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Is 'bird flu' back in humans?
by Lorna Benson, Minnesota Public Radio
July 23, 2004

Thai worker sprays chemical inside a chicken farm in Suphan Buri province northwesthern of Bangkok. Thailand has failed to learn critical lessons from its last major bird flu crisis. Politicians and health officials warned amid allegations that secrecy and inaction were putting more lives at risk. (PORNCHAI KITTIWONGSAKUL/AFP/Getty Images)

Health officials in Thailand are testing three people with possible bird flu infections. It's been several months since the last confirmed cases in southeast Asia. Infectious disease officials around the world fear that bird flu could become a global problem. In Minnesota, health officials are monitoring the situation daily and hospitals are doing what they can to prepare.

St. Paul, Minn. — Last winter bird flu, also known as avian flu, spread to 34 people in southeast Asia. Twenty-three of those patients died. The disease starts in waterfowl and poultry. Usually humans only get sick if they come in contact with infected birds. But health officials are worried that the virus will mutate and become contagious among humans. Given the frequency of global travel, a new contagious strain of bird flu could spread like wildfire around the world.

Michael Osterholm is director of the Center for Infectious Disease Research and Policy at the University of Minnesota. A patient who's already sick with another flu virus could provide the ideal environment for bird flu to mutate, said Osterholm.

"Those two viruses getting together could be the ultimate worst match because now they can swap additional genetic material that makes this new virus now capable of being transmitted human to human. That is in essence the real trigger point for starting a pandemic influenza," he said.

It sounds like the stuff of science fiction, but flu pandemics broke out three times during the 20th century -- in 1968, 1957 and 1918. The one in 1918 killed an estimated 20 to 40 million people worldwide. Genetic testing shows that all three flu pandemics started with birds.

A flu vaccine could stop such a senario from happening. But one hasn't been developed yet. Dr. Greg Poland, who heads Mayo Clinic's Vaccine Research Group in Rochester, says scientists can't develop a vaccine for a virus that hasn't yet mutated. "Just like we make new influenza vaccines every year, we would have to know what precise strain we would be dealing with and then develop a vaccine and that would take at a minimum, I mean if you just an emergency crash program of several months and more likely longer than that," according to Poland.

"This is not a matter of if. This is a matter of it will happen. And it's really a situation of planning how we are going to get through it." - Infectious disease expert, Michael Osterholm

Researchers still use chicken eggs to grow vaccines. That technology hasn't advanced since the 1950s. But there are new methods that appear promising. Poland thinks scientists will figure out how to develop vaccines rapidly in just a few years time.

That won't help if bird flu mutates in the human population before then, but there are other options for patients. In the U.S., doctors have access to a limited number of anti-viral medications that appear to be effective against avian flu.

But most health officials think their best defense against bird flu is constant surveillance. In Minnesota hospitals are monitoring the situation closely. Like many area hospitals, Hennepin County Medical Center in Minneapolis has a contingency plan for dealing with biological outbreaks, including bird flu.

"We're always watching these kinds of influenza patterns and this is a serious strain that we're you know watching through CDC and the World Health Organization to determine what next steps might be. But it is of concern and yet there's been very little evidence of transmission from human to human so far. We know that it's transmitted from birds to humans and we're standing on alert," said Jeanne Pfeiffer, who manages HCMC's Infection Control Program.

If bird flu showed up in Minnesota, Pfeiffer said HCMC would isolate patients and might even treat them at an off-site location. Just like with other flu cases, regular hand washing slows the spread of the virus. So do masks.

When it comes to bird flu, there are many "ifs." Infectious disease expert, Michael Osterholm said that wouldn't be the case, if research had kept pace.

"What this should be is a wake up call that we have to invest in these areas in science because if we don't Mother Nature will find unfortunately the ways to bring these kinds infectious agents back. This is not a matter of if. This is a matter of it will happen. It will happen sometime in the not so distant future and it's really a situation of planning how we are going to get through it," Osterholm said. Health officials still recommend that people get an annual flu shot, even though that will have little effect in the event of a possible bird flu outbreak. Each year, common influenza kills on average 36-thousand people in the United States.

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