The purpose of this study is to prospectively determine the rotavirus VP7/VP4 genotypes associated with moderate to severe disease (requiring emergency room (ER) consult or hospitalization) in a large public hospital from Valparaiso and another from Santiago.

Rotavirus is the leading cause of gastroenteritis in children. Our group has developed a surveillance system for acute rotavirus diarrhea in two large hospitals in Chile since 2006. Patients visiting the ER for acute non-bloody diarrhea will be enrolled after an informed consent is signed by parents. A fresh stool sample will be collected to prospectively determine the rotavirus VP7/VP4 genotypes associated with moderate to severe disease (requiring emergency room (ER) consult or hospitalization. Stool samples will be tested for rotavirus by ELISA IDEIA - Rotavirus - OXOID. Rotavirus positive samples will be genotyped as described previously (Iturriza-Gomara et al. J. Clinical Virol 2004). Overall medical visits and hospitalizations, proportion of visits and hospitalizations caused by acute diarrhea, estimated numbers of rotavirus visits and hospitalizations will be calculated for each site. Proportion of rotavirus VP7 and VP4 genotypes will be calculated for three month periods per center. Differences in proportion will be compared by chi square and Fischer's exact test when appropriate.

Inclusion Criteria:

• Children with acute diarrhea
• Children younger than 5 years

Exclusion Criteria:

• Illiterate parents
• Chronic gastrointestinal disease

Children younger than 5 years of age with acute diarrhea or related diagnosis requiring emergency room and hospital admission in two large cities in Chile