Dr. Kelly Reynolds, 40, is a native of West Virginia who lives in Tucson, Ariz., where she is a professor and microbiologist at the University of Arizona. She is launching a Web site later this summer about germs and viruses (www.learnaboutgerms.com).
Q. Do you travel much to other countries?
Yes: Europe, Asia, Latin America and Canada. … I'm there professionally to give talks, primarily on public health: how to stay healthy and avoid germs. Internationally, I probably travel once a year; most of my travel is domestic.
Q. From a health perspective, walk us through the drill. First you get off the airplane …
Hold on. There are quite a few things you need to know about the airplane, so let's start there. A number of studies have been done on this.
You're in a confined space with a number of people who are sharing the same environment – the same tray tables used by the passengers before. If they weren't adequately cleaned, you can be exposed to a lot of germs. My tip is to make sure you have some disinfectant wipes or gel hand sanitizer. Any time you touch food, you need a way to wash your hands.
Many are concerned about air flow, and think germs are transmitted that way on a plane. In fact, there's little air exchange between the front and back; the air flow is up and down.
You're much more likely to be exposed to germs by surface contamination.
Viruses tend to stay in the air for about two hours, then settle on surfaces – like tray tables and armrests – where they can survive for 72 hours. Here's the good news: It's easier to disinfect a surface than it is to disinfect the air you're breathing.
Q. Off the plane?
If you go to the rest room, wash your hands – your hands are the primary transmission route for germs. About 50 percent of the population doesn't wash them. Wash them properly, with a 20- or 30-second wash cycle.
Once you're at your hotel, you're around other hot spots – again, confined spaces used by many people. We find cleanings between occupancies aren't always efficient. Crews often use cleaners that aren't disinfectants designed to kill germs. We've witnessed people dipping mops in the toilet and using that water to clean the whole bathroom!
Some spots that don't get cleaned? Remote controls, doorknobs, light switches. Anything people touch frequently that's cleaned infrequently is where germs are going to reside.
Q. How closely are particular countries correctly associated with particular illnesses?
We're now a global society: There are about a billion people all over the world who every year travel by airplane. The potential exposure to germs anywhere is greater than it ever has been. Any contagious person can be anywhere in the world within 24 hours. The point I'd like to make is that you're never risk-free.
That said, some places still have diseases that have largely been eradicated in the U.S. The levels of sanitation, hygiene and vaccination all play a role. There are certain places where germs have a better chance of persisting.
Q. For example?
Avian influenza. There have been no cases reported in the U.S.; all have been in Southeast Asia.
It's rare to have a case in the United States of SARS – Sudden Acute Respiratory Syndrome, which is a virus.
Q. What about climate? Are you at less risk from germs in, say, the Arctic than you'd be in a hot, damp place?
Microbes are very good at adapting to climate. You wouldn't be exposed to the same types of virus, but there'd be something else there.
Climate does play a role. We have vector-borne diseases – illnesses transmitted by rats, mosquitoes, ticks – in some areas of the world you won't find somewhere else.
Q. How do you find healthy places to go?
Look for countries that have the infrastructure for wastewater disposal and treatment and sewage containment.
Other routes of virus transmission are water and food. With water, you're safest in places that have municipal water treatment. Food safety is more difficult to control. In the U.S., there are food guidelines through the FDA
Education level is a factor: Do people where you're going know about proper hygiene and the safe cooking of food? Also, are vaccinations in place? If so, there's not as much endemic disease in the population.
Q. Ever get sick in another country?
The sickest was in Mexico, where I had severe dysentery. But from the stories I've heard, I got off very lucky.
Q. What else can you do to stay well?
At the CDC site, there are advisories on vaccines. I'd definitely recommend checking that site. (At www.cdc.gov, click “Travelers' Health.”)
But there's a lot you can do on your own. It's important to remember the basic routines for sanitation and hygiene.
When you're there, stay hydrated and get enough rest: Jet lag and not eating well can run you down and weaken your immune system.
When you're in a new environment and not sure about the water or food quality, eat foods that can be peeled – like fruit – or that are properly cooked; make sure meats are completely and thoroughly cooked.
Q. When you get back home?
You don't need to visit a doctor if you're feeling OK. But at the first signs of symptoms, inform your doctor that you've been in a foreign country, and let him or her know what diseases are endemic to that country. Keep a record of where you've traveled, so you can trace back where you've been. This will help you get the right treatment more quickly.