U.S. Prepares in Case Bird Flu Crosses the Pacific

ATLANTA, Georgia, January 29, 2004 (ENS) - For the first time, a U.S. government agency has issued a warning to physicians to be on the lookout for symptoms of the avian influenza virus that has killed at least eight people and caused the deaths of millions of birds in 10 Asian countries.

Dr. Julie Gerberding, director of the Centers for Disease Control and Prevention (CDC), said Tuesday that the agency is alerting U.S. doctors to "take a careful travel history of anyone presenting with influenza-like illness," especially if the patient has traveled to regions of a country where the new flu strain H5N1 is occuring.

Doctors are being asked to take specimens from the respiratory systems of infected people and culture them in a lab in an attempt to detect any case of H5N1 at the earliest possible moment, Dr. Gerberding said. The CDC will work with state and local laboratories to use special tests that will identify this particular virus.

No cases of avian influenza in humans, chickens or any other bird has been found yet, so the risk is now "very low," but she said it could turn into "a very serious problem" if the epidemic in Asia is not contained.

There are 10 confirmed cases of avian influenza in Asia, seven in Vietnam and three in Thailand, and of those, eight people have died, most of them children. But given the widespread regional distribution of the virus in poultry, it would not be surprising to see cases of avian influenza in people in other countries, Gerberding said.

Dr. Julie Gerberding is director of the Centers for Disease Control and Prevention. (Photo courtesy CDC)

"We have six CDC scientists in Vietnam right now," Gerberding said. "We also have other CDC personnel who are stationed in Asia who are contributing to some of the activities going on in several of the countries."

In Bangkok Wednesday, government ministers from the affected countries met with international health experts to craft strategies that might help who health officials fear could be a global pandemic. They worry that the H5N1 bird flu virus could mutate into a virus that is efficiently transmitted from one person to another.

To prevent that mutation, officials are working to keep human flu viruses and avian flu virus from infecting the same person. Most at risk are the workers who are killing poultry flocks that are known or suspected to be infected with the H5N1 virus - millions of birds.

The World Health Organization says that cullers and transporters of infected birds should wear protective clothing and respirator masks, goggles, and boots. They should wash and disinfect their hands frequently, and environmental cleanup should be carried out in areas of culling, health officials advise.

Everyone exposed to infected chickens or to farms under suspicion should be under close monitoring by local health authorities. The drug oseltamivir, sold as Tamiflu, should be available to treat suspected cases of H5N1 avian flu in farm workers involved in the mass culling.

Free range chickens in the Vietnam's Thanh Hoa province (Photo courtesy Food & Fertilizer Technology Center)

All persons at risk both environmentally and occupationally should be vaccinated with the current WHO recommended influenza vaccine as soon as possible prior to anticipated risk exposure, the international agency said, as two weeks are required to develop preventive immunity by vaccination. This does not specifically protect against H5N1 infection.

To assist the World Health Organization in its efforts towards early detection and proper clinical care of the patients, the CDC has translated information about the H5N1 virus and updated infection control recommendations into the languages spoken in the affected countries.

The CDC is also developing diagnostic test kits in conjunction with the international health agency and is making these kits available in Asia so that doctors there can accurately diagnose bird flu cases.

One of the things officials worry about, said Gerberding, is that cases might be missed and the disease could be more widespread than anyone realizes because the virus is spreading in rural areas that may not have the same kind of disease detection capability that exists in the United States and other developed countries.

Gerberding said the CDC is reviewing its own infection control guidance for the United States, which is similar to that for regular influenza or for SARS, "so in the worst-case scenario, if we should have a patient with this disease and there's any suggestion of the possibility of person-to-person transmission, which we haven't seen yet, we would have the appropriate infection control guidance already in place."

"Right now," said Gerberding, "the virus does not appear to be efficiently transmitted from birds to humans, and it does not appear to be transmitted efficiently from one person to another.

Missouri state inspector visits a poultry farm. (Photo courtesy Missouri Department of Natural Resources)

These viruses are prone to evolve over time, so person-to-person transmission could become more efficient, she said.

While two of the traditional drugs that used to treat influenza are ineffective against H5N1, this virus does appear to be sensitive to oseltamivir, and the drug is available because it is being used to treat the H3N2 strain of human flu that has been circulating in the United States this season, Gerberding said.

To ensure adequate supplies, the agency currently is stocking up on oseltamivir. In the midst of the most severe phase of the H3N2 outbreak earlier this season, Health and Human Service Secretary Tommy Thompson directed the CDC to increase its supply of oseltamivir, a recommendation that Gerberding called "very prescient." The agency is "in the process of accessing a significant stockpile of drug," she said.

Meanwhile, federal and state agriculture officials are monitoring U.S. poultry for signs of bird flu, by conducting surveillance in sentinel chickens, Gerberding said, and watching for illnesses in migratory birds.

U.S. authorities have not issued a travel alert or advisory to Americans traveling to the areas of Asia that are affected. Still, the government is advising people who travel to countries that have confirmed poultry cases, to avoid contact with poultry farms, to stay away from live animal markets, and avoid contact with items or surfaces that may have been contaminated with excrement from an infected bird.

Gerberding said that 11 out of the last 12 emerging infectious diseases in the world have arisen from animal sources. "So what we really need to work on is not only recognition of illnesses in flocks of farm animals," she said, "but also the relationship between the human health surveillance system and the animal health surveillance system."