Houston doctor warns of seasonal parasite spike tied to popular raw summer foods

HOUSTON - Federal and local health officials are monitoring a seasonal spike of a foodborne parasitic illness that has spread across 17 states, including Texas.

Cyclospora in Texas: CDC tracking cases across the state, US

The Centers for Disease Control and Prevention reports 145 domestic cases of Cyclospora nationwide, resulting in 20 hospitalizations and no deaths. Federal investigators stated there is currently no evidence linking the cases to a single, massive nationwide outbreak. Instead, health experts attribute the spike to a recurring summer pattern typically associated with contaminated fresh produce imported from outside the United States.

In Texas, case numbers currently remain in the low double digits.

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Why you should care:

The microscopic parasite targets the small intestine and is most commonly found on raw food items that do not undergo the cooking process, such as salads, garnishes, and salsas.

"This is caused by food, most commonly fresh food, like raspberries, cilantro, lettuce, fresh basil," said Dr. Linda Yancey, an Infectious Disease Specialist with Memorial Hermann in Houston. "It's killed by cooking, so you tend to see it in things that you're not cooking."

While washing produce under clean, running tap water is recommended, Dr. Yancey warned it does not entirely eliminate the risk. Smooth-skinned fruits like blueberries and grapes are easily cleaned, but parasites can easily lodge inside the complex structural cavities of raspberries and blackberries.

Best cleaning practices 

What you can do:

Yancey warned consumers against using aggressive cleaning methods in the kitchen.

"Definitely do not wash your produce with soap, that's bad for you," Yancey said. "And even those vegetable sprays... they're not effective for getting off parasites."

Delayed reaction

What to look out for:

Symptoms of a Cyclospora infection generally surface about a week after consuming the contaminated food. 

"The illness typically begins with general malaise and flu-like symptoms, followed by abdominal pain, severe bloating, vomiting, and watery diarrhea," Yancey said.

While the vast majority of healthy individuals recover without intervention, the illness can be dangerous for young children and immunocompromised patients, such as individuals undergoing chemotherapy or taking high-dose steroids.

Left untreated, the infection can last up to six weeks and frequently relapses. Yancey urged individuals experiencing prolonged gastrointestinal symptoms for more than a week to bypass retail wellness products and seek traditional medical evaluation.

"The parasite cleanses are pseudoscience. They are people trying to take your money," Yancey said. "Not only do they not remove parasites, they can be bad for your health."

A definitive diagnosis requires a specific stool test explicitly ordered by a physician, as standard hospital routine cultures do not screen for the parasite. Once identified, the illness is easily treated and cured with common prescription sulfa drugs, Yancey stated.