Epidemiological mapping of schistosomiasis and soil-transmitted helminthiasis for intervention strategies in Nigeria

Abstract

Helminth infections caused by schistosomes and soil-transmitted helminths (STHs) are among the most prevalent afflictions of humans who live in areas of poverty in the developing world. The level of morbidity and mortality caused by these helminthes requires urgent intervention. This study reports on the epidemiological mapping and intervention strategies for the control of schistosomiasis and STH in Nigeria. Epidemiological survey on the prevalence of schistosomiasis and STH was conducted in Nigeria between November 2013 and May 2015 in 19 States of the Federation and the Federal Capital Territory (FCT), covering 2,160 schools /communities in 433 LGAs. Urine and faecal samples were collected from 108,472 pupils comprising 57,670 (53.2%) males and 50,802 (46.8%) females of age range 5 to 16 years. The samples were analysed using urine filtration and KatoKatz techniques. The target population for intervention was determined using the World Health Organization Guidelines for intervention strategies. Prevalence of 9.5% and 27% were recorded for schistosomiasis and soil transmitted helminthiasis respectively from the pupils sampled. Highest prevalence of 26.1% was recorded in Niger State for schistosomiasis while the lowest was in Rivers State (0.1%). STH had highest prevalence in Akwa Ibom State (58.4%) and lowest in Yobe State (1.4%). Niger State also had the highest prevalence for co-infection (8.96%). Based on the prevalence of schistosomiasis observed, a total of 202 LGAs fall within the low risk category, 153 moderate and four LGAs were high risk category. The high risk LGAs were located in Niger and Kebbi States. Case-based management is required for STH in 191 LGAs while 177 LGAs fall within the low-risk and 60 LGAs were in the high risk categories. The findings of this study highlighted the treatment interventions required to facilitate scale up of appropriate mass administration of medicine, water, sanitation and hygiene intervention in the 19 States of the Federation and the FCT.

Keywords: Schistosomiasis; soil-transmitted helminthiasis; prevalence; intervention strategy; risk; control; treatment.