Nineteen more people were confirmed by the health ministry Monday to have contracted dengue fever in Tokyo, bringing the total to 22 in the first cases of domestic infection in Japan since 1945.
None of the people had recently traveled overseas, but all had recently spent time in Tokyo’s Yoyogi Park and are thought to have been bitten there by mosquitoes carrying the virus. The disease is not transmitted directly from person to person.
The Health, Labor and Welfare Ministry called on anyone experiencing a high fever three to seven days after suffering a mosquito bite to seek medical attention, but noted that serious complications of dengue fever are rare.
Of the 19 confirmed patients, 13 are residents of Tokyo, two are from Kanagawa Prefecture and one each from Saitama, Chiba, Ibaraki and Niigata prefectures, the ministry said.
Infection was confirmed in three other people last Wednesday and Thursday. Two were from Saitama and one was from Tokyo.
The ministry is now investigating whether anyone close to the confirmed patients has also been infected.
Two personalities of the TBS variety show “King’s Brunch” are among those thought to have contracted the illness, the TV station said Monday.
Eri Aoki, 25, and 20-year-old Saaya, who goes by only her first name, are thought to have been bitten while filming on location in Yoyogi Park on Aug. 21, TBS said.
After the first case came to light last Wednesday, the Tokyo Metropolitan Government sprayed insecticide around parts of Yoyogi Park, the vast green area next to Meiji Shrine popular with young people and performance artists, on Thursday in an effort to eradicate mosquitoes.
Dengue fever, an illness found in tropical and subtropical areas in Asia, Latin America and Africa, is transmitted by tiger and dengue mosquitoes.
Sufferers are struck with a sudden fever around three to seven days after transmission, accompanied by head and muscle pains and a rash.
Most patients have mild symptoms, but in some cases significant bleeding can develop, which can be life-threatening.
Japan sees dozens of imported cases of dengue fever each year, mostly in tourists who catch the illness while traveling in tropical regions.
The disease, which is transmitted only by mosquito, was common in Japan during World War II, but there have been no outbreaks for several decades.