Cryptosporidiosis is an infection of the intestine which results in severe diarrhea. It is caused by a parasite called Cryptosporidium parvum .

Cryptosporidium parasites live in the intestines of infected people and animals. They can also live outside the body for a long time because they have a protective outer shell. The parasites contaminate objects and surfaces that people touch, as well as soil where food is grown and recreational waters where people swim.

Cryptosporidiosis is caused by swallowing the parasite. When the parasite enters your intestine, it comes out of its shell, multiplies, and may cause an infection. Eventually, it is passed from your body through a bowel movement.

Most healthy adults recover from this infection in a few weeks. However, it can be life threatening for young children, the elderly, and very sick people.

You can get cryptosporidiosis by swallowing something that has come into contact with the feces of an infected person or animal.

Some sources of cryptosporidiosis are:

• Humans and animals:
  • Contact with diapers or clothing that are contaminated with the infection
  • Contact with animal feces by touching animals, cleaning cages, or visiting barns
  • Sexual activity that involves contact with feces
• Food:
  • Eating food grown in, or contaminated by, infected soil
  • Drinking unpasteurized milk, dairy products, or apple juice
  • Eating food that was handled by someone who is infected or washed in contaminated water
• Water:
  • Accidentally swallowing water in contaminated recreational water, such as a lake, ocean, bay, stream, hot tub, swimming pool, or water park
  • Drinking water or ice that is contaminated

A risk factor is something that increases your chance of getting a disease or condition. People who are at increased risk for cryptosporidiosis include:

• Young children, especially if they are in day care
• Day care workers or those who work in a group setting
• People whose immune system is weakened by cancer, AIDS , or an organ transplant
• People who engage in oral-anal sex
• International travelers, backpackers, hikers, and campers

Symptoms of cryptosporidiosis usually begin about a week after infection. Some people will not have any symptoms at all.

Symptoms consist mainly of:

• Watery diarrhea
• Stomach cramps
• Upset stomach, vomiting
• Slight fever
• Weakness
• Weight loss
• Dehydration

The symptoms may come and go before you are finally better.

To diagnose cryptosporidiosis, your doctor will take one or more stool samples to be examined in the laboratory.

People with healthy immune systems usually recover from cryptosporidiosis without needing treatment. Recovery can take several weeks and up to one month. If you have severe diarrhea, you may be given intravenous fluids or antidiarrheal drugs. A new drug call nitazoxanide has recently been approved to treat the diarrhea associated with cryptosporidiosis in healthy people.

People with a weakened immune system, particularly people with AIDS, have a greater risk of getting this infection. They are also likely to have a more severe and longer-lasting infection. Although treatment with antiretroviral drugs may help, these patients may be permanently infected.