ASHEVILLE, N.C. (828newsNOW) — Henderson County has confirmed 18 cases of cyclosporiasis, an unusually high number for the rare intestinal illness, as North Carolina’s statewide outbreak continues to grow.

The Henderson County Department of Public Health said the county typically sees just two to three cases in an entire year. Communicable disease nurses are investigating each case while working with the North Carolina Department of Health and Human Services and other public health partners to identify possible sources of infection.

The county’s update comes as NCDHHS reported 561 confirmed cases of cyclosporiasis across North Carolina as of July 20. The statewide total has risen sharply from the 307 cases reported through July 14, highlighting the rapid increase in confirmed illnesses.

State health officials are continuing to work with local, state and federal partners to identify the source or sources of the outbreak and are urging North Carolinians and restaurants to follow food safety precautions to reduce the risk of infection.

State officials say the North Carolina outbreak does not appear to be connected to the multistate outbreak linked to shredded iceberg lettuce served at certain Taco Bell restaurants.

Investigators have not identified the source of the North Carolina outbreak. However, parsley, cilantro and lettuce are among the foods most commonly reported by people who became sick. Health officials stress those ingredients have not been confirmed as the source and remain part of the ongoing investigation.

Officials recommend washing hands before preparing food and rinsing fresh fruits and vegetables under running water. While washing produce may remove some of the parasite, they caution it does not guarantee complete removal.

Because Cyclospora is most often associated with foods eaten raw, health officials also recommend considering fully cooking parsley, cilantro and lettuce until more is known about the outbreak. Anyone experiencing severe or persistent diarrhea should contact a health care provider.

Cyclosporiasis is an intestinal illness caused by the parasite Cyclospora cayetanensis. Symptoms typically include prolonged watery diarrhea, loss of appetite, weight loss, stomach cramps, bloating, nausea and fatigue. Symptoms generally begin about a week after consuming contaminated food or water.