World bird-flu risk is 'gravest possible'

Posted in Other | 24-Feb-05 | Author: Thomas Crampton| Source: International Herald Tribune

World Health Organisation Regional Director Dr. Shigeru Omi makes opening remarks during the opening of a three-day conference on avian influenza in Ho Chi Minh City February 23, 2005.
Expert urges action in 'radical new ways'

HONG KONG The risk that Asia's outbreak of avian influenza could turn into a deadly global pandemic has increased sharply in recent months, a top international health official warned on Wednesday.

"The world is now in the gravest possible danger of a pandemic," said the official, Dr. Shigeru Omi, Western Pacific director of the World Health Organization. "We need to consider urgent and decisive action in radical new ways."

Speaking by telephone from the sidelines of an avian flu conference in Vietnam, Omi said that in recent months it had become clear that strains of avian influenza that emerged last year were now entrenched, endemic, versatile and transmitted through animals showing no symptoms of the disease. If mutated to transmit between humans, he said, the deadly strain of influenza could spread quickly around the world and infect millions.

"As regional director for the World Health Organizations, I have many very important issues, but avian influenza has now the highest priority for me," Omi said. "There are many terrible diseases in Asia, but this one is the most urgent because global health is now at risk."

The conference, which opened on Wednesday in Ho Chi Minh City and is to run for three days, is bringing together delegates from 20 countries and several agencies of the United Nations, including the Food and Agriculture Organization and the World Organization for Animal Health.

The current outbreak of the A(H5N1) bird flu virus began at the end of January 2004 and came in waves, so far killing 42 of the 55 people infected, according to the World Health Organization. The vast majority of deaths were in Vietnam, and almost all were traced to direct contact with sick birds.

Millions of dollars from multilateral donors have been spent on the crisis since late 2003, about $8 million in Vietnam alone.

"It is in the interest of both developed and developing countries to invest in the control and containment of avian influenza," Samuel Jutzi, director of animal production and health for the Food and Agriculture Organization, was quoted as saying by Agence France-Presse. "There is an increasing risk of avian influenza spread that no poultry-keeping country can afford to ignore. We must assume that avian influenza will persist for many years in some of the countries that had disease outbreaks in 2004-2005."

According to Omi, the most grave concern to emerge about the disease in recent months is how deeply entrenched avian influenza has become in the region.

"We have not reached the point of a travel advisory or warning like during SARS," he said, referring to the outbreak of severe acute respiratory syndrome, which killed nearly 800 people in 2003. "But we need to look at this disease in a very new way that goes beyond the mandate of the World Health Organization."

He added: "We are now confident in our judgment that this virus has become endemic in the Asia. We have been through three waves of human cases of the virus in Vietnam over the last year."

New cases in Cambodia and Vietnam are of great concern, Omi said, because they show that a reservoir exists for the disease. Avian influenza has killed 12 people since January in Vietnam and 1 in Cambodia in late January.

"We cannot tell if a seasonal pattern has been established," Omi said, "but the recent cases certainly show that the disease has not been contained."

He added, "We may now assume that the disease is entrenched, which is a very difficult situation to come out of."

In contrast to smallpox, eradicated by the World Health Organization, and polio, now near elimination, avian influenza will be a much more difficult disease to battle, Omi said.

"For both smallpox and polio, we had a vaccine and humans were the only source of the disease," he said. "With avian influenza we have no vaccine and we are still learning how many species can carry and spread the disease."

Recent strains of the disease have shown striking ability to jump between species, Omi said, adding: "The implication is not entirely clear when we find recent strains of the virus in domestic cats and tigers. But we can conclude that the virus exists in a pool that includes not just one or two species, but many."

This adaptability contrasts previous outbreaks of avian influenza, he said.

"Laboratory studies show this virus is more pathogenic than the one we isolated from the Hong Kong outbreak," Omi said, referring to one in 1997 that infected 18 humans and killed 6. "This strain is smart, versatile, and resilient."

The current strain can also be transmitted by ducks, which show no apparent symptoms of the disease.

"Ducks have a critical role in the transmission chain of this disease," Omi said. "They remain asymptomatic, yet spread the virus to chickens and humans."

Classic actions taken to combat an emergent disease - vaccination, surveillance and stockpiling of medicines - are not enough in the case of this strain of avian influenza, Omi said.

"We must address the root causes of this disease to have any impact," he said. "The key is stopping transmission routes between animals and humans."

Researchers have long cited the living condition that place poultry, pigs and humans in close proximity as the reason southern China has long been world's primary source of emergent influenza strains.

"We need to look beyond strict issues of public health and address lifestyle issues in Asia," Omi said. "Coordination will be needed between ministries of health, ministries of agriculture and on an international level from donor countries."

In concrete terms, unsanitary ways in which poultry is raised must be eliminated and Asia's live animal markets, prime locations for transmission, must better segregate species, Omi said.

By the end of closed-door sessions at the meeting in Ho Chi Minh City, Omi said, he hopes that a strategy can be created that will make clear the areas in which UN agencies, ministries and donor countries can help out.

"We need more resources to address these two issues since many countries cannot afford to deal with it on their own," he said. "Large-scale firms have the financial and technical resources to deal with the situation and change their methods, but rural farmers will face problems."

Changing the ways of rural poultry farmers will be essential, Omi said, since their farms can serve as reservoirs of the disease.

"This will not be easy, but we really have not choice," he said. "If this endemic situation persists we will end up with a pandemic."