Background

Cyclosporiasis is an intestinal infection caused by a pathogenic protozoan Cyclospora cayetanensis, It is a single cell parasite that is spread by feces or feces-contaminated food and water. The most common symptom is watery diarrhea. Other symptoms may include nausea, loss of appetite, resulting in weight loss, cramping, bloating and fatigue.
This study was a public health report from the North York Public Health Department describing a 1996 outbreak of Cyclosporiasis.

Methods

The investigation was started by a report for a local physician who treated three family members with diarrhea. The offending organism was identified in stool samples. All three had attended a catered luncheon at a religious institution 11 days earlier. The hostess of the luncheon had contacted 15 guest and learned that many had a similar illness. All of the guests had attended only this luncheon in common. The caterer had prepared the cooked food in an off-sight kitchen. The fresh food was prepared at the institution’s kitchen. There had been a report of the filtration system failure at the mikveh causing the rain water to become brackish around the time of the luncheon. The authors hypothesized that the guest became ill through exposure to the mikveh water.
Everyone attending the luncheon was interviewed regarding symptoms, food and beverage consumption and demographic data. This included 49 guest, 2 relatives and the 4 catering staff. Everyone was asked to supply a stool sample. The authors also attempted to identify all people who used the mikveh during the month prior to the luncheon or two weeks following the luncheon. Employees of the institution and the attached school were also interviewed. Attendance records were examined to look at patterns of student absenteeism in the time period in question. Hosts of other events who worked with the same caterers were contacted and asked about guest illnesses. The environment was investigated. Samples were taken from the kitchen faucets and water traps, the mikveh, the rainwater collection system, the street water main, the institutional plumbing, and the caterer’s kitchen. Food items served at the luncheon were traced back with the health of public health inspectors.

Results

35 of 49 (71%) guests became ill. All age groups (4-76 years) were affected. No one needed to be hospitalized. Incubation for symptoms was 6-13 days after the luncheon. 4 additional people became ill. Two people who ate food that was brought home from the luncheon and 2 of the catering staff. The food source was traced back the strawberry flan that was garnished with fresh berries washed in the kitchen.
Cross contamination was found between the mikveh filtration system and the institution's hot water line.

Discussion

The cluster of food-borne Cyclosporiasis was related to the mikveh filtration system causing contamination of the potable hot water line. It appears to be a human error caused by a plumbing blunder.