International Journal of Research and Scientific Innovation (IJRSI) |Volume X, Issue I, January 2023|ISSN 2321-2705
Okwa, O.O*, Oladipupo, Y.A, Adesina, A.R and Ibukun T. R
Department of Zoology and Environmental Biology, Faculty of Science, Lagos State University, Lagos State, Nigeria.
*Corresponding author
Abstract:- 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.
Key words: Open defeacation, geohelminthes, soil contamination, intestinal parasites, parasites
I. Introduction
Soil-transmitted helminthes (STHs), also known as geohelminthes are causes of serious global health problems. This group of intestinal parasites thrives in soils in warm humid climates where the soil is humid and sanitation and hygiene are poor (Darlan et al., 2019). Soil transmitted helminthes affect more than two billion people worldwide with Nigeria having the highest burden in sub-Saharan Africa (Otubanjo, 2013). The geographical distribution of STHs is influenced by various factors including environmental conditions like soil, absence of sanitary facilities, types of toilet and human factors including age, sex, socio-economic status, sociocultural beliefs and occupation (Belyhun et al., 2010).
Human-soil contact is a major predisposing factor in transmission of the STHs. Open defeacation usually leads to contamination of soil with eggs and larvae of STHs (Ekundayo et al., 2007). Open defeacation occur due to lack of suitable toilet facilities, which is occasioned by poverty and cultural misconceptions. This activities lead to parasitism which kills about 1.8 million people yearly, many of which are children (Okwa et al., 2018).
Soil transmitted helminthes are among the world’s neglected tropical diseases (NTDs) and are the largest contributor to NTDs, which accounts for 85% of the disease burden (Ojurongbe, 2013). Unfortunately, STHs have received less attention by health policy makers, especially in this COVID-19 era even though they inflict tremendous disability and suffering. However, Soil transmitted helminthes can be avoided, controlled or eliminated (WHO, 2012).
The precise global distribution of STHs infection rate and risk of morbidity remains poorly defined (WHO, 2017). This had limited how national governments and international organizations define and target resources to combat the burden of STHs infections (Brooker, 2010). Despite the increased emphasis on the role of good sanitation and hygiene in the control of STHs, majority of the population still do not understand the relationship between unhealthy practices and STHs infections, particularly in rural villages