Avian Enemy

Bird flu raises special concerns for deployed troops.

On Sept. 12, 1918, a soldier at Camp Devens, Mass., came down with the flu. It was the first recorded case in the U.S. military of what would become known as the Spanish flu pandemic. Within eight days, soldiers at 11 other camps fell ill with the virus and by the end of the month, every military installation in the United States reported cases of flu. Military records show that 127,975 troops became ill in that first month, and 3,369 died. Some succumbed within hours of showing symptoms. Most died within five days due to the subsequent onset of pneumonia. By October, the government was forced to cancel the draft.

More than 25 million Americans became infected with the flu virus during the 1918 pandemic-nearly a quarter of the population. More than 500,000 died. The situation was so alarming that local governments passed draconian laws in an attempt to quell the spread of disease. In Chicago, for example, city fathers criminalized sneezing in public. It was the only year in the 20th century when the United States reported a nega-tive population growth. Worldwide fatality estimates range from 20 million to 50 million. Those most likely to die were healthy young adults 15 to 40 years old.

For the U.S. military, the virus had enormous consequences, says Army Lt. Col. Wayne Hachey, director of deployment medicine and surveillance in the Office of the Assistant Secretary of Defense for Health Affairs. Under Army Gen. John J. Pershing, commander of military operations in Europe during World War I, 70,000 troops were already sick by early fall in 1918. Pershing requested 15,000 nurses and another 90,000 troops to compensate, but the War Department could provide only half that because there weren't enough healthy replacements to spare. While 50,280 troops were killed in combat, even more died of flu, Hachey says.

There is no evidence yet that the virulent H5N1 avian influenza A virus now circulating in Asia and Europe has adapted to humans (thus far it has been transmitted from birds to humans, but not from humans to humans), but the potential for that adaptation is setting off alarms in the public health community.

Hachey, a medical doctor certified in preventive medicine, spoke in January at the military's annual medical conference in Washington about the challenges Defense officials face. With more than 130,000 troops deployed to Iraq alone, where the virus was discovered to have spread earlier this year, the concerns are more than academic.

Defense operates a constellation of medical facilities that conduct disease surveillance and influenza research across the globe in conjunction with international health organizations. In addition, key officials at military treatment facilities have been put in charge of developing pandemic response plans, as well as measures they would need to take to improve surge capacity, Hachey says. "Each installation has a public health emergency officer responsible for looking at the installation's pandemic plans and making sure that fits with the community, so we have a unified pandemic response even at the local level."

At this point, the military has not pre-positioned any vaccine in Iraq or elsewhere in the field. "The vaccine currently is in bulk storage at the manufacturers," says Hachey. "The reason why we kept it in bulk storage is to increase the shelf life and to wait for the results of the [ongoing] antigen study." Medical officials estimate they now have 1.6 million doses of vaccine, but the antigen study could show that the vaccine would stretch much further. Hachey estimates that it would take six weeks to get the vaccine out to deployed troops.

"The reality is, until a pandemic actually starts, you don't know what vaccine will be effective," he says.