In a move that could exacerbate the already shrinking pool of blood donors, the Japanese Red Cross Society (JRC) is asking people who recently visited Yoyogi Park and other Tokyo parks where mosquitoes are spreading dengue fever to refrain from donating, an official said Friday.
The dengue fever virus is not transmitted from person to person, but it can be contracted through blood transfusions.
As of Thursday, the JRC said on its website that people who have recently visited Yoyogi, Shinjuku Chuo and Sotobori parks should wait at least four weeks before making a blood donation.
“We aren’t aware yet of any cases where those people who have a recent history of visiting these parks have shown up to offer blood (but were rejected.) But it cannot be entirely ruled out that non-infected people might also feel discouraged to donate their blood,” said JRC staffer Yasunori Nohara.
Despite recent pickups, the number of blood donors in Japan has generally been on the decline. The annual number fell from 6.6 million in 1994 to 5.2 million in 2011, according to a health ministry survey.
Blood is in constant demand, Nohara said, because donated blood cannot be kept indefinitely. Some components are good only for four days.
Nohara nonetheless stressed that the new policy is necessary to ward off the worst-case scenario.
“There have been some cases reported overseas where blood transfusions from dengue-infected patients led to further infections. We can’t risk that,” he said, adding that he is not overly concerned about an immediate shortage of donors.
The Japan Society of Obstetrics and Gynecology, meanwhile, issued a statement Thursday recommending that pregnant women take preventive measures, such as wearing long-sleeved clothing, because their symptoms could be more severe if infected.
The health ministry said Friday that the number of people in the country infected with the virus stands at 115, including a teenage girl in Akita Prefecture and 10 others newly found to have the virus.
The infection path for the Akita girl, identified Thursday as having the virus, is still under investigation because she visited China before going to Yoyogi Park, where most of the people were infected with the virus through mosquito bites.
The other 10, found Friday to have the virus, are believed to have contracted the disease in Yoyogi Park, said the Ministry of Health, Labor and Welfare. One person had also visited Shinjuku Chuo Park in Tokyo, another dengue hot spot.
The cases were found in Tokyo and neighboring Kanagawa Prefecture, with the exception of a man in Kochi Prefecture, the first known case there.