Rare swine flu strain H1N2 detected in Minn. infant

(CBS) An infant from Minnesota has developed an extremely rare strain of swine flu. It's called the H1N2 virus and is common in pigs in the Upper Midwest, CBS local affiliate WCCO reported. The boy is only the second human ever to contract H1N2.

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Why did the infant contract the H1N2 virus? Not because of anything he did - neither he nor his family had direct contact with swine. His case is an unusual mutation of the flu virus.

While Minn. health officials say there's little reason to worry, they also say the boy is living proof of just how difficult it is to pin down the flu virus.

"Typically, influenzas change a little bit," Dr. Aaron DeVries of the Minn. Department of Health told WCCO. "When the virus changes substantially, that is when a pandemic can occur and that is what happened in 2009."

As many as 6,000 people died in the U.S. in 2009 during a seven-month outbreak of the H1N1 swine flu virus. This boy's strain of H1N2 is not as serious, proved by his quick recovery, and does not spread as easily.

"We haven't observed any additional cases," since the child developed symptoms, DeVries told the Star Tribune.

The boy has since recovered from the virus, which was diagnosed in October.

H1N2 is not protected against by the flu shot, which does cover the H1N1 virus.

The CDC has more on the flu virus.