Epidemiology and burden of rotavirus diarrhea in Thailand: results of sentinel surveillance

Diarrhea remains an important cause of morbidity and mortality among children in Thailand, with >1 million cases reported in 2002. In anticipation of the development of vaccines against rotavirus, we evaluated the disease burden associated with rotavirus infection in Thai children and evaluated the rotavirus serotypes now circulating in Thailand. Diarrhea surveillance was conducted at 6 Thai hospitals in different geographic areas. Community-based surveillance was conducted in Huaykrajao District, Kanchanaburi Province. During the 24 months of surveillance, 4057 children were admitted to the 6 participating hospitals, and 1950 stool samples were collected. Of these stool samples, 43% (838) were positive for rotavirus. All rotavirus-positive stool samples were evaluated to identify their serotypes; 54.8% of samples were of serotype G9, which was predominant each year. Other identified rotavirus serotypes included G2, G4, G1, and G3 (17.2%, 5.3%, 0.8%, and 0.1% of isolates, respectively). Approximately one-half of the children hospitalized with rotavirus diarrhea were <1 year old. Community surveillance showed the proportion of cases of rotavirus diarrhea in the community to be much lower than that in the hospitalized population (12.2% vs. 43.0%).