With hundreds of new coronavirus cases reported in South Korea, a spike of deaths in Iran, and a 10-town lockdown in Italy, the rapidly spreading COVID-19 may be on the verge of becoming a pandemic.
This is only the latest outbreak to show how quickly pathogens can spread in a changing world.
And the worldwide response is a testament to the immediate need for intervention and containment: flights canceled, cruise ships quarantined, travel banned, and a rigorous monitoring of the Chinese response.
What is now beyond dispute is that airplanes are giving the virus a big boost.
This is nothing new. Air travel is a way to spread many virulent infectious diseases including diphtheria, hepatitis A, influenza A and B, measles, mumps, meningococcus, rubella, tuberculosis, norovirus, etc.
In the US, airlines move more than two-and-a-half million people per day, squeezing them into long metal cylinders where all share the same air, the same restrooms, and take meals shoulder-to-shoulder for hours and hours.
One plane carrying a single symptomatic SARS patient saw the disease develop in at least 16 others. Transmission of seasonal influenza during flights is well documented as well.
There is no doubt that close contact, especially when prolonged, spreads contagion. This is true for respiratory droplets, direct skin contact, and sometimes, fecal or oral spread. Making matters much worse: Airlines, taking people from place to place, turn what might otherwise be local outbreaks into worldwide crises.
It’s hard to conceive a more efficient way to spread infectious disease.
Now, CDC maintains a “do-not-board” list prohibiting people with a communicable disease from flying. Yet these policies only work for patients already diagnosed, or with overt symptoms, and viral disease transmission typically begins days, even weeks, before symptoms appear.
For example, the incubation period for COVID-19 is believed to be between 2 days and 2 weeks. In these situations, the current policies don’t work.
That said, basic facts suggest that airlines and airports are key to stopping the spread of disease. Public health interventions should obviously focus on them. After all, it’s where the impact is likely to be greatest.
