Dr. Njaanake Humphrey Kariuki

Schistosomes and soil-transmitted helminths (STH) (hookworm, Trichuris trichiura and Ascaris lumbricoides) are widely distributed in developing countries where they infect over 230 million and 1.5 billion people, respectively. The parasites are frequently co-endemic and many individuals are co-infected with two or more of the species, but information on how the parasites interact in co-infected individuals is scarce. The present study assessed Schistosoma haematobium and STH infection and morbidity patterns among school children in a hyper-endemic focus in the Tana River delta of coastal Kenya.

Pathological changes due to infection with Schistosoma haematobium include cytokine-mediated urinary tract inflammation. The involved cytokines may be excreted in urine and their presence in urine may therefore reflect S. haematobium-related urinary tract pathology. The present study, for the first time, reports on the relationship between selected cytokines in urine and infection with S. haematobium in children from an area highly affected by this parasite.

Schistosoma haematobium and soil-transmitted helminthic (STH) infections are important public health problems in Kenya but their prevalence, intensities and the resultant morbidity vary widely from one endemic focus to another in the country. There is, therefore, an urgent need for investigations on the extent of disease burden, risk factors associated with the infections and effects of treatment from different endemic settings as a background for designing and implementing programs for successful control of these infections.
Objective: To assess morbidity patterns, response to treatment and spatial distribution of S. haematobium and STH infections in school-going children of the Tana Delta District, coastal Kenya.
Methods: At baseline, urine samples were collected from primary school children and examined for S. haematobium eggs, haematuria, and eosinophil cationic protein (ECP) and selected cytokines [interleukin (IL)-6, interferon (IFN)- γ, tumour necrosis factor (TNF)-α and IL-10] levels. Stool samples were also collected and examined for soil-transmitted helminth eggs, ECP and eosinophil protein X (EPX) levels. One sample of venous blood was taken from each child and tested for haemoglobin level, serum IL-6, TNF-α, IFN- γ and IL-10 levels. Height and weight of each child were taken and each child was subjected to ultrasound examination of the urinary tract for S. haematobium infection-related morbidity. The children were interviewed on their behaviour in relation to infection with S. haematobium and STH, related symptoms. At the end of the baseline survey each child was treated with praziquantel (40 mg/ kg body weight) and albendazole (400 mg).
During the follow-up survey, 3 months after treatment, stool and urine samples were examined for S. haematobium and STH eggs and haematuria as in the baseline. The weight of each child was also recorded. A household survey was conducted during which parents were interviewed to elucidate the socio-economic conditions which would predispose to infections. Geographical co-ordinates of the main houses in the households and the local water contact points were also recorded. p-values less than 0.05 were considered significant in all statistical tests.