Effect and Adverse Effect of Erythromycin Internal Use for Prevention of Whooping Cough Infection

Abstract

information about demographic data, illness and travel history, group gatherings, possible family clusters, hand hygiene, type of lunch, drinking water, and school cleaning assignments. Rectal swabs were collected from suspect cases, their contacts and the school cooks. We investigated the sewage system, potable and non-potable water in the school. Stool and water samples were sent for cultures and pulsed-field gel electrophoresis (PFGE). Results: There were 275 suspect cases (attack rate = 37.1%) occurred during the 4 weeks before November 22, 2007. A total of 57 confirmed and 7 asymptomatic cases were found during the outbreak. Poor hand hygiene after toilet was associated significantly with illness (odds ratio = 1.52; 95% confidence interval: 1.03—2.23). Environmental investigation revealed that groundwater used for hand-washing in lavatories was contaminated by a leaked septic tank. One of these water samples yielded Shigella sonnei. The bacteria isolated from rectal swabs and from the water sample had an indistinguishable PFGE pattern. Conclusion: It was a Shigella waterborne outbreak. The outbreak ended after all hand-washing facilities switched to using tap water exclusively. The outbreak did not spread to the community. Using tap water was recommended to avoid such outbreaks in schools. However, in such an outbreak, hand hygiene is still a protecting factor.