Season change could spread swine flu in Asia-Pacific

Isabel Reynolds, Reuters Published: Friday, May 22, 2009

Yuriko Nakao/ReutersJapanese elementary school students wear masks as a precaution against swine flu during a tour at the upper house of the Parliament in Tokyo, May 22, 2009.

TOKYO -- Japan scaled back measures for handling the H1N1 flu on Friday but there was no let up for the rest of Asia as experts warned of more trouble with the approach of winter in the southern hemisphere.

Japan's move came after most of the nearly 300 infections in the country appeared to be mild and officials tried to reduce disruption the contagious new disease brought to everyday life.

"It is important to make it possible for the local government to respond flexibly depending on the situation of the region," Prime Minister Taro Aso told a meeting on influenza.

Japanese central bank governor Masaaki Shirakawa said on Friday the flu was not having a major impact on the country's economy.

With Japan's new guidelines, suspected patients in areas where infections are rapidly increasing can go to regular medical institutions rather than "fever centres" and schools would not be automatically shut down.

Quarantine checks on most airplanes will also no longer be conducted. Japan also relaxed its travel warning for Mexico.

Julian Tang, a consultant with the microbiology division at Singapore's National University Hospital said the scaling back of measures, such as in Japan, was understandable.

"This virus will continue to spread. I'm not saying we should stop trying to prevent its spread at this point - particularly in countries where there are few or no cases, but this seems to be a well-adapted human flu virus that may well become part of the seasonal circulating influenza viruses in the future," he said.

"The type of extreme quarantining used in Hong Kong for their first case, in retrospect, may no longer be necessary -- given the relatively mild nature of this virus so far."

An expert in the southern hemisphere warned of more trouble ahead with winter approaching.

Robert Booy who heads Sydney university's immune research and surveillance centre said more people than usual in Southern hemisphere countries could become infected this winter and die from the new swine flu because of the "novelty" of the virus.

"Once you have enough virus out there, evolution is simple," Mr. Booy said, adding the H1N1 virus could change to the point that it could get "nasty".

The H1N1 flu strain is a never-before-seen mixture of swine, bird and human viruses that spreads easily between people. It has killed 85 people and infected more than 11,000 in 41 countries, according to the World Health Organization.

So far the symptoms of the new virus appear mild, but it is starting to cause more severe effects as it spreads.

U.S. federal health researchers said on Thursday the seasonal flu vaccine provides virtually no protection against the new flu.

Their study also supports an intriguing theory that people over the age of 60 have some immunity to the new H1N1 strain, perhaps because it resembles an older version of seasonal flu.

In Australia, where cases have spread across several states and two of its 11 infections were locally contracted, the government raised its flu alert level to mid-range "containment" on Friday. This would give it power to shut schools.

In Hong Kong, the epicentre of the SARS epidemic in 2003, officials were taking no chances even though it has had only three cases of H1N1 so far, all imported.

"If there are many patients, we will have designated clinics that will perform checkups and monitor them and administer antiviral drugs (Tamiflu) if needed. We will require them to be quarantined at home," health secretary York Chow said.