(CNN) -- Having traveled about 2 million miles for business during his career, Mark Hill, chief marketing officer for a fine art reproduction company, lists three downsides to flying so much: all the waiting and security hassles; discomfort; and winding up on the same plane with somebody who has a drug-resistant, sometimes fatal, form of tuberculosis.
Business travelers are more at risk than the average traveler for illness because they are less likely to take precautions.
Hill was on the Air France flight on May 12 from Atlanta to Paris, 16 rows away, he says, from Andrew Speaker -- the Atlanta lawyer who sparked congressional investigations by flying to Europe and back while infected with a rare form of tuberculosis, known as XDR TB. Hill found out about it two weeks later on the news, along with other passengers.
Hill's business-travel health scare is less common than most. More everyday examples were the high-profile experiences of both Bush presidents. George W. Bush came down with a stomach ailment after traveling to the Group of Eight summit last week in Germany -- recalling his father's televised "tiny bout of the flu" 15 years ago during a summit in Tokyo.
Inevitably, a health scare in the news makes frequent travelers wonder: Am I at risk?
Hill believes such risks are on the rise. "I'm not one of those people who get sick that easily; I have a fairly high resistance," he says. "But I run into a lot of people who get sick on flights."
'Your risk is never zero'
Dr. Phyllis Kozarsky, an expert on travelers' health, explains the problem. "We live in a globally mobile society and people have to understand that your risk is never zero wherever you go and whatever you're doing."
Kozarsky teaches medicine and infectious diseases at Emory University School of Medicine and is a consultant for the Centers for Disease Control and Prevention on traveler's health. She also co-edits CDC Health Information for the International Traveler, the latest edition of which is being published this month.
The doctor does not mean to sound alarmist about air travel.
"Yes, there are possibilities of acquiring illnesses on airplanes, if you're sitting next to, or close to, somebody who has an illness that may be transmitted through the respiratory route, such as measles or the common cold," Kozarsky says. "But if you're on a bus, on a train or in a movie theater, or in any confined space for a period of time, you could face the same risk."
In fact, she says, the air filtration systems in airplanes take out 99 percent of infectious material, far more efficient than the systems in most offices.
While it is true that more people are getting sick while traveling, that's because more people are traveling -- statistics show that 900 million trips are taken every year internationally, Kozarsky says -- and the trips are increasingly to places that the average traveler would not have visited in the past.
The main risks for Americans traveling to developing nations fall into three categories:
1. Vaccine-preventable diseases
2. Insect-borne diseases
3. Gastrointestinal illnesses, such as diarrhea, which is caused by contaminated food and water
But this is misleading, Kozarsky says. "In fact, the major cause of preventable deaths in American travelers is injuries."
In any case, preventive measures can reduce the possibility of all these problems -- from making sure one's vaccines are up-to-date to drinking only bottled water.
If business travelers are more at risk than the average traveler, it is because they are less likely to take the necessary precautions, Kozarsky says.
"They're asked to travel somewhere in the developing world, they're staying at a nice hotel, they think it's just the same as going to Kansas City. But it's not the same."
Savvy companies recommend or require their employees to seek advice from a travel health clinic at least a month before the trip. (Local clinics may be found through the Web site of the International Society of Travel Medicine, http://www.istm.org/). Kozarsky believes a good place to start any trip is to visit the CDC travel Web site, www.cdc.gov/travel.
"The lifestyle of the busy business traveler doesn't lend itself to the greatest health maintenance," Kozarsky says. "But traveler's health is mostly common sense."
For example, she says, business travelers should give themselves time to recover from the trip instead of scheduling meetings soon after they get back.
President Bush can be excused, however. "Obviously his schedule is very hectic, but he has sleeping quarters on the plane, people monitor his food. All this shows is that anybody can get sick at any time." E-mail to a friend