Mononucleosis

Definition

Infectious mononucleosis is caused by the Epstein-Barr virus, which in teenagers and young adults may result in acute symptoms that last for several weeks. Fatigue and low energy can linger for several months.

Description

Infectious mononucleosis (IM), also called mono or glandular fever, is commonly transmitted among teenagers and young adults by kissing or sexual activity; hence it is sometimes called the "kissing disease."

By age 35–40, approximately 95% of the population has been infected with the Epstein-Barr virus (EBV) that causes IM. Although anyone can develop mononucleosis, primary (first) infections commonly occur in young adults between the ages of 15 and 35. Symptoms of IM are particularly common in teenagers. In the developed world, 15–20% of people are infected during adolescence and about half of these teens become ill. Among adults, 30—50% of those contracting IM become ill. Although males and females are equally susceptible, in the United States whites are 30-fold more likely than blacks to contract IM.

Typically IM runs its course in 10–30 days. However people with weakened or suppressed immune systems, such as AIDS or organ-transplant patients, are especially vulnerable to potentially serious complications from mononucleosis.

Following IM, the EBV remains dormant (latent) in a few cells in the throat and blood for the remainder of one's life. Periodically the virus may reactivate and be transmitted through saliva; however IM symptoms rarely reoccur.

Causes & symptoms

Causes

Infectious mononucleosis is caused by the first infection with the Epstein-Barr virus, also called herpes virus 4. It is one of the most common human viruses and is endemic throughout the world. EBV is a member of the herpes family of DNA viruses. This family of viruses includes those that cause cold sores, chickenpox , and shingles . Most people are infected with multiple strains of EBV. The different EBV strains are found in separate parts of the body: the circulating lymphocytes (white blood cells), cell-free blood plasma, or the oral cavity.

EBV is spread by contact with viral-infected saliva through coughing, sneezing , kissing, or the sharing of items such as drinking glasses, eating utensils, straws, toothbrushes, or lip gloss. Some evidence indicates that in teens and young adults IM is primarily transmitted by sexual intercourse. However EBV is not highly contagious and household members have only a very small risk of infection unless there is direct contact with infected saliva.

Symptoms

Less than 10% of children under age 10 develop symptoms with EBV infection. The incubation period after exposure to EBV is generally about 7–14 days in children and teens and 30–60 days in adults. An infected person can transmit EBV during this period and for as long as five months after symptoms disappear.

The first symptoms of IM are usually general weakness and extreme fatigue. An infected person may require 12–16 hours of sleep daily prior the development of other symptoms. IM symptoms are similar to cold or flu symptoms:

• Fever and chills occurs in about 90% of IM cases. EBV is most contagious during this stage of the illness.
• An enlarged spleen, causing pain in the upper left of the abdomen, occurs in about 50–60% of infections.
• Sore throat and/or swollen tonsils occurs in less than 50% of mononucleosis infections.
• Swollen lymph glands (nodes) in the neck, armpits, and/or groin develop in less than 50% of infections.
• Jaundice (yellowing of the skin and eyes) develops in more than 20% of patients, depending on age, and indicates an inflamed or enlarged liver.
• A red skin rash, particularly on the chest, occurs in about 5% of infections.
• loss of appetite
• stomach pain and/or nausea
• muscle soreness and/or joint pain
• headache
• chest pain
• coughing
• rapid or irregular heartbeat

These acute symptoms usually last one to two weeks.

Splenic enlargement generally peaks during the fourth week after symptoms appear and then subsides. However an enlarged spleen may rupture in 0.1–0.2% of cases, causing sharp pain on the left side of the abdomen. Additional symptoms of a ruptured spleen include light-headedness, a fast heart rate, and difficulty breathing. Splenic rupture most often occurs within the first three weeks and is the most common cause of death from mononucleosis. It requires immediate medical attention and may require emergency surgery to stop the bleeding.

There are other rare—but potentially life-threatening—complications of mononucleosis:

• Neurological complications affecting the central nervous system may develop in 1–2% of infections. Bell's palsy is a temporary condition caused by weakened or paralyzed facial muscles on one side of the face.
• The heart muscle may become inflamed.
• A significant number of the body's red blood cells or platelets may be destroyed and there may be reduced number of circulating red and white blood cells.

Diagnosis

A variety of conditions can produce symptoms similar to those of IM; however if cold or flu-like symptoms persist for longer than two weeks, mononucleosis may be suspected. Mononucleosis usually is diagnosed by a blood test—called a mono spot test—that measures anti-bodies to EBV. Antibodies may not be detectable until the second or third week after the onset of symptoms. The antibodies peak between weeks two and five and can persist at low levels for up to a year.

About 90% of IM cases show a positive mono spot. Infants and young children do not make the type of anti-bodies that are measured by the mono test. If the mono spot is inconclusive, additional blood tests may be performed that measure an increase in the overall number of white blood cells or an increase in abnormal-appearing lymphocytes that make antibodies against EBV. Other tests can identify at least six specific types of EBV anti-bodies that may be present in the blood.

Treatment

The most effective treatment for infectious mononucleosis is rest, followed by a gradual return to normal activities. If the spleen is enlarged, all contact sports, heavy lifting, and jarring activity such as cheerleading, should be avoided until the enlargement has subsided completely. However exercise such as swimming, running, and other non-contact sports may be resumed. Since mononucleosis can involve the liver, it is important not to consume alcohol.

Although there is no cure for mononucleosis, alternative remedies may help the body to fight the infection and relieve symptoms. Medical practitioners recommend eating four to six small daily meals of unprocessed foods, fresh fruits, and vegetables. It is important to drink plenty of water. Meat, sugar, saturated fats, and caffeinated and decaffeinated drinks should be avoided. Gargling with salt water (one half teaspoon in one cup of warm water) or lozenges may relieve a sore throat.

Vitamins A, B-complex, and C, and magnesium, calcium , and potassium supplements can boost the immune system and increase energy levels.

Herbals

Herbal remedies may help treat mononucleosis, although they are unproven:

• astragalus (Astragalus membranaceus ) for physical weakness
• cleavers (Galium species) to cleanse the lymphatic system
• echinacea (Echinacea augustifolia ) to boost the immune system
• elder (Sambucus nigra ) flower to reduce fever
• garlic to fight viral infection
• goldenseal (Hydrastis canadensis ) to relieve sinus congestion
• slippery elm bark and licorice can be gargled to soothe a sore throat
• St. John's wort (Hypericum perforatum ) to relieve anxiety and depression
• vervain (Verbena officinales ) to relieve anxiety and depression and treat jaundice
• wild indigo (Baptisia tinctoria ) to cleanse the lymphatic system
• yarrow (Achillea millefolium ) to reduce fever

Other remedies

The following treatments may help relieve symptoms of mononucleosis:

• acupressure point Lung 6 may boost lung function and the immune system
• aromatherapy with bergamot, eucalyptus, and lavender essential oils may relieve fatigue and other symptoms
• Chinese medicine utilizes acupuncture and Xiao Chai Hu Wan (Minor Bupleurum pills) in combination with otherherbs.
• Homeopathic physicians choose remedies based on a patient's specific symptoms
• relaxation techniques such as biofeedback, visualization, meditation , and yoga can reduce fatigue by relieving stress

Allopathic treatment

Acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) may relieve symptoms of IM. Aspirin should be avoided because mononucleosis has been associated with Reye's syndrome—a serious illness in children and teens—that is aggravated by aspirin.

Although antibiotics are ineffective for treating EBV, a sore throat from mononucleosis can be complicated by a streptococcal infection, sinus infection , or an abscess or pocket of infection on the tonsils. Such bacterial infections can be treated with antibiotics. A five—day course of corticosteroid anti-inflammatory medications (Prednisone) occasionally is prescribed for breathing difficulties caused by swollen tonsils or lymph nodes in the neck or throat.

Prognosis

Most people with IM return to their normal daily routines within two to three weeks, although it may take up to six months for normal energy levels to return.

A large study suggested that EBV infection increases the risk for Hodgkin lymphoma, a highly treatable cancer of the lymphatic system. About one-third of Hodgkin tumors contain EBV and about one in 1,000 young adults with mononucleosis will develop the cancer, typically about four years after IM.

The development of two other rare types of cancer—Burkitt's lymphoma and nasopharyngeal carcinoma—appears to be associated with EBV. There also is some evidence that people with high levels of antibodies against EBV are at a higher risk of developing multiple sclerosis .

Prevention

Even though IM is not highly contagious, there is no way to completely avoid infection with EBV. In the majority of cases, IM is without symptoms. Furthermore EBV can be transmitted long after the symptoms of infection are gone and, indeed, periodically throughout the remainder of life. Good hygiene, particularly hand washing and the habit of not sharing toothbrushes or eating utensils may help prevent EBV infection.

Resources

BOOKS

Decker, Janet M., et al. Mononucleosis. New York: Chelsea House, 2004.

Mononucleosis—A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References. Icon Health Publications, 2004.

PERIODICALS

Ambinder, Richard. "Infection and Lymphoma." New England Journal of Medicine 349 (October 2, 2003): 1309–11.

Bates, Betsy. "Mononucleosis Means Delaying Contact Sports. (1-3 Months After Symptom Onset.)" Pediatric News 36 (October 2002): 10–11.

Cherian, Benny. "Latest Thinking on Glandular Fever." Pulse September 15, 2003: 54.

Sitki-Green, Diane L., et al. "Biology of Epstein-Barr Virus During Infectious Mononucleosis>" Journal of Infectious Diseases 189 (February 1, 2004): 483–92.

ORGANIZATIONS

National Institute of Allergy and Infectious Diseases. National Institutes of Health. 6610 Rockledge Drive, MSC 6612, Bethesda, MD 20892-6612. <http://www.niaid.nih.gov>.

OTHER

Epstein-Barr Virus and Infectious Mononucleosis. National Center for Infectious Diseases. Centers for Disease Control and Prevention. October 26, 2002 [cited May 9, 2004]. <http://www.cdc.gov/ncidod/diseases/ebv.htm>.

Infectious Mononucleosis. KidsHealth. October 2001 [cited May 9, 2004]. <http://kidshealth.org/parent/infections/bacterial_viral/mononucleosis.html>.

Margaret Alic, PhD

Mononucleosis

Introduction

Disease History, Characteristics, and Transmission

Scope and Distribution

Treatment and Prevention

Impacts and Issues

Primary Source Connection

BIBLIOGRAPHY

Introduction

Mononucleosis is a self-limiting viral disease caused by the Epstein-Barr virus (EBV). EBV is considered to be one of the most common viruses among humans and most people become infected with the virus at some point during their lives. When infection with EBV occurs during adolescence or young adulthood, the infection develops into mononucleosis 35–50% of the time. The disease occurs worldwide.

EBV infection during early childhood is usually asymptomatic. When an adolescent or young adult develops mononucleosis the symptoms include fever, sore throat, swollen glands, swollen lymph nodes, and general fatigue. In severe cases, patients may display symptoms for months, but usually they will resolve within four weeks of initial infection. There is no vaccine to prevent mononucleosis and treatment of symptoms relies largely on rest and rehydration.

No areas have been identified as having an increased risk of infection and most cases occur sporadically with no reports of outbreaks. The long incubation period of infection coupled with the universal presence of the viral agent makes epidemiological control impractical.

Disease History, Characteristics, and Transmission

Mononucleosis is also known as Pfeiffer's disease, Filatov's disease, the kissing disease, glandular fever, or, simply, mono. The disease was first termed glandular fever by a group of German physicians in the 1880s due to the obvious swelling of the lymph nodes and glands. In 1920, scientists discovered that the infection was associated with white blood cells called mononuclear leukocytes, and thus it was also called infectious mononucleosis. The causative agent wasn't identified as EBV until 1968, when Michael Epstein (1921–) and Yvonne Barr (1932–) discovered the virus.

EBV is a member of the family of human herpes viruses. It is one of the most common human viruses and is responsible for 90% of mononucleosis cases. Cytomegalovirus is another member of this family of viruses and may cause mononucleosis in a small number of cases. EBV causes mononucleosis by infecting lymphocytes, or white blood cells, which subsequently reduces host immunity for the period of infection. EBV has also been implicated in more severe diseases, such as post-transplant lymphoproliferative disease, Hodgkin's disease, nasopharyngeal carcinoma, and Burkitt's lymphoma.

Mononucleosis has an incubation period of 4–7 weeks, during which symptoms may not be present. Most children are exposed to EBV at a young age, which generally results in a mild, asymptomatic infection. If initial infection occurs during adolescence or young adulthood, symptoms may present as a persistent cold or flu and may include fever, enlarged lymph nodes on the neck, sore throat, muscle aches, fatigue, and white patches on the tonsils. Enlargement of the spleen occurs in 25–75% of cases and poses threat of further complications due to the possibility of rupture. Other symptoms may include abdominal pain, headache, jaundice, depression, weakness, skin rash, and swollen liver. The broad spectrum of possible symptoms means that almost all cases of mononucleosis are unique to each patient.

Generally the infection is self-limiting within 2–4 weeks, but in some cases the course of disease is considered chronic and patients may suffer from symptoms for months, or even years. In most cases, hospitalization is seldom required unless complications, such as ruptured spleen or liver problems, arise. There have been no indicating factors to suggest why some people develop more serious symptoms than others, however it is postulated that external stressors in a patient's life could potentially play a key role. The EBV infection does not necessarily affect only people with compromised immunity and quite often, those that contract mononucleosis appear fit and healthy.

Mononucleosis is considered relatively contagious and is transmitted through contact with saliva or mucus, which can occur by kissing or by the sharing of drinks and utensils. In some instances, transmission has been linked to blood and may occur through transfusion. Infected people may be contagious while symptomatic but even asymptomatic persons can carry and spread the virus for life, and, as such, remain a primary reservoir for transmission.

Scope and Distribution

EBV is found worldwide. Mononucleosis most frequently occurs in young adults between 15 and 17 years of age, but it potentially affects people of all ages. One to three percent of college students are affected annually.

Generally, most people will contract EBV at some stage of their life and in the United States, 95% of 35 to 40 year-olds have previously been infected. In most cases, previous infection will have occurred without recognition or diagnosis. This is due to the fact that during early childhood, infection is mild, usually producing no symptoms, or only mild symptoms similar to the common cold.

The statistics are much the same for developing nations, where 90% of children contract asymptomatic EBV when under five years old. These individuals are then not susceptible to mononucleosis caused by EBV. It is interesting to note that mononucleosis is a disease that more commonly affects people in developed countries than those in developing countries. Variations in social etiquette and acceptable social behaviors may account for such differences, since mononucleosis is a disease that requires direct contact with saliva for transmission, such as through intimate kissing. Another theory accounting for this difference is that in developing countries, individuals are likely to be exposed to EBV while young, and so would develop a mild form of the infection. In developed countries, individuals may be protected from the virus until adolescence. Without the immunity conferred by prior infection, mononucleosis would develop.

There does not appear to be a strong link between the health status of a person and the extent to which they will develop mononucleosis, but potentially people who have a compromised immune systems may be at higher risk of developing mononucleosis when infected with EBV.

The global scope of EBV almost certainly ensures the continued transmission of the disease. Most cases of mononucleosis occur sporadically and outbreaks are rare. In most cases, people presenting symptoms of the disease have no recollection of possible exposure to the virus, and it is uncommon that infection would be transmitted to a group from a single source. In any large adult group environment, over 90% of the people will probably have been exposed to the EBV previously and, in such situations, an outbreak is unlikely.

There are no known ethnic, racial, or sexual factors that predispose a person to develop mononucleosis. However, it is interesting to note that, in developed countries, infection more often occurs in persons belonging to a higher socioeconomic class. This may be attributed to differences in lifestyle and increased opportunities for the social interactions associated with this disease. In addition, the fact that these individuals receive a higher level of protection from childhood infections may also play a role. The only gender-related factor associated with mononucleosis is that 90% of cases of ruptured spleens occur in males.

Treatment and Prevention

Diagnosis of mononucleosis may be confirmed through serological testing to determine the presence of abnormal white blood cells. The “mono spot” test is a specific test designed to detect the presence of antibodies that have developed as a result of the viral infection. These are known as heterophile antibodies and usually develop about one week after onset of the disease. They peak during the first month of illness, but may persist in the blood for several months and up to one year. Some people infected with mononucleosis may never develop these antibodies and so the test may return a false negative result. Generally, the testing is accurate with false positive results occurring in only a small number of patients.

There is no vaccine or preventative medicine available for mononucleosis, largely due to the fact that it results from a viral infection. However, the severity of other infections related to EBV, in addition to a further understanding of the virus, has prompted scientists to investigate avenues for creating a potential vaccine. It is likely that the vaccine would be targeted towards minimizing the clinical manifestations of primary infection with EBV, rather than towards malignancies associated with the disease.

The fact that EBV infection in early childhood seldom results in development of mononucleosis, while primary infection occurring after adolescence develops into the disease in 35–50% of cases has encouraged researchers. This observation suggests that a vaccine generating a minimized immune response may potentially limit the clinical symptoms of mononucleosis. The limiting factor in this area of research is that such a vaccine requires the use of an attenuated (weakened) virus, which has been deemed unsafe for administration to healthy adolescents. For this reason, it is unlikely that the vaccine would meet strict licensing laws.

In most cases, mononucleosis resolves within four weeks after symptoms first arise, during which time treatments are targeted at the symptoms of the infection. Rest is one of the key elements to recuperation and maintenance of fluid intake is essential. Patients are also advised to avoid heavy activity for at least one month following initial infection to reduce the risk of spleen rupture. Nonsteroidal anti-inflammatory (NSAID) medication may be used to treat pain and reduce fever and swelling, and dietary supplements may help boost the immune system. Antibiotics may be useful in treating throat infections often accompanying mononucleosis, but will not be effective against EBV. It is not recommended that patients use aspirin due to the possibility of developing Reye's syndrome, a potentially fatal disease.

The typically benign and self-limiting course of mononucleosis, in addition to the ubiquitous nature of the virus, makes prevention virtually impossible. With over 90% of the western adult population returning positive tests for previous infection, person-to-person infection remains highly likely in societies worldwide.

Prevention of the disease may not be beneficial. As noted, childhood infection with EBV typically results in few or no symptoms. In contrast, infection during adolescence tends to result in a more serious disease. This suggests that intentional early primary exposure could potentially be used as a method of preventing the later onset of mononucleosis.

Impacts and Issues

The statistics show that inevitably, at some stage of their life, almost the entire world population will be exposed to, contract, and harbor the Epstein-Barr virus. However, the majority of people who encounter infection during early childhood will not even develop mononucleosis. It is the omnipresence of EBV that prevents the eradication of the infection.

WORDS TO KNOW

ANTIBODY: Antibodies, or Y-shaped immunoglobulins, are proteins found in the blood that help to fight against foreign substances called antigens. Antigens, which are usually proteins or polysaccharides, stimulate the immune system to produce antibodies. The antibodies inactivate the antigen and help to remove it from the body. While antigens can be the source of infections from pathogenic bacteria and viruses, organic molecules detrimental to the body from internal or environmental sources also act as antigens. Genetic engineering and the use of various mutational mechanisms allow the construction of a vast array of anti-bodies (each with a unique genetic sequence).

CHRONIC FATIGUE SYNDROME: Chronic fatigue syndrome (CFS) is a condition that causes extreme tiredness. People with CFS have debilitating fatigue that lasts for six months or longer. They also have many other symptoms. Some of these symptoms are pain in the joints and muscles, headache, and sore throat. CFS appears to result from a combination of factors.

EPSTEIN BARR VIRUS (EBV): Epstein-Barr virus (EBV) is part of the family of human herpes viruses. Infectious mononucleosis (IM) is the most common disease manifestation of this virus, which once established in the host, can never be completely eradicated. Very little can be done to treat EBV; most methods can only alleviate resultant symptoms.

MONO SPOT TEST: The mononucleosis (mono) spot test is a blood test used to check for infection with the Epstein-Barr virus, which causes mononucleosis.

MONONUCLEAR LEUKOCYTE: A mononuclear leukocyte is a type of white blood cell active in the immune system.

The impact of mononucleosis may be seen on a personal level. Severe cases may keep patients in bed and away from their normal activities for many weeks or even months. This is a particular problem for students, since they may miss classes during this time. In addition, being removed from social groups for extended periods may generate emotional issues among adolescents. This is especially significant considering that the disease commonly occurs at an important time in social development.

In addition, social pressures can occur when adults contract mononucleosis. Adults may lose income due to an inability to work, which may put economic pressures on families and further strain family relationships. Such concerns may lead individuals to shorten their recovery period and return to their regular activities earlier than recommended. In these cases, symptoms of fatigue may persist for longer than usual and result in lower productivity.

In some chronic cases of the disease, patients suffer symptoms for more than six months and sometimes for years. In many chronic cases, it is considered that the mononucleosis contributed to the development of chronic fatigue syndrome (CFS). Although the exact causes of CFS have not been identified, approximately 10% of mononucleosis patients will go on to suffer from it and so CFS is considered a possible side effect of the disease. In these situations, people are unable to work, study, or socialize for long periods of time and, sometimes, permanently.

Cases of mononucleosis are generally much more severe in people with compromised immunity, and the complications that develop from such infections may prove fatal. Immunocompromised individuals include those who have undergone organ or marrow transplants, individuals receiving chemotherapy, and those with autoimmune diseases. The development of an immune disorder later in life may also result in a severe relapse of mononucleosis infection among people who previously only carried the virus in a latent form. While fatalities resulting from mononucleosis were previously a rare occurrence, the growing numbers of people suffering from immune disorders makes this a potentially significant threat in the future.

Bone marrow has been identified as one site of latent EBV persistence within the body. It has also been observed that an EBV-positive individual who receives a bone marrow transplant from an EBV-negative donor is found to be EBV-negative following transplantation. This means that this recipient is again susceptible to infection and most likely, if the transplant occurs during adulthood, will develop mononucleosis. This raises a new concern—the loss of immunity to certain diseases following transplantation. This could become a more serious problem as organ transplantation becomes a more common procedure.

Primary Source Connection

A diagnosis of mononucleosis can mean a period of convalescence for about two months, and that is usually a difficult order for an otherwise healthy teenager or young adult, who are the prime ages for infection with the viruses that cause mono. In the following article from the FDA Consumer, author Judith Levine Willis discusses mono and it's implications for physical and social limitations for young people. At the time the article was published in 1998, Judith Levine Willis was on the public affairs staff of the Food and Drug Administration. She has since authored, as Judith Levine, books about gender, health, and consumer issues.

Mono: Tough for Teens and Twenty-Somethings

Missed parties. Postponed exams. Sitting out a season of team sports. And loneliness. These are a few of the ways that scourge of high school and college students known as “mono” can affect your life.

The disease whose medical name is infectious mononucleosis is most common in people 10 to 35 years old, with its peak incidence in those 15 to 17 years old. Only 50 people out of 100,000 in the general population get mono, but it strikes as many as 2 out of 1,000 teens and twenty-somethings, especially those in high school, college, and the military. While mono is not usually considered a serious illness, it may have serious complications. Without a doubt your lifestyle will change for a few months.

You've probably heard people call mono the “kissing disease.” But if your social life is in a slump, you may wonder, “How did I get this ‘kissing disease’ when I haven't kissed anyone romantically recently?”

Here's how. Mono is usually transmitted though saliva and mucus—which is where the “kissing disease” nickname comes from. But the kissing or close contact that transmits the disease doesn't happen right before you get sick. The virus that causes mono has a long incubation period: 30 to 50 days from the time you're exposed to it to the time you get sick. In addition, the virus can be transmitted in other ways, such as sipping from the same straw or glass as an infected person—or even being close when the person coughs or sneezes. Also, some people can have the virus in their systems without ever having symptoms and you can still catch it from them.

Two viruses can cause mono: Epstein-Barr virus (EBV) and cytomegalovirus (CMV). Both viruses are in the herpes family, whose other members include viruses responsible for cold sores and chickenpox.

EBV causes 85 percent of mono cases. About half of all children are infected with EBV before they're 5, but at that young age, it usually doesn't cause any symptoms. If you don't become infected with EBV until you're a teen or older, you're more likely to develop mono symptoms. After you're infected, the virus stays with you for life, but usually doesn't cause any additional symptoms. Still, every now and then you may produce viral particles in your saliva that can transmit the virus to other people, even though you feel perfectly fine. By age 40, 85 to 90 percent of Americans have EBV antibodies, indicating they have the virus in their systems and are immune to further EBV infection.

CMV is also a very common virus. About 85 percent of the U.S. population is infected with it by the time they reach adulthood. As with EBV, CMV is frequently symptomless, and mono most often results when infection occurs in the teens and 20s. Sore throat is less common in people who have CMV mono than in those infected with EBV.

As another one of its nicknames—glandular fever— implies, perhaps the most distinguishing mono symptom is enlarged glands or lymph nodes, especially in the neck, but also in the armpit and groin.

Another common mono symptom is fever. A temperature as high as 39.5 degrees Celsius (103 degrees Fahrenheit) is not uncommon. Other symptoms include a tired achy feeling, appetite loss, white patches on the back of the throat, and tonsillitis.

“My tonsils got so swollen they were touching each other in back,” says Heidi Palombo of Annandale, Va., who had mono when she was a senior in college. She recalls her throat being “so hot and swollen that the only thing that felt good was ice water.”

Cold drinks and frozen desserts are both ways to relieve sore throat symptoms. Doctors also recommend gargling with saltwater (about half a teaspoon salt to 8 ounces of warm water) and sucking on throat lozenges available over the counter in pharmacies and other stores. If throat or tonsils are infected, a throat culture should be taken so the doctor can prescribe an appropriate antibiotic. Ampicillin is usually not recommended because it sometimes causes a rash that can be confused with the pink, measleslike rash that 1 out of 5 mono patients develops.

For fever and achiness, you can take acetaminophen (marketed as Tylenol, Datril and others) or ibuprofen (marketed as Advil, Motrin, Nuprin, and others). If you're under 20, don't take aspirin unless your doctor approves it. In children and teens, aspirin taken for viral illnesses has been associated with the potentially fatal disease Reye syndrome. Sometimes a person with mono may have trouble breathing because of swelling in the throat, and doctors have to use other medications and treatment. A person who has mono—or those caring for the person—should contact a doctor immediately if the person starts having breathing problems.

Some people with mono become overly sensitive to light and about half develop enlargement of the spleen, usually two to three weeks after they first become sick. Mild enlargement of the liver may also occur.

Whether or not the spleen is enlarged, people who have mono should not lift heavy objects or exercise vigorously—including participating in contact sports—for two months after they get sick, because these activities increase the risk of rupturing the spleen, which can be life-threatening. If you have mono and get a severe sharp, sudden pain on the left side of your upper abdomen, go to an emergency room or call 911 immediately.

Because its symptoms can be very similar to those of other illnesses, doctors often recommend tests to find out exactly what the problem is.

“I was misdiagnosed at first and told I was bit by a spider,” writes John L. Gipson, of Kansas City, Mo., in a note he posted to a Website. “That's what I thought because I had killed a spider in my room. I figured I'd been bitten by a spider in my sleep. A few days after. I had no energy, a fever. and those pea-sized bumps on the back of my neck.” Gipson returned to his doctor, who did blood tests and diagnosed mononucleosis.

Other diagnostic problems can result because enlarged lymphocytes, a type of white cell, are common with mono, but can also be a symptom of leukemia. Blood tests can distinguish between the type of white cell seen in leukemia and that with mono.

If your throat is sore, having a throat culture is usually a good idea for several reasons. First, the symptoms of mono and strep infection (including that caused by Strep-A, a particularly serious form of strep) are very similar. Second, strep throat or other throat infections can develop anytime during or shortly after in the disease. In any case, it's important that throat infections be diagnosed as soon as possible and treated with antibiotics that can kill the organism responsible for the infection.

The test most commonly used to tell whether you have mono or some other ailment is the mononucleosis spot test. This blood test detects the antibodies (proteins) that the body makes to fight EBV or CMV. Because it takes a while for antibodies to develop after infection, your doctor may need to order or repeat the test one to two weeks after you develop symptoms. At that time the test is about 85 percent accurate.

Other tests your doctor might order include a complete blood count (CBC) to see if your blood platelet count is lower than normal and if lymphocytes are abnormal, and a chemistry panel to see if liver enzymes are abnormal.

Bed rest is the most important treatment for uncomplicated mono. It's also important to drink plenty of fluids. Mono is not usually a reason to quarantine students. Many people are already immune to the viruses that cause it. But if you have mono you'll want to stay in bed and out of classes for several days, until the fever goes down and other symptoms abate. Even when you've started to get better, you can expect to have to curtail your activities for several weeks, and it can take two to three months or more until you feel your old self again.

The author of this article had mono herself when she was 16. Though she didn't mind getting out of all that homework (or at least putting it off), having to delay finals only added to her anxiety about college applications that many high school juniors experience. And then there was that guy who never called again.

When you add the time spent recuperating to the fact that most people are not exactly anxious to get close to a person with mono, you can understand why some students find themselves combating loneliness on top of their other troubles.

Getting through mono may be both challenging and depressing—and seem to take forever. But if you rest when your body tells you to, you can lessen the chances of complications and get back your life.

Judith Levine Willis

WILLIS, JUDITH LEVINE. “MONO: TOUGH FOR TEENS AND TWENTY-SOMETHINGS.” FDA CONSUMER (MAY, JUNE 1998): 32,3.

See AlsoBlood Supply and Infectious Disease; Cancer and Infectious Disease; Childhood Infectious Diseases, Immunization Impacts; Demographics and Infectious Disease; Viral Disease.

BIBLIOGRAPHY

Books

Collier, L., and J. Oxford. Human Virology. New York: Oxford University Press, 2006.

Mandell, G.L., J.E. Bennett, and R. Dolin. Principles and Practice of Infectious Diseases. 6th ed. Philadelphia: Elsevier, 2004.

Tselis, A., and H.B. Jenson. Epstein-Barr Virus. New York: Taylor & Francis, 2006.

Umar, C.S. New Developments in Epstein-Barr Virus Research. New York: Nova Science Publishers, 2006.

Web Sites

Centers for Disease Control and Prevention. “Epstein-Barr Virus and Infectious Mononucleosis.” 2007. <http://www.cdc.gov/ncidod/diseases/ebv.htm> (accessed March 7, 2007).

Mononucleosis, Infectious

What Is Mononucleosis?

How Common Is Mononucleosis?

How Is Mononucleosis Spread?

How Do People Know They Have Mononucleosis?

How Is Mononucleosis Diagnosed and Treated?

What Are Some Complications of Mononucleosis?

Can Mononucleosis Be Prevented?

Resources

Infectious mononucleosis (mah-no-nu-klee-O-sis), also known as mono, is an infectious illness usually caused by the Epstein-Barr (EP-steen BAR) virus (EBV). It often leads to fever, sore throat, swollen lymph nodes*, and tiredness.

*lymph

(LIMF) nodes are small, bean-shaped masses of tissue that contain immune system cells that fight harmful microorganisms. Lymph nodes may swell during infections.

KEYWORDS

for searching the Internet and other reference sources

Burkitt’s lymphoma

Cytomegalovirus

Epstein-Barr virus (EBV)

Mono

What Is Mononucleosis?

By the time they are 40, as many as 95 percent of adults in the United States have evidence in their blood of a previous EBV infection. Many of these infections are never recognized, especially if they occur in early childhood, because the symptoms look like those of other childhood viral illnesses. Some people infected with EBV have no symptoms. This occurs in many parts of the world where most people are infected early in life. In the United States, EBV infection is most common during adolescence and early adulthood (ages 15 to 25). One-third to one-half of teens who come into contact with the virus for the first time will develop symptoms of classic infectious mono: sore throat, swollen lymph nodes, fever, and extreme tiredness.

Mono most often is associated with acute* infection by EBV, but it is sometimes seen with acute cytomegalovirus* (CMV) infection, acute HIV* infection, and, rarely, other viruses.

*acute

describes an infection or other illness that comes on suddenly.

*cytomegalovirus

(sy-tuh-MEH-guh-lo-vy-rus), or CMV, infection is very common and usually causes no symptoms. It poses little risk for healthy people, but it can lead to serious illness in people with weak immune systems.

*HIV ,

or the human immunodeficiency (HYOO-mun ih-myoo-no-dih-FIH-shen-see) virus, is the virus that causes AIDS (acquired immunodeficiency syndrome).

Although the symptoms may be unpleasant, mono is generally a mild disease. After a person recovers, the virus remains dormant (inactive) in the body for life. It occasionally may reactivate but it rarely causes symptoms again. When people have been infected with the virus, whether or not they had symptoms, they usually will be immune* to future EBV-related illness.

*immune

(ih-MYOON) means resistant to or not susceptible to a disease.

How Common Is Mononucleosis?

EBV is one of the most common human viruses in the world. In the United States, cases of mono with symptoms most often are found in teens between the ages of 15 and 17. The illness occurs in 2 out of every 1,000 adolescents and young adults and is less common in other age groups.

How Is Mononucleosis Spread?

Mono is contagious, although less so than the common cold. EBV passes from person to person primarily through contact with saliva. Kissing and sharing food, drinks, or utensils commonly spread the virus. Although EBV is present in the respiratory tract*, it usually is not transmitted by coughing or sneezing. Some people will become sick and be able to spread the virus for weeks, especially those who are infected but do not feel sick

*respiratory tract

includes the nose, mouth, throat, and lungs. It is the pathway through which air and gases are transported down into the lungs and back out of the body.

and pass the virus to others without realizing it. The virus usually remains inactive after the first infection, but some people may spread it from time to time throughout their life.

How Do People Know They Have Mononucleosis?

Symptoms of mono develop between 4 and 6 weeks after infection and generally last 2 to 4 weeks. These include swollen lymph nodes, extreme tiredness, fever, sore muscles, and sore throat. Up to 50 percent of people with classic infectious mononucleosis will have a swollen spleen, and some will have an enlarged liver. Other symptoms may include loss of appetite, weakness, nausea (NAW-zee-uh), stiffness, headache, chest pain, and, rarely, jaundice*.

*jaundice

(JON-dis) is a yellowing of the skin, and sometimes the whites of the eyes, caused by a buildup in the body of bilirubin, a chemical produced in and released by the liver. An increase in bilirubin may indicate disease of the liver or certain blood disorders.

How Is Mononucleosis Diagnosed and Treated?

Symptoms of mono usually show up 1 to 4 weeks before the diagnosis is made. A physical exam, the patient’s age, and sometimes a history of contact with an infected person help the doctor make the diagnosis. An adolescent patient with a lasting fever, sore throat, and swollen lymph nodes, with or without an enlarged spleen, is likely to have mono.

Blood tests will confirm the diagnosis. A blood count will show an increased number of lymphocytes*, and many of them will look unusual. A positive rapid screening test may confirm the diagnosis by revealing EBV in the blood, but this test can be negative, especially early in the illness. More accurate antibody* testing may be done to rule out other viruses that can cause mono-like illnesses. Antibody testing checks several antibodies to determine if there is a current infection or evidence of past infection.

*lymphocytes

(LIM-fo-sites) are white blood cells, which play a part in the body’s immune system, particularly the production of antibodies and other substances to fight infection.

*antibody

(AN-tih-bah-dee) is a protein molecule produced by the body’s immune system to help fight a specific infection caused by a microorganism, such as a bacterium or virus.

There is no specific treatment for mono. Because it is a viral illness, antibiotics are not prescribed unless a secondary bacterial illness is present, such as strep throat. The best treatment for mono is rest. Over-the-counter medications such as acetaminophen (uh-see-teh-MIH-noh-fen) or ibuprofen may be taken to relieve fever and pain.

Steroids, medications that reduce inflammation, may be given to decrease swelling in the tonsils* and lymph nodes in the neck if a patient is experiencing difficulty swallowing or breathing. Playing contact sports is prohibited for someone who has mono because when the spleen and liver enlarge, they are more vulnerable to injury. Patients with mono are advised not to play contact sports for at least 1 month and to be examined and get a doctor’s permission before they start again.

*tonsils

are paired clusters of lymphatic tissue in the throat that help protect the body from bacteria and viruses that enter through a person’s nose or mouth.

Symptoms of mono usually clear up 1 to 2 months after they appear, but they can last as long as 4 months.

Kiss and Tell

Mono often is referred to as the “kissing disease” because the infection is spread primarily through direct contact with infected saliva.

What Are Some Complications of Mononucleosis?

Recovery from mono is usually uneventful, but sometimes complications occur. An enlarged spleen may rupture, which is an emergency that needs surgery. Fifty percent of patients with infectious mononucleosis will have some liver inflammation, but only a small number will have significant inflammation, or hepatitis (heh-puh-TIE-tis). Blood problems that can result from the infection include anemia*, decreased white cells (cells that fight infection), and low numbers of platelets (cells that help the blood clot). Mononucleosis also can lead to encephalitis (en-seh-fuh-LYE-tis, inflammation of the brain), Guillain-Barre (GEE-yan bah-RAY) syndrome (an inflammation of the nerves, which causes muscle weakness and paralysis*), and Bell’s palsy (PAWL-zee, a temporary weakness or paralysis of the muscles on one side of the face). Myocarditis (my-oh-kar-DYE-tis, an inflammation of the muscular walls of the heart) is a rare complication.

*anemia

(uh-NEE-me-uh) is a blood condition in which there is a decreased amount of oxygen-carrying hemoglobin in the blood and, usually, fewer than normal numbers of red blood cells.

*paralysis

(pah-RAH-luh-sis) is the loss or impairment of the ability to move some part of the body.

EBV and Cancer

EBV has been linked to the development later in life of Burkitt’s lymphoma (a rare blood disease of the lymph nodes seen mainly in Africa) and nasopharyngeal carcinoma (nay-zo-fair-in-JEE-ul kar-sih-NO-muh, a cancer in the throat area seen mainly in China). EBV also is linked to lymphoma in the United States, most notably in people with weakened immune systems, such as people who have HIV.

EBV also has been associated with cancers, such as lymphoma*, especially in patients with weak immune systems, such as people who have had organ transplants or who have HIV.

*lymphoma

(lim-FO-muh) refers to a cancerous tumor of lymphocytes, cells that normally help the body fight infection.

Can Mononucleosis Be Prevented?

There is nothing specific that a person can do to avoid contracting mono because EBV often is spread in the saliva of healthy people who have been infected in the past and who can still transmit the virus. Normal human behavior makes it practically impossible to prevent the spread of the disease.

See also

AIDS and HIV Infection

Cytomegalovirus (CMV) Infection

Encephalitis

Hepatitis, Infectious

Myocarditis/Pericarditis

Resources

Organizations

U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC is the U.S. government authority for information about infectious and other diseases. It posts information about mononucleosis at its website.

Telephone 800-311-3435 http://www.cdc.gov

U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894. The National Library of Medicine has a website packed with information on diseases such as mononucleosis, consumer resources, dictionaries and encyclopedias of medical terms, and directories of doctors and helpful organizations.

Telephone 888-346-3656 http://www.nlm.nih.gov

Website

KidsHealth.org. KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of children’s health. It contains articles on a variety of health topics, including mononucleosis.

http://www.KidsHealth.org

Infectious Mononucleosis

Definition

Infectious mononucleosis is a contagious illness caused by the Epstein-Barr virus that can affect the liver, lymph nodes, and oral cavity. While mononucleosis is not usually a serious disease, its primary symptoms of fatigue and lack of energy can linger for several months.

Description

Infectious mononucleosis, frequently called "mono" or the "kissing disease," is caused by the Epstein-Barr virus (EBV) found in saliva and mucus. The virus affects a type of white blood cell called the B lymphocyte producing characteristic atypical lymphocytes that may be useful in the diagnosis of the disease.

While anyone, even young children, can develop mononucleosis, it occurs most often in young adults between the ages of 15 and 35 and is especially common in teenagers. The mononucleosis infection rate among college students who have not previously been exposed to EBV has been estimated to be about 15%. In younger children, the illness may not be recognized.

The disease typically runs its course in four to six weeks in people with normally functioning immune systems. People with weakened or suppressed immune systems, such as AIDS patients or those who have had organ transplants, are particularly vulnerable to the potentially serious complications of infectious mononucleosis.

Causes and symptoms

The EBV that causes mononucleosis is related to a group of herpes viruses, including those that cause cold sores, chicken pox, and shingles. Most people are exposed to EBV at some point during their lives. Mononucleosis is most commonly spread by contact with virus-infected saliva through coughing, sneezing, kissing, or sharing drinking glasses or eating utensils.

In addition to general weakness and fatigue, symptoms of mononucleosis may include any or all of the following:

• Sore throat and/or swollen tonsils
• Fever and chills
• Nausea and vomiting, or decreased appetite
• Swollen lymph nodes in the neck and armpits
• Headaches or joint pain

• Enlarged spleen
• Jaundice
• Skin rash.

Complications that can occur with mononucleosis include a temporarily enlarged spleen or inflamed liver. In rare instances, the spleen may rupture, producing sharp pain on the left side of the abdomen, a symptom that warrants immediate medical attention. Additional symptoms of a ruptured spleen include light headedness, rapidly beating heart, and difficulty breathing. Other rare, but potentially life-threatening, complications may involve the heart or brain. The infection may also cause significant destruction of the body's red blood cells or platelets.

Symptoms do not usually appear until four to seven weeks after exposure to EBV. An infected person can be contagious during this incubation time period and for as many as five months after the disappearance of symptoms. Also, the virus will be excreted in the saliva intermittently for the rest of their lives, although the individual will experience no symptoms. Contrary to popular belief, the EBV is not highly contagious. As a result, individuals living in a household or college dormitory with someone who has mononucleosis have a very small risk of being infected unless they have direct contact with the person's saliva.

Diagnosis

If symptoms associated with a cold persist longer than two weeks, mononucleosis is a possibility; however, a variety of other conditions can produce similar symptoms. If mononucleosis is suspected, a physician will typically conduct a physical examination, including a "Monospot" antibody blood test that can indicate the presence of proteins or antibodies produced in response to infection with the EBV. These antibodies may not be detectable, however, until the second or third weeks of the illness. Occasionally, when this test is inconclusive, other blood tests may be conducted.

Treatment

The most effective treatment for infectious mononucleosis is rest and a gradual return to regular activities. Individuals with mild cases may not require bed rest but should limit their activities. Any strenuous activity, athletic endeavors, or heavy lifting should be avoided until the symptoms completely subside, since excessive activity may cause the spleen to rupture.

The sore throat and dehydration that usually accompany mononucleosis may be relieved by drinking water and fruit juices. Gargling salt water or taking throat lozenges may also relieve discomfort. In addition, taking over-the-counter medications, such as acetaminophen or ibuprofen, may relieve symptoms, but aspirin should be avoided because mononucleosis has been associated with Reye's syndrome, a serious illness aggravated by aspirin.

While antibiotics do not affect EBV, the sore throat accompanying mononucleosis can be complicated by a streptococcal infection, which can be treated with antibiotics. Cortisone anti-inflammatory medications are also occasionally prescribed for the treatment of severely swollen tonsils or throat tissues.

Prognosis

While the severity and length of illness varies, most people diagnosed with mononucleosis will be able to return to their normal daily routines within two to three weeks, particularly if they rest during this time period. It may take two to three months before a person's usual energy levels return. One of the most common problems in treating mononucleosis, particularly in teenagers, is that people return to their usual activities too quickly and then experience a relapse of symptoms. Once the disease has completely run its course, the person cannot be re-infected.

KEY TERMS

Antibody— A specific protein produced by the immune system in response to a specific foreign protein or particle called an antigen.

Herpes viruses— A group of viruses that can cause cold sores, shingles, chicken pox, and congenital abnormalities. The Epstein-Barr virus which causes mononucleosis belongs to this group of viruses.

Reye's syndrome— A very serious, rare disease, most common in children, which involves an upper respiratory tract infection followed by brain and liver damage.

Prevention

Although there is no way to avoid becoming infected with EBV, paying general attention to good hygiene and avoiding sharing beverage glasses or having close contact with people who have mononucleosis or cold symptoms can help prevent infection.

Resources

ORGANIZATIONS

National Institute of Allergy and Infectious Disease. Building 31, Room 7A-50, 31 Center Drive MSC 2520, Bethesda, MD 20892-2520. (301) 496-5717. 〈http://www.niaid.nih.gov/default.htm〉.

OTHER

"Communicable Disease Fact Sheet." New York State Department of Health.

"Mononucleosis: A Tiresome Disease." Mayo Clinic Online. 〈http://www.mayo.ivi.com/mayo/9701/htm/mono.htm〉.

Infectious mononucleosis

Definition

Infectious mononucleosis is a contagious illness caused by the Epstein-Barr virus that can affect the liver, lymph nodes, and oral cavity. While mononucleosis is not usually a serious disease, its primary symptoms of fatigue and lack of energy can linger for several months.

Description

Infectious mononucleosis, frequently called "mono" or the "kissing disease," is caused by the Epstein-Barr virus (EBV) found in saliva and mucus. The virus affects a type of white blood cell called the B lymphocyte, producing characteristic atypical lymphocytes that may be useful in the diagnosis of the disease.

The disease typically runs its course in four to six weeks in people with normally functioning immune systems. People with weakened or suppressed immune systems, such as AIDS patients or those who have had organ transplants, are particularly vulnerable to the potentially serious complications of infectious mononucleosis.

Demographics

While anyone, even young children, can develop mononucleosis, it occurs most often in young adults between the ages of 15 and 35 and is especially common in teenagers. The mononucleosis infection rate among college students who have not previously been exposed to EBV has been estimated to be about 15 percent. In younger children, the illness may not be recognized.

Causes and symptoms

The EBV that causes mononucleosis is related to a group of herpes viruses, including those that cause cold sores, chickenpox , and shingles. Most people are exposed to EBV at some point during their lives. Mononucleosis is most commonly spread by contact with virus-infected saliva through coughing, sneezing, kissing, or sharing drinking glasses or eating utensils.

In addition to general weakness and fatigue, symptoms of mononucleosis may include any or all of the following:

• sore throat and/or swollen tonsils
• fever and chills
• nausea and vomiting , or decreased appetite
• swollen lymph nodes in the neck and armpits
• headaches or joint pain
• enlarged spleen
• jaundice
• skin rash

Complications that can occur with mononucleosis include a temporarily enlarged spleen or inflamed liver. In rare instances, the spleen may rupture, producing sharp pain on the left side of the abdomen, a symptom that warrants immediate medical attention. Additional symptoms of a ruptured spleen include light-headedness, rapidly beating heart, and difficulty breathing. Other rare, but potentially life-threatening, complications may involve the heart or brain. The infection may also cause significant destruction of the body's red blood cells or platelets.

Symptoms do not usually appear until four to seven weeks after exposure to EBV. An infected person can be contagious during this incubation time period and for as many as five months after the disappearance of symptoms. Also, the virus will be excreted in the saliva intermittently for the rest of their lives, although the individual will experience no symptoms. Contrary to popular belief, the EBV is not highly contagious. As a result, individuals living in a household or college dormitory with someone who has mononucleosis have a very small risk of being infected unless they have direct contact with the person's saliva.

Diagnosis

If symptoms associated with a cold persist longer than two weeks, mononucleosis is a possibility; however, a variety of other conditions can produce similar symptoms. If mononucleosis is suspected, a physician will typically conduct a physical examination, including a "Monospot" antibody blood test that can indicate the presence of proteins or antibodies produced in response to infection with the EBV. These antibodies may not be detectable, however, until the second or third weeks of the illness. Occasionally, when this test is inconclusive, other blood tests may be conducted.

Treatment

The most effective treatment for infectious mononucleosis is rest and a gradual return to regular activities. Individuals with mild cases may not require bed rest but should limit their activities. Any strenuous activity, athletic endeavors, or heavy lifting should be avoided until the symptoms completely subside, since excessive activity may cause the spleen to rupture.

The sore throat and dehydration that usually accompany mononucleosis may be relieved by drinking water and fruit juices. Gargling salt water or taking throat lozenges may also relieve discomfort. In addition, taking over-the-counter medications, such as acetaminophen or ibuprofen, may relieve symptoms, but aspirin should be avoided because mononucleosis has been associated with Reye's syndrome , a serious illness aggravated by aspirin.

While antibiotics do not affect EBV, the sore throat accompanying mononucleosis can be complicated by a streptococcal infection, which can be treated with antibiotics. Cortisone anti-inflammatory medications are also occasionally prescribed for the treatment of severely swollen tonsils or throat tissues.

Prognosis

While the severity and length of illness varies, most people diagnosed with mononucleosis are able to return to their normal daily routines within two to three weeks, particularly if they rest during this time period. It may take two to three months before a person's usual energy levels return. One of the most common problems in treating mononucleosis, particularly in teenagers, is that people return to their usual activities too quickly and then experience a relapse of symptoms. Once the disease has completely run its course, the person cannot be reinfected.

Prevention

Although there is no way to avoid becoming infected with EBV, paying general attention to good hygiene and avoiding sharing beverage glasses or having close contact with people who have mononucleosis or cold symptoms can help prevent infection.

Parental concerns

The main concern for parents of children with mononucleosis is to keep the child resting until he or she fully recovers from the illness. Parents should also be aware of the symptoms of more serious complications of the liver and spleen, and should seek medical attention for a child who complains of severe abdominal pain, light-headedness, rapid heartbeat, or difficulty breathing.

KEY TERMS

Antibody —A special protein made by the body's immune system as a defense against foreign material (bacteria, viruses, etc.) that enters the body. It is uniquely designed to attack and neutralize the specific antigen that triggered the immune response.

Herpes virus —A family of viruses including herpes simplex types 1 and 2, and herpes zoster (also called varicella zoster). Herpes viruses cause several infections, all characterized by blisters and ulcers, including chickenpox, shingles, genital herpes, and cold sores or fever blisters.

Reye's syndrome —A serious, life-threatening illness in children, usually developing after a bout of flu or chickenpox, and often associated with the use of aspirin. Symptoms include uncontrollable vomiting, often with lethargy, memory loss, disorientation, or delirium. Swelling of the brain may cause seizures, coma, and in severe cases, death.

Resources

BOOKS

Jensen, Hal B. "Epstein-Barr Virus." In Nelson Textbook of Pediatrics. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2004.

Katz, Ben Z. "Epstein-Barr Virus (Mononucleosis and Lymphoproliferative Disorders)." In Principles and Practice of Pediatric Infectious Diseases, 2nd ed. Edited by Sarah S. Long et al. St. Louis, MO: Elsevier, 2003.

PERIODICALS

Auwaerter, P. G. "Infectious mononucleosis: return to play." Medical Clinics of North America 23 (July 2004): 485–97.

ORGANIZATIONS

National Institute of Allergy and Infectious Disease. Building 31, Room 7A-50, 31 Center Drive MSC 2520, Bethesda, MD 20892–2520. Web site: <www.niaid.nih.gov/default.htm>.

Susan J. Montgomery Rosalyn Carson-DeWitt, MD