Cholera; Dengue fever; Traveler's diarrhea; Malaria; Schistosomiasis; Typhoid; Yellow fever
Traveler's diarrhea (TD) is the most common health problem a traveler encounters. It is almost always caused by ingesting certain organisms in contaminated food or water. Diarrhea can also be caused -- particularly in children -- by anxiety, stress, allergies, fatigue, and dietary changes.
Diarrhea frequently occurs within the first week of travel, but may develop at any point, even after returning home. Traveler's diarrhea causes four or five loose or watery stools per day. Vomiting may also occur. It usually lasts 3 or 4 days, but about 14% of cases last longer. In rare cases, the diarrhea lasts more than 3 months. When TD lasts a long time, it can cause post-infectious irritable bowel syndrome. Traveler's diarrhea is rarely life threatening, although it can be severely debilitating, especially in children. Weakness, reduced urine output, lightheadedness, and mental changes require immediate medical attention, especially in children. Life-threatening symptoms include reduced levels of consciousness, seizures, and coma.
Traveler's diarrhea typically affects 40 - 60% of people from industrialized nations who visit developing countries:
A number of infectious organisms, including bacteria, parasites, and viruses, can cause diarrhea in travelers. These organisms are most often transmitted through contaminated food and water. Bacteria and viruses cause diarrhea within a few hours and up to 3 days, while diarrhea from parasites can occur 7 - 14 days after exposure. In about 10 - 50% of cases, the cause is unknown.
Drinking contaminated water is the most common cause of acquiring traveler's diarrhea. The following methods or products help reduce exposure to contaminated water.
Some important tips:
There is no vaccine against traveler's diarrhea. However, vaccination against cholera has been shown to offer some protection against TD in 25% of travelers.
The following drugs can reduce your chance of getting sick:
Pepto-Bismol. Taking two tablets of Pepto-Bismol four times a day before and during international travel can help prevent many cases of diarrhea. Pepto-Bismol should not be taken for more than 3 weeks. Both aspirin and Pepto-Bismol share the active ingredient salicylate, which can be harmful to children. Many medications interfere with salicylate, and people who are allergic to aspirin, pregnant women, and those with ulcers, other bleeding disorders, or gout, should not take Pepto-Bismol without consulting a doctor. Side effects of Pepto-Bismol include ringing in the ears and black stools and tongue.
Prophylactic Antibiotics. Prophylactic antibiotics are those used to prevent diarrhea while traveling. They work well, but there are many reasons that argue against their routine use. Taking prophylactic antibiotics can trigger adverse drug reactions, development of infections with resistant strains, and contribute to the global problem of bacterial resistance. Antibiotics are also NOT effective against parasites or viruses, but their use may give travelers an unwarranted sense of security. At this time, prophylactic antibiotics are not generally recommended unless the person is at increased risk for complications of TD. People at such risk include those with chronic bowel diseases, kidney disease, diabetes, or HIV.
Lactobacilli. Taking capsules that contain protective bacteria called lactobacilli (also called probiotics), may be helpful, although the Infectious Diseases Society of American believes that evidence is insufficient to recommend them. Some studies report that a genetically engineered strain called Lactobacillus rhamnosus strain GG may prevent and reduce severity of diarrhea. In fact, lactobacilli may be used for both prevention and treatment in children without any adverse effects. The capsules can be split open and put into beverages for small children.
Fluid Replacement. If diarrhea develops, the most important steps to take are preventing dehydration and replacing lost fluids, particularly in children. In severe cases, dehydration can be life threatening. Agitation may be an early symptom of dangerous dehydration. Listlessness and a weak pulse are symptoms of severe dehydration. Parents should seek medical help immediately if the child appears to be dehydrated.
Ideally, fluid replacement utilize solutions that contain the important minerals potassium, sodium, and calcium. The following are some suggestions:
Helpful Foods. Foods that help slow diarrhea include rice, bananas, apples, and tea.
Adding milk (but not soy milk) to these foods may help many children. In fact, eating yogurt that contains active lactobacilli cultures may have positive benefits. (However, yogurt drinks in developing countries may carry a high risk for contamination.)
Bismuth subsalicylate (Pepto-Bismol). Pepto-Bismol can be used for treatment of mild diarrhea and nausea. Treatment generally consists of 1 fluid ounce or 2 tablets every 30 minutes for up to 8 doses in a 24-hour period. If diarrhea continues, treatment can be repeated for a second day.
Antimotility Drugs. Antimotility drugs provide prompt but temporary symptomatic relief by reducing muscle spasms in the gastrointestinal tract. They include:
Antimotility drugs should be discontinued if symptoms persist beyond 48 hours. They should NOT be used at all in patients with high fever, if there is blood in the stool, or in children under age 2. Imodium is approved for children 2 years and up, but its use in children is controversial because of reports of severe side effects. Experts do not recommend it.
Note: Lomotil and Imodium work well for treating diarrhea, but are not effective for prevention. Lomotil may even increase the risk for diarrhea.
Antibiotics. Antibiotics are generally effective for treating traveler's diarrhea that develops in an 8-hour period, with three or more loose stools, and especially if associated with nausea, vomiting, abdominal cramps, fever, or blood in the stools. Because antibiotics are prescription drugs, travelers at risk should obtain them before they depart and should receive directions for self-treatment while abroad. Antibiotics should not be used for nausea and vomiting when diarrhea is not present. Although self-treatment is generally safe, a doctor should be sought for any child with diarrhea and for adult patients who develop fever or bloody diarrhea. (Antibiotics are generally not useful for diarrhea in developed nations, since such cases are likely to be caused by viruses.)
In general, patients take one tablet every 12 hours for 5 days. Fluoroquinolones are the preferred antibiotic, unless the person is traveling to SE Asia or India, where bacterial resistance to this class of drugs is high. In these cases, azithromycin (Zithromax) is preferred. Taking a single dose of an antibiotic such as ofloxacin (Floxin), plus an anti-motility drug (usually Imodium), often provides relief within 24 hours for many patients. Other antibiotics used for diarrhea include ciprofloxacin (Cipro), rifaximin (Xifaxan), and levofloxacin (Levaquin).
Parasites do not usually respond to standard antibiotics. Trimethoprim-sulfamethoxazole (Bactrim), for example, has fallen out of favor for routine use because of resistant bacteria, but it may be very effective against the severe diarrhea caused by the parasite Cyclospora. Metronidazole (Flagyl) is the standard drug for Giardia. Erythromycin and similar antibiotics may be useful for Cryptosporidium or Campylobacter. Nitazoxanide is another antibiotic showing promise for treating diarrhea caused by parasites. Antibiotics do not work for diarrhea caused by viruses.
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