A parasitic foodborne illness that causes “explosive” diarrhea is on the rise in the United States, including in the DMV area, where health departments are tracking rising numbers of infections.
As of July 9, cyclosporiasis has caused 843 illnesses and 86 hospitalizations, according to the Centers for Disease Control and Prevention, but the number of cases is likely higher. No death has been reported.
Here’s what to know about the disease and how many cases have been confirmed in Washington, DC, and its neighboring states.
What is cyclosporiasis?
The CDC says cyclosporiasis is caused by a microscopic parasite called Cyclospora catenensis and causes “watery diarrhea with frequent, sometimes explosive, bowel movements.”
Other common symptoms of cyclosporiasis include loss of appetite, weight loss, abdominal cramps/pain, bloating, increased gas, nausea, and fatigue.
The U.S. Food and Drug Administration says, “Cyclospora typically spreads when infected feces contaminates food or water.” “It is unlikely to be transmitted directly from one person to another because the Cyclospora parasite requires time (days to weeks) after a bowel movement to become infectious to another person.”
The CDC says the best ways to prevent cyclosporiasis include washing produce before eating, avoiding untreated water, avoiding contact with human or animal feces, and washing your hands after using the toilet, after changing a diaper, and before handling food.
It’s not clear how food becomes infected with Cyclospora, but health officials say outbreaks so far have been linked to raspberries, basil, cilantro, snow peas and mesclun lettuce.
Cyclosporiasis can be treated with antibiotics, but if left untreated the disease may last for a month or longer.
How many cases of cyclosporiasis are there in Washington DC?
As of July 13, the District of Columbia Department of Health has not reported any cases of cyclosporiasis.
The CDC says cases have been reported in 31 states, including both of D.C.’s neighboring states where the illnesses have occurred.
How many cases of cyclosporiasis are there in Maryland and Virginia?
Health officials said 32 people have been infected with cyclosporiasis in Maryland since May 1.
This is almost double the increase compared to the same period in 2024 and 2025; Maryland reported 19 cases from May 1 to July 7 in 2024, and 18 cases during the same two-plus months in 2025.
Officials have not said where within the state the cases occurred, but MedStar Health told CBS Baltimore that at least one case was in Baltimore.
The Fairfax County Health Department said on July 8 that 10 people in Virginia have been infected with cyclosporiasis. A day later, the CDC reported an increase of 11 to 30 cases in the state since May 1.
States are only required to report cases monthly, but due to the increase in the number of cases, the CDC is now requesting weekly case count updates.