Cyclosporiasis: What to know about the diarrhea outbreak, Taco Bell and California

One of the nation’s largest outbreaks in years of the parasitic infection cyclosporiasis has sickened people in 31 states, and the latest development involves Taco Bell.

A surge in cases began in mid-June, the Centers for Disease Control and Prevention said. Its count of confirmed U.S. cases was 843 as of July 9, but public health officials in Michigan alone — the hardest-hit state — said they had recorded more than 2,600.

Here’s what to know about it.

What is the disease?

The parasite cyclospora causes a gastrointestinal ailment whose principal symptom is watery diarrhea “with frequent and sometimes explosive bowel movements,” the CDC says. It is rarely life-threatening — no deaths have been tied to the current outbreak — and can be treated with antibiotics.

It is most commonly spread by consumption of fruits or vegetables that are tainted by feces-contaminated irrigation water.

Is it in California?

Last week’s CDC update put California among the states that have one to 10 confirmed cases.

What’s the Taco Bell connection?

Last week some Taco Bells in the Detroit area stopped using certain produce ingredients — lettuce, cilantro, onion, pico de gallo and guacamole — and on Tuesday the Washington Post reported that federal and state health officials are examining the fast-food chain’s possible role in the outbreak.

No specific food item or supplier has been definitively linked to the outbreak, but a public statement Monday from Michigan’s health department said “current results point to lettuce or salad greens as a potential source for this outbreak.”

Is this worse than a normal year?

As of last week, the Associated Press reported, CDC data showed a case total four times higher than on the same date last year — and that was without including the hundreds of cases reported by state public health agencies that the CDC has not confirmed.

The CDC noted that there is significant underreporting of cyclosporiasis. Many infected people endure the symptoms without seeking medical treatment.

The Associated Press said available information shows only a small number of documented outbreaks in the last 20 years that have surpassed 1,000 cases. One of the most recent was a 2019 outbreak linked to Mexican basil that sickened more than 2,400 people.

What precautions can be taken?

Fresh produce should be thoroughly washed in running water, and fruits and vegetables with firm rinds should be scrubbed. Wash your hands with soap and water before and after handling produce.

Michigan public health officials have advised buying heads of lettuce rather than bagged salad mixes and discarding the outer two or three layers of leaves before washing the lettuce.