Epstein-Barr virus, or EBV, is one of the most common human viruses in the world. It spreads primarily through saliva. EBV can cause infectious mononucleosis, also called mono, and other illnesses. Most people will get infected with EBV in their lifetime and will not have any symptoms. Mono caused by EBV is most common among teens and adults.

EBV is spread by saliva through—

• kissing
• sharing drinks and food
• using the same cups, eating utensils, or toothbrushes
• having contact with toys that children have drooled on

Epstein-Barr virus (EBV), also known as human herpesvirus 4, is a member of the herpes virus family. It is one of the most common human viruses. EBV is found all over the world. Most people get infected with EBV at some point in their lives. EBV spreads most commonly through bodily fluids, primarily saliva. EBV can cause infectious mononucleosis, also called mono, and other illnesses.

Symptoms of EBV infection can include

• Sick child in bed
• fatigue
• fever
• inflamed throat
• swollen lymph nodes in the neck
• enlarged spleen
• swollen liver
• rash

Many people become infected with EBV in childhood. EBV infections in children usually do not cause symptoms, or the symptoms are not distinguishable from other mild, brief childhood illnesses. People who get symptoms from EBV infection, usually teenagers or adults, get better in 2 to 4 weeks. However, some people may feel fatigued for several weeks or even months.

After you get an EBV infection, the virus becomes latent (inactive) in your body. In some cases, the virus may reactivate. This does not always cause symptoms, but people with compromised immune systems are more likely to develop symptoms if EBV reactivates.

EBV spreads most commonly through bodily fluids, especially saliva. However, EBV can also spread through blood and semen during sexual contact, blood transfusions, and organ transplantations.

EBV can be spread by using objects, such as a toothbrush or drinking glass, that an infected person recently used. The virus probably survives on an object at least as long as the object remains moist. There is no evidence that disinfecting the objects will prevent EBV from spreading.

The first time you get infected with EBV (primary EBV infection) you can spread the virus for weeks and even before you have symptoms. Once the virus is in your body, it stays there in a latent (inactive) state. If the virus reactivates, you can potentially spread EBV to others no matter how much time has passed since the initial infection.

Diagnosing EBV infection can be challenging since symptoms are similar to other illnesses. EBV infection can be confirmed with a blood test that detects antibodies. About 90% of adults have antibodies that show that they have a current or past EBV infection.

For more information, see Laboratory Testing.

There is no vaccine to protect against EBV infection. You can help protect yourself by not kissing or sharing drinks, food, or personal items, like toothbrushes, with people who have EBV infection.

There is no specific treatment for EBV. However, some things can be done to help relieve symptoms, including

• drinking fluids to stay hydrated
• getting plenty of rest
• taking over-the-counter medications for pain and fever

Epstein-Barr virus (EBV), also known as human herpesvirus 4, is a gamma herpes virus that occurs only in humans. Laboratory testing can help distinguish whether someone is susceptible to EBV infection or has a recent or past infection.

Healthcare providers can test for antibodies to the following EBV-associated antigens:

• Viral capsid antigen (VCA)
  • Anti-VCA IgM appears early in EBV infection and usually disappears within four to six weeks.
  • Anti-VCA IgG appears in the acute phase of EBV infection, peaks at two to four weeks after onset, declines slightly then persists for the rest of a person’s life.
• Early antigen (EA)
  Anti-EA IgG appears in the acute phase of illness and generally falls to undetectable levels after three to six months. In many people, detection of antibody to EA is a sign of active infection. However, 20% of healthy people may have antibodies against EA for years.
• EBV nuclear antigen (EBNA)
  Antibody to EBNA, determined by the standard immunofluorescent test, is not seen in the acute phase of EBV infection but slowly appears two to four months after onset of symptoms and persists for the rest of a person’s life. Other EBNA enzyme immunoassays may report false positive results.
• Monospot test
  The Monospot test is not recommended for general use. The antibodies detected by Monospot can be caused by conditions other than infectious mononucleosis. Moreover, studies have shown that the Monospot produces both false positive and false negative results. For example, the heterophile antibodies detected by Monospot are often not present in children with infectious mononucleosis. At best, the Monospot test may indicate that a person has a typical case of infectious mononucleosis, but does not confirm the presence of EBV infection.

Interpretation of EBV Antibody Tests

EBV antibody tests are not usually needed to diagnose infectious mononucleosis. However, specific antibody tests may be needed to identify the cause of illness in people who do not have a typical case of infectious mononucleosis or have other illnesses that can be caused by EBV infection. Symptoms of infectious mononucleosis generally resolve within four weeks. If a person is ill for more than six months and does not have a laboratory-confirmed diagnosis of EBV infection, other causes of chronic illness or chronic fatigue syndrome should be considered.

The interpretation of EBV antibody tests requires familiarity with these tests and access to the patient’s clinical information.

Interpretation of EBV antibody tests and diagnosis of EBV infection is summarized as follows:

• Susceptibility to infection
  People are considered susceptible to EBV infection if they do not have antibodies to the VCA.
• Primary (new or recent) infection
  People are considered to have a primary EBV infection if they have anti-VCA IgM but do not have antibody to EBNA. Other results that strongly suggest a primary infection are a high or rising level of anti-VCA IgG and no antibody to EBNA after at least four weeks of illness. Resolution of the illness may occur before the diagnostic antibody levels appear. In rare cases, people with active EBV infections may not have detectable EBV-specific antibodies.
• Past infection
  The presence of antibodies to both VCA and EBNA suggests past infection (from several months to years earlier). Since over 90% of adults have been infected with EBV, most adults will show antibodies to EBV from infection years earlier. High or elevated antibody levels may be present for years and are not diagnostic of recent infection.

Testing paired acute- and convalescent-phase serum samples is not useful to distinguish between recent and past EBV infections. In most cases, the antibody response occurs rapidly during primary EBV infection. The clinical findings of infectious mononucleosis occur in conjunction with the appearance of IgG and IgM anti-VCA antibodies. However, the antibody pattern is not stable before symptoms appear.

Most people are infected by the Epstein-Barr virus (EBV) in early childhood. It usually causes no symptoms or only a brief, mild illness. When teens or young adults become infected, it can cause infectious mononucleosis, or “mono.” The symptoms of mono are extreme fatigue, fever, sore throat, and swollen lymph nodes. These symptoms can last for two to four weeks. After infection, EBV becomes dormant, and people remain infected throughout their lives without any symptoms.

Previous studies suggested that EBV infection may play a role in the development of systemic lupus erythematosus and other autoimmune illnesses. However, the possible mechanisms to explain this relationship were unknown. A team of researchers led by Dr. John B. Harley at Cincinnati Children’s Hospital Medical Center performed a detailed genetic analysis to investigate the relationship between EBV infection and lupus. Their study was supported by NIH’s National Institute of Allergy and Infectious Diseases (NIAID) and several other NIH components. The results were published online on April 16, 2018, in Nature Genetics.

Past studies had identified more than 50 genetic regions associated with lupus. Most are thought to be involved in gene regulation. The researchers developed a computational and biochemical technique known as the Regulatory Element Locus Intersection algorithm, or RELI. They used RELI to compare the genetic variations tied to lupus with genetic and protein data from EBV-infected human cells.

The team found that a viral protein called EBNA2 was associated with nearly half of the genetic regions associated with the risk for lupus. EBNA2 is known to work through human transcription factors, which bind to DNA and affect the expression of genes nearby. RELI showed that many human transcription factors were associated with the same genetic regions as EBNA2.

The team also used RELI to compare the genetic regions tied to risk of other autoimmune diseases. They found that EBNA2 bound to regions associated with the risk for multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease, type 1 diabetes, juvenile idiopathic arthritis, and celiac disease. Many transcription factors were associated with these regions as well.

These findings suggest that EBV infection drives the activation of genes that contribute to an individual’s risk of developing autoimmune disease. The scientists note, however, that EBV isn’t the only factor that influences the development of these conditions.

“Many cases of autoimmune illness are difficult to treat and can result in debilitating symptoms. Studies like this are allowing us to untangle environmental and genetic factors that may cause the body’s immune system to attack its own tissues,” says NIAID Director Dr. Anthony S. Fauci. “A better understanding of the complex causes of autoimmunity promises to lead to better treatment and prevention options.”

EBV, a type of herpes virus, causes mononucleosis as well as certain types of lymphoma and cancers of the nose and throat. EBV is most commonly transmitted by contact with saliva, such as through kissing or by sharing toothbrushes or drinking glasses. It can also be spread by sexual contact, blood transfusions, and organ transplantation. EBV infection is lifelong. More than 90% of people worldwide will be infected with EBV during their lifetime, and most do not develop any symptoms. There is no vaccine to prevent EBV infection and no specific treatment for EBV infection.