Mononucleosis
Basic Information
Mononucleosis is an acute viral infection that is caused by members of the herpes virus family. It is commonly referred to as "mono" or the "kissing disease". Although the Epstein Barr herpes virus (EPV) is responsible for an estimated 90 percent of all mononucleosis cases, the cytomegalovirus can also cause infectious mononucleosis. There are no vaccines. At the same time, although a person will always carry EPV once infected, a healthy immune system can suppress any further recurrence of the infection. Typically, once a person has had mononucleosis, the person develops a long-lasting immunity and the infection never comes back. It is called mononucleosis because during infection, the number of white cells (called the mononuclear cells) in the blood increases significantly.
EPV infects and multiplies in the salivary glands. It can be transmitted through close contact with infected saliva or mucus, such as through coughing, sneezing, kissing or sharing beverage containers. Although epidemic outbreaks in institutions such as schools or office spaces are possible, most doctors say it is not necessary to quarantine a person with mononucleosis. It is simply suggested that anyone in close proximity to the infected person avoid contact with the person's saliva.
Anybody is at risk of mononucleosis infection. It is an extremely common infection, with almost 80 percent of all people over the age of 40 having had mononucleosis at some time in their lives. It typically affects persons between the ages of 15 and 30. The incidence of mononucleosis in the United States is much lower than other countries. In the United States, mononucleosis affects an estimated 2 out of every 1000 adolescents and young adults, with the rate being significantly higher among college students.
Symptoms
A mononucleosis infection can happen without symptoms, or the symptoms can be so mild that they may not be noticed. When there are symptoms, they may not be present until two to eight weeks after exposure to the virus. The incubation period is even shorter for young children.
The person is most likely carrying an infectious virus several days before symptoms appear. Mononucleosis is self-limiting, which means that the symptoms gradually diminish on their own. This disappearance of symptoms usually takes anywhere from weeks to months. However, the person can still be infectious even after the symptoms have gone away. Certain studies have found the virus still present in the saliva of mononucleosis-infected persons as long as six months after the acute infection has disappeared.
It is possible for young children to not show any symptoms, or to have vague symptoms such as fever, mild sore throat, general malaise, and loss of appetite. Mononucleosis may also be difficult to diagnose in older adults. An adult might have mononucleosis if they have had a high fever for at least a week, have an enlarged liver, or have neurological symptoms. Adolescents or young adults will have the more classic symptoms, which in most cases develop slowly. These symptoms may include:
- fever; lasts approximately one week
- sore throat
- headaches
- white patches on the back of the throat
- swollen lymph nodes (neck, armpit, and throat)
- fatigue and drowsiness
- loss of appetite
- enlarged spleen
- sore muscles
- a pink rash may occur; particularly in those who have been treated with ampicillin
- chilliness
- puffy eyelids
- enlarged tonsils
- facial swelling
- jaundice (yellowing of skin)
Diagnosis/Treatment
When a person goes to a doctor, the first thing most doctors do is ask about symptoms. Unfortunately, symptoms of mononucleosis can be vague or misleading. In many instances, the symptoms resemble those of other diseases or infections. However, once a doctor suspects mononucleosis, there are many tests that can immediately detect the presence of the Epstein-Barr virus in the body. Blood tests are the most common type of test used to determine the diagnosis.
As the Epstein-Barr virus enters the body, the immune system reacts in such a way as to destroy the viral invader. In many cases, a doctor can observe this immune system reaction in order to tell if the person has mononucleosis. For instance, the presence of a foreign virus will trigger the increased production of both atypical lymphocytes (a certain kind of white blood cell that destroys viral infections) and body-protecting anti-bodies. A blood sample can detect unusually high levels of these immune system agents in the bloodstream, and hence, can be used in the diagnosis of mononucleosis. These blood tests are rapid and inexpensive.
Another popular test used to diagnose mononucleosis is the slide agglutination mono "spot test". This is a screen for the elevated levels of antibodies that the body generates to fight off Epstein-Barr virus. It is also rapid and expensive. One problem with the mono spot test is that it can give misleading results, particularly because sometimes the overproduction of antibodies is delayed. It might be necessary to take the test twice. Another problem is that in cases where the classic symptoms are not exhibited, the body might not develop the antibodies at all.
An EPV serologic profile can very precisely determine whether or not the Epstein-Barr virus antigen is present in the body. While most blood tests search for antibodies that can be found in the body during several kinds of viral attacks besides mononucleosis, the EPV serologic profile looks for the appearance of antibody-producing antigens produced by the body specifically to combat mononucleosis caused by the Epstein-Barr virus. The test is extremely accurate, but it can be costly.
A physical examination can also be used to see if the person has either an enlarged spleen or an enlarged liver. If these organs are enlarged, they will be overly sensitive when gently pressed.
Because mononucleosis is self-limiting, most infected persons recover within a month to two months without medication. This is good thing because, currently, there are no antibiotic medications that help. Because the infection will go away on its own, the focus of treatment is the alleviation of symptoms. The most important part of treatment is rest. It is sometimes necessary to avoid strenuous activity for as long as a month or longer. Not only will this conserve the person's energy if they are feeling constant fatigue, but it will also reduce the possibility of damaging the already enlarged spleen. Besides rest, an infected person needs to drink plenty of fluids and have a high protein, decreased fat diet.
If the person has a sore throat, they can gargle with warm salt water. In order to relieve pain, headaches, and chills, the doctor might prescribe acetaminophen or ibuprofen. It is important that children or adolescents with fevers do not take aspirin. This can lead to Reye's syndrome, a potentially fatal illness. In episodes where the infected person gets streptococcal throat infections, the doctor should recommend penicillin rather than ampicillin. Eighty percent of all people infected with mononucleosis who take ampicillin develop a rash.
In most mononucleosis cases, the fever subsides in ten days, the swollen lymph glands and enlarged spleen heal recover in month, and the fatigue goes away after a month or more. Sometimes, however, the infection progresses into a more serious condition. These complications are more likely to happen with older adults. One particular complication that can occur if the patient does not refrain from physical exertion is a ruptured spleen. Although ruptured spleens are rare in people with mononucleosis, it is still important to avoid strenuous exercise. If a person feels pain under the left chest, feels lightheaded, has a rapidly beating heart, or is having trouble breathing, it is important to contact a doctor immediately. In such an instance, the spleen will have to be removed surgically. Other complications that might arise include airway obstruction, secondary throat infection, neurologic problems such as seizures, hepatitis, hemolytic anemia, or inflammation of the heart or central nervous system. Airway obstruction and inflammation of the heart or central nervous system are potentially fatal conditions that can be treated with steroid drugs.