抄録
A total of 160 autochthonous dengue cases transmitted by Aedes albopictus were reported from August to October 2014 in Tokyo Metropolis, Japan. Ae. albopictus is a medically important vector of dengue virus which has been expanding its geographic distribution in temperate regions. The understanding of the distribution and density of biting Ae. albopictus during the dengue outbreak case in Tokyo 2014 is valuable and important to evaluate the epidemic-risk of dengue fever in other highly populated cities in Europe. Of the 160 cases, 134 patients had visited a same park located in central Tokyo, Yoyogi Park. Mosquitoes infected with dengue virus were collected from this park suggesting that the place was the exclusive center of dengue transmission. This study aimed to collect referential data to estimate the transmission threshold of dengue virus in terms of biting density of Ae. albopictus and demonstrated high transmission-risk areas of dengue virus in Yoyogi Park and the vicinity. The overall mean density of biting Ae. albopictus, 7.13/man/8 min, was sufficiently high for successful transmission of dengue virus, and areas with biting densities higher than the overall mean density were classified as high transmission-risk areas of dengue virus in Yoyogi Park.
