Epstein-Barr Virus (EBV)

What Epstein-Barr virus is

EBV is one of eight human herpes viruses, in the same family as chickenpox, cold sores and cytomegalovirus. It infects the cells lining the throat and then B lymphocytes, a type of white blood cell. Like other herpes viruses, it never fully leaves: after the first infection, it stays latent (inactive) in a small number of memory B cells, kept in check by the immune system.

Most people are infected without knowing. In low-income countries, nearly all children catch EBV before age 5, usually with no symptoms. Where hygiene is better, many people first meet the virus in adolescence, and up to about half of them develop infectious mononucleosis.

How Epstein-Barr virus spreads

• Saliva: kissing (mono is called "the kissing disease"), sharing drinks, food, utensils, lip balm or toothbrushes
• Less often: blood transfusion, organ transplant and genital secretions

The incubation period is long, about 4 to 6 weeks. People with mono can shed the virus in saliva for months, and healthy carriers release it intermittently for life. Because so many people shed it without symptoms, isolation is not practical or required.

Epstein-Barr virus symptoms

In young children

Usually none, or mild symptoms that look like a cold or tonsillitis.

Mono in teens and adults

• extreme tiredness, often the most lasting symptom
• fever
• a sore throat, often severe, with swollen tonsils that may have white patches
• swollen lymph nodes in the neck, especially at the back
• swollen spleen (splenomegaly) in about half of cases, sometimes an enlarged liver
• puffy eyelids, headache, muscle aches and loss of appetite
• a rash, especially if amoxicillin or ampicillin is given

The fever and sore throat usually settle within 2 weeks. Tiredness can last several weeks and occasionally months.

In older adults

Mono is less typical: fever and liver inflammation are more common, while sore throat and swollen glands may be absent.

EBV blood tests and how to read them

The monospot (heterophile antibody) test gives a quick answer but can be falsely negative in the first week and in children under 4. The EBV antibody panel is more precise and shows the stage of infection:

A positive VCA IgG and EBNA in an adult is the normal result for most people and does not mean an active illness. Early antigen (EA) antibodies and EBV DNA (viral load) by PCR are used mainly in transplant recipients, suspected chronic active EBV and cancer monitoring. A blood count often shows a high lymphocyte count with "atypical" lymphocytes, and liver enzymes are often mildly raised during mono.

EBV reactivation and "chronic EBV"

In healthy people, the latent virus may periodically become active and appear in saliva without symptoms. Whether this causes fatigue in otherwise healthy people is unproven, and antibody patterns are often over-interpreted. Raised VCA IgG or EA antibodies alone do not diagnose a chronic infection.

Chronic active EBV (CAEBV) is a real but rare and serious disease, more common in East Asia. It causes persistent fever, swollen glands, an enlarged liver and spleen and very high levels of EBV DNA in the blood, and it needs specialist treatment, often stem cell transplant.

Persistent exhaustion after mono overlaps with chronic fatigue syndrome (ME/CFS): around 1 in 10 people still have marked fatigue 6 months after mono.

Conditions linked to Epstein-Barr virus

• Cancers: EBV is found in some Hodgkin lymphoma cases, Burkitt lymphoma (especially in Africa, linked with malaria), nasopharyngeal carcinoma (more common in southern China and Southeast Asia) and some stomach cancers. Only a tiny fraction of infected people ever develop these.
• Post-transplant lymphoproliferative disorder: in organ or stem-cell transplant recipients on strong immune-suppressing drugs.
• Multiple sclerosis: large studies show MS almost never develops without prior EBV infection, and mono raises the risk. EBV appears to be necessary but not sufficient.
• Oral hairy leukoplakia: white, ridged patches on the side of the tongue in people with HIV or weakened immunity.
• Hemophagocytic lymphohistiocytosis (HLH): a rare, life-threatening immune overreaction.

Treatment

There is no specific cure. Treatment for EBV mono is supportive:

• rest and gradual return to activity guided by energy levels
• fluids, throat lozenges and salt-water gargles
• acetaminophen (paracetamol) or ibuprofen for fever and pain; follow the label dose and do not give aspirin to children or teenagers
• avoid alcohol while the liver is inflamed

Antiviral drugs such as acyclovir reduce viral shedding but do not shorten illness, so they are not routinely used. Steroids are reserved for complications such as tonsils swollen enough to threaten the airway. Antibiotics do not help unless there is a separate bacterial infection.

Avoid contact sports and heavy lifting for at least 3 to 4 weeks from the start of mono, longer if the spleen is still enlarged, because of the risk of splenic rupture.

Prevention

There is no licensed EBV vaccine yet, although candidates are in clinical trials. Not sharing drinks, utensils or toothbrushes, and avoiding kissing during acute illness, reduces spread. People who have had mono should not donate blood for at least 6 months.

Frequently asked questions

What are the symptoms of Epstein-Barr virus?

Many people have no symptoms. When EBV causes mono, typical symptoms are severe tiredness, fever, sore throat, swollen neck glands, and sometimes an enlarged spleen, puffy eyelids and a rash. Symptoms usually start 4 to 6 weeks after exposure.

What does a positive EBV antibody test mean?

Most adults test positive for VCA IgG and EBNA antibodies, which means a past infection and lifelong immunity. A positive VCA IgM without EBNA antibodies points to a recent infection. Your doctor interprets the pattern together with your symptoms.

Does Epstein-Barr virus ever go away?

No. After the first infection, EBV stays dormant in white blood cells for life. In nearly everyone the immune system keeps it controlled, and it causes no further illness. You cannot catch mono twice in the usual sense.

Can EBV reactivate and cause symptoms?

The virus reactivates silently from time to time, but in healthy people this rarely causes illness. In people with weakened immunity, such as transplant recipients, reactivation can cause serious disease and is monitored with EBV viral load tests.

Is Epstein-Barr virus the same as mono?

No. EBV is the virus; mono (infectious mononucleosis) is one illness it can cause, mainly in teens and young adults. Most EBV infections never cause mono, and a few mono-like illnesses are caused by other viruses such as cytomegalovirus.

Does Epstein-Barr cause multiple sclerosis?

EBV infection appears to be a necessary trigger for most MS: almost everyone with MS has had EBV, and mono raises the risk. But since about 90% of adults carry EBV and very few develop MS, other genetic and environmental factors are also needed.