Infectious Mononucleosis
Definition
Infectious mononucleosis is a highly contagious disease caused by the
Epstein-Barr virus (EBV) and spread primarily by contact with the saliva
of an infected person. Although the disease is sometimes known as the
mononucleosis can also be spread through blood and genital secretions
(although these forms of transmission are very rare).
Description
EBV is a very common virus worldwide; most people become infected
with it at some point in their lives. Many people become infected with
the virus and never develop noticeable symptoms. Those who do develop
symptoms typically experience about two weeks of fever, sore throat, and
swollen lymph nodes in the neck, throat, or armpits. Although mononucleosis
is not a major threat to health, it is a common cause of absence
from school or work in teenagers and young adults because it can lead
to weeks or months of fatigue and lowered energy.Demographics
In the United States, mononucleosis is most common in teenagers and
young adults; it is more common in younger children in developing
countries. People in any age group can get the disease if they are exposed,
however. As many as 95 percent of American adults between thirty-five
and forty years of age have been infected, although not all of these have
had the symptoms of the illness. When infection with EBV occurs
during adolescence or young adulthood, it causes infectious mononucleosis
between 35 and 50 percent of the time.
Males and females are equally likely to get mononucleosis, as are
people of all races and ethnic groups.
Causes and Symptoms
Infectious mononucleosis is caused by the Epstein-Barr virus, or EBV.
The virus is normally transmitted by contact with the saliva of an
infected person; it is not ordinarily transmitted through the air. The virus
takes about four to six weeks to incubate, and thus infected persons can
spread the disease to others over a period of several weeks. After entering
the patient
a certain type of white blood cell produced in the bone marrow. The
infected B cells are then carried into the lymphatic system, where they
affect the liver and spleen and cause the lymph nodes to swell andenlarge. The infected B cells are also responsible for the fever, swelling of
the tonsils, and sore throat that characterize mononucleosis.
After the symptoms of mononucleosis go away, the EBV virus remains
in a few cells in the patient
life. The virus occasionally reactivates and may appear in samples of
the person
transmitted (given) to a susceptible person. Mononucleosis does not cause
any problems during pregnancy, such as miscarriages or birth defects.
The primary symptoms of mononucleosis are fever, sore throat, and
swollen lymph nodes in the throat, armpit, or neck. Other common
symptoms include:
’s throat tissues or blood for the rest of the person’s’s saliva, it does not cause new symptoms of illness, it may be•
Swelling or enlargement of the spleen or liver•
General discomfort and mild muscle aches•
Sleepiness and fatigue•
Loss of appetite•
Skin rash•
Swollen tonsils or a yellowish coating on the tonsils•
Less common symptoms of mononucleosis that some patients
experience include:
Night sweats•
Headache•
Stiff neck•
Sensitivity to light•
Shortness of breath and chest pain•
Nosebleed•
Hives•
JaundiceDiagnosis
The diagnosis of mononucleosis is usually based on the results of blood
tests combined with the doctor
neck. The doctor will also tap on or feel the patient
whether the liver and spleen have become enlarged.
A patient infected by EBV will have an increased number of certain
white blood cells in the blood sample called atypical lymphocytes, and
antibodies to the Epstein-Barr virus. These antibodies can be detectedby a test called the monospot test, which gives results within a day but
may not be accurate during the first week of the patient
type of blood test for EBV antibodies takes longer to perform but gives
more accurate results within the first week of symptoms.
’s illness. AnotherTreatment
There is no cure for mononucleosis because it is caused by a virus; it
cannot be treated by antibiotics. Treatment consists of self-care at home
until the symptoms go away. Patients should rest in bed if possible and
drink plenty of fluids. Non-aspirin pain relievers like Advil or Tylenol
can be taken to bring down the fever and relieve muscle aches and pains.
Throat lozenges or gargling with warm salt water may help ease the discomfort
of a sore throat.
Because mononucleosis can affect the spleen, patients should avoid
vigorous exercise or contact sports for at least one month after the onset
of symptoms or until the spleen returns to its normal size. This precaution
will lower the risk of rupture of the spleen.
Prognosis
Mononucleosis rarely causes serious complications. In most patients, the
fever goes down in about ten days, but fatigue may last for several weeks
or months. Some people do not feel normal again for about three
months. A patient who feels sick longer than four months, however,
should go back to the doctor to see whether they have another disease
or disorder in addition to mononucleosis. In some cases, the patient is
diagnosed with chronic fatigue syndrome or CFS. The Epstein-Barr virus
does not cause CFS; however, it appears to make some patients with
mononucleosis more susceptible to developing chronic fatigue syndrome.
One way to speed complete recovery from infectious mononucleosis
is to get plenty of rest early in the disease; the more rest patients get at the
beginning, the more quickly they recover.
Severe complications of mononucleosis are unusual but may include
rupture of the spleen, which occurs in 0.5 percent of patients
of them males who returned to sports too quickly. Airway obstruction
may develop in one patient per thousand, most often a small child.
This complication can be treated with steroid medications. Between 1 and
3 percent of patients may develop a form of anemia that can also be
treated with steroids.Prevention
There is no vaccine that can prevent mononucleosis. In addition, the fact
that many people can be infected with the virus and transmit it to others
without having symptoms of the disease means that mononucleosis is
almost impossible to prevent. The best precautionary measure is for
patients who have been diagnosed with mono to avoid kissing, or other
close personal contact with, others and to wash their drinking glasses, food
dishes, and eating utensils separately from those of other family members
or friends for several days after the fever goes down. It is not necessary for
people with mono to be completely isolated from other people, however.
Because the Epstein-Barr virus remains in the body after the symptoms
of mononucleosis go away, people who have had the disease should
not donate blood for at least six months after their symptoms started.
The Future
As of 2008 researchers were working on a vaccine against EBV. In
December 2007 the
developed in Belgium shows promise in preventing mononucleosis. The
vaccine must undergo further clinical trials, however, before it can be
definitely shown to be effective and licensed for use in the United States.
Journal of Infectious Diseases reported that a vaccineSEE ALSO
Chronic fatigue syndromeFor more information
BOOKS
Decker, Janet.
Hoffmann, Gretchen.
2006.
Marcovitz, Hal. PERIODICALS
American Academy of Family Physicians.
Know about Infectious Mononucleosis.
October 1, 2004. Available online at http://www.aafp.org/afp/20041001/
1289ph.html (accessed June 6, 2008).
Baragona, Steve.
“Patient Information: Things to” American Family Physician,“Vaccine Shows Promise in Preventing Mono.” News release,Journal of Infectious Diseases
idsociety.org/Content.aspx?id=8728 (accessed June 6, 2008).
, December 10, 2007. Available online at http://WEB SITES
Mayo Clinic.
health/mononucleosis/DS00352 (accessed June 5, 2008).
National Center for Infectious Diseases.
Mononucleosis
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TeensHealth.
teen/infections/common/mononucleosis.html (accessed June 6, 2008).Mononucleosis. Available online at http://www.mayoclinic.com/Epstein-Barr Virus and Infectious. http://www.cdc.gov/ncidod/diseases/ebv.htm (accessed JuneMononucleosis. Available online at http://www.kidshealth.org/Mononucleosis. Philadelphia: Chelsea House Publishers, 2004.Mononucleosis. New York: Marshall Cavendish Benchmark,Infectious Mononucleosis. Detroit, MI: Lucent Books, 2008.—almost all’s examination of the patient’s throat and’s abdomen to see’s mouth and upper throat, the virus infects B cells, which are
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