What do we all need to know about travelers' diarrhea? WebMD asked Emory University professor Phyllis Kozarsky, MD, the CDC's expert travel health consultant.
What is travelers' diarrhea?
Travelers’ diarrhea is often used as a generic term for any illnesses ranging from an upset tummy to loose stools during or after travel. It could mean just excess gas, or a variety of symptoms that can occur from a change in the types of food or beverages we are used to – or, most commonly, to contamination of food or beverages. And it's not just food and beverages. Touching your mouth or nose with contaminated hands may be all it takes.
How can I prevent travelers' diarrhea?
People often discuss the importance of care in selecting "safe" foods and beverages for consumption. We recommend that foods be freshly cooked and be piping hot; such foods are safer than those on a buffet that have been sitting out for hours. Water should be bottled and sealed, or boiled. Alcohol is OK, but ice cubes are not.
But sometimes people do everything they are supposed to do regarding the selection of food and beverages and still get sick. Often, it's really the lack of sanitation within the food industry -- contamination may occur anywhere from when the food comes out of the ground to the preparer or the server. Food can be tainted at any point along that route. So restaurant hygiene and food service worker hygiene may be out of the traveler's control, but both play a role in whether disease is transmitted.
And sometimes it’s the travelers who contaminate themselves. Remember: Try to clean your hands before eating, whether with soap and water or a hand sanitizer. And travelers should avoid touching their face, mouth, or mucous membranes with their hands.
Can medications prevent travelers' diarrhea?
Yes. Pepto-Bismol has been used for a number of years to prevent travelers' diarrhea. Studies show that if adults take the equivalent of two tabs four times a day, it can decrease the incidence of travelers’ diarrhea up to 60%.
Now, many people who take that amount of Pepto-Bismol end up with severe constipation. I take two tabs twice a day when I go into a risky situation. I do believe that it is very helpful, but most recommend if you’re going to do this, that it should just be for short-term -- up to three weeks.
Some swear by probiotics like lactobacillus for preventing travelers' diarrhea. But studies of this strategy in limited numbers of subjects are inconclusive.
And some people are given prophylactic antibiotics, which are very effective in preventing travelers' diarrhea, but the problem there is we don't feel very good about prescribing antibiotics for a number of reasons for someone if they don’t need them. There are issues such as side effects, or of diarrhea caused by the antibiotics themselves, and increased antibiotic resistance in the normal organisms we harbor in our bodies. Rarely, if it is just for a very important weekend, or occasionally for government officials or someone in an athletic competition, we may prescribe preventive antibiotics.
How can a change in diet trigger travelers' diarrhea?
It's due to eating different kinds of foods, such as much more spicy food or more fat than in our normal diets. That is not something we typically pay as much attention to avoiding when we travel, but we have to be wary of these things. Not every change in our bowel habits is due to infection. Infection is the most important cause of travelers' diarrhea and most is caused by bacteria.
Who is most likely to get travelers' diarrhea?
Some people are more susceptible than others, it's not clear why that is. You can be with a group and all consume the same thing, and some get sick while others do not.
There are a host factors involved. Stomach acid is our first defense mechanism against organisms that we ingest. Therefore, those on antacids, or who just have low stomach acid, often get travelers' diarrhea more easily. People who have underlying diseases of the gut, such as Crohn’s disease or AIDS, may be more susceptible to certain types of organisms causing travelers’ diarrhea.
What kinds of infection cause travelers' diarrhea?
For the most part, we're talking about bacterial infections. Almost 90% of travelers' diarrhea cases are caused by bacteria. The enterotoxigenic E. coli [ETEC, strains of common bacteria that produce a toxin affecting the gut] are most important cause. And then there are others such as salmonella, shigella, campylobacter, vibrio, and others that are less common.
Travelers' diarrhea may also be caused by viruses, such as norovirus, which is in the news a lot because of how quickly it can spread through a cruise ship.
Parasitic travelers' diarrhea is yet another kind. Giardia intestinalis is the most common of these, but there is a large number of parasites that can cause diarrhea. These are less frequent.
Aside from the obvious, how do you know you're coming down with travelers' diarrhea?
Sometimes it starts with fever and chills. You may get cramps, and then, of course very urgent loose stools in various amounts. Sometimes there is vomiting or bloody diarrhea. With norovirus, onset can be sudden, and vomiting is a much more prominent feature.
For bacterial and viral travelers' diarrhea, the incubation period is typically six to 48 hours after infection.
For protozoan travelers' diarrhea, there is usually more of a gradual onset with a few loose stools per day and increased gas and nausea. The incubation period can be one to two weeks.
What is the main treatment for travelers' diarrhea?
Hydration is the primary treatment. Often people with a bout of travelers' diarrhea feel so weak. A good deal of it is due to dehydration. It's not OK just to take a few sips of cola. You need to make the effort to drink a lot of fluid, because often you've lost a lot more than you think. In a lot of cases, just clean water is OK. Better, if you are very dehydrated, is a rehydration solution. Rehydration packets are a great thing to have, especially if you are going to remote areas or places off the usual tourist paths.
Is it okay to take Lomotil, Lonox, or Imodium to relieve travelers' diarrhea?
When we look at anti-diarrheal agents, the most important are those that stop symptoms immediately, such as Imodium and Lomotil. We prefer Imodium, because it does not make you feel drugged and sleepy, but does stop your symptoms. [Note: Imodium is one of several brand names for loperamide. Lomotil and Lonox are brand names for diphenoxylate combined with atropine].
Remember that these agents do not cure the illness. They just stop you up and thus stop the cramping. These drugs are fine to take immediately, right after you feel that urge and pass that first loose stool. It will make you feel better faster.
Some people think that it is not a good idea to take agents such as these with diarrhea because it's better to purge all the "bad stuff" that's in you. But a number of studies show taking something like Imodium does not prolong illness. Now people with high fever or bloody stools or terrible abdominal symptoms should NOT take these drugs. They should seek medical attention.
For people with mild to moderate travelers' diarrhea, there is nothing wrong with taking Imodium and a dose of antibiotic at the same time. For mild diarrhea, if you do not have an antibiotic or are just looking for temporary relief, it is fine to take these drugs without an antibiotic. But if you're looking for a cure and want and need to move on with your travels, in general, it is good to take an antibiotic as well. One to three days of antibiotics will cure most cases of travelers' diarrhea.
What antibiotic should I take for travelers' diarrhea?
It depends. For adults, ciprofloxacin is used most commonly. Sometimes, for those traveling to certain places in Southeast Asia, where bacterial pathogens have increased resistance, some doctors like to prescribe azithromycin. In some cases where you feel that the traveler may likely be exposed to just the coliform pathogens such as E. coli, some prescribe rifaximin.
Of course, antibiotics work only for bacterial causes of travelers' diarrhea. Know that even bacterial travelers' diarrhea usually gets better without antibiotic treatment, although rehydration is always advised and symptoms may take 3 to 5 days or more to subside without treatment.
For those with diarrhea due to parasitic infections, there are agents that are specific for each type of infection. However, for Giardia infections, tinidazole [Tindamax] is often prescribed and is very effective.
Should I see a doctor before starting antibiotics for travelers' diarrhea?
Actually, for self-treatment in the field, we don't really encourage travelers to touch base with a provider before starting treatment. Many travelers will be in areas where providers may not be up to the standard of care that travelers are used to, or may be in places where the medications they can obtain are not safe -- there is a big market in counterfeit medications in some developing nations.
So we urge people to get the medications they may need -- and some education on when and how to use them -- from their provider before traveling. Then they can self-treat as long as they have only a mild to moderate case of travelers' diarrhea.
All of this advice applies to adults. What about children?
Kids can become dehydrated far quicker than adults. Rehydration solutions are more important for children right from the outset.
Doctors are now becoming more open to prescribing antibiotics that children can take in case they get travelers' diarrhea. Azithromycin can be useful in children. Parents should check with their pediatricians before leaving home.
Nursing mothers should continue to breastfeed. The time to wean a child is not in the middle of travel. Continue even if the mother has diarrhea -- but they must ensure that they are getting plenty of hydration.