Scientists create a four-legged flu detector

Before the H1N1 “swine flu” outbreak of last year, the big influenza worry concerned H5N1. The so-called “bird flu” has infected people only 504 times since 2003, but in 299 cases it was deadly – a fatality rate of 59%, according to the World Health Organization.

Scientists believe it is only a matter of time before migrating birds carry the H5N1 virus from eastern Asia to North America. Biologists have fanned out across Alaska to capture birds, swab their hindquarters and send the fecal samples to laboratories to look for evidence of H5N1 and other strains of bird flu.

As you might imagine, the process is expensive and time-consuming. If only there were a more efficient way to sniff out traces of H5N1 among wild birds.

Bruce Kimball, a chemical ecologist at the U.S. Department of Agriculture, says he has found one. Working with colleagues at the Monell Chemical Senses Center in Philadelphia, he has trained mice to figure out whether ducks are carrying H5N1 or other types of flu simply by smelling their poop.

That’s right. Birds droppings containing flu virus have a telltale odor that mice can detect. Think of them as drug-sniffing dogs, except that instead of drugs they’re sniffing flu, and instead of dogs they’re rodents.

Kimball and colleagues trained the mice to find feces from infected ducks inside a maze. Whenever the mice came upon it, they were rewarded with water. However, when they found decoy feces from flu-free ducks, there was no reward. (Apparently, water was a sufficient reward to motivate the mice to learn the difference.)

Kimball presented the results Tuesday evening at the annual meeting of the American Chemical Society in Boston.

“Based on our results, we believe dogs, as well as mice, could be trained to identify a variety of diseases and health conditions,” he explained in a press release.

Another possibility: building machines with the ability to sense the chemicals that give infected poop its distinctive odor.

Any of these scenarios could result in a team of sentinels that scientists could use to “provide us with an early warning about the emergence and spread of flu viruses,” Kimball said.

Karen Kaplan / Los Angeles Times