FEATURE: Japan reviewing flu measures amid fears of possible pandemic
Japanese government officials and scientists are seeking to update measures to prepare for any influenza pandemic among humans amid growing concerns following avian flu's global spread among birds this winter.
Researchers plan to review the government's estimation of damage to be caused by a possible flu pandemic as it was drawn up more than a decade ago and does not reflect the nation's latest medical situation.
"I think that now we need to conduct a comprehensive review of measures in light of changes in the situation," said Nobuhiko Okabe, who chairs a health ministry subcommittee on new strains of flu.
For the winter in Japan, the detection of the highly pathogenic H5N6 strain of the virus began in November among birds, including those kept at farms in some areas, and has since spread across the country.
There had been more than 200 cases of avian flu infections confirmed among wild birds as of early February. Infections at poultry farms led to mass culling operations by local authorities.
Yoshihiro Kawaoka, professor of virology from the Institute of Medical Science at the University of Tokyo, says measures were taken "very swiftly" at the farms.
Promptly taking measures at farms is thought important because failure to do so would increase the risk of the virus gaining entry into bodies of other animals or humans and of it transforming into a type more likely to cause a pandemic.
Governments across the globe have begun to step up measures after the H5N1 strain of flu killed six people in Hong Kong in 1997.
As the type of virus brought down more victims following the initial deaths, world governments began to get down to fuller measures to prevent the disease from developing into a pandemic.
Japan created its first action plan on measures in 2005, estimating based on a U.S. model that up to 640,000 people could die from the disease.
In line with the action plan, Japan has stocked vaccines against the H5N1 strain of the flu.
A global pandemic occurred in 2009, however, not only of the anticipated H5N1 strain but of so-called swine flu from an H1N1 strain. As this strain did not have very high death rates, the Japanese government decided to keep stocking H5N1 vaccines, not H1N1.
In 2013 in China, the H7N9 strain of the virus caused human infections and deaths.
The H5N1 strain, on the other hand, has become more diverse with its spread to many locations including extensive areas of Asia and the Middle East, meaning vaccines may not be effective enough for some varieties.
Against this backdrop, a scientist proposed during a meeting last December of an advisory panel on flu measures for the Cabinet Secretariat that canceling the current way of focusing on stocking H5N1 could be one option.
Moves are under way to review Japan's decade-old casualty estimation because it serves as the basis for measures to be taken.
A research team led by Hiroshi Nishiura, professor of infectious disease epidemiology at Hokkaido University, is planning to draw up an updated damage scenario taking into account multiple conditions, and based on estimations and analyses by experts in various fields.