Health officials are investigating a multi-state outbreak of a foodborne parasite that has sickened at least 145 people across the United States, including cases in Georgia.

According to the Centers for Disease Control and Prevention, the outbreak is caused by the microscopic parasite Cyclospora cayetanensis, which causes an intestinal illness known as cyclosporiasis. The illness is commonly associated with severe, watery diarrhea that can become explosive, along with stomach cramps, nausea, fatigue, loss of appetite and, in some cases, vomiting or a low-grade fever. At least 20 people have been hospitalized, but no deaths have been reported.

The CDC says the illnesses occurred between May and mid-June and involve people ranging in age from 5 to 86. Investigators believe the outbreak is linked to contaminated food consumed in the United States because those infected did not report recent international travel. The exact food source has not yet been identified, and the CDC and FDA continue to investigate.

Cyclospora is spread by consuming food or water contaminated with the parasite. Fresh produce such as cilantro, basil, raspberries, lettuce and other leafy greens have been linked to previous U.S. outbreaks, but officials stress no specific food has been identified in the current investigation.

Symptoms typically begin about one week after exposure and can last for several weeks or even longer without treatment. Doctors often prescribe antibiotics, most commonly trimethoprim-sulfamethoxazole (Bactrim), to treat the infection. Health officials recommend thoroughly washing fresh produce, practicing good hand hygiene, and following safe food handling practices to reduce the risk of infection.