2015 年 19 巻 1 号 p. 1-3
Dengue fever is a mosquito-borne viral disease. Dengue virus (DENV) infections occur in most of the tropical and subtropical areas of the world. DENV infection with any of four serotypes leads to a broad spectrum of clinical symptoms and their severity, including asymptomatic infection, dengue fever (DF) and fatal dengue hemorrhagic fever (DHF). DF/DHF is considered to be one of the most important re-emerging infectious diseases. Physicians and pediatricians in non-endemic countries are often unfamiliar with the symptoms and unaware of the potential importation of patients with DF/DHF. In August of 1942, an epidemic occurred suddenly in Nagasaki city and then in Sasebo city, Osaka and Kobe city. The epidemic in 1942 was subsided in November, but in the next summer it broke out again and recurred every summer until 1945. There were no dengue endemics in Japan since then.
In late August of 2014, three autochthonous dengue cases were reported in Japan. Since then, as of 31 December 2014, a total of 162 autochthonous cases have been confirmed. While cases were reported from throughout Japan, the majority was linked to visiting a large park or its vicinity in Tokyo, and the serotype detected has been serotype 1.