Outbreak Response to Locally-acquired Dengue Fever in the Kaohsiung City-Kaohsiung County-Pingtung County (K-K-P) Region in 2006
2008 Vol.24 NO.1
Correspondence Author： Tuan Yen-Chang
This research describes local laboratory-confirmed cases of dengue fever and dengue hemorrhagic fever in the Kaohsiung City-Kaohsiung County-Pingtung County (K-K-P) region during 2006. It focuses on the scale of the outbreak by analyzing factors such as the distribution of cases, source of reporting, virus serotype, case population demographics, number of medical visits, and examination results. The study also determines the correlation of average weekly temperature and rainfall with vectors. Finally, it evaluates the impact ofcontainer reduction policies on the outbreak.
Results showed that 952 locally-acquired cases of dengue fever were reported in the K-K-P region during 2006, with the peak of 87 cases occurring in Week 43. Most of the cases were distributed in the Cianjhen, Sanmin and Lingya districts of Kaohsiung City and the city of Fongshan in Kaohsiung County. Most cases were reported from hospitals, followed by expanded serum collection activities and then clinics. Of the 406 specimens that were examined using nucleic acid sequencing, 371 cases belonged to dengue virus serotype 3. Among confirmed cases, 442 were male while 510 were female. The age distribution was 0-88 years with a median of 45 years. The average age at infection was higher in females than males. The incidence rate per 100,000 persons was found to increase with age. The number of visits for confirmed cases reported from medical facilities and the lag between disease onset and report date did not change significantly over time (p-value>0.05). In addition, 19 cases of dengue hemorrhagic fever resulted in 4 deaths, with victims’ ages in the range of 66-76 years. Multiple regression was conducted on vectors located in 118 areas that were within 5 kilometers of the Kaohsiung weather station and the average weekly temperature and rainfall. Results showed that the average temperature and rainfall in a given week were correlated with the following week’s Breteau index (Adj. R2=0.6985, p-value<0.01). From November 15-30, 2006, the Kaohsiung City Government’s Environmental Protection Bureau implemented a plan to mobilize cleaning crews to reduce the amount of containers in 77 areas. Among them, only 5 areas had cases of dengue fever occur in 2007.
Keywords: Dengue Fever, Dengue Hemorrhagic Fever, Container Reduction, Weather Factors, Breteau Index, Examination Results