Airplane Cabins and Your Health

30 08 2012

Do you remember SARS (Severe Acute Respiratory Syndrome)? It popped up in China in 2002 and spread to more than 25 countries before we could blink.

PKIDs landed a group of disease prevention educators in China just as the world became aware of this outbreak that would rapidly become an epidemic. It was coincidence, of course. The trip had been planned for months.

But, our proximity to the SARS outbreak was a reminder to us of how efficient air travel is at spreading germs.

In 2009, there were 2.5 billion airline passengers and that number is expected to increase to 3.3 billion by 2014. That’s a lot of sneezing, coughing, and just plain touching of armrests, overheads, and other surfaces going on in small spaces.

Dr. Alexandra Mangili and Dr. Mark Gendreau wrote a piece for the Lancet in 2005 that talks about the mechanics of disease transmission in an airplane. It’s very good, if you have a few minutes to read it.

They explain air flow patterns and how much air is recirculated (50% and that’s through filters). Turns out, air does not flow the length of the plane, but rather in sections or pockets along the width of the plane. Still an efficient method of disease transmission for airborne and large droplet transmission, but not the only way germs are spread onboard.

According to the article, the most common infections on aircraft have been via the fecal-oral route through contaminated food, although that has diminished in the last few years, possibly due to prepackaged food products and more care in the prepping and handling of food.

Mosquitos, a common vector for diseases such as dengue and malaria, often hitch rides on airplanes. Mangili and Gendreau point out that, “Many cases of malaria occurring in and around airports all over the world in people who had not travelled to endemic areas, known as airport malaria, is evidence that malaria-carrying mosquitoes can be imported on aircraft.”

The cabins of airplanes cannot be thoroughly disinfected between flights. Many times, a plane lands, passengers disembark, and more passengers are seated within 30 minutes. Think of all the droplets of goo left behind that the cleaning crew cannot remove, and the many surfaces that can’t be disinfected.

Keeping one’s hands clean throughout the flight will go a long way toward preventing transmission, and staying up-to-date on your vaccinations for your home country and your destination. As for masks, the authors say, “Although masks play a crucial part in infection control in health care settings, their use is unproven in disease control within the aircraft cabin.” But they do recommend masking and isolating someone suspected of having SARS.

The CDC has quite a bit more to say about air travel and travelers’ health in general, if you’re looking for more details.

How do you prevent infections during air travel? What do you do to protect yourself? We’d love to hear! Please share your tips in the comment section.

By Trish Parnell
Image courtesy of WHO





Ask Emily

29 12 2011

Do cold viruses mutate, or are we simply encountering new viruses with each new infection?

If you’re in situations that expose you to frequent cold viruses, I’ve got some bad news for you. First, what we collectively call the “common cold” is a non-medical way of saying “general upper respiratory infection.” Those sniffles and coughs don’t trace to a single virus or even to a single group of viruses. In fact, more than 200 different viruses can cause what we think of as a cold, and they fall into various classes. The most common is the rhinovirus (rhino refers to the nose). These cause up to 40% of colds. The other two types are coronaviruses and respiratory syncytial virus, which is fairly harmless in healthy people but can be dangerous, particularly for premature infants. Coronaviruses made the news when one turned up as the culprit in the SARS outbreak earlier this decade.

Every time we encounter and do battle with one of these viruses, we develop immunity to that specific microbe. But there are another couple of hundred of them out there, waiting to get into our nasal passages with someone else’s cough or sneeze. In addition, it doesn’t take a lot of viral particles to cause an infection, so trace exposures can still lead to illness.

That’s not even the bad news, though. While people probably muse aloud every time they get the sniffles, wondering why scientists have yet to come up with a cure or a vaccine for the common cold, the fact is, a single vaccine is unlikely. Rhinoviruses, for example, are quite complex and mutate fairly rapidly, evading any immunity we’ve built up to previously encountered strains. In that way, it’s like influenza viruses, which reassort around the globe each year and usually turn up as different strains in each new season.

One thing is certain: You won’t get a cold virus just from being cold. You might be more susceptible to infection if you’re stressed or tired or have allergies.

Some people may think they have the flu, but the difference between an influenza virus infection and a cold virus infection is usually quite stark: a flu infection hits hard and fast, often within hours, with a high fever, extreme fatigue, chills, and possibly gastrointestinal involvement. A cold builds up more slowly, peaking after a few days, and fever is relatively uncommon.

Is there anything you can do to at least ease the symptoms of this incurable but usually benign blight on humanity?  Washing hands is one way to avoid picking up a nasty cold virus, but once symptoms develop, your options are limited. Antibiotics are useless against any viral infection. Vaporizers, fluids, some TLC, and time are your best weapons against riding out infection with any of the viruses that cause the common cold.

And go ahead and resign yourself to the idea that even when you’re over this one, new versions linger out there, waiting to find their way up your nose.

Do you have a question for Emily? Send it to: pkids@pkids.org

By Emily Willingham