OUTBREAK OF NONBACTERIAL GASTROENTERITIS AT A SCHOOL

An outbreak of gastroenteritis occurred in a school affecting more tha n 30% of its 535 students. An epidemiological survey questionnaire was given to all students as well as staff and maintenance personnel. Sto ol cultures and electronic microscopy were used to detect the presence of a Norwalk-like virus. Several analyses of water samples were also done. This outbreak occurred simultaneously in the two wings of the sc hool (East and South). Those who used the East wing were most affected by the disease (RR = 1.45 CI 95%: 1,14-1,85). There was no indication of food or water supply contamination. A Norwalk-like virus was ident ified in the stool sample of one child. This along with the clinical c haracteristics strongly suggested that the pathogen was indeed a Norwa lk-like virus. The analysis suggests transmission via contaminated sur faces but also via airborne transport of the infectious agent.