CDC HEALTH ADVISORY
MARCH 08, 2004

Outbreak of Cyclosporiasis Among Conference Participants

The Centers for Disease Control and Prevention (CDC) has been notified of an outbreak of gastroenteritis caused by the parasite Cyclospora cayetanensis .

The outbreak is associated with a conference held February 6-8 at a hotel in Irving (near Dallas), Texas. The conference was attended by ~40 persons from ~16 states. The meals eaten by the group were catered by the hotel, with the exception of one meal eaten at a local restaurant.

O n February 27th, a State health department reported a laboratory-confirmed case of Cyclospora cayetanensis infection in a conference attendee to staff of the Division of Parasitic Diseases (DPD), NCID, CDC. On March 4, DPD laboratory staff confirmed the case, by examining the patient's stool specimen. This patient developed gastroenteritis approximately 1 week after the conference. Initial investigations suggest that at least 16-19 persons became ill; one person is known to have been hospitalized. Active case-finding is ongoing.

The outbreak may not be limited to persons who attended this conference. Although no food item has been implicated to date, a contaminated "vehicle" might have was distributed to other states/localities. Previous foodborne outbreaks of cyclosporiasis have been linked to various types of fresh produce (e.g., basil, mesclun lettuce, raspberries). Clinicians evaluating persons with symptoms consistent with cyclosporiasis (see below) should specifically request stool testing for Cyclospora (most laboratories do not do such testing unless it is requested). 

Disease Symptoms and Characteristics

Cyclospora is spread by people ingesting something (e.g. water or food) that was contaminated with infected stool.  Cyclospora needs time (days or weeks) after being excreted in stool into the environment to become infectious. Therefore, it is unlikely that Cyclospora is passed directly from one person to another.

The incubation period between acquisition of infection and onset of symptoms averages 1 week. Cyclospora infects the small intestine and typically causes watery diarrhea, with frequent, sometimes explosive, bowel movements. Other symptoms can include loss of appetite, substantial loss of weight, bloating, increased flatus, stomach cramps, nausea, vomiting, muscle aches, low-grade fever, and fatigue. If untreated , illness may last for a few days to a month or longer, and may follow a remitting-relapsing course. Some infected persons are asymptomatic.

Treatment Protocol

Trimethoprim/sulfamethoxazole (TMP/SMX, or Bactrim*, Septra*, or Cotrim*) has been shown in a placebo-controlled trial to be effective treatment for Cyclospora infection. Adults should receive TMP 160 mg plus SMX 800 mg (one double-strength tablet) orally twice a day for 7 days. Children should receive 5 mg/kg of the TMP (25 mg/kg of SMX) twice a day for 7 days. Some patients may require longer courses of therapy. Patients with AIDS may need higher doses of trimethoprim/sulfamethoxazole and long-term maintenance treatment.

Reporting:

Healthcare providers and laboratory staff should report suspect and confirmed cases of cyclosporiasis to their local and State health departments. State Health Departments should report cases to DPD/CDC:

EISO: Adria Prosser (770-488-4520; aprosser@cdc.gov )

Epidemiologic associate: Michele Hlavsa (770-488-7319; mhlavsa@cdc.gov )

Medical epidemiologist:  Barbara Herwaldt (770-488-7772; bherwaldt@cdc.gov )

For more information on cyclosporiasis see: http://www.cdc.gov/ncidod/dpd/parasites/cyclospora/default.htm

http://www.dpd.cdc.gov/dpdx/

Categories of CDC Health Alert messages:
Health Alert: conveys the highest level of importance; warrants immediate action or attention.
Health Advisory: provides important information for a specific incident or situation; may not require immediate action.
Health Update: provides updated information regarding an incident or situation; unlikely to require immediate action.

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