Food and Water Precautions and Travelers' Diarrhea
Date last rev'd: July 12, 1996
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.
WATER
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 may be made from unsafe water and should be
avoided. It is safer to drink from an unopened can or bottle than from a container that is
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.
TREATMENT OF WATER
Boiling is the most reliable method to make water safe 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 chemical disinfectants. Adding a pinch of salt or
pouring water from one container to another will improve the taste.
Chemical disinfection 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, 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.
CDC makes no recommendation as to the use of any of the portable filters on the market
due to lack of independently verified results of their efficacy.
As a last resort, if no source of safe drinking water is available, tap water that is
uncomfortably hot to touch may be safer than cold tap water. However, many disease-causing
organisms can survive the usual temperature reached by the hot water in overseas hotels,
and boiling or proper disinfection is still advised.
FOOD
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 that has been cooked and is still hot is
generally safe.
For infants less than 6 months of age, breast feed or give powdered commercial formula
prepared with boiled water.
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.
TRAVELERS' DIARRHEA
The typical symptoms of travelers' diarrhea (TD) are diarrhea, nausea, bloating, urgency,
and malaise. TD usually lasts from 3 to 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, depending on the type of eating establishment the traveler
visits - from low risk in private homes, to high risk for food from street vendors. TD is
slightly more common in young adults than in older people, with no difference between
males and females. TD is usually acquired through ingestion of fecally contaminated food
and water.
The best way to prevent TD is by paying close attention to choice of food and beverage.
CDC does not recommend use of antibiotics to prevent TD because they can cause additional
problems themselves.
Bismuth subsalicylate, taken as an active ingredient in Pepto-Bismol* (2 oz.
4 times daily, or 2 tablets 4 times daily), appears to be 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 travelers' diarrhea, it is usually self-limited and treatment
requires only 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 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 or discarded
within 12 hours if held at room temperature, or 24 hours if held refrigerated.
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 (1 oz of liquid or 2 262.5 mg tablets every 30
minutes for eight doses) decreases the rate of stooling and shortened the duration of
illness in several studies.
Treatment was limited to 48 hours at most, with no more than 8 doses in a 24-hour
period. There is concern about taking, without supervision, large amounts of bismuth
subsalicylate, especially in individuals who may be intolerant to salicylates, who have
renal insufficiency, or who take salicylates for other reasons. Travelers should consult
their physicians before using this or any other medications.
Antidiarrheals, such as Lomotil* or Immodium*, can decrease the
number of diarrheal stools, but can cause complication 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, trimethoprim/sulfamethoxazole (Bactrim™ ,
Septra™ ), and fluoroquinolenes (ciprofloxacin and norfloxacin) may shorten the
length of illness. Consult your physician for prescriptions and dose schedules.
It is important for the traveler to consult a physician about treatment of diarrhea in
children and infants, because some of the drugs mentioned are not recommended for them.
The greatest risk for children and especially infants is dehydration. Dehydration is best
prevented by use of WHO ORS solution in addition to the infant's usual food. ORS packets
are available at stores or pharmacies in almost all developing countries. ORS is prepared
by adding one packet to boiled or treated water. The dehydrated child will drink ORS
avidly; ORS is given ad lib to the child as long as the dehydration persists. The
infant who vomits the ORS will usually keep it down if the ORS is offered by spoon in
frequent small sips. Packet instructions should be checked carefully to ensure that the
salts are added to the correct volume of water. Breast-fed infants should continue nursing
on demand. For bottle-fed infants, full-strength lactose-free or lactose-reduced formulas
should be administered. Older children receiving semi-solid or solid foods should continue
to receive their usual diet during diarrhea. Immediate medical attention is required for
the infant with diarrhea who develops signs of moderate to severe dehydration, bloody
diarrhea, fever in excess of 102° F, or persistent vomiting. While medical attention is
being obtained, the infant should be offered ORS.
Most episodes of TD resolve in a few days. As with all diseases it is best to consult a
physician rather than attempt self-medication, especially for pregnant women and children.
Travelers should seek medical help if diarrhea is severe, bloody, or does not resolve
within a few days, or if it is accompanied by fever and chills, or if the traveler is
unable to keep fluid intake up and becomes dehydrated.
* The use of trade names is for identification only
and does not imply an endorsement by the Public Health Service or the U.S. Department of
Health and Human Services.
Division of Quarantine
National Center for Infectious Diseases
Centers for Disease Control and Prevention
Atlanta, GA
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