than the national 8.4% (of the last decade); T. trichiura was the most prevalent, followed by A. lumbricoides and hookworms. Multiple infections occurred where children were infected by more than one roundworm; factors associated with STHs were age, sex, spring water use, and information about STHs.^[3] Between 2017 and 2023, two mobile and one fixed surveillance site were selected annually from Hainan Island, and at least 200 people aged ≥ 3 years participated per village, and ≥ 1,000 people per site.^[4] Fresh stool samples were collected to detect eggs of hookworm, T. trichiura, A. lumbricoides, and Enterobius vermicularis; and the perianal cellophane tape swab was used for E. vermicularis detection in children between 3 and 9 years. The STH rate was 5.76%, including 29,669 people from 128 villages and 88 townships in 18 county-level divisions, with hookworms, A. lumbricoides, T. trichiura, and E. vermicularis as prevalent; differences were observed, and infection rates varied by sex, age, ethnicity, occupations, and education levels.^[4] Integrated health and hygiene education programs and interventions will improve sanitation.