Epstein-Barr Virus (EBV)

EBV can cause mouth sores.

The Epstein-Barr virus (EBV) is a member of theherpesvirus family (humanherpesvirus4). EBV is found worldwide and is a common cause of viralpharyngitis, especially in young adults. EBV is transmitted from person to person and then infects human B cells, which in turn spread the infection throughout the entire reticuloendothelial system (RES, or theliver, spleen, and peripherallymph nodes). About 50% of the population has antibodies to the virus by age 5; about 12% of susceptible adults (college-age) develop antibodies to the virus, and one-half of those adults develop the disease termedmononucleosis(also termedinfectious mononucleosis,mono,glandular fever, and kissing disease), which produces symptoms oflymph node, spleen, and liver swelling,fever, inflamed throat, malaise, andrash.

The cause of an Epstein-Barr virus infection ormonois the infection of circulating B cells by EBV and the body's response to the presence of the virus. Risk factors include

• intimate contact with body secretions (primarily mouth secretions but including other body fluids like those found in the cervix and semen);
• young age (children, adolescents, and young adults are most often infected);
• sharing items such as eating utensils, toys, or toothbrushes;
• rarely, blood transfusions or organ transplants.

Yes, the Epstein-Barr virus iscontagiousand easily passed from person to person mainly by mouth secretions. EBV can be spread by sharing contaminated objects like cups, toothbrushes, or eating utensils.

EBV is transmitted mainly through the saliva secreted in the mouth during kissing or sharing items that can pass saliva to other individuals (for example, cups, spoons, straws, and other utensils). There is evidence that semen and the fluid from the cervix may also contain transmittable EBV. The disease is sometimes subclinical (meaning there are no symptoms in the infected individual), and the virus has been transmitted rarely byblood transfusionand/or organ transplants. In addition, EBV remains in the individual for life and occasionally may become reactivated (the person develops symptoms). If EBV is reactivated, the person becomes contagious. A person may be contagious even during the incubation period (see below).

An Epstein-Barr virus is contagious during its long incubation period (four to seven weeks, see below) and then until symptoms are gone; however, there is evidence that some people may still spread the virus to others for many months even after symptoms are gone. Some studies indicate that some individuals can be contagious for as long as 18 months.

The incubation period (time period between initial infection and development of symptoms) for EBV is unusually long. It takes about four to seven weeks for symptoms to develop.

The symptoms and signs of an Epstein-Barr virus infection are as follows:

1. Malaise ortiredness
2. Fever
3. Chills
4. Dizziness
5. Muscle aches
6. Bloating
7. Headaches
8. Sore throat
9. Rash
10. Sweats
11. Loss of appetite
12. Lymph node swelling
13. Liver swelling
14. Spleen swelling

Symptoms may last about two to four weeks; however, some individuals still feel tired for a few weeks more.

Many EBV infections are diagnosed simply by the symptoms. However, there are tests for EBV, but they need to be interpreted appropriately. The U.S. Centers for Disease Control andPrevention(CDC) recommends the following for EBV testing:

CDC recommendations for EBV testing

• Susceptibility to infection: People are considered susceptible to EBV infection if they do not have antibodies to the VCA (viral capsid antigen).
• Primary (new or recent) infection:人们认为一个主EBV infection if they have anti-VCA IgM but do not have antibodies to EBNA (EBV nuclear antigen). 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.

美国疾病控制和预防中心不建议g Monospot测试eneral use because of both false-positive and false-negative results and because the antibodies detected can be caused by other conditions. However, the test is still used to detect antibodies that are often present in EBV-infected patients about two to nine weeks after EBV infection. It is used as a screening test and is not specific for EBV infection.

The above tests can help differentiate EBV infection from other medical problems (for example,chronic fatigue syndromeormultiple sclerosis).

Unfortunately, there is no specific treatment for EBV. However, some physicians may usecorticosteroidsto reduceswelling of tissues(for example, swelling in the throat, andenlarged spleen). Most of the treatments are designed to reduce symptoms (see home remedies below).

Although home remedies do not cure EBV infections, some provide relief from the symptoms of the disease. The most common home remedies are as follows:

• Rest
• Fluids
• Over-the-counterpainmedications (Do not giveaspirinto children.)

Avoid any potentialtrauma(such as sports like football or boxing) because the spleen is especially vulnerable to rupture or laceration until its swelling abates.

Light-colored cells areleukemiacells that contain EBV; SOURCE: CDC

Possible complications of EBV are as follows:

• Enlarged spleen
• Red spots and/or rash
• Liver inflammation and/or swelling
• Jaundice
• Anemia
• Splenic rupture
• Severe swollentonsils
• Breathingdifficulties (usually due to swollen throat tissue)
• Irregular heartbeat
• Possible increased risk forcancer(lymphomas)

The prognosis for most individuals who are infected with EBV is usually good as most people recover completely without any of the complications described above. If complications develop, the majority of patients usually recover, even if the recovery time is prolonged. Rarely, splenic rupture occurs, which requires surgery and can result in death.

There is novaccineavailable to prevent EBV infections. Individuals can reduce their risk of infection by not using utensils, toys, or other objects used by infected individuals and by practicing good hand-washing techniques. Avoiding contact with any body fluids, especially saliva, may reduce the chance of infection. Prevention is difficult because EBV is widespread in populations and can be transmitted even when an infected person has no symptoms.