Surveillance for Soil-Transmitted Helminths in High-Risk County, Mississippi, USA

Abstract

Recent reports of hookworm infection in Alabama, USA, has prompted surveillance in Mississippi, given the states' similar environmental conditions. We collected stool specimens from 277 children in Rankin County, Mississippi. Kato-Katz microscopic smear, agar plate culture, and quantitative PCR indicated no soil-transmitted helminths. Nevertheless, further surveillance in other high-risk Mississippi counties is warranted.

Keywords: Enterobius; Mississippi; Necator americanus; Strongyloides; United States; hookworm; parasites; pediatric; soil-transmitted helminths.

Figure

Results of microscopic analyses using Kato–Katz smear, saturated NaNO₃ flotation, and agar plate culture for Strongyloides and hookworm larvae, in addition to multiparallel qPCR results, for 784 stool specimens from 277 school-age children representing 129 households in a surveillance study for STH infection, Rankin County, Mississippi, USA, February 2020–September 2021. Multiparallel qPCR targeted Necator americanus, Ancylostoma duodenale, Trichuris trichiura, Strongyloides stercoralis, and Ascaris lumbricoides. Enterobius vermicularis eggs only were recovered in the 2 positive NaNO₃ flotation results. PCR could not be performed for 9 specimens from 9 children, but all were negative by Kato–Katz smear and saturated NaNO₃ flotation, agar plate culture for Strongyloides, and hookworm larvae. Of those, 8/9 were from children who submitted 3 specimens total each and whose other specimens tested negative by PCR and 1 child submitted only 1 specimen. NaNO₃, sodium nitrate; ND, not done; qPCR, quantitative PCR; STH, soil-transmitted helminth; –, negative; +, positive.