GASTROINTESTINAL DISORDERS - Medicine for Mountaineering and Other Wilderness Activities - page 251

Infectionisusuallyspreadbyfecalcontaminationofwaterorfoodandismorecommon
in countries with inadequate sewage disposal and water disinfection. However, the illness
may be contracted anywhere.
Traveler's diarrhea can be prevented in several ways. Avoiding infection is clearly best
but is not always easy. Water is the major source of infection. In developing countries,
even in modern hotels, tap water is usually contaminated and must be disinfected before
being consumed or even used just for brushing teeth. (Many of the better—and more ex-
pensive—hotels provide bottled water for drinking and brushing teeth.) However, some of
these hotels serve drinks containing ice prepared from undisinfected water. Beer, bottled
soft drinks, and bottled carbonated water are safe. Bottled noncarbonated water usually is
safe, but some unscrupulous street vendors refill bottles with undisinfected water.
Bringing water to a boil, regardless of altitude, kills all organisms that cause diarrheal
diseases. Most are destroyed by appropriate exposure to iodine or chlorine. Unfortunately,
Cryptosporidia and possibly Cyclospora , two diarrhea-producing parasitic infestations re-
cognized in the last twenty-five years, are resistant to chlorine and iodine and must be re-
moved by filtration ( Chapter 6: Sanitation, Arthropod Avoidance , and Water Disinfection).
Infectious bacteria may survive well in food stored in a refrigerator, at room temperature,
and even at temperatures too hot to touch comfortably. Food and beverages are safe only if
they have been brought to boiling or near boiling temperatures prior to consumption.
Previously peeled fruits and salads containing leafy vegetables are well-recognized
sources of infection. Fruits with a protective rind that is not eaten are generally safe, but
such fruits split open for display in markets are often splashed with undisinfected water so
they will remain attractive. Melons sold by the pound are often injected with undisinfec-
ted water to increase the weight. All fruits and vegetables should be thoroughly washed in
disinfected water and peeled by the consumer. Contamination of food during preparation
mustbeavoided.Modernconceptsofsanitation,evensuchsimplemeasuresashandwash-
ing after defecation, are totally alien to many natives of developing countries. They must
bemonitoredtoensuretheywashbeforepreparingfood.Stoolculturestodetectcarriersof
infectious diseases are desirable for the native personnel in large parties, particularly those
engaged in preparing meals, but are essentially impossible to obtain. Disinfection of wa-
ter used for food preparation as well as for drinking may be necessary. Unfortunately, such
precautions are not universally effective and are difficult to sustain for a prolonged time.
The incubation period for traveler's diarrhea is usually twelve to forty-eight hours, and
the disorder usually lasts two to five days. The onset is characterized by rapidly develop-
ing generalized abdominal distress culminating in waves of cramps and diarrhea. During
spasms of pain, infected individuals may draw their knees up against the abdomen for re-
lief. However, the periods between spasms are relatively free of pain. Nausea is common
andmaybeaccompaniedbyvomiting.Occasionallynauseaandvomitingarethedominant
features of the illness.