Cryptosporidiosis

Overview

What is cryptosporidiosis?

Cryptosporidiosis is an infection resulting from exposure to parasites called Cryptosporidium. The parasite is common in the digestive tracts of humans and animals.

People become infected when they eat or drink contaminated water or food. Infection also can spread from person to person.

For most people, cryptosporidiosis causes manageable symptoms. Symptoms often go away without treatment. But crypto symptoms may cause life-threatening complications for some people. People with weakened immune systems, infants, young children, and pregnant women should take extra care.

Who is likely to have cryptosporidiosis?

Anyone can become infected with Cryptosporidium. This species of parasite is common throughout the United States and the world.

Symptoms and Causes

What causes cryptosporidiosis?

Cryptosporidiosis results from infection with Cryptosporidium parasites. The parasite lives in the digestive tract of both humans and animals. It sheds (leaves the body) in feces (stool).

Cryptosporidium is also often found in recreational water supplies. These can include swimming pools, hot tubs, water parks, lakes, rivers, and fountains. The parasite is not killed by freezing or by the normal levels of chlorine in pools and hot tubs.

Eating or drinking contaminated water or food exposes many people to the infection. Additionally, some people contract Cryptosporidium from direct contact with another infected person.

What are the symptoms of cryptosporidiosis?

Symptoms typically begin 2-10 days after initial infection with the crypto parasite. In most cases, symptoms resolve after 1-2 weeks. Symptoms rarely last for more than 1 month.

While some people have no symptoms, most people experience watery diarrhea. Other symptoms may include:

  • Dehydration
  • Fever
  • Nausea
  • Stomach cramps or pain
  • Vomiting
  • Weight loss

Diagnosis and Tests

How is cryptosporidiosis diagnosed?

Your doctor diagnoses cryptosporidiosis by examining samples of your stool for evidence of the parasite. You may need to submit several stool samples over several days for a definite diagnosis.

Management and Treatment

How is cryptosporidiosis treated?

Some individuals with healthy immune systems recover with no treatment. Others may need treatment with antiparasitic medications like nitazoxanide or drugs like loperamide to reduce diarrhea.

People living with HIV/AIDS need additional treatment. Doctors will prescribe antiretroviral medications. These drugs help the immune system function as effectively as possible.

Severe diarrhea could cause problems with dehydration. It is very important to drink plenty of fluids. Certain people may require fluid replacement therapy.

What complications are associated with cryptosporidiosis?

Cryptosporidiosis may cause life-threatening complications for people with compromised immune systems. This includes people who:

  • Have cancer or HIV/AIDS
  • Live with certain inherited diseases that weaken the immune system
  • Take immunosuppressive drugs after an organ transplant

Infants, young children, and pregnant women are at higher risk for complications from this infection. Complications may include prolonged diarrhea resulting in severe dehydration. This condition requires immediate medical treatment.

Prevention

Can cryptosporidiosis be prevented?

People with healthy immune systems can prevent exposure to Cryptosporidium by:

  • Avoiding exposure to feces, including at child care facilities and swimming pools
  • Avoiding water that may be contaminated, such as hot tubs and pools
  • Practicing good hand hygiene
  • Practicing safer sex to make it less likely that you will be exposed to stool
  • Not drinking water or using ice in countries with contaminated water supplies
  • Thoroughly washing and cooking food such as vegetables or fruits
  • Boiling water to kill the parasite

People with compromised immune systems or those who may be at higher risk for complications should take extra caution. They can minimize their exposure to the parasite by avoiding animals and their stool, in addition to following the recommendations listed above.

Outlook / Prognosis

What is the prognosis (outlook) for people with cryptosporidiosis?

With treatment, most people with cryptosporidiosis recover completely. A person who has AIDs or another severe immune system issue might find that symptoms come back if the immune status gets worse. Pregnant women and very young children are more susceptible to severe dehydration and may need additional attention from healthcare providers.

Living With

When should I call my doctor?

Call your doctor immediately if you develop any symptoms of cryptosporidiosis, especially prolonged, watery diarrhea. Early treatment may help you avoid potentially serious complications.

Last reviewed by a Cleveland Clinic medical professional on 07/17/2019.

References

  • Centers for Disease Control and Prevention. Parasites – Cryptosporidium (also known as “Crypto”). (https://www.cdc.gov/parasites/crypto/index.html) Accessed 7/18/2019.
  • Merck Manual Professional Version. Cryptosporidiosis. (https://www.merckmanuals.com/professional/infectious-diseases/intestinal-protozoa-and-microsporidia/cryptosporidiosis) Accessed 7/18/2019.
  • Safe Water Drinking Foundation. Cryptosporidium. (https://www.safewater.org/fact-sheets-1/2017/1/23/cryptosporidium) Accessed 7/18/2019.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy