Killer Bird Flu Pandemic Is Preventable, Expert Says

Stefan Lovgren in Bangkok, Thailand
for National Geographic News

November 10, 2005

With the H5N1 avian flu virus spreading from Asia to Europe, many people seem to think an influenza pandemic that could kill millions of humans is inevitable.

One man at the frontline of the bird flu battle disagrees.

"Some scientists believe a pandemic can't be stopped, but I think they're wrong," Kumnuan Ungchusak, director of the bureau of epidemiology at the Thai Ministry of Health, said in an interview. "I believe we can contain the outbreak at its beginning … and avert a flu pandemic."

No Asian country has been more aggressive than Thailand in its efforts to contain the spread of the disease. Tens of millions of chickens have been culled, and the virus has been driven back into just a handful of provinces.

Since the outbreaks in Asia began, Thailand has recorded 20 human cases of bird flu, 13 of which have been fatal. By comparison, Vietnam has a far higher infection rate.

Experts credit Thailand's relative success in part to a vast surveillance system, which is overseen by Kumnuan: Hundreds of thousands of village volunteers throughout Thailand have been enlisted to watch for any signs of bird flu.

"Thailand has stayed ahead of the problem through a combination of poultry and human surveillance using basic volunteers at the village level," said William Aldis, the World Health Organization (WHO) representative to Thailand, who is based in Bangkok.

"This is a low-tech approach that makes sense, because you can farm out lab tests, but you can't farm out detection," he said. "It's an innovative system that any country can adopt."

Backyard Chickens

There are several avian flu strains, but the most dangerous is the H5N1 strain, which first appeared in Asia in 1997 and since 2003 has caused mass mortality in chickens.

The virus is hard for people to catch, but there have been 125 reported human cases of avian flu in the past two years, 64 of them fatal. All of these cases have occurred in the Southeast Asian nations of Thailand, Cambodia, Vietnam, and Indonesia.

Most deaths have been linked to human handling of infected poultry. Authorities have tried to stamp out poultry outbreaks as rapidly as possible. They aim to reduce opportunities for the virus to mutate into a form that can be easily transmitted between people.

But that is a major challenge in Thailand, where 50 percent of rural people raise their own chickens.

"Industrial chicken farms are not a problem," Kumnuan said in an interview at his Bangkok office. "The biggest problem is poultry in backyards."

The Thai government pays rural farmers 75 percent of the market value for sick birds that have to be culled. But some villagers may try to hide sick or dead chickens for fear that all their birds will be slaughtered.

Rapid Response

Overseeing a country of 63 million people, Thai officials have nowhere near the resources or staff necessary to monitor every village for bird flu outbreaks. So the government has created a network of some 800,000 volunteers, one for every village in Thailand, who watch for any unusual chicken die-offs.

"We have mobilized village volunteers as watchdogs for the disease in both animals and humans," Kumnuan said. "They are our most important resource. We are totally dependent on them to help us."

Thailand also has about a thousand rapid response teams ready to investigate any suspected human cases of bird flu. Villagers who experience any flu symptoms are advised to seek free medical care immediately.

Awareness of the disease appears to be strong. Late last month, one 50-year-old woman from Bangkok was hospitalized with bird flu. She had developed flu symptoms only three days earlier after visiting her husband at their family farm north of Bangkok, where backyard chickens had just begun to die.

"She knew about H5N1," Kumnuan said. "As soon as she developed the symptoms [of bird flu] she rushed to the hospital and informed her doctors. She is recovering fine."

But the case also underscores the continuing danger that bird flu presents. The incident follows a recurrence of confirmed bird flu outbreaks in poultry in six Thai provinces.

"We have admitted that we can't eradicate this virus within months, but that [eradication] will take several years," Kumnuan said.

"But if we can increase our capacity [to deal with the outbreak] in the very beginning, we can contain it. We can avert the next influenza pandemic by cutting the transmission of the virus from city to city, country to country."

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