Coxsackievirus A16 Antibody Test (2nd Specimen)
A blood test that detects antibodies against Coxsackievirus A16, a virus that commonly causes hand, foot, and mouth disease and can affect the heart.
This test checks for antibodies to Coxsackievirus A16 in your blood A 2nd specimen means blood was taken twice to compare antibody levels over time It helps diagnose current or recent infection, especially if you have heart-related symptoms The test is useful for confirming if a heart condition may be related to this viral infection No special preparation is needed; just a standard blood draw
Key facts at a glance
- LOINC
- 24303-0
- Short code
- COXA16 Ab
- Synonyms
- CV A16 Ab sp2 Titr Ser
- Category
- cardiac
- Sample
- serum
- Container
- Serum separator tube (SST/Gel tube) or plain red top tube
- Units
- N/A
- Ref low
- 8
- Ref high
- 8
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Enzyme-linked immunosorbent assay (ELISA) or indirect immunofluorescence assay (IFA)
- CPT
- 86658
- SNOMED
- 371949004
- Specimen volume
- 1.0 to 2.0 mL of serum
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 5-7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 50
- Lipemia max
- 40
- Icterus max
- 20
- TAT
- 72–168 hours
- Order
- routine
What is this test?
The Coxsackievirus A16 Antibody test is a blood test that looks for specific antibodies (your immune system's defense proteins) against Coxsackievirus A16. This virus is a common type of enterovirus that typically causes Hand, Foot, and Mouth Disease (HFMD), especially in children. However, it can also affect the heart and may be linked to myocarditis (heart muscle inflammation).
Why is a second blood sample needed?
The '2nd specimen' in the test name means your doctor took two blood samples, usually 2-4 weeks apart. This is important because it helps doctors see how your antibody levels change over time. A rising level of antibodies between the first and second test indicates a recent or ongoing infection. This approach is called testing in 'acute' (early) and 'convalescent' (recovery) phases.
Why might my doctor order this test?
Your doctor may order this test if you have symptoms of Hand, Foot, and Mouth Disease, especially if the rash or sores are severe or unusual. More importantly, this test is often ordered when you have heart-related symptoms like chest pain, shortness of breath, fatigue, or abnormal heartbeats, and your doctor suspects a viral infection may be the cause. It helps determine if Coxsackievirus A16 might be responsible for conditions like myocarditis or pericarditis.
What happens during the test?
A healthcare professional will draw a small amount of blood from a vein in your arm using a needle. You may feel a brief pinch or sting. The blood sample is sent to a laboratory where technicians look for antibodies specifically targeting Coxsackievirus A16. If you are providing a second specimen, this process will be repeated at a later appointment, and both samples will be compared.
Are there any risks?
The risks are minimal and similar to any routine blood test. You may experience slight bruising, soreness, or bleeding at the needle site. Some people may feel lightheaded. These side effects are usually temporary and resolve quickly.
Reference range
Negative: <1:8; Equivocal: 1:8 to 1:16; Positive: >1:16. A four-fold rise in titer between acute and convalescent specimens indicates recent infection.N/A
No special preparation required. Patient may eat and drink normally before specimen collection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Coxsackievirus A16 is one of the most common viruses causing Hand, Foot, and Mouth Disease, characterized by sores in the mouth and a rash on the hands and feet. While usually mild in children, this virus can occasionally cause complications. The cardiac classification of this test reflects the virus's potential to cause heart-related complications, including myocarditis (inflammation of the heart muscle), pericarditis (inflammation of the heart's outer lining), and in rare cases, more serious heart conditions. A positive antibody test with rising levels between specimens suggests your immune system is actively fighting a recent Coxsackievirus A16 infection, which may be related to any heart symptoms you are experiencing. This information helps your doctor confirm a diagnosis and guide appropriate treatment, which is usually supportive care for viral infections.
Frequently asked questions
Do I need to fast before this test?
How long does it take to get results?
What do the results mean?
Is this test painful?
Can this test tell if I am currently contagious?
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 10, 2026. · Read our editorial policy