Cryptosporidium Antigen in Stool (Qualitative)
This test checks for the presence of Cryptosporidium parasites in your stool, which can cause diarrhea and other gastrointestinal symptoms. It helps diagnose infections that may require treatment.
["Looks for parasites that may cause persistent diarrhea, especially in immunocompromised individuals."]
Key facts at a glance
- LOINC
- 20780-3
- Short code
- Cryptosp TLGI/TSMI Ql Acid fast Stn
- Synonyms
- Cryptosp TLGI/TSMI Ql Acid fast Stn
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- acid-fast-stain
- CPT
- 84484
- SNOMED
- 302774002
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Doctors may order this test if you have symptoms like chronic watery diarrhea, abdominal pain, or weight loss that don’t improve with usual treatments. It’s also recommended for people with weakened immune systems (e.g., after organ transplants, with HIV/AIDS, or on certain medications).
What to Expect Before the Test
No special preparation is needed. You’ll provide a fresh stool sample in a container provided by your healthcare provider. If you’re using a stool collection kit, follow the instructions carefully to avoid contamination. Avoid using toilet paper or cleaning products in the sample area.
What the Test Results Mean
A positive result means Cryptosporidium parasites were found in your stool. This confirms an infection and may guide treatment decisions. A negative result means no parasites were detected, but other causes of diarrhea could still be present. Follow-up testing or additional evaluations may be needed if symptoms persist.
Possible Side Effects or Risks
There are no significant side effects from this test. However, improper sample handling or contamination could affect results. If you have a sensitive immune system, discuss any concerns with your doctor before the test.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
Stool Cryptosporidium Test
Frequently asked questions
Cryptosporidium is a microscopic parasite that can cause severe, long-lasting diarrhea, especially in people with weakened immune systems. It spreads through contaminated food, water, or person-to-person contact. Early diagnosis helps prevent dehydration and supports proper treatment with medications like nitazoxanide or paromomycin.
A positive result means you likely have an active Cryptosporidium infection. Your doctor may recommend treatments to reduce symptoms, improve hydration, and support your immune system. They may also suggest avoiding contact with others to prevent spreading the infection.
Yes, Cryptosporidium can spread even if you don’t feel sick. Practice good hand hygiene (wash hands thoroughly with soap and water after using the toilet) and avoid sharing personal items to help prevent spreading the infection to others, especially children or people with weak immune systems.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy