Spatial patterns of soil-transmitted helminths in soil environment around Ibadan, an endemic area in south-west Nigeria

Abstract

The dominant species and variation in prevalence pattern of Soil Transmitted Helminths (STHs) eggs and/or larva in soil around Ibadan metropolis south-west Nigeria were determined in order to project the monthly spread in relation to geographic location. A total of 720 soil samples collected between July 2014 and June 2015 from 3 locations within each of 5 selected Local Government Areas were examined for the presence of parasites using standard culture and concentration techniques. Mapping protocol was used for predictive risk prevalence of parasites. A total of 483 (67.1%) out of the soil samples examined had parasites. Ova of Ascaris and Trichuris species, adults and larva of Strongyloides and larva of hookworm species were encountered. The variation in distribution is statistically significant (x²=65.245; p<0.05) in relation to months. November had the highest proportion (90.0%) of contaminated soil samples followed by February (78.3%) and the least proportion (50.0%) was observed in the month of September. Akinyele Local Government consistently had between very high and high rates of contaminated soil samples. Other local government areas had prevalence varying from high to low contaminated soil samples. The predictive patterns showed that Akinyele area in the northern suburb was the highest risk zone of STHs transmission. The high prevalence of parasites (67.1%) in soil samples examined showed a high risk of exposure to STH and explains the need for interventions to protect the population at risk of STH infections.

Keywords: Endemic area; patterns, Ibadan; soil-transmitted helminthes; sanitation; Akinyele