BEIJING - The scene was reminiscent of early 2003, just before the world learned about SARS: A small room in central Beijing, filled with journalists skeptically asking World Health Organization experts this week about a potential new health threat in China.
The questions were about China's response to an outbreak of avian flu that has killed more than 5,000 migratory birds in China's far west: the weeks of delays in giving access to the WHO, the continuing delay in providing any samples of the virus that is killing the birds, the paucity of flu tests for people in the affected area, the news blackout on the subject.
It reminded some experts of the last time a deadly disease jumped from animals to people - the spread of SARS in southern China - and how China's government helped make the virus an international threat by covering it up for months.
The Chinese government clearly shares the serious concerns of international health officials about a potential human outbreak of avian flu, and it has responded aggressively to episodes such as the recent bird deaths, the WHO's chief representative in Beijing, Henk Bekedam, said after this week's news conference.
Yet Chinese officials still appear to be reluctant to cooperate fully. Officials give out information, but only piecemeal and on their timetable, often withholding the most important nuggets for weeks or longer without clear justification.
"You get information officially, but that's kind of the end of the line. It's not clear where the information is coming from," said Meirion Evans, an epidemiologist in Wales who in 2003 was part of a WHO team that visited southern China to research the outbreak of SARS that infected thousands and killed 774 people worldwide. "It's that kind of information gap which then leads to concerns about [whether we] are seeing the whole picture."
China has an obvious motive to control information. The government might fear that its poultry industry would be crippled by reports of avian flu hitting chicken farms, and it probably dreads a much worse outcome for the economy if human cases of avian flu emerge.
More than 50 people have died from the H5N1 strain of bird flu since the beginning of 2004, when the virus began showing up in chicken farms throughout Southeast Asia. There are no reported human cases of avian flu in China, and the virus is not known to have mutated so that it can spread from human to human, the threshold that could trigger a pandemic threatening millions.
But in China the sole source for such information is the government. Foreign journalists and experts are not allowed to travel freely to hot spots, and on the rare occasions when state media outlets report on avian flu in China, they are required to regurgitate the spare dispatches issued infrequently by the official New China News Service.
The result of this information void is that unreliable Internet reports have gained currency among health experts and others attempting to figure out what is really going on.
The most widely circulated report of this kind, posted on a Chinese-language site based in the United States, claimed that avian flu had infected people in the area where the migratory birds are dying, in western China's Qinghai province.
"Within one hour we shared it with the government," Bekedam said in an interview this week. Officials quickly reported back with a blanket denial of any human cases. Bekedam said he believes that, and he also believes that the WHO will be told if anyone tests positive for the avian flu: "Of course, we also have to rely on a level of trust as well."
Bekedam and other health experts have stressed that in defending against the avian flu, the world health system is only as strong as its weakest link. Based on the official information coming out of China, at least, the weakest link might yet be elsewhere.
"The most vulnerable would be a country with a relatively poor infrastructure, and therefore a poor surveillance system; a poor system for collecting information from the bottom up; and a poor system for implementing control measures from the top down," Evans said. "And I would say that probably isn't China."
But health and agricultural experts have long noted that China has special characteristics - a highly mobile, densely packed human population in close everyday contact with animals - that make it fertile ground for the next disease outbreak, as it was for SARS.
A transparent flow of information is thus essential, critics say. Yet Beijing continues to delay providing information and access that, considering the fast pace at which viruses can move and mutate, could be essential to the WHO's efforts to combat the H5N1 virus.
After making the U.N. health organization wait for weeks to get permission to visit the region hardest hit by the bird flu, the agency continues to wait for permission to visit the neighboring region of Xinjiang in the remote northwest, where migratory birds have also died of avian flu.
For some time now, according to the WHO, Chinese government experts have isolated genetic sequences of the H5N1 flu strains that are killing the birds in western China, but the government has yet to make the information or samples of the virus publicly available.
The doctor-diplomats of the United Nations organization are constrained by diplomatic protocol and by politics, and critics say China has put considerable political pressure on WHO officials not to embarrass their Beijing hosts.
The result is that the health experts the United Nations relies on to lead the fight against avian flu must wait in Beijing for weeks, time could be used to help China track the virus. Beijing was first aware of deaths likely caused by the avian flu as early as the first week of May, but the WHO was allowed to visit the region only last week.
Experts found they are running out of time to test the 189 species of birds said to be in the area before mating season ends in a couple of months, when up to 100,000 birds are set to fly off during their migration through China and other parts of Asia.
The Chinese government has tested only the five species of birds that are getting sick and dying of the disease; the WHO is far more concerned with possible carriers of the disease that don't get sick and thus could carry avian flu to other countries.
The WHO also found, based on statistics provided by Chinese officials, that there has been very poor surveillance of the human population to determine whether the flu has spread. The government has clinics that area residents are supposed to visit if they have such flu symptoms as fever, but so far only two people have been tested.
And WHO officials can't have much idea of what threat the virus might pose to humans without seeing the samples and genetic sequences of the latest strain of H5N1, which China has yet to provide.
Such issues could delay the reporting of what Evans calls "signals" of change in the virus and who it infects that could be helpful one day in raising the alarm to prevent a pandemic.
"Time is certainly crucial," Evans said. "If there's a delay in the signals, then as was the experience with SARS, there's potential for the virus to spread to other areas and across borders into other countries."
SARS, or severe acute respiratory syndrome, began spreading in the southern Chinese province of Guangdong in late 2002 and January 2003, only to be misunderstood and covered up by officials. Then millions of Chinese traveled to their family homes for Chinese New Year, and some unknowingly spread a new deadly disease they hadn't heard any warnings about.
By the end of Chinese New Year, Guangdong had a mysterious outbreak that doctors and nurses were unprepared for, compounding the spread of the disease, and it began spreading to Beijing, Hong Kong and, by air travel, around the world.
All of these developments went unreported in the Chinese state media because of a news blackout, save for a small number of articles about the Guangdong outbreak. The government misled the World Health Organization about the extent of the problem.
But it soon became clear to the government that the disease had spread beyond its control - and so had the information about it. In April 2003, the government reversed course by firing the health minister and the mayor of Beijing.
For previous articles about avian flu, go to baltimoresun.com/avianflu.