Epstein-Barr Virus Infection
Epstein-Barr Virus (EBV) is a member of the herpes virus family and one of the most common viruses affecting humans, particularly known for causing infectious mononucleosis, often referred to as “mono.” While many individuals may carry the virus without symptoms, EBV can lead to more serious health issues, including autoimmune disorders and various cancers, particularly in immunocompromised individuals. The virus is transmitted through oral and nasal secretions, making activities like kissing and sharing utensils common routes of infection.
Most people are exposed to EBV by young adulthood; however, in developing countries, early exposure typically occurs without symptoms. Symptoms of EBV infection can include fever, swollen lymph nodes, fatigue, and in some cases, complications like liver inflammation or respiratory issues. Diagnosis often involves clinical evaluation and laboratory tests to confirm the presence of the virus.
Treatment primarily focuses on supportive care, as antibiotics are ineffective against viral infections. Preventative measures include minimizing contact with saliva, especially in children. Research is ongoing to develop vaccines and new treatment modalities to combat EBV-related diseases and reduce symptoms post-infection.
Epstein-Barr Virus Infection
ANATOMY OR SYSTEM AFFECTED: All
Definition
Epstein-Barr virus (EBV) is a herpes virus that was first isolated in 1964. It is best known as the cause of one of the most common viruses in humans, infectious mononucleosis, which is usually benign. In a few cases, EBV can cause more serious illnesses, such as autoimmune disorders or cancer.
Causes
As one of the most prevalent viruses, EBV has been present in the nasopharyngeal secretions of up to 95 percent of people around the world, although most people experience no symptoms. The route of transmission is through oral and nasal secretions. While the virus is infectious for four to six weeks, it remains dormant in all who have been infected, giving each person the lifelong potential for excreting and spreading EBV.
In developing countries, in which children are typically exposed to more infections, EBV usually strikes by the age of three years, causing no symptoms. In industrialized countries, in which young people are typically more protected from infection, EBV is usually delayed, striking in the teenage to young adult years and causing infectious mononucleosis in 35 to 69 percent of infected persons.
Risk Factors
In its most common form, mononucleosis, EBV can be spread by kissing, sharing drinking glasses, eating utensils, toothbrushes, or similar personal items, or by touching items close to the nose or mouth of an infected person.
A severe manifestation of EBV, Burkitt’s lymphoma, a tumor common to African children, is also associated with malaria. Non-Hodgkin’s and Hodgkin’s lymphomas are often tied to EBV. Immunocompromised persons carry special risks. For example, EBV may be fatal to persons with Duncan syndrome, a disease of excess lymphocytes. Persons with ataxia-telangiectasia (a rare neurodegenerative disease), Chédiak-Higashi syndrome (autosomal recessive disorder), Wiskott-Aldrich syndrome (recessive disease), common variable immunodeficiency, post-transplant lymphoproliferative disorder, and immunodeficiencies related to cancer treatments are all at increased risk for being infected by EBV and for being further debilitated.
EBV can also cause systemic lupus erythematosus, rheumatoid arthritis, Sjögren’s syndrome (inflammation of the glands), salivary gland tumors, thymomas (tumors of the epithelial cells of the thymus), and nasopharyngeal carcinomas. In persons with acquired immunodeficiency syndrome (AIDS), complications such as hairy leukoplakia, leiomyosarcoma, central nervous system lymphoma, and lymphoid interstitial pneumonitis are related to EBV, but EBV is not implicated in all cases.
Symptoms
A person with EBV may notice swollen lymph nodes of the neck, armpits, and groin, and a persistent fever. Other common symptoms include fatigue and discomfort. A skin rash may appear on an infected person. Enlarged tonsils can cause dehydration, difficulty swallowing, or airway obstruction.
Certain people may experience complications of the liver (mild hepatitis), respiratory system (upper airway obstruction or pneumonitis), or spleen (rupture). Rarely occurring neurological complications include encephalitis (brain inflammation), aseptic meningitis (viral infection of the central nervous system), Guillain-Barré syndrome (autoimmune disorder of the peripheral nervous system), and transverse myelitis (inflammation of the spinal cord). Complications affecting the heart are unusual. EBV can cause rare cancers, such as Burkitt’s lymphoma or nasopharyngeal carcinoma, in a limited group of persons.
Screening and Diagnosis
Diagnosis of infectious mononucleosis from EBV is first indicated by the person’s age and by clinical symptoms such as fever, sore throat, and swollen lymph glands. A physical examination may show an enlargement of the liver or spleen with tenderness. Typically, laboratory tests are done for confirmation, and if the person is infected with EBV, the tests will show an elevated white blood cell count with increased atypical white blood cells and a positive reaction to a monospot test, a form of the heterophil antibody test.
Polymerase chain reaction is used to diagnose persons who are immunocompromised. Most persons with acute infectious mononucleosis will have elevated liver function tests. Additional screening tests are available for rare conditions such as cancers and disorders of the immune system.
Treatment and Therapy
For persons with mononucleosis that was transmitted by EBV, physicians typically recommend supportive measures such as bed rest and increased fluids. Sore throat, fever, and myalgia (pain) may be treated with over-the-counter remedies such as saline gargles, acetaminophen, or ibuprofen. Antibiotics have no effect on the virus. Acyclovir can reduce virus production in the throat, but it does not shorten the duration of the disease.
In cases where mononucleosis occurs with a streptococcal throat infection, antibiotics may be prescribed. In severe cases with swelling, corticosteroid drugs may be used. Burkitt’s lymphoma is sensitive to chemotherapy. Physicians do not agree on strategies for persons with post-transplant lymphoproliferative disorder (PTLD), which may respond to treatments such as antiviral therapy, chemotherapy, or surgery or by reducing immunosuppression.
Prevention and Outcomes
The spread of EBV can be curtailed by limited contact with saliva, such as avoiding kissing children on the mouth. Other commonsense measures include monitoring young children for drooling and hand-to-mouth actions, maintaining cleanliness in settings such as daycare, and restricting children from sharing toys. Teens and adults should avoid all activities that could transmit oral and nasal secretions.
Researchers are investigating new therapies, including interferon-alpha and cytotoxic T cells that are specific to EBV. Additionally, an investigation is underway to develop a vaccine that would block primary infection with EBV. In clinical trials, scientists are also trying a peptide-based vaccine. A vaccine remedy also has the potential to block persons with PTLD from contracting EBV. In addition, researchers are looking for ways to use vaccines to limit symptoms that occur after infection.
Bibliography
Cohen, J. I. “Epstein-Barr Virus Infections, Including Infectious Mononucleosis.” In Harrison’s Principles of Internal Medicine, edited by Joan Butterton. 17th ed. New York: McGraw-Hill, 2008.
“Epstein-Barr Virus.” Cleveland Clinic, 13 Aug. 2022, my.clevelandclinic.org/health/diseases/23469-epstein-barr-virus. Accessed 30 Oct. 2024.
National Center for Infectious Diseases. “Epstein-Barr Virus and Infectious Mononucleosis.” 9 May 2024, www.cdc.gov/epstein-barr/about/index.html. Accessed 30 Oct. 2024.
Pollard, Andrew J., and Adam Finn, eds. Hot Topics in Infection and Immunity in Children II. New York: Springer, 2005.
Rickinson, Alan B. “Human Cytotoxic T Lymphocyte Responses to Epstein-Barr Virus Infection.” Annual Review of Immunology 15 (April, 1997): 405-431.
Robertson, Erle S., ed. Epstein-Barr Virus. Wymond-ham, England: Caister Academic Press, 2005.
Tselis, Alex C., and Hal B. Jenson, eds. Epstein-Barr Virus. New York: Taylor & Francis, 2006.
Umar, Constantine S., ed. New Developments in Epstein-Barr Virus Research. New York: Nova Science, 2006.
Wilson, Joanna B., and Gerhard H. W. May, eds. Epstein-Barr Virus Protocols. Totowa, N.J.: Humana Press, 2001.
Zuckerman, Arie J., et al., eds. Principles and Practice of Clinical Virology. Hoboken, N.J.: Wiley, 2004.