Overview
Cryptosporidiosis is an infectious disease caused by tiny parasites called Cryptosporidium. These parasites mainly affect the intestines and cause watery diarrhea. The disease is not a genetic condition — it is caused by swallowing the parasite, usually through contaminated water, food, or contact with infected people or animals. Note that this Orphanet entry (code 1549) is marked as OBSOLETE, meaning it is no longer actively maintained as a rare disease classification, likely because cryptosporidiosis is now recognized as a relatively common infectious disease rather than a rare condition. When someone becomes infected, the parasites attach to the lining of the small intestine and cause inflammation. The most common symptom is watery diarrhea that can last one to two weeks. Other symptoms include stomach cramps, nausea, vomiting, low-grade fever, and dehydration. In people with healthy immune systems, the infection usually clears on its own. However, in people with weakened immune systems — such as those with HIV/AIDS, organ transplant recipients, or people on immunosuppressive medications — cryptosporidiosis can become severe, long-lasting, and even life-threatening. Treatment options are limited. Nitazoxanide (brand name Alinia) is the only FDA-approved medication for cryptosporidiosis and works best in people with healthy immune systems. For immunocompromised patients, restoring immune function (for example, through antiretroviral therapy in HIV patients) is the most important step. Supportive care including fluid replacement to prevent dehydration is a key part of management.
Key symptoms:
Watery diarrheaStomach crampsNauseaVomitingLow-grade feverDehydrationWeight lossLoss of appetiteFatigueBloating and gas
Variable
Can begin at different ages, from infancy through adulthood
Treatments
No FDA-approved treatments are currently listed for OBSOLETE: Cryptosporidiosis.
View clinical trials →Clinical Trials
View all trials with filters →No actively recruiting trials found for OBSOLETE: Cryptosporidiosis at this time.
New trials open frequently. Follow this disease to get notified.
Specialists
View all specialists →No specialists are currently listed for OBSOLETE: Cryptosporidiosis.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to OBSOLETE: Cryptosporidiosis.
Community
No community posts yet. Be the first to share your experience with OBSOLETE: Cryptosporidiosis.
Start the conversation →Latest news about OBSOLETE: Cryptosporidiosis
No recent news articles for OBSOLETE: Cryptosporidiosis.
Follow this condition to be notified when news becomes available.
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.How severe is my infection, and do I need any special treatment beyond supportive care?,Should I be tested for any immune system problems?,How can I prevent spreading this to my family members?,What signs of dehydration should I watch for, and when should I go to the emergency room?,How long should I stay away from work or school?,When is it safe for me to use swimming pools again?,Are there any dietary changes that can help me recover faster?
Common questions about OBSOLETE: Cryptosporidiosis
What is OBSOLETE: Cryptosporidiosis?
Cryptosporidiosis is an infectious disease caused by tiny parasites called Cryptosporidium. These parasites mainly affect the intestines and cause watery diarrhea. The disease is not a genetic condition — it is caused by swallowing the parasite, usually through contaminated water, food, or contact with infected people or animals. Note that this Orphanet entry (code 1549) is marked as OBSOLETE, meaning it is no longer actively maintained as a rare disease classification, likely because cryptosporidiosis is now recognized as a relatively common infectious disease rather than a rare condition. W