[Analysis on the epidemiologic features of Dengue fever in Guangdong province, 1990-2000]

To determine the epidemiological characteristics and risk factors of Dengue fever in Guangdong province in 1990-2000, and to develop the strategy for its prevention and control.

Sequential of the partial nucleotide fragments in E/NS1 gene junction was analysed.

A total of 9,747 cases were reported with three deaths in Guangdong province, 1990-2000. The average incidence was 1.27 per 10,000 (range: 0-9.75 per 10,000). Outbreaks were commonly seen, with 13 cities (61.9%) involved, but most of the cases occurred in Guangzhou, Chaozhou, Zhaoqing and Foshan cities. Numbers of cases reported monthly were gathered with sporadic imported cases reported from January to June while the period of epidemics was from July to December. Sex ratio of patients was 1.04, but all age group was susceptible. Four sero-types of Dengue virus were found during these epidemics. The partial nucleotide fragments in E/NS1 gene junction of 12 isolated viruses were sequenced and 2 sub-gene types were identified in Guangdong province. The clinical symptoms seemed typical. Social and natural factors were responsible for the epidemic of Dengue fever in the regions.

The epidemic of Dengue fever in Guangdong was closely related to the situations of neighboring countries, indicating the possibility of importation of virus from these countries. The epidemics usually started with imported cases. However, the endemic nature of the disease had not been identified yet.