What is cryptosporidiosis?

Cryptosporidiosis (often called Crypto for short) is a highly contagious intestinal infection. It results from exposure to Cryptosporidium parasites, which live in the intestines of humans and other animals and are shed through the stool.

According to the Centers for Disease Control and Prevention (CDC), Crypto affects about 750,000 people per year. Most people recover within a few weeks with no problems. However, the watery diarrhea, nausea, and abdominal cramps that come with the infection can linger for some people.

For young children or people with a weakened immune system, the infection can be particularly dangerous.

The CDC reports that Crypto is found in every part of the country and even around the world.

A person can develop Crypto after coming in contact with contaminated feces. This exposure often happens by swallowing recreational swimming water. Anywhere people congregate in water — swimming pools, water parks, hot tubs, lakes, and even the ocean — can contain Cryptosporidium. Other serious infections can also be contracted in these environments.

According to the National Foundation for Infectious Diseases, Cryptosporidium germs are a leading cause of waterborne disease in this country. Young children who often splash and play in water are susceptible to the infection, which peaks in prime swimming season in the summer and fall.

The CDC reports that millions of Cryptosporidium parasites can be shed in the bowel movement of just one infected person, making Crypto highly contagious. And because the parasite is surrounded by an outer shell, it’s resistant to chlorine and other disinfectants. The parasite can live for days, even in pools properly treated with chemicals.

Crypto germs can also be spread through hand-to-mouth contact. They can be found on any surface that’s been contaminated with infected feces. Because of this, the infection can also be transmitted by:

  • playing with contaminated toys
  • touching bathroom surfaces without properly washing your hands
  • handling animals
  • having sex
  • drinking untreated water
  • touching dirty diapers
  • handling unwashed produce grown in contaminated soil

The telltale symptoms of Crypto include:

  • frequent and watery diarrhea
  • nausea
  • vomiting
  • stomach cramps
  • fever

Symptoms generally begin within a week of exposure and can last two weeks. However, in one study published in BMC Public Health, some people had symptoms that persisted 24 to 36 months.

With long-term symptoms, a person is at increased risk of weight loss, dehydration, and malnutrition. This can be particularly life-threatening in young babies and people with weakened immune systems, such as those who have HIV or who are undergoing chemotherapy. There are several parasitic infections that can have similar or different symptoms.

Anyone who comes into contact with contaminated feces runs the risk of contracting Crypto. Children younger than 10 years often get sick with the infection because they’re most likely to swallow swimming water.

Others who are also at increased risk of Crypto include:

  • childcare workers
  • parents of infected children
  • animal handlers
  • people exposed to untreated drinking water, such as travelers to undeveloped countries and campers or hikers who may drink from streams

If your doctor suspects Crypto, they’ll send a sample of your stool out to a lab for testing. Multiple samples may have to be viewed because the Cryptosporidium organisms are very small and difficult to see under a microscope. This can make the infection difficult to diagnose. In rare cases, your doctor may need to sample tissue from your intestines.

A person with Crypto needs to increase fluid intake to combat the dehydrating effects of severe diarrhea. If dehydration persists or becomes worse, a person may be hospitalized and given intravenous fluids.

Your doctor may prescribe the antidiarrheal drug nitazoxanide, but it’s only effective in people with healthy immune systems. People with weaker immune systems, such as those with HIV, may be given drugs to boost the immune system as a way of fighting the infection.

The best way to avoid being infected with Crypto and contributing to its spread is to practice good hygiene. Teach children good hygiene habits while they’re young.

The CDC recommends you scrub your hands with soap and water for at least 20 seconds in the following cases:

  • after using the bathroom, changing a diaper, or helping others use the bathroom
  • before eating or cooking
  • after handling an animal
  • after gardening, even if you used gloves
  • when caring for someone with diarrhea

The CDC also recommends these other tips for preventing Crypto infection:

  • Stay home or keep young children home when you or they have an active case of diarrhea.
  • Don’t drink unfiltered water.
  • Shower before using recreational swimming facilities to wash away any potential Cryptosporidium organisms on your body.
  • Don’t swallow pool water.
  • Wash all produce before eating it. Peeling the skins will also reduce your risk.
  • Take young children at the pool to the bathroom frequently.
  • Change children’s diapers often.
  • Stay clear of the water if you or your children have diarrhea. Stay out of the water for a full two weeks after the diarrhea subsides.

Crypto is a common intestinal infection, especially in summer when many people enjoy pools, water parks, and other swimming facilities.

Most people with a healthy immune system can recover from Crypto without any problems, but for others, the infection and its symptoms wax and wane. For still others, it can prove deadly.

Two of the best ways to prevent getting or spreading this highly contagious infection are with thorough hand-washing and avoidance of recreational water spots when you or your children have diarrhea.

If you think you or your child may have Crypto, see a healthcare provider. Medication and help with fluid loss may be necessary.