REINFECTION DYNAMICS OF GEOHELMINTHS AMONG INTERNALLY DISPLACED PERSONS IN A CAMP IN NORTH-CENTRAL NIGERIA

Abstract

Geohelminths, also known as soil-transmitted helminths (STHs), remain a persistent public health challenge in internally displaced persons (IDP) settings, where overcrowding, poor sanitation, and environmental contamination sustain continuous transmission cycles. Although anthelmintic mass drug administration (MDA) is widely implemented as recommended by the World Health Organisation, persistence and/or early reinfection following treatment continues to undermine long-term control, particularly in high-transmission humanitarian contexts. This study assessed the short-term dynamics of geohelminth infection following anthelmintic MDA among school-aged children residing in an IDP camp in North-Central Nigeria. A prospective observational study was conducted among 112 school-aged children (5–14 years) with confirmed geohelminth infections. Each participant provided two stool samples: one at baseline before treatment and a second sample collected 21 days post-treatment. Samples were analyzed using the Kato-Katz technique to determine prevalence and infection intensity (eggs per gram of faeces, EPG). At baseline, 112 stool samples were collected from 112 children, all of whom had confirmed geohelminth infections. Ascaris lumbricoides was the most prevalent species (61.61%; 69/112), followed by hookworms (38.39%; 43/112), while Trichuris trichiura had the lowest prevalence (3.57%; 4/112). Following albendazole administration, a second assessment conducted 21 days post-treatment demonstrated marked reductions in prevalence: A. lumbricoides declined to 20.53% (23/112), and hookworms to 11.60% (13/112), while T. trichiura was not detected. Infection intensity also decreased substantially across all species. Despite these reductions, persistence and/or early reinfection of A. lumbricoides and hookworms was observed, indicating ongoing transmission within the study environment. Anthelmintic MDA significantly reduced geohelminth prevalence and infection intensity in the short term; however, persistence and/or early reinfection, particularly for Ascaris lumbricoides and hookworms, limit the sustainability of control in IDP camp environments. These findings highlight the need for integrated strategies combining repeated MDA, improved water, sanitation, and hygiene (WASH) interventions, and expanded population coverage to achieve sustained interruption of transmission.