The latest human bird flu infection on the Chinese mainland is
worrying as it shows the H5N1 virus may have mutated and become as
infectious in warm months as in cooler ones, Hong Kong's health
chief said on Friday.
The virus thrives in lower temperatures and is usually most
infectious in the cooler months between October and March.
But confirmation on Thursday that a 31-year-old truck driver in
the southern city of Shenzhen has been infected has caused
uneasiness.
"Is this because the virus has changed, so that it is highly
infectious all year round? Or, if it is happening in summer, winter
would be even worse?" said the Secretary for Health, Welfare and
Food, York Chow.
He said the virus might have become "more virulent and spread
wider than we've expected," though its mutation was not
confirmed.
"If that is the case, the risk for humans to be infected in the
future is higher," he added.
The truck driver was admitted to hospital and was critically ill
on Friday. He had visited a market where live poultry was sold and
eaten chicken before he fell ill. But he is not known to have had
any other close contact with poultry.
University of Hong Kong microbiology head Yuen Kwok-yung said
the Shenzhen case was abnormal and worried the disease would spread
in winter.
"If there are human infections from June to August, it means the
virus is extremely active. I am worried that a major outbreak will
happen in winter," he said.
In neighbouring Shenzhen, authorities have stepped up virus
prevention and surveillance efforts.
The local government said it will now report the situation
relating to human bird flu cases every day.
The Shenzhen Centre for Disease Control and Prevention has been
asked to enhance its surveillance of any pneumonia-like cases.
So far the city has not reported any poultry infections.
But vendors said they are required to disinfect shelves twice a
day and stop on-the-spot slaughtering. Some supermarkets have
stopped selling live chickens.
"Business is really bad. I didn't even sell one chicken today,"
said a vendor at a Xiangmei Road market.
(China Daily June 17, 2006)