Abstract

Genomic Diversity of Group A Rotavirus Strains Infecting Humans in Eastern India Soma Das 1 , A. Sen 1 , G. Uma 1 , V. Varghese 1 , S. Chaudhuri 1 , S. K. Bhattacharya 2 , 3 , T. Krishnan 1 , P. Dutta 2 , D. Dutta 2 , M. K. Bhattacharya 2 , U. Mitra 2 , N. Kobayashi 4 , and T. N. Naik 1 , 3 , * 1 Division of Virology 2 Division of Clinical Medicine 3 ICMR Virus Unit, GB-4, ID and BG Hospital Campus 4 Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo 060, Japan ABSTRACT Between 1998 and 2000, a total of 266 samples were found positive for group A rotaviruses by RNA electrophoresis. Samples were collected from patients admitted to two leading hospitals in Calcutta. Serotyping could be done only with 22% of the positive samples, leaving 78% untypeable. The G (VP7 genotypes) and P (VP4 genotypes) types were determined for 159 samples by reverse transcription and multiplex PCR. The predominant genotype was G1P(8) (20%), followed by G2P(4) (15%) and G4P(8) (6%). A number of uncommon genotypes, G1P(4) (4%), G2P(8) (2.5%), G2P(6) (0.6%), G4P(4) (2.5%), and G4P(6) (1.25%), were also detected during this study period. Twenty two percent of specimens showed mixed infections, 38 (24%) of the total samples remained untypeable for either VP7 or VP4, while only 4 (2.5%) of the samples were untypeable for both genes. Eleven specimens collected from Manipur were also genotyped and revealed a very high degree of genomic reassortment.