In Japan, infectious diseases including mosquito-borne diseases are controlled based on the Infectious Disease Control Act (April 1999) which allows public health authorities to take various control measures against the designated infectious diseases. These measures include mandatory notification by physicians, active surveillance of cases and vector-control program etc. Under the Infectious Diseases Control Act, approximately 10 mosquito-borne diseases are designated; such as malaria, dengue fever, chikungunya fever. Every year, a number of imported cases of these mosquito-borne diseases have been reported. However, as auto-chthonous cases, we only have less than 10 cases of Japanese encephalitis annually in these years due to the effective implementation of vaccination.
Meanwhile, at the end of August 2014, an autochthonous case of dengue fever was confirmed for the first time in the past 70 years. The patient never travelled abroad, and was considered to be infected with dengue virus in Yoyogi Park located in the center of Tokyo based on the activity history and other evidence. This was followed by the report of approximately 160 autochthonous cases by the end of October, and most of the patients had visited Yoyogi Park or its adjacent areas. Through the response to this dengue outbreak in 2014, it was revealed that the knowledge and experience in mosquito control had been weakened or even lost among Japanese public health authorities. To solve this problem and to promote mosquito-control measures, in April 2015, Ministry of Health, Labour & Welfare announced the “Special Guidance on Mosquito-borne Diseases” which identifies the roles to be played by each stakeholder including the Government, prefectural and municipal governments, physicians/medical institutes and the general public. It is expected that mosquito-borne disease control will be further enhanced by active promotion of this Guidance.