What you don’t see CAN hurt you


More than 500 customers of McDonalds have become infected with a nasty little parasite that goes by the name Cyclospora. Twenty-four people have been hospitalized, according to CDC.

Cyclospora is a single-cell, microscopic parasite that is transmitted through contaminated food or water. The most common symptom of infection is watery diarrhea. Other symptoms may include loss of appetite, weight loss, cramping, bloating, increased gas, nausea, vomiting, low-grade fever and fatigue.

Symptoms appear, on average, 7 days following initial infection (incubation period ranges from 2 days to more than 2 weeks) and can persist for several weeks. Cyclospora infections are not usually life-threatening.

outbreak_mapMC_8.23.18
Geographic distribution, courtesy of CDC

Confirmed cases have been reported by fifteen states and by New York City (which boasts a larger population that many of the states). Consumers in Connecticut, Florida, Iowa, Illinois, Indiana, Kentucky, Michigan, Minnesota, Missouri, Nebraska, Ohio, South Dakota, Tennessee, Virginia, Wisconsin, and New York City.

According to CDC, the largest numbers of illnesses occurred in Illinois (273), Iowa (99) and Missouri (52). Multiple cases also were reported in neighboring states. Outbreak victims in Connecticut, New York City, Tennessee, and Virginia purchased salads while traveling in Illinois; the Florida patient purchased a salad while traveling in Kentucky.

Most of the reported cases materialized in late June and early July.

The parasite was recovered from a packaged romaine lettuce/carrot mix supplied to the restaurant chain by Fresh Express.  The investigation is ongoing and FDA is currently reviewing distribution and supplier information for both the romaine and the carrots.

FDA offers the following suggestions for restaurants, food service facilities and consumers.

What Do Restaurants and Retailers Need To Do?

Based on current information available Cyclospora may be resistant to routine chemical disinfection methods such as those using chlorine. However, restaurants and retailers should still follow basic food safety practices:

  • Retailers, restaurants, and other food service operators should always practice safe food handling and preparation measures. It is recommended that they wash hands, utensils, and surfaces with hot, soapy water before and after handling food. Wash and sanitize display cases and refrigerators where potentially contaminated products were stored.
  • Wash and sanitize cutting boards, surfaces, and utensils used to prepare, serve, or store potentially contaminated products.
  • Wash hands with warm water and soap following the cleaning and sanitation process.
  • Regular frequent cleaning and sanitizing of food contact surfaces and utensils used in food preparation may help to minimize the likelihood of cross-contamination.

What Do Consumers Need To Do?

Consumers who have symptoms of cyclosporiasis should contact their health care provider to report their symptoms and receive care. Most people infected with Cyclospora develop diarrhea, with frequent, sometimes explosive, bowel movements. Other common symptoms include loss of appetite, weight loss, stomach cramps/pain, bloating, increased gas, nausea, and fatigue. Vomiting, body aches, headache, fever, and other flu-like symptoms (relapse).