standards are less stringent than those in their home area.
Drinking water contaminated with feces or eating foods
prepared with contaminated water often causes the dis-
ease. This includes fruit and salad vegetables that have
been washed in contaminatedwater. The organisms caus-
ing traveler’s diarrhea can also be transferred to food by
food handlers who have washed their hands in contami-
nated water or are infected. Eating raw or undercooked
meat and seafood can also cause symptoms of traveler’s
diarrhea. Eating food bought from street vendors
increases the chances of getting sick with traveler’s diar-
rhea. In high-risk countries, eating in restaurants is no
guarantee that conditions are sanitary and that the food
will not be contaminated.
Many different organisms can cause traveler’s
diarrhea. According to the United States Centers for
Disease Control (CDC), about 85% of all cases are
caused by bacteria. Another 10% are caused by para-
sites, and the remaining 5% by viruses. In practical
terms, this means that no single treatment will cure
every case of traveler’s diarrhea.
Symptoms of traveler’s diarrhea caused by bacte-
ria—nausea, diarrhea, abdominal cramps, and some-
times vomiting and fever— come on suddenly, most
often during the first week of travel. The most com-
mon cause of traveler’s diarrhea is infection with the
bacteriaEnterotoxigenic Escherichia coli(ETEC).E.
coliare a larger genus of bacteria many of which are
found in the intestines of mammals. Some subtypes of
E. coliare helpful. In humans they help with digestion
and the absorption of nutrients in the intestines. Many
other subtypes ofE. coliare neither helpful nor harm-
ful. Some, such as ETEC andEnteroaggregative E. coli
(EAEC), can cause unpleasant digestive upset. Both
these types of E. coli cause watery diarrhea and
abdominal cramps but little or no fever.
Campylobacterare a genus of bacteria that are a
more common cause of traveler’s diarrhea in Asia than
in other parts of the world. Some members of this
genus cause bloody diarrhea and fever.Campylobacter
bacteria are found in contaminated water, but they are
also found in almost all raw poultry, even in developed
countries such as the United States and Canada.
Cooked food can be contaminated if it is placed on
an unwashed surface that previously held raw poultry.
Shigellaare another common genus of bacteria that,
like Campylobactercause bloody diarrhea, nausea,
vomiting, fever, and abdominal cramps.
Giardia lambiais the most common parasite to
cause traveler’s diarrhea. Symptoms of traveler’s diar-
rhea caused by parasites take longer to appear than do
symptoms caused by bacterial or viral infections.
Often symptoms persist for several weeks, much lon-
ger than the 3–5 days that most bacteria-caused trav-
eler’s diarrhea lasts.
Viruses cause only a small amount of traveler’s
diarrhea, although they are the largest cause of gastro-
intestinal upsets in the United States and other indus-
trialized countries. Their symptoms are similar to
those caused by bacterial infections.
The main symptom of traveler’s diarrhea is frequent
loose, watery stools that begin fairly abruptly. Stools
may or may not contain blood, depending on the organ-
ism causing the disease. Diarrhea may lead todehydra-
tion. Other common symptoms that appear along with
the diarrhea are nausea, vomiting (in about 15% of
people), bloating, abdominal cramps, and fever. Trav-
eler’s diarrhea usually lasts only 3–5 days even without
treatment except for disease caused by parasites, which
tends begin more slowly and to linger longer.Diagnosis
Diagnosis is made on the basis of signs and symp-
toms. Laboratory tests are usually not done unless
there are unexpected complications.TreatmentIn addition to drinking fluids, over-the-counter
medications such as bismuth subsalicylate (Pepto-
Bismol) and loperamide (Imodium) help give the
individual more control over their bowel movements.
However, these medications should not be used if by
people who have blood in their stool or who have a
high fever and bismuth subsalicylate should not be
used by people allergic to aspirin.
Although bacteria cause most traveler’s diarrhea,
antibiotics are not usually prescribed to prevent the
disease. They may, however, be used to treat traveler’s
diarrhea. The specific antibiotic depends on symptoms
such as whether the stool is bloody and whether diarrhea
is accompanied by fever or vomiting. Ciprofloxacin
(Cipro), azithromycin (Zithromax) and rifaximin
(Xifaxan) are the antibiotics most often prescribed.
Medical care may be difficult to obtain in underdevel-
oped countries. Depending on where they plan to travel,
individuals may want to discuss the possibility of trav-
eler’s diarrhea with theirdoctor before leaving home and
take along a supply of antibiotics, over-the-counter med-
ications, and oral rehydration salts to be used as needed.
Although most traveler’s diarrhea clears up
within a few days, medical care should be sought if
severe symptoms continue for more than two or three
days, if a high fever develops, if there is blood in theTraveler’s diarrhea