Fluorescent Antibody Assay for Anticryptosporidium Antibodies (Serum/Plasma)
This test detects antibodies in your blood that may indicate past or current infection with *Cryptosporidium*, a microscopic parasite that can cause gastrointestinal illness.
["Helps identify if you’ve been exposed to *Cryptosporidium*, a common cause of diarrhea in both children and adults."]
Key facts at a glance
- LOINC
- 39536-8
- Short code
- FLUAV Ab Ser CF-aCnc
- Synonyms
- FLUAV Ab Ser CF-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- comp-fix
- 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
What This Test Measures
The test uses a fluorescent antibody technique to detect specific antibodies (immunoglobulins) produced by your immune system in response to *Cryptosporidium*. These antibodies appear in your blood after infection or exposure. The presence of these antibodies suggests prior infection, though they may not always correlate with active symptoms.
How the Test Works
A small blood sample is taken and analyzed using an immunoassay method. Fluorescent markers bind to your antibodies if they are present, allowing lab technicians to identify them under a microscope.
Common Uses
This screening test is often used in healthcare settings to diagnose or rule out *Cryptosporidium* infection, particularly in patients with persistent diarrhea, immunocompromised individuals, or those traveling to regions with higher parasite risk.
What to Expect Before the Test
No special preparation is needed. You may have a simple blood draw, usually at a clinic or lab. If you’re immunocompromised or have a history of frequent infections, your doctor may recommend this test if you’re experiencing symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Cryptosporidium Antibody Screen
Frequently asked questions
This test helps confirm a diagnosis of *Cryptosporidium* infection, which can cause watery diarrhea, stomach cramps, nausea, and dehydration. While antibodies indicate exposure, they don’t always mean you’re currently infected. Results may guide further testing or treatment decisions, especially in vulnerable groups like those with weakened immune systems.
Your doctor may recommend this test if you have unexplained diarrhea lasting more than a few days, if you’re immunocompromised (e.g., due to HIV, chemotherapy, or organ transplant), or if you’ve traveled to areas with higher parasite risks.
A positive result means your blood contains antibodies against *Cryptosporidium*, suggesting past exposure. However, it doesn’t always mean you’re currently infected. Your doctor may order additional tests to check for active infection if needed.
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