Prevalence and Genetic Diversity of Group a Rotaviruses In Children with Acute Gastroenteritis Post Vaccine Introduction In Kericho County Referral Hospital, Kenya

Abstract

Rotavirus infections are the chief source of acute gastroenteritis in children of five years and below causing 600,000 deaths globally and about 80% occurring in Sub-Saharan Africa and South Asia. Rotavirus has caused more than 3908 infant deaths in Kenya. After introducing the vaccine, a limited amount of information on the effects of this in Kericho County has been made available to the public. The study focused on determining the prevalence, demographic characteristics and the diversity of rotavirus strains in children seeking medical attention at the Kericho County Referral Hospital. The study used a hospital-based cross- sectional survey design. Simple random sampling was employed to recruit the study participants. The study population was children aged five years and under seeking medical attention for gastroenteritis. A sample size of 200 stools was collected using sterile stool collection polypots and transferred to the National Rotavirus Laboratory based at The Kenya Medical Research Institute, Nairobi. Demographic characteristics of the participants in the study were obtained using structured questionnaires. Identification of rotavirus-positive samples was done using Enzyme-Linked Immunosorbent Assay (sandwich ELISA). Long and short eletropherotypes were characterized of using Sodium dodecyl sulphate Polyacrylamide gel electrophoresis (SDS-PAGE). Molecular characterization of rotavirus strains was done using Reverse Transcriptase –Polymerase Chain Reaction (RT-PCR) genotyping of G-genotypes and P-genotypes. Among the 200 samples, 23 tested positive for rotavirus when subjected to Enzyme-Linked Immunosorbent Assay (sandwich ELISA). This resulted in a prevalence of 11.5%. Among the twenty three samples, fourteen were from male participants (60.87%) while nine (39.13%) were from female children. All the children had been vaccinated, except for one whose guardian was uncertain. This study confirmed that children above 20 months of age were most affected. SDS-PAGE indicated that all positive samples were long electropherotypes.RT-PCR confirmed G3 genotype as the leading serotype affecting the children. In conclusion, the ROTARIX ® vaccine currently in use by the National Immunization Program might

not completely protect against rotavirus infections in the age-group being studied. There might be a need for the introduction of a vaccine booster for older children and the inclusion of a multivalent vaccine for emerging strains. The data generated from this study is of benefit to the County Government of Kericho and National Ministry of Health.