RESUMEN
A total of 1,141 rotavirus-negative stool specimens collected from diarrheic children in 4 distinct regions under sentinel surveillance in Thailand between 2006 and 2008 were examined by reverse-transcription (RT)-PCR for norovirus (NoV) and sapovirus (SaV). Three hundred 3 specimens (26.6%) were positive for NoV, with 34 and 269 belonging to genogroup I (GI) and genogroup II (GII), respectively. Twelve specimens (1.1%) were positive for SaV. Mixed infections were found in 5 specimens: 3 samples indicated the presence of both NoV GI and GII, and 2 samples indicated the presence of both NoV GII and SaV. Analysis of the monthly distribution of NoV and SaV revealed that NoV GII was clustered between September and February, while NoV GI was detected mainly in June and July; SaV was found in May, June, and July. In addition, 3 outbreaks of acute gastroenteritis at 2 junior high schools in Phichit and Bangkok, and at a university in Phitsanulok, Thailand in 2006 were found to have been caused by NoV infection. Sequence analysis of NoVs from sporadic cases and outbreaks showed them to be genotypes GII.4 and GII.6.
Asunto(s)
Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/virología , Gastroenteritis/epidemiología , Gastroenteritis/virología , Norovirus/aislamiento & purificación , Sapovirus/aislamiento & purificación , Adolescente , Coinfección/epidemiología , Coinfección/virología , Brotes de Enfermedades , Heces/virología , Femenino , Humanos , Masculino , Norovirus/clasificación , Norovirus/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estaciones del Año , Tailandia/epidemiología , Adulto JovenRESUMEN
The distribution of the G type of human rotavirus was surveyed in Thailand between July 1993 and June 2007. A significant yearly change in the distribution of the G type distribution was found. From 1993-1994 to 1998-1999, the G1 type was the most dominant. In 1999-2000, G9 began to appear at a high frequency. In 2000-2001, 2001-2002, and 2002-2003, G9 was very common. In 2003-2004, G1 became the most prevalent type again, and since then it has been detected at the highest frequency. G12 strains, which were first detected in 1998-1999, were also found in 2004-2005 and 2006-2007. The G4 and G3 types were moderately prevalent in 2001-2002 and 2004-2005, respectively. Nucleotide sequence analysis of the VP7 genes of the G9 and G12 strains which reemerged in Thailand showed that they were each similar to the contemporary strains in other countries.
