Pertussis Outbreak in a Junior High School-Yunlin County, 2009

Ya-Lin Liu1、Hui-Chen Lin1,2、Mei-Ling Wu1、Chaio-Wen Lin1、Chin-Sheng Chi1、Yi-Chun Wu1

2010 Vol.26 NO.7

Correspondence Author: Ya-Lin Liu



In June 2009, the largest outbreak of pertussis in campus occurred in Yunlin County. Taiwan Centers for Disease Control started to investigate the outbreak that finally ended on July 28. There were total 24 confirmed cases, including 20 students, 3 teachers, and 1 parent. Symptomatic students in six different classes were found, with the index case occurred in early April. Initially, the index case in the 2nd grade only had minor symptoms that were easily overlooked; but subsequently, many students and faculty members also started coughing. To prevent further transmission, the Public Health Bureau of Yunlin County gave prophylactic treatment to 251 close contacts. After prophylactic treatments and application of control measures, the number of symptomatic subjects decreased gradually and we successfully prevented it from spreading into communities.
Investigation revealed the major causes that led to this outbreak. First, immunity against pertussis in teenagers who had received DTP vaccination in the past decayed. Second, close contacts via mixed classes, post-curricular activities, and sharing diets occurred frequently in these students. Third, teachers and school nurses were not vigilant enough to notice the unusual increased number of students with prolonged cough in the non-influenza season. Finally, health care workers could be more cautious so that the late reporting would not delay effective control measures. In response to this pertussis outbreak, we should remind health care providers and school authorities to be more vigilant and suggest re-evaluating the vaccination policy.