The pinpointing of a small Mexican village as the probable epicenter of the /*swine flu outbreak*/ has given virus trackers a place to start in their struggle to predict what the virus might do in this country.
5-year-old Edgar Hernandez is the first known person to come down with swine flu. He had a headache and sore throat.
Now researchers are working to compare the local virus that jumped from pigs to humans in La Gloria, to samples from cases in the U.S. and beyond. At his lab in San Francisco, /*UCSF*/ virologist Charles Chiu, M.D., is expecting a culture sample later this week. He says by sequencing the virus's genome, may help predict future changes.
"This will provide insights into how this virus arose, what its capacity for human-to-human transmission as well as whether it will have the capability to become resistant to current drugs that we have for influenza," says Chiu.
Currently, swine flu can be successfully treated with Tamiflu, an anti-viral drug, but UCSF pharmacology professor Conan MacDougall PharmD says flu viruses can also mutate as they spread.
"Currently circulating during this flu season was another seasonal H1N1 virus. That H1N1 strain was resistant to Tamiflu," says MacDougall.
The most common scenario, MacDougall says is for viruses to develop resistance to a specific drug after it's in widespread use. However, the Tamiflu-resistant strain that surfaced this year, originated in European countries where the drug isn't widely used -- suggesting that it mutated on its own. That underscores the importance of tracking changes in the swine flu virus.
"There can be multiple mutations and they can occur sequentially. So one small mutation could lead to a small amount of resistance, but several mutations in combinations might lead to higher level of resistance. So by sequencing genome strains coming in, we can track the organism's evolution and see whether or not it's headed down a path that were more worried about a drug resistant virus," says MacDougall.
Researchers said they expect doctors will be careful in their prescription of anti-viral drugs during this outbreak, specifically because of the resistance issue.