In the past week, another 41 people were confirmed infected by Cyclospora parasites in an outbreak traced to Fresh Express salad mix used in salads sold by McDonald’s.

Of the 436 sick people, 20 have had such severe symptoms that they had to be admitted to hospitals, according to this week’s update from the Centers for Disease Control and Prevention. State health departments have not reported any deaths in the 15-state outbreak.

State health officials will likely report additional cases in the weeks to come because there is up to a six-week lag between when a person becomes sick with cyclosporiasis symptoms and when the infection is lab-confirmed and added to the CDC’s count.

To see a larger version of this graphic, please click on the image.

The most recent person confirmed with the parasitic infection became ill on July 20, the CDC reported.  

“Exact date of illness onset is not available for six cases,” according to the update. “Data are preliminary and subject to change. Illnesses that began after June 28 might not have been reported yet…”

The confirmed victims started getting sick on May 20. In the CDC’s July 13 outbreak update, which was the first one to name McDonald’s, the agency reported 61 confirmed infections across seven states.

McDonald’s stopped serving salads made with the Fresh Express product at the implicated restaurants on July 13, according to the Food and Drug Administration’s outbreak report on that date. The FDA did not publicly name Fresh Express as the salad mix supplier until Aug. 1. Officials with the fast food icon reported they have found another supplier. Fresh Express is a subsidiary of Chiquita Brands.

The confirmed outbreak victims range in age from 14 to 91 years old, with a median age of 53. They are from 15 states, but the sick people in Connecticut, Tennessee, and Virginia purchased salads while traveling in Illinois. The Florida patient purchased a salad while traveling in Kentucky, according to the CDC.

Illinois has been hardest hit, reporting 219 confirmed illnesses, followed by Iowa with 95 and Missouri with 52. Other states that have reported outbreak patients are Indiana, Wisconsin, Michigan, Ohio, Minnesota, Nebraska, South Dakota, Montana, North Dakota, Kentucky and West Virginia.

Advice to consumers
Anyone who has eaten a McDonald’s salad and developed symptoms of cyclosporiasis should seek medical attention and tell their doctors about their possible exposure to Cyclospora parasites.

Symptoms usually include 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 may be noted.

Some people who are infected with Cyclospora parasites do not have any symptoms. If not treated, the illness may last from a few days to a month or longer. Symptoms may seem to go away and then return one or more times, making diagnosis difficult.

“The Cyclospora parasite needs time — days to weeks — after being passed in a bowel movement to become infectious for another person,” according to the Food and Drug Administration. “Therefore, it is unlikely that cyclosporiasis is passed directly from one person to another.”

Cyclospora parasites can contaminate foods or beverages, but in the United States they are most often found on fresh produce, according to federal officials.

(To sign up for a free subscription to Food Safety News, click here.)