Contaminated food and drink are the major sources of stomach or intestinal illness while traveling. Intestinal problems due to poor sanitation are found in far greater numbers outside the United States and other industrialized nations.
In areas with poor sanitation only the following beverages may be safe to drink: boiled water, hot beverages, such as coffee or tea made with boiled water, canned or bottled carbonated beverages, beer, and wine. Ice should be avoided because it may be made from unsafe water. It is safer to drink from a can or bottle of beverage than to drink from a container that was not known to be clean and dry. However, water on the surface of a beverage can or bottle may also be contaminated. Therefore, the area of a can or bottle that will touch the mouth should be wiped clean and dry. Where water is contaminated, travelers should not brush their teeth with tap water.
Boiling is the most reliable method to make water safer to drink. Bring water to a vigorous boil, then allow it to cool; do not add ice. At high altitudes allow water to boil vigorously for a few minutes or use chemicals disinfectants. Adding a pinch of salt or pouring water from one container to another will improve taste.
Chemical disinfectant can be achieved with either iodine or chlorine, with iodine providing greater disinfection in a wider set of circumstances. For disinfection with iodine use either tincture of iodine or tetraglycine hydroperiodide tablets, such as Globaline, Potable-Aqua and others.
These disinfectants can be found in sporting goods stores and pharmacies. Read and follow the manufacturer’s instructions. If the water is cloudy, then strain it through a clean cloth and double the number of disinfectant tablets added. If the water is very cold, either warm it or allow increased time for disinfectant to work.
The CDC makes no recommendations as to the use of any of the portable filters on the market due to lack of independently verified results of their efficacy.
Food should be selected with care. Any raw food could be contaminated, particularly in areas of poor sanitation. Foods of particular concern include: salads, uncooked vegetables and fruit, unpasteurized milk and milk products, raw meat, and shellfish. If you peel fruit yourself, it is generally safe. Food left uncovered and out in the open can become contaminated with feces by way of flying insects, especially flies.
Some fish are not guaranteed to be safe even when cooked because of the presence of toxins in their flesh. Tropical reef fish, red snapper, amberjack, grouper, and sea bass can occasionally be toxic at unpredictable times if they are caught on tropical reefs rather than open ocean. The barracuda and puffer fish are often toxic and should generally not be eaten. Highest risk areas include the islands of the West Indies and the tropical Pacific and Indian Oceans.
The typical symptoms of traveler’s diarrhea (TD) are diarrhea, nausea, bloating, urgency, and malaise. TD usually lasts from 3-7 days. It is rarely life threatening. Areas of high risk include the developing countries of Africa, the Middle East, and Latin America. The risk of infection varies by type of eating establishment the traveler visits—from low risk in private homes to high risk for food purchased from street vendors. TD is slightly more common in young adults than in older people, but there is not difference in rates of infection between males and females. TD is usually acquired through ingestion of food and water contaminated by feces.
Antidiarrheals, such as Lomotil or Imodium can decrease the number of diarrheal stools but can cause complications for persons with serious infections. These drugs should not be used by anyone with a high fever or blood in their stools.
Antimicrobial drugs such as doxycycline, fluroquinolones (ciprofloxacin), and trimethoprim sulfamethizole may shorten the length of illness. Consult your physician for prescriptions and dose schedules.
Bismuth subsalicylate, taken as an active ingredient of Pepto-Bismol (2oz. 4 times daily) appears to be an effective preventative agent for TD, but is not recommended for prevention of TD for periods of more than three weeks. Side effects include temporary blackening of tongue and stools, occasional nausea and constipation, and rarely, ringing in the ears. Bismuth subsalicylate should be avoided by persons with aspirin-allergy, renal insufficiency, gout, and by those who are taking anticoagulants, probenecid, or methotrexate. It is important for the traveler to consult a physician about the use of bismuth subsalicylate, especially in children, adolescents, and pregnancy.
If you do become ill with TD, it is usually self-limited and treatment requires only a simple replacement of fluids and salts lost in diarrheal stools. This is best achieved by use of an oral rehydration solution such as World Health Organization Oral Rehydration Salts (ORS) solution. ORS packets are available at stores or pharmacies in almost all developing countries. ORS is prepared by adding one packet to boiled water or treated water. Packet instructions should be checked carefully to ensure that the salts are added to the correct volume of water. ORS solution should be consumed to discarded within 12 hours if held at room temperature, or 24 hours if refrigerated.
Treatment for mild diarrhea:
Avoid milk, citrus juices and tomato juice for fluid replacement.
Iced drinks and noncarbonated bottled fluids made from water of uncertain quality should be avoided. Dairy products can aggravate diarrhea in some people and should be avoided.
Bismuth subsalicylate preparation (1oz of liquid or two 262.5 mg tablets every 30 minutes for 8 doses) decreased the rate of stooling and shortened the duration of illness in several studies.
If you have bloody diarrhea, severe pain, high fever, and progressive dehydration, you should seek medical care.