UNIVERSITY PARK — With nearly 7,000 confirmed or suspected cases of cyclosporiasis reported in several states, including Pennsylvania, Penn State food safety experts are offering guidance on the parasite, its symptoms and ways to reduce the risk of infection.

Cyclospora is a microscopic parasite that can contaminate fresh produce through contact with human waste or contaminated water during growing, harvesting or processing. It is not typically spread directly from person to person because it must mature in the environment before becoming infectious.

Symptoms generally begin about a week after contaminated food is eaten but may appear from two days to two weeks after exposure. They include frequent watery diarrhea, loss of appetite, weight loss, stomach cramps or bloating, nausea, fatigue and a low-grade fever.

Without treatment, symptoms may last several weeks or longer and can improve before returning. Anyone experiencing prolonged diarrhea should contact a healthcare provider. Laboratory testing is required to diagnose an infection, and people can be infected more than once.

Health officials have identified lettuce and salad greens as a potential source of the current outbreak, although other foods have not been ruled out.

Penn State Extension recommends washing hands with soap and water for at least 20 seconds before and after handling produce. Fruits and vegetables should be rinsed under cool running water before they are eaten, cut or cooked. Firm produce should be gently rubbed or cleaned with a produce brush, and the outer leaves of lettuce, cabbage and other leafy vegetables should be discarded. Separate cutting boards should be used for produce and raw meat, poultry and seafood.

Washing cannot guarantee removal of cyclospora, but it can remove dirt and reduce other contaminants. There is no scientific evidence that vinegar, baking soda or commercial produce washes destroy the parasite.

The U.S. Food and Drug Administration states that food must be cooked to at least 158 degrees to inactivate cyclospora. Many foods associated with outbreaks, including leafy greens, herbs and berries, are generally eaten raw.

Consumers should not avoid fresh produce unless public health officials identify a specific food connected to the outbreak. Shopping at small farms or farmers markets does not eliminate the risk because contamination can occur on farms of any size.

Consumers are encouraged to monitor the Centers for Disease Control and Prevention for outbreak updates and possible recall information. Additional produce-handling guidance is available through Penn State Extension.