GASTROINTESTINAL DISORDERS - Medicine for Mountaineering and Other Wilderness Activities - page 258

typically about two weeks, but may recrudesce. Infective cysts may be shed for a longer
time.
Cyclosporiasis
Cyclospora cayetanensis is a parasite first reported in New Guinea in 1977 and found
in New York and Peru in 1985. Among the names it was given is blue-green algae. Cyc-
losporiasis has now been reported from all over the world. This organism gained notoriety
in the United States in 1996 when 1465 infections were reported to the CDC. Investiga-
tion clearly indicated that most of the infections were related to raspberries shipped from
Guatemala.
Waterborne outbreaks have also occurred. In Nepal in 1992, twelve of fourteen British
soldiers were infected by Cyclospora in their drinking water. The water had been chlorin-
ated, which suggests that Cyclospora , like Cryptosporidia , may be halide resistant.
Cyclospora involve the small intestine and are capable of completing their entire life
cycle within a single host. However, infected individuals excrete cysts that require days to
weeks to become infectious. As a result, direct human-to-human transmission of infection
is unlikely. Humans are the only identified host for this parasite.
Infection typically causes watery diarrhea with frequent, sometimes explosive, stools.
Other symptoms can include loss of appetite and substantial weight loss; bloating and in-
creased flatus; cramps, nausea, and vomiting; and muscle aches, low-grade fever, and fa-
tigue. Untreated illness may last for a few days to a month or longer and may follow a
remitting-relapsing course. As would be expected, some infected individuals are asympto-
matic. Diagnosis is dependent upon identifying the organism in stool.
Trimethoprim-sulfamethoxazole (TMP-SMX, trade names Bactrim or Septra®) is ef-
fective treatment. No alternative drugs for individuals who are intolerant of TMP-SMX
have been identified.
Irritable Bowel Syndrome
Irritable bowel syndrome (IBS), previously known as mucus colitis or spastic colon, is
a common disturbance of large intestinal function that may result in diarrhea, constipation,
or both. The syndrome is at least partially emotional in origin and is often related to stress
in susceptible persons. Most individuals with this disorder have had a history of similar
symptoms for many years. New onset during a wilderness outing would be very unusual
and should not be considered.
Abdominal pain relieved by defecation, looser stools at pain onset, more frequent stools
at pain onset, abdominal distension, and the passage of mucus are commonly associated
with this condition. Stools may be thin and tapered (pencil shaped).
Recognizing the nature of the disorder and reassuring the person are important aspects
oftreatment.Inindividualswithconstipation,ahigh-fiberdiet,possiblysupplementedwith