By Charlene Porter
USINFO Staff Writer

Washington - Indonesian health authorities are reporting another human death from a dangerous strain of avian influenza - the fourth in that nation in 2007, according to case histories compiled by the World Health Organization (WHO).

Indonesia’s latest deaths push its fatalities from this strain of bird flu - H5N1- to 61, the highest number for any of the 10 countries where humans have become infected with the virus.

WHO spokesman Dick Thompson said in a USINFO interview January 17 that seasonal factors may enter into the appearance of the recent human cases.

“Now that we have accumulated a few years of experience with the virus, we can see that there has been an upturn in cases in the Northern Hemisphere winter months,” Thompson said. “We don’t know if it is coincidental or if there is some causative factor. That’s still to be determined.”

Worldwide, the virus has killed 161 people since its most recent appearance in humans about three years ago. Almost all these individuals contracted the virus directly from exposure to poultry or their droppings. Health officials are concerned that this strain of influenza might develop properties to become contagious among humans. That could spark a disease pandemic because humans do not have immunity to this influenza strain.

In January 2004, WHO issued the first reports about the appearance of an avian influenza virus with the potential to cause a pandemic. The fact that viral mutation has not been detected and pandemic influenza has not emerged in humans is no cause for relief, Thompson said.

“This is no time to relax or think we’ve dodged a bullet at all,” he said, speaking from WHO headquarters in Geneva. “We believe that the threat is every bit as real now as it was two or three years ago.”

PANDEMIC IN ANIMALS

As Indonesia experiences a creeping human toll from avian influenza, other nations in the region are seeing an upsurge in animal cases, after long periods with no reports of disease. Japan and Thailand both are trying to control outbreaks among poultry, according to news reports, after an absence of the virus in each nation for extended periods.

Since widespread outbreaks of H5N1 began occurring in Southeast Asia several years ago, 55 nations have spotted the virus in domestic animals, wild birds or other wildlife. More than 220 million birds have died or been destroyed in an effort to prevent further spread of the virus, according to the U.N. Food and Agriculture Organization.

That level of disease among domestic flocks has been characterized as an animal pandemic, and a costly one. The World Bank estimates that losses in the Southeast Asian poultry sector have reached $10 billion, and African poultry producers are facing an estimated $60 million loss.

Authorities suspect that migratory flocks may carry the virus in their cross-continental seasonal movements, but it also is likely that the virus is transported in agricultural trade, experts say. The pathogen is able to travel like a stowaway, remaining viable in the mud on shoes or tires and on crates and cages in which birds have been transported.

The farther and wider the virus spreads among poultry, the greater are the chances that it could undergo the transformation to become a pathogen contagious among humans, experts say. That is a particularly acute risk when the virus spreads in developing countries with poor capability and infrastructure to detect the disease rapidly and quell it, whether among animals or humans.

The United States has been a leading nation in the international effort to build surveillance and response capability among developing nations, having pledged $434 million to support international efforts to improve preparedness, disease surveillance and containment. The United States is working to strengthen international organizations' capacity to address the threat, as well as directly supporting efforts in at least 70 nations. (See fact sheet.)

See Bird Flu (Avian Influenza) for ongoing coverage.