Rotavirus remains among the leading causes of pediatric gastroenteritis requiring hospitalization in the world. Surveillance studies revealed that more than 90% of the global circulating rotavirus strains were predominated by several major genotypes. Clinical trials and post-marketing studies have demonstrated that the currently available rotavirus vaccine can provide sufficient protection against strains of the prevalent genotypes. However, the emerging strains with new genotypes were increasingly reported in the past decade, an ongoing surveillance of the strain changes is needed in the regions where the pediatric population is either fully or partly immunized. In this project, the investigators will setup a hospital-based gastroenteritis surveillance network by incorporating 8 major hospitals in northern, central, southern and eastern Taiwan. From 2013 to 2015, children aged 5 years or younger hospitalized to one of the 8 sentinel hospitals due to acute gastroenteritis will be screened for rotavirus infection, and viral proteins 7 [VP7] (G type) and viral proteins 4 [VP4] (P type) genotypes of rotavirus will be determined for each infected case. The demographics and clinical manifestations of study subjects will also be collected and analyzed. Through this project, the investigators will be able to detect emerging genotypes of rotavirus and delineate the strain distribution during the two years of study in Taiwan. The investigators can also have more comprehensive understanding of the epidemiology of rotavirus regarding to the incidence, disease characteristics, temporal and geographic variations of severe rotavirus gastroenteritis in Taiwanese children. Results from this project will provide valuable information for future implementation of mass immunization against rotavirus in Taiwan.

Inclusion Criteria:

• aged less than 60 months,
• hospitalized in 1 of the 8 hospitals,
• having diarrhea not caused by any known underlying diseases.

Exclusion Criteria:

• No

Hospitalized children having diarrhea and less than 60 months of age