Diversity of human rotavirus VP6, VP7, and VP4 in Lagos State, Nigeria

Abstract

This study investigated the diversity of rotavirus strains recovered from young children in Lagos, Nigeria, during December 1996-January 1997. In total, 287 children, aged 1-60 month(s), presenting with diarrhoea to the Gbaja Health Centre of Massey Street Children Hospital and the Lagos University Teaching Hospital, were included in the study. Rotavirus-positive specimens were characterized by monoclonal antibody enzyme-linked immunosorbent assay (ELISA) for VP6 subgroup and VP7 serotype and by polymerase chain reaction (PCR) for VP4 genotype and VP7 strains (that were non-reactive to ELISA). Of 84 samples tested for VP6 subgroup epitope, subgroup II was predominant (51%) with only a few subgroup I strains (4%), while many could not be typed at all (45%). For the VP7 serotypes, G1 was the most prevalent strain (45%), followed by G3 strains (5%). Neither G2 nor G4 strains were found, although mixed G1/G2 has been reported for the first time in Nigeria. Of strains that were non-reactive to ELISA, 29 (34%) could not be typed by PCR for G type. A subset of 23 samples was selected on the basis of RNA electropherotype, VP7 serotype, and included nine strains of VP7 that were non-reactive to ELISA. VP4 genotype of this subset was determined by PCR, and the most prevalent genotype was P[6] (30%), followed by P[8] (26%). Only one P[4] strain was identified. This study has shown the diversity of rotavirus strains circulating in West Africa.