Epidemiology and burden of rotavirus infection among children in Hangzhou, China.

Rotavirus is the most common cause of acute diarrhea in children younger than 5 years worldwide. However, few data have been collected on children with rotavirus diarrhea basing on outpatient department surveillance.To define the epidemiology of rotavirus diarrhea and to investigate the burden associated with diarrhea and rotavirus infection in Hangzhou, China.Systematic surveillance of rotavirus diarrhea was conducted in inpatient wards and outpatient department from January 2007 to December 2008 in the Children's Hospital of Zhejiang University School of Medicine. All stool specimens were tested for rotavirus by latex agglutination test.46,499 stool samples were collected and 15,649 (33.7%) were tested positive for rotavirus. Positive rate for rotavirus was highest among children aged 12-24 months (39.0-39.6%). 92.4% children with rotavirus infection were <2 years, with constitution ratios of 21.8%, 41.8%, 21.8%, 8.4% and 6.2% in children aged 0-6 months, 7-12 months, 13-18 months, 19-24 months and >24 months, respectively. The percentage of children whose samples were tested positive for rotavirus ranged from 22.6% to 44.9% at different months, with a peak in October, November and December. The estimated annual rotavirus-associated outpatient visit and hospitalization incidences were 20.1 episodes/1000 children and 2.1 cases/1000 children for children <5 years of age, and were 39.1/1000 and 4.1/1000 for children <2 years of age in Hangzhou, respectively.Rotavirus is the leading cause of severe diarrhea of children in Hangzhou, especially for children <2 years, which highlight the need of widespread rotavirus immunization for young children.