U.S. Cyclosporiasis Cases Near 7,000 With Michigan Reporting Over 3,300

Nearly 7,000 potential cases of cyclosporiasis have been recorded across the United States, with more than 3,300 reported in Michigan alone as of Tuesday. State officials identified tainted lettuce as the likely source of the outbreak. The actual number of infections is believed to be substantially higher.

Most people do not seek medical care for diarrhea, and standard laboratory panels do not test for the parasite.

Jeanne Marrazzo, CEO of the Infectious Diseases Society of America, estimated that reported cases are at least double the Centers for Disease Control and Prevention's figures. She cited both underdiagnosis and mild cases that go unreported. Cyclosporiasis is not included in routine gastrointestinal testing panels.

The infection produces prolonged diarrhea that can last days or weeks, according to Marrazzo.

Public health officials have advised thorough washing of produce. Taco Bell stated it had voluntarily and temporarily removed limited ingredients at select restaurants as a precautionary measure. Norman Beatty, associate professor at the University of Florida, said the parasite resists bleach and common commercial sanitizers.

Cooking destroys the organism, but lettuce and berries are typically eaten raw.

Bill Marler, a lawyer specializing in food-poisoning cases, said most historical cyclosporiasis outbreaks have been linked to imported produce. Domestic outbreaks have occurred in the past decade, including one tied to bagged lettuce from an Illinois facility.

Marler noted that once the parasite enters the water supply used for crop irrigation, contamination can spread across large volumes of produce. The organism is also resistant to chlorine used in municipal water treatment. Beatty said the outbreak demonstrates how quickly an organism can move through national food-distribution networks and could eventually be reported in all 50 states.