Bird Flu: Treatments In Short Supply

Culling chickens in Turkey in an effort to contain bird flu (AFP) Governments around the world are now stockpiling the antiviral drug Tamiflu in preparation for a possible bird-flu pandemic. But supplies are low and will remain so.

Washington, 11 January 2005 (RFE/RL) – As countries around the world prepare themselves to combat bird flu, one drug is increasingly being mentioned as a defense: Tamiflu.

But how much hope can be pinned on it? Stockpiles of Tamiflu are small – and, according to the World Health Organization, existing manufacturing capacity would take 10 years to produce enough Tamiflu to treat even 20 percent of the world's population.

Moreover, a study published in December in the "New England Journal of Medicine," a prestigious U.S. medical publication, suggests that the avian flu virus may be able to develop a resistance to Tamiflu. The study reported that four out of eight patients infected with bird flu in a Vietnamese hospital died even though they were treated with Tamiflu.

One of the things to do in a place like Armenia, where you have very high education levels and you have very high access to radio, is to do a lot of radio commercials.

Doctors say that in these cases the virus mutated into a new version with high resistance to the drug, which works by suppressing virus replication.

Despite such findings, "Tamiflu is the best drug that we have right now for dealing with avian flu," says Andrew T. Pavia, chairman of the public health committee of the Infectious Diseases Society of America.

One of the things to do in a place like Armenia, where you have very high education levels and you have very high access to radio, is to do a lot of radio commercials.

"We know that it is quite effective in regular seasonal flu clinically, in that it prevents deaths. It prevents hospitalizations. And if taken early enough, it has a fairly significant impact on [the] disease," Pavia says. He adds, though, that "it has a number of limitations even in a normal setting, such as, if you begin it too late, it has relatively little effect. And there have been rare instances of resistance emerging."

Another drug that has proved effective is Relenza, says Pavia. Like Tamiflu, "it's quite effective used early on and within that 48-hour window." After that, its benefits wane.

Relenza may prove to have one advantage. "With Relenza we have not seen the resistance issues yet," Pavia says, though that might change. "Every microorganism at some point will develop a resistance to drugs if it has enough chance."

But Relenza is "in very limited supply right now," even less so than Tamiflu, and "the fact that it has to be used as an inhaler…makes it somewhat more difficult in very sick people."

Dr. Anne Moscona, an expert on viral diseases at the Weill Medical College of Cornell University in New York, says that viruses have a harder time developing resistance to Relenza. But Relenza only treats the lungs, while bird flu is known to attack other organs of the body.

Both drugs are also too expensive for most lower-income countries.

Fighting The Flu Without Money

So, with the two most effective drugs being both expensive and in short supply and with many rich countries talking about creating stockpiles, how can poorer countries respond to the bird-flu threat?

Prevention is the strategy emphasized by Maureen Lewis, a senior fellow at the Washington-based Center for Global Development. There are options other than Tamiflu for countries such as Armenia, geographically close to the Turkish town that was home to the first three human victims of bird flu recorded outside China and Southeast Asia. "It's not that good a drug, and Armenia spends less than one percent of GDP on health, so I'm not sure that it makes sense for Armenia to stockpile Tamiflu given its other demands," she says.

"One of the things… we've learned from what happened in Turkey [that] is instructive… is that the children [who died] were playing with a dead bird or dead birds. One of the things to do in a place like Armenia, where you have very high education levels and you have very high access to radio, is to do a lot of radio commercials. Don't touch dead birds. Report birds. Have people be part of the solution in terms of surveillance. I think that's going to help even more than having stockpiles of Tamiflu," Lewis argues.

A lot may depend on how local governments manage their agricultural sectors. Bird flu is "not a human-to-human problem. It's an agricultural problem," says Arthur Monto, a professor of epidemiology at the University of Michigan's School of Public Health. "Countries have to be aggressive in dealing with this. And that is one of the reasons why Thailand was quite successful in controlling it. Because they are a little more organized, more regimented."

If the virus does start to spread from person to person, the already difficult challenge of managing an outbreak of avian flu will rise exponentially.

The United States is currently testing a vaccine on human volunteers that would prevent the current form of avian flu from developing in humans. But even if a vaccine is found, the world lacks the capacity to produce it quickly enough and in sufficient quantity.

For the time being, prevention, containment, and Tamiflu and Relenza remain the chief defenses against the virus.