By Lucy Hornby
BEIJING, June 11 (Reuters) - One month after H1N1 arrived on its shores, China's stringent quarantine measures have prevented the disease from spreading among the general population, a health ministry spokesman said on Thursday.
With China's huge population, uneven health infrastructure and occasional cases of the more lethal bird flu, experts fear losing control of the H1N1 strain if it spreads widely in the country.
The World Health Organization is poised to declare a global flu pandemic after a spike in cases in Australia, where five people have been admitted to intensive care units and 1,263 cases of the new flu have been confirmed.
"We think that the method we are using has been pretty successful. One full month on, there have been over 100 cases, but we haven't found the disease has spread widely," said Mao Qun'an, the Chinese Health Ministry's spokesman.
China monitors all incoming international airline passengers, and has instituted a strict hospitalisation and quarantine scheme. So far, of the 111 recorded H1N1 cases in China, only a handful were infections that occurred locally.
Every international flight is greeted by technicians in white suits and masks, who aim a temperature "gun" at each passenger. Those with an elevated temperature are tested for H1N1 and if the test is positive, those nearby are also quarantined.
Visitors to China have chafed at spending their vacations locked in a hotel, as well as at the long lines in airports caused by the screening.
TIP OF THE ICEBERG
If the flu starts spreading rapidly, the Chinese government may need to rethink its quarantine policy, said Vivian Tan, the WHO's spokeswoman in China.
"This is something which can be done on a small scale when there are few in numbers, but if the numbers increase dramatically, China may want to reassess that policy as it's too resource intensive and it may not be sustainable," she said.
China has adjusted its procedures with better understanding of the disease, Mao said. While it initially quarantined all passengers on a plane with an infected person, it now only quarantines those who had sat close to the person.
So far, China has not had a case where the source could not be traced, Mao said.
Lo Wing-lok, an infectious disease expert in Hong Kong, said any country with trading relations and open borders could not keep out influenza because it spreads too quickly.
"People can be incubating the virus, be totally asymptomatic on arrival and only develop symptoms a day or two after arrival," Lo told Reuters. "Those with symptoms and who are identified at airports are only the tip of the iceberg."
Flu viruses incubate for about 2 days before an infected person starts showing symptoms, and the person is already infectious 24 hours before symptoms develop.
This means a person who is infected shortly before taking a short 5-hour flight can start spreading the virus in the community the next day -- all the while feeling perfectly well.
"If you only start tracing and quarantining other passengers who took the same flight as the person (after he has gone into the community), it is pretty useless. Flu is something you can't prevent with quarantine and contact tracing," Lo added.
There have been 27,737 cases reported in 74 countries to date, including 141 deaths, according to the WHO's latest tally.