Confirmed cases of cyclosporiasis had reached 110 in Maryland as of Tuesday, up from 69 just a week ago, state health officials said, part of a nationwide surge in the gastrointestinal illness that causes nausea, fatigue, bloating and severe diarrhea.
Nationally there were 4,173 cases reported in 41 states through Tuesday, more than doubling the 1,645 cases that had been confirmed in 34 states last week, according to the latest data from the Centers for Disease Control and Prevention.
The CDC said that in addition to the number of laboratory-confirmed cases, there were another 7,400 cases reported nationwide that are awaiting laboratory confirmation. The highest concentration of cases has been recorded in Midwestern states, with Michigan leading all stages.
The Maryland Department of Health said that 106 of the in-state cases had been recorded since May 1. In Maryland, 27 of the cases were contracted domestically, 47 were acquired internationally and 36 are still being investigated, according to a statement Wednesday from the state Health Department.
Cyclosporiasis is a foodborne illness caused by a microscopic parasite called cyclospora, according to the CDC. People can contract cyclosporiasis if they ingest food or water that contains the parasite.
“Symptoms appear about 1 to 14 days–usually a week–after eating contaminated food or drinking contaminated water,” a statement from the Maryland Health Department said. “The most common symptom is watery diarrhea with frequent, sometimes explosive, bowel movements.”
Dr. Cynthia Sears, a professor of medicine in John Hopkins University’s infectious diseases division, said people should seek treatment if they are experiencing these symptoms for more than a few days or if the symptoms become particularly severe.
The parasite typically sticks to crevices in food, which can make foods like berries, lettuce and herbs potential sources of contamination, according to Sears.
The CDC is investigating multiple clusters of cyclosporiasis around the country, and has traced at least one outbreak to contaminated iceberg lettuce.
Food and Drug Administration regulators have linked one outbreak to Taylor Farms iceberg lettuce from central Mexico, that is sold in groceries and served at some restaurants. The FDA announced Sunday that its test of Taylor Farms lettuce turned out to be a false positive. But the company still issued a voluntarily recall of iceberg lettuce sourced from central Mexico on July 17, and the FDA said in a post on X that it still recommends avoiding iceberg lettuce grown in Mexico for Taylor Farms.
Sears said people should take a few extra precautions while the outbreak progresses, including avoiding lettuce that has been recalled. If you choose to eat lettuce, she recommends buying locally sourced products and thoroughly cleaning all fresh produce. She also said that food that has been cooked is not as likely to transmit the parasite, which is heat sensitive.
“All lettuce at this point should be thoroughly washed under running water,” Sears said. “If possible, you should remove the outer layer of the lettuce because that’s the most likely to be contaminated, and discard that. Anything that says it’s pre-washed should be re-washed right now.”
Sears noted that there is a common antibiotic that can be used to treat cyclosporiasis, and that most healthy people can recover from the illness without treatment, but they will experience symptoms for longer.
But, Sears said people who are immunocompromised should take some more precautions to avoid cyclosporiasis because they may not respond as promptly to therapy. She also stressed that it is very important for anyone diagnosed with cyclosporiasis to stay hydrated, and should seek medical care if they are having trouble doing so.
While cases of cyclosporiasis typically increase during the warmer months, Sears said the unusually high number of illnesses this season is what makes the current outbreak noteworthy.
“[Foodborn illnesses] are very common,” Sears said. “So I wouldn’t be fearful, I’d just be cautious, especially given that we have at least a hint of where this outbreak comes from.”
— Shalina Chatlani of Stateline contributed to this report.