Frequently Asked Questions
is Brainerd diarrhea?
Brainerd diarrhea is a syndrome of acute onset of watery diarrhea
( 3 or more loose stools per day) lasting 4 weeks or longer, which
can occur in outbreaks or as sporadic cases. It is named after
Brainerd, Minnesota, the town where the first outbreak occurred
in 1983. Patients typically experience 10-20 episodes per day
of explosive, watery diarrhea, characterized by urgency and often
by fecal incontinence. Accompanying symptoms include gas, mild
abdominal cramping, and fatigue. Nausea, vomiting, and systemic
symptoms such as fever are rare, although many patients experience
slight weight loss.
causes Brainerd diarrhea?
Despite extensive clinical and laboratory investigations, the
cause of Brainerd diarrhea has not yet been identified. Although
it is thought to be an infectious agent, intensive searches for
bacterial, parasitic, and viral pathogens have been unsuccessful
so far. The possibility remains that Brainerd diarrhea is caused
by a chemical toxin, but no such toxin has yet been found.
can Brainerd diarrhea be diagnosed?
Because the etiologic agent is unknown, there is no laboratory
test that can confirm the diagnosis. Brainerd diarrhea should
be suspected in any patient who presents with the acute onset
of nonbloody diarrhea lasting for more than 4 weeks, and for whom
stool cultures and examinations for ova and parasites have been
negative. Care should be taken to exclude other causes of chronic
diarrhea, both infectious and noninfectious (e.g., lymphocytic
colitis, collagenous colitis, tumors, drug reactions). Brainerd
diarrhea is not characterized by any specific laboratory abnormalities.
On colonoscopy, petechiae, aphthous ulcers and erythema may be
observed. Microscopic examination of colonic tissue biopsy specimens
often reveals mild inflammation, with an increased number of lymphocytes,
particularly in the ascending and transverse colon. The stomach
and small intestine generally appear normal.
can Brainerd diarrhea be treated?
There is no known curative treatment for Brainerd diarrhea. A
variety of antimicrobial agents have been tried without success,
including trimethoprim-sulfamethoxazole, ciprofloxacin,
doxycycline, ampicillin, metronidazole, and paromomycin. Neither has there
been any response to steroids or antiinflammatory agents. Approximately
50% of patients report some relief in symptoms with high doses
of opioid antimotility drugs, such as loperamide, diphenoxylate,
there long-term consequences to Brainerd diarrhea?
Brainerd diarrhea is a self-limited illness. Symptoms may last
a year or more, and typically have a waxing and waning course.
Long-term follow-up studies have shown complete resolution in
virtually all patients by the end of 3 years. There have been
no known cases of sequelae or relapse once the illness has completely
common is Brainerd diarrhea?
Seven outbreaks of Brainerd diarrhea have been reported since
1983. Six occurred in the United States, five of which were in
rural settings. One outbreak occurred on a South American cruise
ship based in the Galapagos Islands. The original Brainerd outbreak,
which involved 122 persons, was the largest outbreak. An outbreak
in Henderson County, Illinois, involved 72 persons; the Galapagos
Islands outbreak involved 58. A survey of gastroenterologists
suggested that many patients who are not associated with a recognized
outbreak seek treatment for illness compatible with Brainerd diarrhea.
Further work needs to be done to establish the incidence of sporadic
cases of Brainerd diarrhea.
do people get Brainerd diarrhea?
In the original Brainerd outbreak, raw (unpasteurized) milk was
implicated as the vehicle for disease transmission. Contaminated
and inadequately chlorinated or unboiled water has been identified
as a source of Brainerd diarrhea in several other outbreaks. For
example, illness was strongly associated with drinking untreated
well water in theHenderson County outbreak. Persons who drank
the same water after it was boiled did not get sick. Contaminated
water was also implicated in the Galapagos Island outbreak. The
diarrheal illness does not spread contagiously from one person
to the next.
can a person do to prevent this illness?
Avoiding drinking raw (unpasteurized) milk and water that has
not been properly chlorinated or boiled will help reduce the risk
for Brainerd diarrhea and many other diseases. Once the cause
of Brainerd diarrhea is identified, more specific prevention measures
can be formulated.
is being done about Brainerd diarrhea?
Outbreaks of Brainerd diarrhea have been extensively investigated
by Centers for Disease Control and Prevention and state health
departments. Laboratory investigation continues at CDC to try
to identify the etiologic agent.