The government suspects mosquitoes living in a few separate locations in Tokyo’s Yoyogi Park may have been responsible for the recent mysterious dengue fever outbreak, NHK reported Tuesday.
The Health, Labor and Welfare Ministry, after looking into the activities of the people contracting the tropical disease, has found that some of them recently visited locations in the park that were more than 100 meters apart. As individual mosquitoes’ geographical range is believed to be limited to within a 100-meter radius, the ministry suspects these people may have been bitten by the virus-carrying insects in separate habitats inside the park, according to NHK.
In the first outbreak in some 70 years that started last week, 19 people in six separate prefectures, including Tokyo and Kanagawa, were newly cofirmed Monday to have contracted the disease, bringing the number to 22. As all were found to have visited Yoyogi Park or its vicinity in August, authorities suspect they contracted the disease from mosquito bites during their visits at these locations.
Dengue fever, which is common in Asia and Latin America, is believed to be only transmitted by mosquitoes, and is never contracted through human contacts.
The ministry is currently working with local authorities to determine the exact route of transmission, including a furthersurvey of the patients, on the assumption dengue-carrying mosquitoes lived in several separate locations in the park, NHK said.
“If we can pinpoint where those mosquitoes were located, we could then get rid of them more effectiely and alert people more effectively,” NHK quoted a ministry official as saying. “I recommend that people experiencing fever after a mosquito bite consult a doctor as soon as possible.”
The Tokyo Metropolitan Government plans to start on Tuesday to catch mosquitoes in Yoyogi Park twice a week to determine how the virus is spreading. To contain the disease, the local government drained the ponds inside the park and cleaned 275 ditches in the park, according to NHK.