Double Flu Infections Pose Risk

The bird flu virus infected several people who were also sick with seasonal flu, risking a genetic mixing of the two that could result in a greater threat.

Nov 4, 2011
Edyta Zielinska

H1N1 virus particlesCDC / CYNTHIA GOLDSMITH

Recent surveillance has shown that several people in Cambodia were co-infected with avian influenza and the circulating flu virus, risking a re-combination event that could generate a greater viral threat.

“Influenza viruses are continually changing,” Patrick Blair, director of respiratory diseases at the US Naval Health Research Center in San Diego, said in a press release. Each flu virus contains genetic material that gives it particular properties. Researchers worry that the H5N1 strain, commonly called avian influenza, which hasn't been spreading well between humans, will obtain genetic material from seasonal flu that will allow it to jump between humans with ease. With a mortality rate of about 60 percent, a faster rate of spread could make avian flu a major risk.

However, in this case, the infected individuals recovered and the two strains tested did not show evidence of recombination. But the identification of such individuals demonstrates that the risk exists.  “Even though there may be a very small chance of this occurring, avian flu is still percolating in Southeast Asia and it continues to exhibit an extraordinarily high fatality rate in humans,” said Blair.