Official websites use

A website belongs to an official government organization in the City of Boston.


Secure .gov websites use HTTPS

A lock or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Heat Emergency in Boston
Mayor Wu announced a heat emergency in the City of Boston through Wednesday, July 17. Cooling centers will be open at 14 BCYF community centers Monday through Wednesday, from 9 a.m. - 5 p.m.
Last updated:


This fact sheet answers frequently asked questions about cyclospora.

Cyclospora is a parasite that can make people sick. The parasite is too small to see without a microscope. You can find cyclospora all over the world, but it is most common in tropical and subtropical regions. Cyclospora causes an infection called cyclosporiasis.

The basics

What kinds of foods are likely to have cyclospora?

Cases of cyclospora infections have come from fresh fruits and vegetables, such as raspberries and lettuce. These items likely came into direct contact with an infected person or contaminated water. Fruits and vegetables grown or packed outside of the United States may have a higher risk of contamination. Washing fruits and vegetables with water and a brush may help get rid of cyclospora. Cooking will kill the parasite. Fruits and vegetables that you peel are safer to eat.


What are the symptoms of having cyclospora? 

The most common symptom is watery diarrhea. Other symptoms include weight loss, bloating, gas, cramps, nausea, vomiting, sore muscles, and loss of appetite. Sometimes people who seem to be getting better may get sick again. For most people, the diarrhea will last only a few days, but if not treated, some people can be sick for several weeks.

How is cyclospora spread? 

The parasite spreads when people consume contaminated food or water. Cyclospora parasites do not get a person sick right away. Days or even weeks are sometimes needed to make a person sick. Cyclospora infection is not spread from person to person directly. It is unknown if animals can carry or spread the infection to people.


How can I prevent the spread of cyclospora? ​

  • ​Wash fresh fruits and vegetables thoroughly using clean, drinkable water. Peeling fruits and vegetables should make them safer
  • Only drink water from a source you know to be safe
  • Careful hand washing prevents the spread of cyclospora and many other diseases
  • Wash your hands thoroughly with soap and water before eating, before handling food, after using the toilet, and after changing diapers
  • If you are taking care of someone who has diarrhea, scrub your hands with plenty of soap and water after helping them
  • If you or your child has persistent diarrhea (with or without a fever), or if the diarrhea is very bad, call your doctor or health center for advice.
  • Cook all food from animal sources thoroughly. If the meat or poultry is still pink in the center, it is not cooked all the way

Are there any restrictions for people infected with cyclospora?

There are no special restrictions for people diagnosed with cyclospora infection. However, health care providers and laboratories must report cases to local boards of health.

To protect the public, people who have diarrhea who work in food-related jobs must stay out of work until they are completely well. Food-related jobs include: working in a restaurant, sandwich shop, hospital kitchen, cafeteria, supermarket or grocery store, dairy, or food-processing plant.

People who feed, give mouth care, or give medicine to patients or clients in schools, residential programs, day-care, and health facilities must also stay out of work until they are completely well.


How is cyclospora diagnosed and treated? 

If you think you might have cyclospora, you should see a health care provider. They will test a stool sample in the lab. If you have cyclospora, your doctor will treat you with antibiotics. If you have diarrhea, you should rest and drink plenty of clear fluids. Do not take any medicine until you talk to your doctor. People who have already had a cyclospora infection can get it again.

Back to top