Bird Flu: Cause for Alarm?

Sept. 29, 2005 — -- The bird flu has not spread as widely as had been feared, but health officials say the potential risks the virus poses merit ruffling more than a few feathers.

David Nabarro, the newly appointed United Nations avian influenza czar said that the world is long overdue for a flu outbreak. "It would be extremely wrong to be ignoring this threat," Nabarro said at a news conference in New York today.

He laid out the United Nations' three-part strategy, including prevention, preparedness and appropriate response, stressing that governments must work together to contain the potential risk to a flu pandemic.

Separately, animal health experts urged Southeast Asian countries to help raise money and endorse a global plan to curb avian flu, which has killed at least 65 people.

The World Organization for Animal Health, the Food and Agriculture Organization and the World Health Organization are planning a bird flu conference in December to try to raise the $102 million they say is needed to contain the virus.

Officials at an international conference held in Kuala Lumpur, Malaysia, in early July, declared that the bird flu poses a problem, especially in Asia, and that ridding it from the world will not be easy.

An investigation in Vietnam revealed that, despite concerns of a massive outbreak, the virus had not mutated or spread significantly among humans, said Joseph Domenech, chief veterinary officer for the United Nation's Food and Agricultural Organization.

As a result there was no need to raise the level of widespread alert in Asia, he said. His calming words, however, were followed by calls for international action.

"The virus continues to circulate in poultry and wild birds and requires highest attention," he said during the conference, which was jointly organized by FAO, WHO and the animal health organization.

Domenech added that many questions remain unanswered and money needs to be invested to control any further outbreaks.

Asian Problem?

The killer avian influenza, also known as bird flu, broke out in eight Asian countries late in 2003, according to the Centers for Disease Control and Prevention. Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand and Vietnam all reported infected poultry.

In late June 2004, lethal outbreaks of infection among poultry broke out again, including in China and Malaysia. The following March, North Korea reported its first outbreak of bird flu. More than 140 million birds have died from the disease or have been killed to prevent further spread.

In August of this year, bird flu spread to Russia and Kazakhstan, causing world health officials to issue their strongest warning yet about the global threat posed by bird flu. Russian doctors suspect that migratory birds brought the virus to Siberia.

Humans have not gone unaffected.

Sporadic human cases of the bird flu, identified as H5N1, started popping up in Southeast Asia.

The human cases of avian influenza A in Vietnam, Thailand and Cambodia have resulted in at least 65 deaths.

Airborne Danger

Bird flu was believed to infect birds only until 1997 when the first human cases were seen in Hong Kong. Humans contract the disease through close contact with live infected birds. The virus is particularly dangerous because it's an airborne disease that acts swiftly. Birds that survive infection excrete the virus for at least 10 days, orally and through their feces.

The disease, which was first identified in Italy more than 100 years ago, occurs worldwide. There are 15 different strains of the virus, but the current strain deadly to humans is identified as H5N1.

All birds are thought to be susceptible to the flu, though some species are more resistant to infection than others. Infection causes a wide spectrum of symptoms in birds, ranging from mild illness to a highly contagious and rapidly fatal disease.

For humans, the symptoms are similar to other types of flu -- fever, sore throat and cough. Not all cases are fatal.

Following the 1997 outbreak, Hong Kong implemented a number of preventive actions, including human and poultry surveillance programs, and stockpiling antiviral drugs for treatment. The WHO stresses the importance of sharing information openly to streamline preventive strategies.

"Eradication of the virus from the eight affected Asian countries will not be easily achieved," said Domenech. In Vietnam's case, he even suggested massive vaccination as the only way to reduce infection.

Two top science journals, Science and Nature, reported that the deadly H5N1 flu virus has spread among migratory geese in China. Previously, the occasional wild bird had been found dead near an infected poultry farm, but this was the first time scientists have seen the virus spread among wild birds. The migratory nature of these birds leaves open the possibility that they could spread the virus. Genetic analysis of the virus shows that it is similar to the virus that caused human illness in Thailand and Vietnam.

Drugs Not the Answer

Popping pills to ward off infection won't do the trick, either.

"The use of an antiviral drug in poultry will create drug resistance and will hamper the treatment of avian flu in humans," Domenech said. All type A influenza viruses, like the bird flu H5N1, are genetically adaptable and readily mutate, according to WHO.

Its adaptability makes it all the more threatening. Experts fear it could evolve into a human virus, making it all the more deadly. At least two people have contracted the virus from another person.

Based on historical patterns, the WHO expects influenza pandemics to occur, on average, three to four times each century when new virus subtypes emerge and are readily transmitted from person to person. In the 20th century, the great influenza pandemic of 1918-19, which caused an estimated 40 million to 50 million deaths worldwide, was followed by pandemics in 1957 and in 1968.

Experts agree that another influenza pandemic is inevitable and possibly imminent.

Fighting the Virus

Most influenza experts believe that the prompt culling of Hong Kong's entire poultry population in 1997 probably averted a pandemic.

The CDC predicts that a "medium-level epidemic" could kill up to 207,000 Americans, hospitalize 734,000, and sicken about a third of the U.S. population. Direct medical costs would top $166 billion, not including the costs of vaccination. An H5N1 avian influenza that is transmittable from human to human could be even more devastating, assuming a mortality rate of 20 percent and 80 million illnesses.

Right now, the FAO's main focus remains the more affected countries. It estimates it will take more than 10 years for China and Indonesia to get rid of the virus, while Vietnam could wipe it out in six years.

The U.N. agencies want further transparency and better surveillance to fight the disease. In addition, they would like to set up a $102 million fund to help countries for the next three years. More than half of the money will be spent in Vietnam, Indonesia, Cambodia and Laos.