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.