I think all of us have figured out that mass transportation devices are good disease vectors. Anyone who is familiar with the Black Death knows that it was ship docking in Genoa in 1347 that initiated the plague’s spread throughout Europe, where it subsequently wiped out up to a third of the European population. I can’t say, therefore, that I was surprised to hear that, in the event of an epidemic, air travel will be an effective vector. Indeed, I’d figured that one out on my own. In any event, if this thought hadn’t already occurred to you, here is the beginning of a news report about the study that explains it all:
Scientists have found what they call the first real evidence that restricting air travel can delay the spread of flu — a finding that could influence government plans for battling the next influenza pandemic.
Air travel has long been suspected of playing a role in flu’s gradual spread around the globe each year, but yesterday, Boston researchers said they finally have documented it: The drop in air travel after the September 11, 2001, terrorist attacks seemed to delay that winter’s flu season by about two weeks.
“This is the first time that a study has been able to show a direct link between the numbers of people traveling and the rate of spread of a virus,” said John Brownstein, an epidemiologist at Children’s Hospital of Boston, who led the research.
Other scientists stress that the study doesn’t prove that restricting air travel helps in the long run — there was no drop in the number of deaths, just a delay. So if a pandemic were to strike, the question is whether a mere two-week delay would outweigh the economic chaos of severe travel restrictions.
By the way, I’m unimpressed by the argument that limiting travel will just delay the inevitable. Whether it delays or halts the disease depends on the disease’s incubation time. If it’s a disease that manifests quickly after infection, you can actually practice the old-fashioned idea of a quarantine, which would include restricting air travel. It’s only with a disease that has a slow incubation period that you’ll have people who look healthy traveling around, shedding the virus as they go. Flu falls into that category and that’s why the article is correct that, with ordinary flu, there’s no point in stopping air travel.