The reemergence of dengue in China.

In 1978, dengue was reported in China for the first time in 32 years. Since then, epidemics involving hundreds of thousands of people have occurred in Guangdong and Guangxi provinces and on Hainan Island. These epidemics were caused by all four types of dengue virus. Aedes aegypti was the vector in coastal areas, while Aedes albopictus was the vector in inland regions. During these epidemics, case rates were very high (greater than 50%) in some areas. Case-fatality rates were generally less than 0.1% except during the 1986 outbreak on Hainan Island, when the rate was 0.25%. Hemorrhagic disease occurred in both children and adults. On Hainan Island, hemorrhagic disease was more than three times as common in the 1986 outbreak as in the 1980 outbreak; the 1980 outbreak was caused by dengue virus type 3 and the 1986 outbreak by dengue virus type 2. The weight of the evidence suggests that the reemergence of dengue in China resulted from the introduction of the infection by travelers and refugees from areas of Asia where dengue is endemic.