"This report shows our system of being able to detect new and emerging influenza viruses is working," he said.
Skinner added that the flu viruses known to go from person-to-person are those seen during the flu season, which usually starts in December.
This year's seasonal flu vaccine contains the same strains as last year's, which are the ones seen now in the Southern Hemisphere, he said. Skinner urged people to get a flu shot before the flu season begins in North America this winter.
Flu expert Dr. Marc Siegel, an associate professor of medicine at New York University School of Medicine in New York City, said "there is no concern for the public at this point."
"You have to remember that swine flu strains and bird flu strains are coming out all the time, and two cases doesn't mean anything," Siegel said.
Pigs are mixing vessels for flu, Siegel explained. "We see this every year. The key here is that we don't see any tendency toward sustained human spread," he said.
The U.S. Centers for Disease Control and Prevention has more about flu.
SOURCES: Tom Skinner, spokesman, U.S. Centers for Disease Control and Prevention; Marc Siegel, M.D., associate professor, medicine, New York University School of Medicine, New York City, author of The Inner Pulse: Unlocking the Secret Code For Sickness and Health; Sept. 2, 2011, CDC, Morbidity and Mortality Weekly Report
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