Maryland health officials are investigating an increase in Cyclosporiasis cases as hundreds of infections involving the intestinal parasite are reported across the United States.
The Maryland Department of Health confirmed 32 cases in the state during 2026. Health officials said investigators have not identified a common source connecting the Maryland cases.
Cyclosporiasis is an intestinal infection caused by the microscopic parasite Cyclospora Cayetanensis. People generally become infected after eating food or drinking water contaminated with feces containing the parasite. The illness is unlikely to spread directly from one person to another because the parasite must remain in the environment for days or weeks after leaving the body before it becomes infectious.
Cases are most commonly identified during the spring and summer. Federal health officials consider May 1 through August 31 the primary Cyclosporiasis season in the United States.
As of July 9, the Centers for Disease Control and Prevention had received reports of 843 domestically acquired cases across 31 states. At least 86 patients were hospitalized, and no deaths had been reported. The CDC was also reviewing more than 1,500 additional illnesses to determine whether they qualified as domestically acquired Cyclosporiasis cases.
The federal total does not include another 343 infections involving people who became sick after traveling outside the United States.
Several clusters are being investigated by local, state and federal health agencies. However, authorities have not identified one food item or source responsible for all illnesses, and no nationwide recall has been announced in connection with the overall increase.
Foodborne outbreaks involving Cyclospora have previously been associated with fresh produce. Investigators often have difficulty identifying the source because symptoms may not begin until approximately one week after contaminated food or water was consumed.
Symptoms of Cyclosporiasis
The most common symptom is frequent watery diarrhea. Other symptoms can include:
- Frequent or sometimes explosive bowel movements
- Stomach cramps
- Loss of appetite
- Substantial weight loss
- Extreme fatigue
- Gas and bloating
- Nausea or vomiting
- Low-grade fever
Symptoms typically begin one to 14 days after exposure, with most people becoming sick after approximately one week. Symptoms may disappear and then return. Without treatment, the illness can continue for several weeks or longer.
People with weakened immune systems may experience a longer or more severe illness.
Anyone experiencing persistent or severe diarrhea should contact a healthcare provider. Patients should tell their provider about recent travel and foods eaten before symptoms began.
Testing can require a specific request because many laboratories do not routinely screen stool samples for Cyclospora. A patient may also need to provide more than one stool sample before the parasite is detected.
Cyclosporiasis is commonly treated with the prescription antibiotic trimethoprim-sulfamethoxazole, also known as TMP-SMX. People who are allergic to sulfa medications should discuss other options with their healthcare provider.
Reducing the Risk of Infection
Health officials recommend washing hands with soap and water before and after preparing food and thoroughly rinsing fruits and vegetables under running water before eating, cutting or cooking them.
Firm produce, including melons and cucumbers, should be scrubbed with a clean produce brush. Damaged or bruised areas should be removed, and cut or peeled produce should be refrigerated within two hours.
Washing produce may lower the risk of illness, but it may not remove every Cyclospora organism from contaminated food. Routine chemical disinfectants and sanitizers may also be ineffective against the parasite.
Maryland health officials are continuing to monitor reported infections as the state moves through the period when Cyclosporiasis cases are most frequently detected.
