Google Earth Used To Track Bird Flu Evolution

Google Flu Trends has helped medical researchers track flu outbreaks. Now scientists have used Google Earth to understand how the avian flu virus is gaining resistance to antiviral drugs through evolutionary selection.

Researchers from the University of Colorado at Boulder recently found that the avian flu, a subtype of influenza A known as H5N1, is evolving resistance to adamantanes, one of two classes of antiviral medications used to treat the flu.

The study, "Evolution of drug resistance in multiple distinct lineages of H5N1 avian influenza," was published last October in the journal Infection, Genetics, and Evolution. Its co-authors included CU-Boulder doctoral student Andrew Hill, CU-Boulder associate professor Robert Guralnick, recent CU-Boulder graduate Meredith Wilson, Farhat Habib of Kansas State University, and Daniel Janies of Ohio State University.

Google Earth played an important role in the scientists' research. It allowed them to map individual gene mutations in H5N1 as the virus spreads around the globe. "Our mapping of a phylogeny based on full genome analysis of H5N1 into Google Earth shows that adamantine-resistant lineages have spread and emerged independently in various regions of South East Asia over a period of only four years," the report states.

The researchers have made their flu map available as a KMZ file, which is a geospatial data format used by Google Earth.

Hill told the CU-Boulder news service that the reason for H5N1's growing resistance to adamantane antivirals is that Chinese farmers have been overusing the drugs by adding them to chicken feed to prevent bird flu.

If Tamiflu (oseltamivir), the other major class of antivirals for the flu, is ever used this way, Hill expects it too could become more widely resisted.

"Taken as a whole, our results suggest that widespread antiviral drug use changes the selective landscape ... for H5N1 influenza," the report states. "Going forward, natural selection may lead to further emergence and spread of resistance to antiviral drugs."