Estimation of Geohelminthes prevalence in Soil Samples and risk factors to exposure in Ojo Area of Lagos State, Nigeria

Soil transmitted helminths (STHs) are intestinal parasites causing neglected tropical diseases of public health concern. It is important to map out soil environments contaminated with STHs and to project which communities people need health interventions. This study investigated the prevalence of STHs in relation to the soil type and risk factors in four communities in Ojo Local Government Area of Lagos State, Nigeria. A total of 100 soil samples with 25 samples from each community were collected. The soil samples were sorted out by texture and categorized into sandy, loamy, humus and clay soils. The parasite stages from soils were identified microscopically after isolation by floatation and sedimentation methods. Sandy soil was the predominant soil type collected (> 40%) in the four communities. Bivariate Pearson’s correlation was used to assess the relationship between soil types and STHs. There was a correlation between sandy soil and STHs contamination. Overall, 78% of the soil samples were positive for STHs with sandy soil having 51.2% contamination. Toilet areas had the highest contamination with STHs (25.6%) followed by walkways (24.3%). Strongyloides stercoralis was the most prevalent STHs (3.84 %), followed by Ascaris lumbricoides (30.7 %), Necator americanus (20.5 %) and Trichuris trichiura (2.56 %). Mixed infections of S. stercoralis and A. lumbricoides (7.69%) was recorded. The prevalence of STHs was highest at Alaba- Rago (37.1 %) and lowest at Iba Estate (11.5%). Multinomial logistic regression analysis showed that the factors that influenced the high prevalence of STHs at Alaba-Rago included poor environmental sanitation, lack of toilets, low level of awareness and open defeacation. Health education with provision of public toilets with regular and efficient water supply is advocated. Targeting affected communities for soil decontamination and deworming programmes is also recommended.