Genetic diversity of norovirus and sapovirus in hospitalized infants with sporadic cases of acute gastroenteritis in Chiang Mai, Thailand

Abstract

Stool specimens from hospitalized infants with sporadic gastroenteritis in Chiang Mai, Thailand, between July 2000 and July 2001 were examined for norovirus and sapovirus by reverse transcription-PCR and sequence analysis. These viruses were identified in 13 of 105 (12%) specimens. One strain was found to be a recombinant norovirus.

FIG. 1.

Phylogenetic analysis of sequences isolated in Thailand. (a) Norovirus capsid sequences (264 bp). (b) Sapovirus capsid sequences (376 bp). The numbers on each branch indicate the bootstrap values for the genotype. Thai sequences are represented in bold. For example, Mc2 is the strain isolated at McCormic Hospital from patient 2. Mc, McCormic Hospital; St, Sanpatong Hospital; N, Nakornping Hospital. Norovirus sequences were classified according to the scheme of Katayama et al. (11), and sapovirus sequences were classified based on the scheme of Okada et al. (18). GenBank accession numbers for the reference strains are as follows: Vietnam 026, AF504671; Alphatron/98-2/1998/NET, AF195847; Amsterdam/98-18/1998/NET, AF195848; Arg320, AF190817; Camberwell, U46500; Chiba/000671T/1999, AJ412805; Chiba/990727S/1999, AJ412795; Chiba/991172S/1999, AJ412797; Chiba/010469F/2001, AJ412820; Cowden, AF182760; DSV395, U04469; Erfurt/546/00/DE, AF427118; Hawaii virus/1971/US, U07611; Houston/86/US, U95643; Houston/27/90/US, U95644; Jena, AJ011099; Leeds/90/UK, AJ277608; London/29845/92/UK, U95645; Lordsdale, X86557; Lyon/598/97/F, AJ271056; Mex340/1990, AF435812; MX, U22498; 408/97003012/1996/FL (NV 95/96-US), AF080558; Saitama U1, AB039775; Sapporo/82/Japan, U65427; Seacroft/90/UK, AJ277620; Sindlesham/95/UK, AJ277615; SMV, AY134748; Stockholm/318/97/SE, AF194182; VA98387/1998, AY038600; Winchester/94/UK, AJ277609; Wortley/90/UK, AJ277618; and WUG1, AB081723.