Intestinal Parasitic Infections in School Children in the Peri-Urban Sub County of Njiru, Nairobi County, and the Associated Risk Factors

Abstract

Enteric pathogens occur in high concentrations in untreated sewage water. In areas where untreated sewage water is used to irrigate agricultural land for cultivation of horticultural crops, it may pose a health risk to consumers, farm workers, handlers of the produce, and possibly, the community that lives within the vicinity of wastewater irrigated land. A cross-sectional survey, targeting 446 school children aged 6-12 years was conducted in 5 public primary schools in Njiru Sub-County, on the eastern side of Nairobi County. The objectives of the study were to determine the prevalence, intensity, and risk factors associated with the presence of intestinal parasitic infections (IPIs) in the study area. Fecal samples were collected from children whose parents or guardians had consented to their participation in the study. Ova and parasite detection was performed using both the formal-ether concentration and the Kato-Katz procedures. The intensity of infection was classified as light, moderate and heavy. Risk factors associated with the presence of IPIs such as education level of parents/guardians, hand washing habits, source of water for household use were assessed using a questionnaire, which was administered to parents/guardians. The overall prevalence of intestinal parasites was 37%, (95%CI 32.5-41.7%) with protozoan infections accounting for 26.7% and helminth infections, 15.1%. Entamoeba histolytica/dispar (39%) and Giardia duodenalis (8.1%) occurred in moderate to heavy intensities. Other protozoan parasites present were Entamoeba coli (2%), and Pentatrichomonas hominis (<1%).The most common helminth parasites were Ascaris lumbricoides (14.8%) and Trichuris trichiura (12.8%) with many children having light intensities of infection. Other common helminth infections present were hookworm (8.5%) and Schistosoma mansoni (5.8%). Other parasites detected were Enterobius vermicularis (4.3%), Hymenolepis nana (3.4%), Taenia species (1.6%), Diphyllobothrium latum (0.2%), Fasciola hepatica (0.2%) and Hymenolepis dimunita (0.2%). Children whose parents or guardians had primary education only (LR test=10.11, df=4, P=0.0386) and those who used the river as their main water source (P=0.027), were more likely to become infected. IPIs were common among the children in the Njiru area. Further investigations are needed to determine the impact of these infections on the children living in this locality. School-based interventions are recommended for control of these infections in the area.