Cyclosporiasis parasitic illnesses increase by dozens in Maryland since May

Maryland is investigating a rise in cases of cyclosporiasis, a parasitic illness linked to severe diarrhea.

The state’s Department of Health has had 32 confirmed cases of cyclosporiasis in 2026, with 28 reported since May 1. MedStar Health said that at least one case was confirmed in Baltimore.

The Centers for Disease Control and Prevention says cyclosporiasis has infected hundreds of people in at least 18 states, and health officials are still trying to pinpoint the source.

A common link for the cases reported from May 1 to July 7 has not been identified, the Maryland Department of Health said.

Maryland health officials say the summer and spring months are when cyclosporiasis cases increase, mainly from May 1 through August 31.

In Maryland, there were 128 confirmed cases in 2025, with 18 reported from May 1, 2025, to July 7, 2025. In 2024, there were 204 confirmed cases in Maryland, with 19 reported between May 1 and July 7.

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Doctors say cyclosporiasis is different from typical food poisoning, and there are symptoms you shouldn’t ignore.

Symptoms include watery diarrhea, stomach cramps, loss of appetite, and extreme fatigue, and they can take about a week to appear -- making it much harder for investigators to trace where the parasite came from.

They also say the parasite changes as it replicates, making it even more difficult to link cases to a single source.

While doctors say washing fresh fruits and vegetables thoroughly can help reduce your risk, if you develop persistent watery diarrhea, they recommend seeing a health care provider, because parasites can be treated with antibiotics.

“A fecal-oral transmission, meaning it comes from stool that then contaminates food sources and then gets into another person’s system,” Dr. Jonathan Thierman, president of Expresscare Urgent Care Centers, explained. “Most typical contaminants are fresh produce, and so they’ve seen it in lettuce, they’ve seen it in berries, I think raspberries is one of the most significant, because it’s the most difficult to wash because there’s a lot of crevices. So it’s these little eggs of these parasites that are very sticky and stick on the surface of produce.”

WJZ is a media partner of The Banner.