Epstein-Barr virus (EBV) antibody test
Note: this site is for informational purposes only. To view test results or book a test, use the NHS app in England or contact your GP.
This blood test checks whether you have been infected with the Epstein-Barr virus (EBV). EBV is the virus that causes glandular fever. The test can tell whether your infection is current, recent, or from the past.
Who needs this test
You are most likely to need this test if your doctor thinks you may have glandular fever. Glandular fever is most common in teenagers and young adults. It is caused by EBV spreading through saliva – which is why it is sometimes called the ‘kissing disease’.
Your doctor may arrange EBV antibody testing if you have:
- a very sore throat with swollen tonsils
- swollen lymph glands in your neck, armpits, or groin
- persistent tiredness or fever
- a tender or enlarged spleen or liver
Less commonly, EBV testing is used to check whether you have ever had the virus in the past. This matters if you are about to start an immunosuppressive medication or have a transplant. People who have not previously had EBV are at higher risk of a more severe infection if they catch it while their immune system is suppressed.
EBV infection is extremely common. By the age of 40, around 95% of people in the UK will have been infected. Most people catch it in childhood, when it causes little or no illness. If infection happens for the first time in adolescence or adulthood, glandular fever is more likely to develop.
Preparing for your test
No special preparation is needed. You can eat and drink normally before the test.
A healthcare professional will take a small blood sample from a vein in your arm. It takes a few minutes. You may feel a brief sting when the needle goes in.
Results usually take around 7 working days. Some tests may take longer if the sample is sent to a specialist laboratory.
Understanding your results
What the test measures
When your body encounters EBV, the immune system produces different types of antibodies at different stages of infection. By looking at which antibodies are present – and which are absent – the laboratory can tell whether your infection is happening now, occurred recently, or happened in the past.
The main antibodies tested are:
- VCA-IgM – the first antibody your body produces in response to EBV; present in the first few weeks of a new infection
- VCA-IgG – produced alongside VCA-IgM during a new infection; remains in your blood for life once you have been infected
- EBNA-IgG – develops several weeks after infection begins; once present, it stays in your blood for life. Its absence during an acute illness helps confirm that the infection is genuinely new
Some laboratories also test for EA‑D IgG (an antibody to an ‘early antigen’), which can indicate active viral replication. Its role varies by laboratory and clinical situation
The laboratory will usually need to run more than one EBV test on your blood sample to build a complete picture. The combination of positive and negative results tells the story – a single test on its own is rarely enough.
What your results mean
The three most common patterns of results are described below. Your results letter may use the antibody names directly – this guide explains what they mean.
All results negative: no previous EBV infection
If VCA-IgM, VCA-IgG, and EBNA-IgG are all negative, you have not had EBV infection before. Your current illness is due to something else.
If your doctor still suspects an early infection, you may be asked for a repeat blood test in 2–4 weeks, as antibodies can take a few weeks to reach detectable levels after the virus first enters the body.
VCA-IgM and VCA-IgG positive, EBNA-IgG negative: current or recent infection
This pattern means you have a current or very recent EBV infection – usually within the last 4–6 weeks. This is the pattern seen in active glandular fever.
Your doctor will discuss what this means for you. The most important practical advice is to rest and to avoid contact sports and heavy lifting for several weeks to months. This is because EBV can cause your spleen to enlarge, making it more vulnerable to injury.
VCA-IgG and EBNA-IgG positive, VCA-IgM negative: past infection
This pattern means you have had EBV infection in the past – typically more than 6–8 weeks ago. The virus is no longer actively causing illness. Your current symptoms are probably due to a different cause.
This is also the pattern seen in people who were infected years or decades ago. Almost all adults with no current EBV-related illness will show this pattern.
What if my results are not clear-cut?
Sometimes the first set of results does not fit neatly into one of these patterns – for example, if you were tested very early in the illness. In that case, your doctor may ask for a follow-up blood test in 2–4 weeks to see how the antibody levels have changed.
The Monospot test and its limitations
Before EBV antibody testing, many laboratories first do a Monospot test – a quick bedside test that looks for a different type of antibody called a heterophile antibody. A positive Monospot test strongly suggests glandular fever.
However, the Monospot test is not always reliable. It frequently gives false-negative results in young children and in the first 1–2 weeks of infection, before heterophile antibodies have built up. EBV antibody testing is more accurate, so your doctor may arrange this alongside or instead of the Monospot test.
If you have glandular fever, avoid all contact sports, heavy lifting, and vigorous physical activity for at least 4 weeks, and until your doctor says it is safe. A ruptured (burst) spleen is a rare but serious complication. You should go to A&E immediately if you develop sudden, severe abdominal pain.
Your spleen may be enlarged during and after glandular fever. This makes it more fragile and at risk of rupture from physical impact or straining. Your doctor will advise you on how long you should avoid high-risk activity. This is typically a minimum of 4 weeks from the start of illness but may be longer depending on how you recover.
Questions to ask your doctor
What happens next
There is no specific antiviral treatment for glandular fever, and no vaccine to prevent EBV infection. Recovery is mainly about rest and time. Most people feel significantly better within 2–4 weeks, though fatigue can linger for several weeks or months in some cases.
Treatment focuses on relieving symptoms. Paracetamol or ibuprofen can help with fever and sore throat. Aspirin should be avoided in anyone under 16. Staying well hydrated is important, especially if a sore throat makes swallowing painful.
Antibiotics do not treat viral infections. If amoxicillin or ampicillin is given to someone with glandular fever, it often causes a widespread rash – this is not a true penicillin allergy, but a reaction specific to glandular fever. Your doctor will be aware of this.
If you have a weakened immune system (for example, due to HIV, or after a transplant), EBV infection can cause more serious illness. Specialist treatment may be needed. Your care team will guide you.
What can affect your results
Several factors can make EBV antibody results harder to interpret:
- Testing too early – antibodies take time to develop after infection. Testing in the first week or two may give a negative or unclear result even if you have active glandular fever
- Age – the Monospot test is often unreliable in younger children; EBV antibody tests are more accurate but may still show different patterns in young children compared with adolescents and adults
- Laboratory method – different laboratories may use slightly different tests or cut-off values; always compare results from the same laboratory
- Other infections – in rare cases, other viral infections can cause a similar pattern of antibodies, which may make interpretation more complex
Other tests you might need
Several other tests are commonly done alongside or instead of EBV antibody testing:
- Full blood count (FBC) – often done first; glandular fever typically causes a raised lymphocyte count with unusual-looking lymphocytes (called atypical lymphocytosis)
- Monospot test – a quick screening test, usually done before EBV antibody tests
- CMV antibody test – cytomegalovirus (CMV) can cause a very similar illness to glandular fever and is often tested at the same time
- Toxoplasmosis test – another infection that mimics glandular fever; particularly important to exclude in pregnant women, as toxoplasmosis can harm the baby (EBV itself has not been shown to cause harm in pregnancy)
- HIV test – HIV can also cause a glandular fever-like illness and should be considered, particularly if other risk factors are present
- Liver function tests – EBV commonly causes mild liver inflammation; more significant liver involvement occasionally occurs
About glandular fever
Glandular fever (also called infectious mononucleosis) is an illness caused by EBV infection in older children, teenagers, and young adults. It causes a sore throat, swollen lymph glands, fever, and extreme tiredness. Most people recover fully within a few weeks, though fatigue can last longer.
See NHS site - https://www.nhs.uk/conditions/glandular-fever/