Characterization of human rota virus group a serotypes causing gastroenteritis among children below five years and hiv-infected adults of viwandani slum in Nairobi, Kenya

Abstract

Rotavirus remains a leading cause of severe diarrhoea in children worldwide, especially in developing countries where about 2000 children die each day from rotavirus-related gastroenteritis infection. Due to HIV/AIDS scourge in Kenya, it is possible that rotavirus caused gastroenteritis has been aggravated. The Global Alliance for Immunizations has ranked rotavirus as a priority for vaccine. To ensure the success of this, it is important to document the local strain(s) of rotavirus in circulation in various regions. This study was aimed at characterizing human rotavirus group A serotypes causing gastroenteritis among children below 5 years of age and HIV-infected adults in Viwandani slum, Nairobi. A cross-sectional, hospital based study was conducted and a total of 260 faecal specimen samples were collected for analysis (128 from children and 132 from HIV infected adults) during the period between August 2012- July 2013 from two health centres in viwandani slums in Nairobi. The samples were detected for rotavirus strains using antigen based enzyme immune-sorbent assay (ELISA) to detect the prevalence of rotavirus infection, Polyacrylamide gel electrophoresis was used to detect rotavirus electropherotypes and finally genotyping was done by RT-PCR to confirm rotavirus genotypes using genotype-specific primer sets targeting VP4 and VP7 genes. Rotavirus was detected in 23% and 8% of children and adults respectively. This study found out that rotavirus was in circulation throughout the year however, with high incidence cases being detected during wet and cold months of March April and November and dry month of August. Prevalence was high among children aged two yrs and adults above age of 48 yrs. The common globally distributed strains, G1 and G3, accounted for 60% detections while the unusual G9 strain accounted for 80% infection in adults. G1[P8] was the common genotypic combination in children, accounting for 40% infection, whereas G9[P8] accounted for 60% of the infection in adults. This study concludes that there is strain diversity in rotavirus circulating in Viwandani slums in Nairobi. In addition, the study asserts that the two rotavirus vaccines recommended for world, cover all the circulating in Viwandani. It is recommended that molecular epidemiology of rotavirus especially in low income settlement be a continuous process especially among HIV infected.