Incidence and Molecular Characterization of Neonatal Human Rotavirus Strains in Accra

Abstract

Specific and sensitive tests for the detection and typing of rotavirus strains are essential for a more assessment of the epidemiology of rotaviral infection in a community. In this study, 200 stool specimens obtained from October, 1999 to March, 2000 from neonates at the Babies Unit of the Korle-Bu teaching and Legon Hospitals were examined. Group A rotavirus was detected in 30% and Non-group A in 2.5% of the samples tested by either enzyme-linked immunosorbent assay (ELISA) for the detection of VP6 antigen and/ or polyacrylamide gel electrophoresis (PAGE) of double-stranded RNA respectively. Reverse transcription-PCR (RT-PCR) was used for the amplification of the VP7:G (1,062 bp) and VP4:P (876 bp) genes. Five positive specimens were positive by PAGE but negative by ELISA. G and P typing was carried out by nested amplification of variable sequences of the VP7 and the VP4 genes with six G- and five P-type-specific primers (multiplex PCR). The observed P and G types were as follows: G2, 57.1%; G3, 7.1%; G9, 10.7%; G2G3, 3.6%; P6, 67.9%; P8, 3.6%; P6P10, 14.3%. 21.4% of G type and 14.3% of P type were nontypeable. The G-P type combination most frequently found was G2P6 (42.9%), which is the most commonly found in neonates worldwide. Unusual strains of the type G3P6, G9P6 accounted for 7.1% and 3.6% respectively while mixed infections with more than one type were found in 17.9% of the samples typed. Samples whose either P and/ or G could be typed accounted for 28.6%.