If you've been watching the news lately, you've probably seen reports about an increase in stomach illnesses in our area. While many people immediately assume it's a case of "food poisoning" or a stomach virus, health officials have identified another culprit, a microscopic parasite called Cyclospora.

Cyclospora (Cyclospora cayetanensis) is a single-celled protozoan parasite that infects the intestines. Although tiny and invisible to the naked eye, it can make people feel miserable for days or even weeks.

The most common symptoms include prolonged watery diarrhea, stomach cramps, nausea, loss of appetite, bloating, fatigue, weight loss and occasionally a low-grade fever. Unlike many common stomach viruses that run their course in a day or two, Cyclospora infections often linger and may even seem to improve before returning.

People become infected by eating food or drinking water contaminated with the parasite. In recent years, outbreaks have frequently been linked to fresh produce, including bagged salads, lettuce, basil, cilantro, parsley, raspberries, blackberries, and other fruits and vegetables that are often eaten raw. Because these foods are not cooked, the parasite can survive if proper sanitation has not been followed during growing, harvesting or packaging.

Although washing fruits and vegetables under running water is an important step in reducing dirt, bacteria and some contaminants, it does not guarantee the removal of Cyclospora. The parasite is remarkably resistant to the levels of chlorine routinely used to disinfect drinking water and wash fresh produce. In other words, simply rinsing produce or relying on chlorinated water is not enough to completely eliminate the risk. However, washing fresh produce thoroughly is still strongly recommended because it helps remove many other harmful microorganisms and reduces overall contamination.

Avoid washing produce with soap, bleach or household detergents. Plain running water is the safest choice. Rub firm fruits and vegetables such as apples, cucumbers, and peppers while rinsing. Separate the leaves of lettuce and other leafy vegetables to wash them more thoroughly.

Practice good kitchen hygiene. Wash your hands with soap and water for at least 20 seconds before preparing food, after using the bathroom, and after handling raw meat. Clean cutting boards, knives, countertops and other food preparation surfaces regularly to prevent cross-contamination.

For most healthy individuals, Cyclospora is unpleasant but treatable. However, the infection can be far more serious for people with weakened immune systems, including those undergoing chemotherapy, organ transplant recipients taking anti-rejection medications, individuals with advanced HIV infection, or others with immune deficiencies. In these individuals, diarrhea may be more severe, last much longer, and lead to dehydration, weight loss, and hospitalization. Older adults and people with chronic medical conditions should also seek medical attention promptly if symptoms develop.

If you experience diarrhea lasting more than a few days, especially after eating fresh produce or traveling, contact your healthcare provider. Cyclospora is diagnosed through specialized stool testing and is usually treated with a prescription antibiotic. Because it is a parasite, not a virus. Waiting for it to "run its course" may unnecessarily prolong the illness.

The recent increase in Cyclospora infections reminds us that food safety begins long before food reaches our kitchens, but it continues at home. Careful handwashing, proper washing of fruits and vegetables, purchasing produce from reputable sources, and following good food preparation practices remain some of the best defenses against foodborne illness.

Sometimes the smallest organisms cause the biggest problems. Fortunately, a little extra care—and a healthy respect for food safety—can go a long way toward keeping these microscopic invaders off our dinner plates.

Michael Kossove is professor emeritus and an adjunct professor of microbiology at Touro University’s School of Health Sciences. He is a polio researcher, international polio lecturer and polio survivor, and writes opinion columns for the River Reporter.