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Epstein-Barr Virus and Infectious Mononucleosis
What is Mono
or EBV?
Epstein-Barr virus, frequently
referred to as EBV, is a member of the herpesvirus family and
one of the most common human viruses. The virus occurs
worldwide, and most people become infected with EBV sometime
during their lives. In the United States, as many as 95% of
adults between 35 and 40 years of age have been infected.
Infants become susceptible to EBV as soon as maternal antibody
protection (present at birth) disappears. Many children become
infected with EBV, and these infections usually cause no
symptoms or are indistinguishable from the other mild, brief
illnesses of childhood. In the United States and in other
developed countries, many persons are not infected with EBV in
their childhood years. When infection with EBV occurs during
adolescence or young adulthood, it causes infectious
mononucleosis 35% to 50% of the time.
What are the
symptoms of Mono and EBV?
Symptoms of infectious
mononucleosis are fever, sore throat, and
swollen lymph glands. Sometimes, a swollen spleen or liver
involvement may develop. Heart problems or involvement of the
central nervous system occurs only rarely, and infectious
mononucleosis is almost never fatal. There are no known
associations between active EBV infection and problems during
pregnancy, such as miscarriages or birth defects.
Symptoms of infectious
mononucleosis usually resolve in 1 or 2
months. The EBV virus will remain dormant or latent in a
few cells in the throat and blood for the rest of the person's
life. Periodically, the virus can reactivate and is commonly
found in the saliva of infected persons. This reactivation
usually occurs without symptoms of illness.
EBV also establishes a lifelong
dormant infection in some cells of the body's immune system. A
late event in a very few carriers of this virus is the
emergence of Burkitt's lymphoma and nasopharyngeal carcinoma,
two rare cancers that are not normally found in the United
States. EBV appears to play an important role in these
malignancies, but is probably not the sole cause of disease.
Most individuals exposed to
people with infectious mononucleosis have
previously been infected with EBV and are not at risk for
infectious mononucleosis.
How is Mono
Transmitted?
Transmission of EBV requires
intimate contact with the saliva (found in the mouth) of an
infected person. Transmission of this virus through the air or
blood does not normally occur. The incubation period, or the
time from infection to appearance of symptoms, ranges from 4
to 6 weeks. Persons with infectious mononucleosis may be able
to spread the infection to others for a period of weeks.
However, no special precautions or isolation procedures are
recommended, since the virus is also found frequently in the
saliva of healthy people. In fact, many healthy people can
carry and spread the virus intermittently for life. These
people are usually the primary reservoir for person-to-person
transmission. For this reason, transmission of the virus is
almost impossible to prevent.
How is Mono
or EBV Diagnosed?
The clinical diagnosis of
infectious mononucleosis is suggested on the
basis of the symptoms of fever, sore throat, swollen lymph
glands, and the age of the patient. Usually, laboratory tests
are needed for confirmation. Serologic results for persons
with infectious mononucleosis include an elevated white blood
cell count, an increased percentage of certain atypical white
blood cells, and a positive reaction to a "mono spot" test.
There is no specific treatment
for infectious mononucleosis, other than
treating the symptoms. No antiviral drugs or vaccines are
available. Some physicians have prescribed a 5-day course of
steroids to control the swelling of the throat and tonsils.
The use of steroids has also been reported to decrease the
overall length and severity of illness, but these reports have
not been published.
There has been some reports
from sufferers to indicate that short-term high doses of
Ester-C (only Ester-C, not standard vitamin C) and
Echinacea (both available over-the-counter at
pharmacies) help minimize the duration of symptoms
greatly. Consult your physician before using any
treatment to avoid serious complications.
It is important to note that
symptoms related to infectious mononucleosis caused by EBV
infection seldom last for more than 4 months. When such an
illness lasts more than 6 months, it is frequently called
chronic EBV infection. However, valid laboratory evidence for
continued active EBV infection is seldom found in these
patients. The illness should be investigated further to
determine if it meets the criteria for chronic fatigue
syndrome, or CFS. This process includes ruling out other
causes of chronic illness or fatigue.
What
are the Complications?
The most common complication of
mono is dehydration. Dehydration can develop because of
inadequate fluid intake. Severe throat pain is often a reason
why individuals do not intake adequate fluid. More rare
complications include blood disorders, neurological and
psychological problems.
Rupture of the spleen, a rare
but potentially serious complication, can occur. The
development of severe pain under the left rib cage requires
immediate medical evaluation.
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