Epidemiological survey of diarrhea outbreak in a school in Sajia county, Tibet

June 27-July 8, 2009, an outbreak of diarrhea occurred in a school in Sajia county in Tibet, a total of 220 cases were reported without death. The attack rate was 11.57%. The outbreak affected 26 classes in 2 grades. Bacterial detection indicated that Escherichia coli was detected from the source water and the fecal coliforms and total bacterial count exceed the limits. Shigella was detected in the patients stool samples. The case control analysis indicated that the differences on the diarrhea incidences by drinking stream water directly, contacting stream water and drinking tap water directly were statistical significant (P0.01).