The study also found, in contrast to conventional wisdom, children were no more likely to spread the flu to other family members than people in other age groups.
Most transmissions of the flu among family members occur either shortly before or after the first patient shows symptoms of infection, said study author Simon Cauchemez, of Imperial College London. The average time between the first person in the household showing flu symptoms and someone else in the household having symptoms was 2.6 days.
In a related study in the same issue of the journal, Johns Hopkins researchers reported on an outbreak of H1N1 flu in a New York City high school. The scientists found that although the infection spread rapidly and widely, it did not cause severe illness for the most part.
For more on H1N1 swine flu, visit the U.S. Department of Health and Human Services.
SOURCES: Lyn Finelli, Dr.P.H., lead, Epidemiology and Surveillance H1N1 Response Team, U.S. Centers for Disease Control and Prevention, Atlanta; Simon Cauchemez, Ph.D., Imperial College London; Pascal James Imperato, M.D., dean and distinguished service professor, School of Public Health, State University of New York Downstate Medical Center, Brooklyn, N.Y.; Marc Siegel, M.D., associate professor, medicine, NYU Langone Medical Center, New York City; Dec. 31, 2009, New England Journal of Medicine
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