H1N1 swine flu, seasonal flu and complications

December 23, 2009 3:19:49 PM PST
It's been the worst flu season in 40 years, and now, we're finally getting some answers as to who's really at greatest risk for swine flu. Two articles in the New England Journal of Medicine are shedding some light on the flu epidemic. Rachel Jones is 18 weeks pregnant. A few weeks ago, she came to the office of Dr. Miriam Greene for a routine checkup, including a vaccine shot for H1N1, the swine flu. But...

"She looked so ill, we put her in the room immediately," Dr. Greene said. "And I said, 'You're not getting your swine flu shot, I think you have swine flu.'"

"I was upset being pregnant, having asthma, that I was at such a high risk that I was exposed to it, and worried about the complications," she said.

On Tamiflu, Rachel got better fast. But she's right to be concerned about complications. Though pregnant women are at higher risk than most of getting even the seasonal flu, the first study found that those with H1N1 had a higher risk of severe complications. Even worse, their death rate was so high that the researchers felt the numbers might push up the annual maternal death rate from any cause in the U.S.

There's another group that was at high risk and was the subject of the second article in the journal - young children and teens.

The study found that children were put in the hospital twice as frequently as with the seasonal flu. Again, the worst was that the death rate was 10 times that for the seasonal flu. Because kids and young adults have no past exposure to flu strains similar to H1N1, they have much less immunity than those born before 1957, the time of the last flu epidemic flu with a strain similar to H1N1.

"This is the first flu strain to emerge in 40 years," said Dr. Martin Blaser, with NYU-Langone Medical Center. "It's like a forest that's been really dry for 50 years. It's really dry. You light a match and everything goes up."

Dr. Blaser is chairman of the Department of Medicine at NYU-Langone and an infectious disease expert. He says, for H1N1 flu, the next 12 months are a mystery. The virus could disappear,or cases might spike again in the spring. It may become part of the 2010 seasonal flu. The H1N1 vaccine is safe and effective, and could be a lifesaver for expectant moms and young people.