Business Travel Contributes to Regional Spread of Virus
Adults who travel for business largely contribute to the regional spread of the flu, according to a study published online on Thursday by the journal Science, Scripps Howard/Detroit News reports (Bowman, Scripps Howard/Detroit News, 3/31).
For the study, researchers at NIH and the University of Pennsylvania compared flu deaths with transportation data from the Census Bureau and the Department of Transportation from 1972 through 2002.
According to the study, "The regional spread of infection correlates more closely with rates of movement of people to and from their workplaces than with geographical distance." The results are "not necessarily contrary to the current consensus that children drive the local spread of influenza (within schools, household and cities in general)," but the "long-distance dissemination" of the virus largely results from business travel between cities or states, according to the study.
In an average year, the flu took 5.2 weeks to spread across the 48 contiguous states, the study finds (Fox, Reuters, 3/30).
The study also finds that states with larger populations are more likely to reach epidemic flu levels at the same time as other large states and that states with smaller populations have more irregular patterns (Scripps Howard/Detroit News, 3/31).
In addition, the study finds that flu season begins in California more often than in other states, in part because of the large population (AP/Seattle Post Intelligencer, 3/30).
Co-author Mark Miller, associate director for research at the Fogarty International Center at NIH, said, "It had been hypothesized that air travels were the key determinants of the regional spread of influenza, but we show that work-related travels are more important." Business travel includes trips by car, train and airplane, he said.
"Importantly, our study does not go against the theory that kids drive the local transmission of season flu, within a state or city, through schools and household," Miller said (Scripps Howard/Detroit News, 3/31).
According to Reuters, the study "could have implications for controlling any future influenza pandemic, as well as for trying to control annual flu outbreaks" (Reuters, 3/30). An abstract of the study is available online.