Avian Flu: A Second and Deadlier SARS?

By staff reporters Cao Haili, Zhang Fan, Chang Hongxiao, Li Yan, Lou Yi and intern Ji Minhua

In the end, the once-horrific SARS epidemic of 2003 claimed less than 1,000 lives worldwide. But experts warn that the toll of the lethal avian flu, better known as bird flu, may be far more frightening, killing hundreds of millions of people.

Far from an apocalyptic prediction, that scenario is a real possibility. Scientists have matched the strain of the virus now spreading in birds and animals, and occasionally passed on to humans, with viral material gathered from the body of a 1918 Spanish Flu victim. That epidemic killed between 20 and 40 million people worldwide.

The United States held an international conference on controlling the deadly flu on October 6. Health officials and experts from more than 80 countries and regions participated, calling on all governments to share information and promote transparency to prevent a large-scale pandemic. US President George W. Bush even promised to call in armed forces to intervene if necessary.

The high-profile alert is well-founded, and it is overdue. Just months ago, many people considered avian flu warnings to be alarmist. But the virus is highly prone to mutation, frustrating attempts to develop human vaccines using pre-mutation strains.
Once the virus moves from ducks and chickens into humans, it could quickly mutate to develop the ability to pass from person to person. 'That''s the spark that sets off the forest fire of a global pandemic,' said flu expert Dr. William Schaffner of Vanderbilt University.

The issue is hardly a new one. Chinese scientists found H5N1 in two geese in Guangdong Province in 1996, when authorities insisted they were only isolated cases. In August 1997, Hong Kong reported the first human victim affected by the Type A, H5N1 strain of the avian flu virus, now deemed a major threat to human health and one that could potentially trigger a global crisis.

The flu remained relatively dormant until 2003, with a handful of cases occurring sporadically in several countries. In February 2003, the H5N1 strain of avian flu reoccurred in Hong Kong; one man and his daughter died of a respiratory disease, and the man was later confirmed to have been infected with the H5N1 virus.

The SARS crisis broke soon afterwards, and shifted global attention away from the flu threat. But later that year, other Asian countries and regions also confirmed significant numbers of cases of H5N1 infection. By the end of January 2004, authorities across Asia had all confirmed cases of the virus, including South Korea, Vietnam, Japan, Thailand, Cambodia, Laos, Indonesia, and mainland China. The World Health Organization initiated its Pandemic Preparedness Plan in early 2004 and issued warnings to its members'' epidemic monitoring networks.

Europe issued a continental avian flu alert this month when Turkey and Romania were forced to cull hundreds of infected birds and quarantine villages after outbreaks were reported in both countries.

Laboratory tests show that the H5N1 virus found last year had become stronger than previous H5N1 forms, although they are referred to by the same name. Experts warn that the new virus is better able to adapt to conditions in the human body, potentially setting the stage for mass infection.

Worse, the migrant birds have carried the virus from place to place, making it more difficult to control. In remote northwestern China''s Lake Qinghai region, wild birds, including bar-headed and brown-headed geese, started succumbing to the deadly virus in May. The lake is a major breeding area for several species of migratory birds that then move on to winter in southeast Asia, Tibet and India.

Jia Youling, director general of the Veterinary Bureau of the Ministry of Health (MOH), said that although a small number of water and migratory birds were infected with the virus, evidence was not sufficient to claim the flu has been rooted in the bird species. Other specialists claim that although the original sources are unknown, it is clear the danger is imminent. 'This means the avian flu occurrence is no longer a regional issue or an issue faced by a single country,' said Liu Jinhua, a flu expert with the China Agricultural University.

David Nabarro, the UN coordinator for Avian and human influenza, warned that if a major influenza erupted, between 5 million and 150 million people around the globe would fall victim.

The international community has started to become aware of the coming challenge. There is consensus that the keys to mounting an effective fight against the deadly flu include a greater political commitment; an improved emergency planning and response system; the international exchange of information; better transparency of policies; and true global cooperation.

China has dealt seriously with the issue. In 1995, the official Xinhua News Agency warned that avian flu could devastate the country''s poultry industry. Although the flu virus identified at that time, H9N2, was not as dangerous, the Ministry of Agriculture (MOA) reminded the public of the possibility that it would mutate into more lethal strains.

When Chinese scientists identified H5N1 in Guangdong in 1996, however, the authorities denied that China had been substantially affected by the bird flu. As late as 2003, official animal epidemic reports had never listed avian flu. That official stance contradicted scientific research results during the same period, which revealed several cases of avian flu infection.

In 2004, in the wake of the SARS crisis, the animal epidemic became more transparent. Avian flu is no longer a state secret. The 49 H5N1 infection cases among ducks and chickens in early 2004 were publicly disclosed, a move that won widespread applause.

The MOH updated its preparedness plan for the spread of the flu last year, releasing emergency plans and organizing specific working groups. A nationwide monitoring network was established early last year, enabling most grassroots health institutions to report potential cases directly to the central authorities.

The MOA has also drafted emergency response plans in September, but those plans have not been publicized. 'The plan has been released [internally] and those who should know it have been informed,' a MOA official told . 'There is no need to disclose it to the public.'

Analysts point out that inadequate coordination between the MOH and MOA is the foremost concern, since it may block smooth information flow and undermine China''s aggressive efforts to control the flu before it turns into an epidemic. In China''s central government, the MOA manages poultry-related flu planning and the MOH handles human-related issues. Yang Gonghuan, deputy director of Chinese Center for Disease Control and Prevention, said that in a hypothetical epidemic, the MOH would not intervene until the flu had clearly passed from animals to humans. Gan Menghou, an expert from the China Agricultural University, said the weakest link in the government''s planning to date is that that no ministry has specific jurisdiction over poultry-to-human transmission, potentially the epidemic''s most important element.

When the pig-borne bacterium Streptococcus suis surfaced in August in Sichuan Province, the two ministries seldom exchanged information, releasing death tolls of pigs and humans separately. In mid-October, with the flu threat looming large, the two belatedly established cooperation mechanism, which, experts say, is a crucial step in China''s anti-flu campaign.

Another bottleneck blocking the country''s prevention work is that only one epidemic monitoring institution – the Harbin Veterinary Institute of the Chinese Academy of Agricultural Science, directed by the MOA – is allowed to conduct relevant flu research. As