Urinary interleukins (IL)-6 and IL-10 in schoolchildren from an area with low prevalence of Schistosoma haematobium infections in coastal Kenya.

Urinary cytokines are gaining traction as tools for assessing morbidity in infectious and non-infectious inflammatory diseases of the urogenital tract. However, little is known about the potential of these cytokines in assessing morbidity due to S. haematobium infections. Factors that may influence the urinary cytokine levels as morbidity markers also remain unknown. Therefore the objective of the present study was to assess how urinary interleukins (IL-) 6 and 10 are associated with gender, age, S. haematobium infections, haematuria and urinary tract pathology and; 2) to assess the effects of urine storage temperatures on the cytokines. This was a cross-sectional study in 2018 involving 245 children aged 5-12 years from a S. haematobium endemic area of coastal Kenya. The children were examined for S. haematobium infections, urinary tract morbidity, haematuria and urinary cytokines (IL-6 and IL-10). Urine specimens were also stored at -20°C, 4°C or 25°C for 14 days before being assayed for IL6 and IL-10 using ELISA. The overall prevalence of S. haematobium infections, urinary tract pathology, haematuria, urinary IL-6 and urinary IL-10 were 36.3%, 35.8%, 14.8%, 59.4% and 80.5%, respectively. There were significant associations between prevalence of urinary IL-6, but not IL-10, and age, S. haematobium infection and haematuria (p = 0.045, 0.011 and 0.005, respectively) but not sex or ultrasound-detectable pathology. There were significant differences in IL-6 and IL-10 levels between urine specimens stored at -20°C and those stored at 4°C (p<0.001) and, between those stored at 4°C and those stored at 25°C (p<0.001). Urinary IL-6, but not IL-10, was associated with children's age, S. haematobium infections and haematuria. However, both urinary IL-6 and IL-10 were not associated with urinary tract morbidity. Both IL-6 and IL-10 were sensitive to urine storage temperatures.

Schistosoma haematobium and soil-transmitted Helminths in Tana Delta District of Kenya: infection and morbidity patterns in primary schoolchildren from two isolated villages.

BACKGROUND: 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. METHODS: Two hundred and sixty-two children aged 5-12 years from two primary schools were enrolled in the study. For each child, urine was examined for S. haematobium eggs and haematuria, stool was examined for STH eggs, peripheral blood was examined for eosinophilia and haemoglobin level, the urinary tract was ultrasound-examined for S. haematobium-related pathology, and the height and weight was measured and used to calculate the body mass index (BMI). RESULTS: Prevalences of S. haematobium, hookworm, T. trichiura and A. lumbricoides infection were 94, 81, 88 and 46 %, respectively. There was no significant association between S. haematobium and STH infection but intensity of hookworm infection significantly increased with that of T. trichiura. Lower BMI scores were associated with high intensity of S. haematobium (difference =-0.48, p > 0.05) and A. lumbricoides (difference =-0.67, p < 0.05). Haematuria (both macro and micro) was common and associated with S. haematobium infection, while anaemia was associated with high intensity of S. haematobium (OR = 2.08, p < 0.05) and high hookworm infections OR = 4.75; p < 0.001). The majority of children had eosinophilia, which was significantly associated with high intensity of hookworm infection (OR = 5.34, p < 0.05). Overall 38 % of the children had ultrasound-detectable urinary tract morbidity, which was associated with high intensity of S. haematobium infection (OR = 3.13, p < 0.05). CONCLUSION: Prevalences of S. haematobium and STH infections among the primary school children were high and the parasites were responsible for significant morbidity. A clear synergistic interaction was observed between hookworm and T. trichiura infections. Increased coverage in administration of praziquantel and albendazole in the area is recommended to control morbidity due to these infections.

Urinary cytokines in Schistosoma haematobium-infected schoolchildren from Tana Delta District of Kenya.

BACKGROUND: 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. METHODS: Children aged 5-12 years from two primary schools in Tana Delta District of Kenya were examined for S. haematobium eggs using urine filtration technique, for haematuria using dipstix and for eosinophil cationic protein (ECP), IL-6, IFN- γ, TNF-α and IL-10 levels using ELISA, and for S. haematobium-related urinary tract pathology using ultrasonography. In addition, venous blood was examined for serum IL-6, IFN- γ, TNF-α and IL-10 levels using ELISA. RESULTS: There was no significant correlation between urinary and serum levels of IL-6, IFN- γ, TNF-α or IL-10. There was no significant difference in geometric mean intensity (GMI) in any of the serum cytokines, or in urinary TNF-α or IFN-γ, between children with light and heavy S. haematobium infections. However, children with heavy S. haematobium infections had significantly higher GMI of urinary IL-6 (p < 0.001) and lower GMI of urinary IL-10 (p = 0.002) than children with light infections. There was also a significant positive correlation between urinary IL-6 and urinary ECP (p < 0.001) and a significant negative correlation between urinary IL-10 and urinary ECP (p = 0.012). CONCLUSION: Urinary IL-6 was positively correlated to and IL-10 was negatively correlated to infection intensity and urinary tract inflammation in S. haematobium-infected children. Urinary IL-6 and IL-10 ELISA may be a useful non-invasive tool to complement the already available tools for studying S. haematobium-related urinary tract pathology in children.