Officials monitor Tokyo dengue fever cases
YOKOTA AIR BASE, Japan -- The Japanese Ministry of Health, Labor, and Welfare recently confirmed that as of Sept. 4, there have been 56 cases of dengue fever acquired in Tokyo's popular Yoyogi Park.
The Tokyo Metropolitan Government has temporarily closed most of Yoyogi Park and is performing pesticide applications, taking measures to eliminate mosquito breeding sites, and surveying for the presence of infected mosquitoes. Japan's National Institute of Infectious Diseases has alerted prefectural governments to be on the lookout for more cases, and does not anticipate a widespread outbreak because the approaching cool weather will effectively kill any of the mosquitos carrying the virus.
Military mosquito surveillance programs at Yokota Air Base are ongoing--dengue has not been found in any of the mosquitoes collected.
"We acknowledge the risk of contracting dengue is low here at Yokota Air Base, but we still encourage our members and their families to avoid the Yoyogi Park area until further notice and take prudent measures to avoid mosquitos," said Col. Eveline Yao, 374th Medical Group commander. "There are several ways to mitigate mosquito contact, such as staying out of shaded areas, leaving outside locations before dusk, using an insect repellent containing DEET or Picaridin on clothing and exposed skin, and wearing long sleeves and pants."
Officials said that Japan does not have the Aedes aegypti mosquito species which is primarily responsible for transmitting the disease in tropical areas and which readily survives in urban areas. Additionally, the mosquito responsible for the Yoyogi cases is most likely Aedes albopictus, which generally does not survive well in urban areas. A mosquito's life cycle is short and their flight range is typically around 50 meters, which greatly limit the time and territory in which they can transmit the virus.
Dengue fever is caused by a virus transmitted to humans by mosquitoes infected with the dengue virus; it is not transmitted from person to person. Symptoms include fever, headache, muscle and joint pain and a rash. There is no specific treatment and no vaccine, however, most patients fully recover. It rarely occurs in the southern United States, but is widespread in Puerto Rico and in many parts of Latin America, Southeast Asia, Africa, and the Pacific islands.
A concise and informative "Just the Facts" handout about dengue fever is available for download at: http://phc.amedd.army.mil/PHC%20Resource%20Library/Dengue.pdf. More in-depth information is readily available on the Center for Disease Control's dengue page: http://www.cdc.gov/dengue/