| Clinical Features |
Profuse and chronic watery diarrhea typically associated with urgency and incontinence that begins acutely and lasts from 2-36 months. |
| Etiologic Agent |
Unknown. |
| Incidence |
An estimated 5,000-8,000 patients with chronic diarrhea clinically similar to Brainerd diarrhea are cared for by U.S. gastroenterologists each year. Approximately every 3 years, CDC investigates an outbreak of Brainerd diarrhea affecting 50-100 people. |
| Sequelae |
No known sequelae; however, many people suffer adverse psychologic consequences related to the long duration of an incapacitating illness. |
| Transmission |
Untreated water has been implicated in several outbreaks and unpasteurized cow's milk has been implicated in one. |
| Risk Groups |
The elderly appear to be at greatest risk for Brainerd diarrhea, although several cases among children and young adults have been described. |
| Surveillance |
No surveillance system exists for Brainerd diarrhea or for other chronic diarrheal syndromes of unknown etiology (e.g., collagenous colitis, microscopic colitis). |
| Trends |
Data are insufficient to indicate an increase or decrease in incidence. |
| Challenges |
Despite numerous intensive laboratory investigations, the etiologic agent of Brainerd diarrhea remains a mystery. Histologic criteria for distinguishing Brainerd diarrhea from other chronic diarrheal syndromes were developed from outbreak-related specimens, but need to be evaluated in specimens from patients with sporadic cases of chronic idiopathic secretory diarrhea. |
| Opportunities |
Newer techniques, such as ribosomal RNA amplification on sterile site tissue biopsies may shed new light on the etiologic agent. The histologic criteria can be tested against specimens from a recent outbreak. |
