Coxsackievirus A16 Antibody Test, Cerebrospinal Fluid (CSF)
This test measures antibodies that your body has produced against Coxsackievirus A16 in a sample of cerebrospinal fluid (CSF), the clear liquid that surrounds and protects your brain and spinal cord. Doctors use it to help determine whether this virus is causing an infection of the nervous system, such as meningitis or encephalitis, when symptoms like severe headache, fever, or neck stiffness suggest a neurological problem.
{"The test looks for immune response to Coxsackievirus A16 in the fluid surrounding the brain and spinal cord","It helps doctors diagnose viral meningitis, encephalitis, or other neurological infections","A sample of cerebrospinal fluid is collected through a lumbar puncture (spinal tap)","A positive result indicates the patient's immune system has responded to the virus","Results help guide appropriate treatment for the infection"}
Key facts at a glance
- LOINC
- 109457-2
- Short code
- COXA16ABCSF
- Synonyms
- CV A16 Ab Msmt CSF
- Category
- cardiac
- Sample
- csf
- Container
- Sterile polypropylene tube (labeled for CSF collection), typically tube #1 or #2 for microbiology/serology
- Units
- N/A
- Ref low
- 10
- Ref high
- 20
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Enzyme-linked immunosorbent assay (ELISA) or immunofluorescence assay (IFA)
- CPT
- 86658
- SNOMED
- 122444009
- Specimen volume
- 1-2 mL of cerebrospinal fluid; minimum volume 0.5 mL
- Stability
- Refrigerated (2-8°C): up to 72 hours; Frozen (-20°C or below): up to 30 days; Avoid repeated freeze-thaw cycles
- Hemolysis max
- 200
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The Coxsackievirus A16 antibody test is a laboratory test performed on cerebrospinal fluid (CSF), the clear liquid that surrounds and protects the brain and spinal cord. This test detects whether your body has produced specific antibodies (immune proteins) against Coxsackievirus A16, a type of enterovirus that can sometimes cause infections affecting the nervous system.
Why is this test performed?
This test is ordered when a patient shows symptoms of a neurological infection such as meningitis (inflammation of the membranes surrounding the brain) or encephalitis (inflammation of the brain). Symptoms may include severe headache, fever, neck stiffness, sensitivity to light, confusion, or seizures. The test helps doctors determine if Coxsackievirus A16 is the cause of these symptoms.
How is the sample collected?
The cerebrospinal fluid sample is collected through a procedure called a lumbar puncture, commonly known as a spinal tap. A healthcare provider inserts a thin needle between the bones in the lower spine to withdraw a small amount of CSF. The procedure usually takes about 15-30 minutes, and you may be asked to lie flat for a short time afterward to reduce the risk of headache.
What do the results mean?
A positive result means that antibodies against Coxsackievirus A16 were detected in your cerebrospinal fluid, indicating that your body has mounted an immune response to this specific virus. This suggests that a recent or ongoing infection with Coxsackievirus A16 is likely causing your neurological symptoms. A negative result means no antibodies were detected, suggesting the infection is not caused by this specific virus or that the infection is too early for antibodies to be detected.
Are there any risks?
The main risks of lumbar puncture include headache (which usually resolves within a day or two), minor bleeding, or very rarely, infection. Your healthcare provider will discuss these risks with you and take appropriate precautions. The benefits of obtaining a definitive diagnosis usually outweigh these small risks.
Reference range
Negative: < 1:4 titer or < 10 AU/mL; Equivocal: 1:4 to 1:8 titer or 10-20 AU/mL; Positive: >= 1:8 titer or >= 20 AU/mLN/A
No fasting required. Patient should be informed of the lumbar puncture procedure and consent obtained. No special dietary restrictions necessary before sample collection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
The Coxsackievirus A16 antibody test is clinically significant because it helps differentiate viral infections of the central nervous system. While most Coxsackievirus A16 infections cause mild hand, foot, and mouth disease in children, this test is crucial when the virus affects the brain or surrounding membranes. Accurate diagnosis guides treatment decisions, helps avoid unnecessary antibiotics, and informs prognosis. It also helps public health officials track outbreaks of enterovirus infections in the community.
Frequently asked questions
Is Coxsackievirus A16 the same as hand, foot, and mouth disease?
How long does it take to get results?
Do I need to prepare anything special for this test?
Is the lumbar puncture painful?
What happens after I get my results?
Sources
- 1
- 2
- 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