Cryptosporidiosis
What is cryptosporidiosis?
Cryptosporidiosis (krip-toe-spo-rid-e-o-sis), often called “Crypto,” is an intestinal infection caused by a microscopic, one-celled parasite, Cryptosporidium parvum. The main carrier of cryptosporidiosis is thought to be cattle, sheep and pigs.
What are the symptoms of cryptosporidiosis?
Symptoms of cryptosporidiosis vary from person to person. Some people who are infected do not have symptoms, while others may have watery diarrhea, headache, stomach cramps, nausea, vomiting or a slight fever. The first symptoms usually appear two to 10 days after infection, and in otherwise healthy people, usually last one to two weeks.
How is cryptosporidiosis spread?
You can get cryptosporidiosis by putting anything in your mouth that has been contaminated with feces from an infected person or animal. These sources may include contaminated water or soil, raw or undercooked food, or your hands, if you haven’t washed them after touching something that may be contaminated.
Cryptosporidiosis is highly infectious; you don’t have to be able to see the contamination
on your hands or food for it to make you sick.
What should you do if you think you have cryptosporidiosis?
- If you think you may have cryptosporidiosis, or if you have diarrhea, contact your health care provider as soon as possible. Cryptosporidiosis is diagnosed by a laboratory test that examines a stool sample. Your provider will give you the sample container and instructions for testing.
- Because cryptosporidiosis is highly infectious and easily transmitted, children
with diarrhea should not attend daycare.
- People with diarrhea who work in food preparation or care for ill or elderly
individuals should not work, and should be tested as soon as possible.
Can cryptosporidiosis be treated?
Currently, no medication has been found to be routinely effective in treating cryptosporidiosis. Since diarrhea may cause dehydration, people with cryptosporidiosis should drink plenty of fluids and get extra rest. Sometimes dehydration may be severe enough to require administration of intravenous fluids.
Is there any way to prevent cryptosporidiosis?
You can reduce your risk of getting cryptosporidiosis. The more of these actions you take, the less likely you are to get infected.
- Always wash your hands well before you handle food and after you use the toilet, change diapers, or may have come in contact with feces (handling pets or gardening, for example).
- If you work in a child care center and change diapers, wash your hands and the diaper changing surfaces after each child. If you wear gloves, throw the gloves away and wash your hands after diapering each child.
- If you provide care for patients that have or had diarrhea, wash your hands after bathing patient, changing soiled linen, or emptying bedpans. Cryptosporidium can still be present in the stool even if symptoms are gone.
- Avoid drinking water from lakes, rivers or streams. Water should be at a rolling boil for one minute to kill the Cryptosporidium parasite whenever you aren’t sure about the safety of the water supply.
- Avoid swallowing water when using a swimming pool, water park or hot tub. Cryptosporidium is not killed by the amount of chlorine normally used in these settings.
- Avoid eating or drinking unpasteurized food products. Wash raw fruits and vegetables well, and peel them before eating.
Additional Guidance for Immunosuppressed Individuals
In people whose immune system is weakened, cryptosporidiosis can be a severe and long-lasting infection. These individuals should follow “safer sex” guidelines and avoid sexual practices that may result in contact with feces.
Know your water source - Since Cryptosporidium is resistant to chlorine, you may choose to install a special water filtration system or to boil tap water used for drinking, ice cubes and brushing teeth. Do not assume that bottled water is free of risk unless it is steam distilled. Take extra caution when traveling to other countries, where water treatment and food sanitation may be below standard. Talk to your health care provider about other guidelines for travel.
For more information:
Vermont Department of Health:
- 1(800) 640-4374 or 863-7240 human illness questions
- 1(800) 439-8550 or 863-7220 private water supply, water filter & treatment questions
Vermont Department of Environmental Conservation:
- 1(800) 823-6500 or 241-3400 public and municipal water supply questions


