The Epidemiology of Imported Dengue Fever Cases in Taiwan, 2007 and the Performance of Thermo-screening at Taiwan Taoyuan International Airport

Wen-Chih Yang

2009 Vol.25 NO.6

Correspondence Author： Wen-Chih Yang

Abstract：

There were a total of 179 imported cases of dengue fever in Taiwan during 2007, which consisted of 74 cases (41%) detected through fever screening at international airports and 105 cases (59%) reported by community doctors according to report sources. There were 54 residents of dengue fever cases in Tainan City/County and Kaohsiung City/County. Besides, the imported cases were mainly dengue type 2 virus infections, the same as most endemic cases in southern Taiwan in 2007. Countries where cases got infection were mainly Southeast Asian countries: Vietnam (55 cases, 31%), Indonesia (40 cases, 22%), and Philippine (22 cases, 12%). The main months for cases getting dengue fever were June to August (72 cases, 40.8%) and October to November (46 cases, 25.7%).We divided cases into two groups which included cases reported through fever screening stations at international airports and through community doctors. The statistical data showed that the time from date of illness onset to report date were 4.8 days in average at the first group and 10.2 days at the other.
In addition, we divided the 54 imported cases that consisted of residents in Tainan City/County and Kaohsiung City/County into two groups included cases reported through fever screening stations at international airports and through community doctors. According to the transmission period of dengue fever, we compared time correlation of the two groups with endemic cases in the cities/counties mentioned above. We discovered that there were 23 cases at the first group, of which, one case (1/23, 4%) exhibited time correlation with the first outbreak of dengue fever endemic in the county. There were 31 cases in the second group, of which, 5 cases (5/31, 16%) exhibited time correlation with the first outbreak of dengue fever endemic in the county within three weeks after returning places of residence. The results of using Fisher’s exact test to analyze the protective factor that educating public health guidelines to cases reported through fever screening stations could reduce cases in endemic places. Public health education to patients could prevent endemic dengue fever in their places of residence. However, no statistical significance was showed in Fisher’s exact test (P value=0.0922). By primary statistical analysis about the period from the onset date to the medical start date, we found that educating public health guidelines separately to cases detected through fever screening stations at international airports could influence their medical care seeking behavior.
Keywords: dengue fever, imported cases, fever screening stations, dengue fever transmission period, time correlation