Parasitic Stomach Bug Cases Likely to Continue Through August, CDC Says

The CDC is now investigating multiple clusters of Cyclospora cases, including a multistate outbreak that’s been linked to iceberg lettuce served at Taco Bell.

“This is much higher than what we’ve seen last year or the year before,” said Gwen Biggerstaff, ScD, deputy director of CDC’s Division of Foodborne, Waterborne, and Environmental Diseases, in a press conference on July 21. “We anticipate continuing to see cases increase, possibly through the end of August, which is the end of the cyclosporiasis season.”

How Cyclosporiasis Spreads

While the current case count is high, cyclosporiasis infections are common this time of year, according to public health officials.

“Outbreaks commonly occur between May and August,” says Robert H. Hopkins, MD, the medical director of the National Foundation for Infectious Diseases.

During these late spring and summer months, people tend to eat more fresh fruits and raw vegetables that may carry the parasite responsible for the illness.

• Parsley
• Cilantro
• Basil
• Mesclun lettuce
• Raspberries
• Snow peas

How the Cyclospora Parasite Causes Illness

When swallowed, the parasites burrow into the lining of the small intestines and reproduce, says Peter Chin-Hong, MD, an infectious disease specialist and a professor of medicine at the University of California San Francisco School of Medicine.

“The lining of the small intestine gets destroyed, and as a result, loses its ability to effectively absorb water and nutrients from food,” he says.

The gut may also mount an immune response to the parasites, triggering inflammation and swelling.

“The end result is that a large volume of unabsorbed water rushes through the intestine,” says Dr. Chin-Hong. “This leads to sudden and forceful high-volume diarrhea that has been described as ‘explosive.’”

Symptoms and Treatment for Cyclosporiasis

• Frequent watery diarrhea
• Loss of appetite
• Weight loss
• Stomach cramps and bloating
• Nausea (vomiting is less common)
• Low-grade fever

Cyclosporiasis is not usually life-threatening, and most people typically feel better within a week or two.

Dehydration is a major concern with frequent diarrhea; in severe cases, it can lead to hospitalization, so it’s important to get plenty of fluids if you’re sick.

Anyone experiencing gastrointestinal illness, such as sudden and ongoing diarrhea, should contact their healthcare provider as soon as possible. Your provider can diagnose cyclosporiasis by testing a stool sample.

Dr. Hopkins notes that individuals at the highest risk of severe and prolonged diarrhea include young children, the elderly, and those who are immunocompromised, such as people with advanced HIV, organ transplant recipients, and cancer patients.

How to Protect Yourself Against Cyclosporiasis

Health authorities recommend:

• Wash your hands before and after preparing food.
• Wash all fruits and vegetables thoroughly under running water before eating, cutting, and cooking.
• Scrub firm fruits and vegetables, such as melons and cucumbers, with a clean produce brush.
• Cut away any damaged or bruised areas on fruits and vegetables before preparing and eating. Remove outer leaves of lettuce and cabbage.