SEOUL, Aug. 4 (UPI) -- Airports that tried to detect people with H1N1 by screening people with a fever were not effective because about half have no fever, researchers in Seoul say.
Researchers led by Dr. Sang Won Park, a professor at the Seoul National University, investigated confirmed cases of people with H1N1 who were hospitalized and quarantined in the early stages of the pandemic in 2009.
The study, published in the American Journal of Infection Control, showed 45.5 percent of the study subjects confirmed to have H1N1 had fever.
Individuals with mild infection and no fever have the potential to evade detection at airports or medical triage units, but since they are still contagious, continue the spread of infection.
"Our study found that fever is not reliable for case definition, even though it has been regarded as a key factor in determining influenza infection," Park said in a statement.
"We are aware of other studies that show fever present in as few as 31 percent of confirmed cases of influenza. We found that the most sensitive indicator was cough."
