A Dengue outbreak investigation among students in a college A, Rayong Province, 7–19 August 2015

Abstract

Background: On 7^th August 2015, Bureau of Epidemiology was notified a fatal dengue hemorrhagic shock case and cluster of dengue fever–liked illness among students in a college A, Rayong province. Therefore, investigation and control team conducted an investigation to confirm the diagnosis and outbreak, describe epidemiology characteristic, and implemented disease control and prevention.
Methods: A descriptive study was conducted by reviewing medical and laboratory records in the hospital. We interviewed fatal case’s parents. An active case finding was performed to identify additional cases in the college. An environmental survey was conducted to assess vector density.
Results: We identified 17 cases (attack rate 14.41 %) and 1 death case in the Department of Home Economics of college A. There were 5 suspected dengue fever (DF), 8 probable DF, 2 probable Dengue Haemorrhagic Fever (DHF), 1 confirmed DHF cases and 1 confirmed Dengue Shock Syndrome (DSS) case. Epidemic curve demonstrated a propagated source outbreak. Most of cases were 2nd high vocational certificate students and linked with 1st vocational certificate students. Both grades were linked and lived in high risk areas. The prevalence of mosquito larvae indexes was higher than the standard. The highest HI in the college was 15.38% and CI was 23.53%. The cafeteria and plastic bucket were the most containers which found mosquito larvae.
Conclusions and discussions: The most of the cases might be infected from both inside and outside the college because Rayong Province has high reported dengue cases across all areas. Vector control must focus on aggressive larval control in the college and continuing action. Furthermore, most of the cases were exposure in the same time. It implied that the source of infection might be within the college.