Microbes on a plane

I blogged back in March about World TB day, the theme of which was "TB anywhere is TB everywhere." We know that someone can simply hop on a plane halfway across the world, and be practically anywhere else on the globe in the span of about a day--and their bacteria and viruses are just along for the ride. This is particularly disconcerting when it comes to respiratory diseases, where fellow airline passengers may be coughing and sneezing all over you, or touching shared objects without washing their hands. This is also a scenario that's known to have spread SARS, and may spread a future pandemic influenza strain.

What's equally worrisome is that this method of travel also has the ability to spread highly antibiotic-resistant bacteria, such as extremely drug-resistant Mycobacterium tuberculosis (XDR-TB) all around the globe. And it's more than just a hypothetical. A new story reveals that a passenger did, indeed, board a plane here in Atlanta, flew to Paris, ended up in Prague, and then flew back to Montreal and drove back into the U.S.--and he was infected with XDR-TB.

More after the jump...

CDC director Julie Gerberding noted:

"During these two long flights, the patient may have been a source of infection to the passengers."

Those most at risk would have been seated within two rows of the man, she said, adding that she was not sure what seats he occupied. Still, she said, CDC is recommending that all passengers be notified.

And this is just what they're doing--notifying passengers who were present on those jets. I have to wonder, though, about his route; about his layovers--did he have a long conversation in the airport while waiting to catch his flight out of Atlanta? Out of Prague? Was he coughing at the gate? It's unlikely he would have effectively exposed anyone there, but it's still within the realm of possibility. The article notes that his sputum was negative for the presence of bacteria, meaning he was unlikely to be coughing up or exhaling a significant number of organisms. However:

Because the man's sputum does not test positive under the microscope for the bacillus, the chance that he would infect others is considered low, Gerberding said. "But we know it isn't zero," she said, adding that 17 percent of TB cases are transmitted by such carriers.

The bad part is that the passenger knew he had TB, though it's not clear whether he knew he had the highly drug resistant strain:

The man's tuberculosis had been diagnosed before his departure, but he disregarded his doctors' recommendation that he not travel, she said. "The patient had compelling reasons for traveling and made the decision to go ahead and meet those personal responsibilities," she said, adding that federal authorities did not know until he had left the country that he had the rare form of the disease. The man himself may not have known either, she said.

He also apparently ignored recommendations not to return on a commercial flight, and went ahead and did so anyway--potentially exposing even more people. Because of this, he's currently in an enforced isolation (which I noted is still legal), and he drove there voluntarily, so at least it appears he's cooperating--now. Better late than never, I suppose.

[Edited to add: Revere has some complementary information on airplane airflow and microbial spread that may be of interest to readers.]

[Edited again to add: be sure to see the additional information on this story here as well.]

Image from http://www.freepatriot.com/imagewarehouse/airplane-departing.jpg