Cyclospora cases top 1,000 nationwide as parasitic illness reaches Alaska

While Alaska has seen only a handful of cases so far, the state appears on the Centers for Disease Control and Prevention’s surveillance map, which shows between one and 10 domestically acquired cases reported this season. The outbreak has been far more severe in parts of the Midwest, particularly Michigan and Ohio, but health officials expect additional cases to be identified throughout the summer as investigations continue.

The CDC’s latest update, released July 9, reports 843 confirmed domestically acquired cases in 31 states since May 1, along with 86 hospitalizations and no deaths. Federal officials say they are also aware of more than 1,500 additional suspected cases that are still undergoing confirmation and classification, meaning the true number of illnesses is substantially higher than the official confirmed count.

An additional 343 travel-associated cases have been reported from people who became ill after consuming contaminated food or water while traveling outside the United States. Those cases have been reported by 32 states, resulted in 18 hospitalizations, and likewise have caused no deaths.

Cyclosporiasis is caused by the microscopic parasite Cyclospora cayetanensis. Unlike many gastrointestinal illnesses, it is not spread from person to person. Instead, people become infected by consuming contaminated food or water, most commonly fresh produce such as leafy greens, herbs, berries, peas, or other fruits and vegetables that have been exposed to contaminated water or human waste. Investigators have not yet identified a single food source responsible for this year’s outbreak.

The illness typically develops about a week after exposure. Symptoms include watery diarrhea, stomach cramps, fatigue, nausea, bloating, loss of appetite, and weight loss. Without treatment, symptoms can persist for weeks or even recur after temporarily improving. Severe or prolonged infections are generally treated with antibiotics.

It is not contagious from person to person. Transmission occurs only when someone ingests food or water contaminated with feces containing the parasite’s oocysts.

Because no common source has yet been identified, health professionals recommend taking routine food safety precautions. Produce should be thoroughly washed under clean running water before eating, even if labeled “pre-washed.” Firm fruits and vegetables should be scrubbed with a clean produce brush when appropriate.

Health experts note that soaking produce in vinegar or baking soda has not been shown to reliably eliminate the parasite.

Anyone who develops persistent watery diarrhea lasting more than a few days, particularly after eating fresh produce, should contact a healthcare provider. Stool testing can confirm the infection, and prompt treatment may shorten the illness and prevent dehydration.

Although Alaska’s case count remains low, the state’s inclusion in the nationwide outbreak may mean public health officials expect additional cases to be reported here and elsewhere before the outbreak subsides.

Find out more about this parasite at the CDC.