OXIDATIVE STRESS IN SCHOOL CHILDREN CO-INFECTED WITH SCHISTOSOMA MANSONI AND SOIL-TRANSMITTED HELMINTHS

Introduction : Oxidative stress has been implicated as a cause or as a complication of various chronic diseases such as atherosclerosis, diabetes, HIV and Hepatitic infections. Intestinal helminths rank first among chronic infections in developing countries where several foci of Schistosoma mansoni and soil transmitted helminths (STH) exist. Studies have shown that oxidative stress is involved in tissue damage in intestinal helminthiasis. Children of school age are usually the most infected with Schistosoma mansoni, Ascaris, and Trichuris . These insidious infections cause poor school performance, growth retardation, malnutrition and the loss of up to 4 Disability-Adjusted-Life-Years (DALY) amongst these children. Objectives : The main objective of this study was to determine the effect of S. mansoni and STH infections on the levels of oxidative stress markers in school children. This was achieved by identifying children infected with S. mansoni and STH, and measuring the levels of their oxidative stress. Methods: This was a transverse and comparative study carried out from November 2010 to March 2011. It involved healthy primary school pupils. Ethical Clearance was obtained from the National Ethics Committee of Cameroon. Administrative and local authorities of Makenene, together with the head teachers and parents of the pupils gave their consent on the study. Stool and blood samples were collected from the pupils. Helminth eggs were counted in the stool using the Kato technique, and oxidative stress markers measured in the serum samples The markers analysed included Malondialdehyde (MDA), Ferric Reducing Antioxidant Power (FRAP), Catalase and Superoxide dismutase (SOD) activities, as well as total protein concentration. Infected children were treated with praziquantel and albendazole. Statistical analyses were done using Microsoft Windows Excel 2007, Sigma Stat version 3.01A statistical analysis and SPSS version 17 software. A p value of 0.05). Those infected with only S. mansoni had significantly higher MDA levels (p = 0), lower FRAP levels (p < 0.001), lower Catalase and SOD activities (p < 0.001) than the uninfected children; they equally had a significantly lower Catalase activity than the children infected with only STH (p < 0.001). Children infected with STH had a significantly lower SOD than the uninfected (p < 0.001). The variation of the oxidative stress markers did not correlate significantly with the intensity of infection. The decrease in FRAP and the elevated MDA are probably due to a decrease in SOD activity in the STH group, a decrease of catalase activity in the Schistosomiasis group, and a decrease of both catalase and SOD activities in those with co-infections. Conclusion & recommendation: Makenene is still a focus of intestinal helminthiasis. The infected children had high oxidative stress status. The parasites probably induce oxidative stress through a fall in antioxidant mechanisms. Oxidative stress is more severe in individuals with co-infections. We recommend an intensification of the anti-helminth strategies already in place and an adjuvant antioxidant therapy in the management of intestinal helminthiasis.