An Outbreak of a Newly Recognized Chronic Diarrhea Syndrome Associated With Raw Milk Consumption

Abstract

A previously undescribed chronic diarrhea syndrome affected 122 residents of Brainerd, Minn, between December 1983 and July 1984. The illness lasted at least one year for 75% of case-patients and was characterized by acute onset, marked urgency, a lack of systemic symptoms, and a failure of response to antimicrobial agents. Clinical and laboratory data indicate that the diarrhea was caused by a secretory mechanism. Consumption of raw milk from a single dairy was associated with illness (odds ratio, 28.3; 95% confidence interval, 9.0 to 89.0). A median incubation period of 15 days was determined for seven case-patients. Possible secondary transmission was noted in one family. Extensive laboratory examination did not identify an etiologic agent. Outbreaks or sporadic cases of a similar illness have occurred in at least seven states; the outbreaks were less extensively investigated and findings were not published, but raw milk consumption was common in the affected persons. This illness appears to represent a previously unrecognized but important clinical entity and public health problem. The etiology and effective therapy for this illness must be determined by further studies of sporadic cases and outbreaks.

Clinical Practice: Milk of Nonhuman Origin and Infectious Diseases in Humans

“…A diarrhea syndrome (later named Brainerd diarrhea) occurred among 122 residents of Brainerd, Minnesota, during the period December 1983-July 1984 [33]. It was characterized by acute onset, marked urgency, lack of systemic symptoms, failure to respond to conventional antimicrobial agents, and a long median duration of illness (median duration, 16.5 months).…”

“…It was characterized by acute onset, marked urgency, lack of systemic symptoms, failure to respond to conventional antimicrobial agents, and a long median duration of illness (median duration, 16.5 months). The syndrome was linked to consumption of raw milk from a single dairy [33]. No etiologic agent was ever isolated.…”

“…No etiologic agent was ever isolated. The outbreak of Brainerd diarrhea stopped when all of the dairy's output was diverted and pasteurized [33] (M. T. Osterholm, personal communication). Subsequent outbreaks in Illinois and Texas were not directly associated with milk, although cattle had been in the vicinity of an Illinois well that had its water implicated as a vehicle of transmission [34].…”

A National Outbreak ofSalmonella enteritidisInfections from Ice Cream

“…Our experience in Minnesota has repeatedly demonstrated the power of the case-control study to identify a contaminated vehicle in the absence of supporting laboratory evidence. 4,[13][14][15][16][17][18][19][20][21][22][23][24][25] The highest level of product contamination documented in this outbreak was only six organisms per half-cup (65-g) serving of ice cream. Prior reports of outbreaks of salmonellosis have suggested the presence of similarly low levels of contamination.…”

Deaths due to Unknown Foodborne Agents

“…The other reports described three distinctive illnesses, but two of the illnesses did not lead to any deaths and therefore appeared to be nonfatal ( 6 , 8 , 10 ). Brainerd diarrhea, the best known example of an illness caused by an unknown foodborne agent, also appears to be nonfatal ( 12 ). …”