But proof of a link is hampered by the fact that the study failed to demonstrate direct transmission of the pathogens between children and older adults, Imperato said.
"Another confounding variable is the role of influenza infections, which are common at this time of year and which predispose adults to pneumonias caused by a variety organisms," he added.
In another, related report in the same journal issue, researchers from Emory University in Atlanta examined lung tissue samples from people who died in the 1918 pandemic flu and found that pneumonia secondary to the flu was "an important cause of death."
The findings may have relevance today: The researchers suggest that children who get the pneumococcal vaccine greatly reduce their chance of getting pneumonia during a bout of the current pandemic H1N1 flu.
The current H1N1 swine flu hits children and young adults the hardest, according to the CDC.
Further, they note that deaths among children in developing countries from the H1N1 flu could be greater than currently estimated, because there is limited availably of pneumococcal vaccine in the developing world.
For more information on pneumococcal pneumonia, visit the U.S. National Institute of Allergy and Infectious Diseases.
SOURCES: Marc Siegel, M.D., associate professor, medicine, New York University, New York City; Pascal James Imperato, M.D., M.P.H. and T.M., dean and professor, School of Public Health, State University of New York Downstate Medical Center, Brooklyn, N.Y., Dec. 24, 2009, New England Journal of Medicine
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