An Outbreak Investigation of Unknown Cause Respiratory or GI Symptoms at a Secondary School Located in Hualien City

Donald Dah-Shyong Jiang

2007 Vol.23 NO.5

Correspondence Author: Donald Dah-Shyong Jiang


From the period of December 17th 2006 to January 15th 2007, several students from a secondary school in Hualien City developed respiratory symptoms together with gastrointestinal (GI) disturbances. The health authorities launched a joint epidemiological investigation, aiming at estimating extend of the outbreak, possible underlying pathology, routes of transmission, and also assessing the efficiency and effectiveness of the control measures implemented in the event. From analyzing the 734 returned questionnaires designed specifically for this outbreak from both junior and senior school students, the results indicated 299 students experienced respiratory symptoms with or without GI disturbances (141 students had GI symptoms and 158 had not) whereas there were only 94 students who experienced GI disturbances only with no respiratory complains. Therefore, a total of 131 students from the first group has fulfilled the criteria and definitions of a typical influenza case with an infestation rate of 17.8%, whereas the 94 students in the second group were suspected to be cases of norovirus infection.