Infectious
MononucleosisInfectious mononucleosis, infectious mono or "kissing
disease", how it has sometimes been called, is a form of severe tonsillitis,
but also is a protracted systemic viral illness and can have some hidden implications
in the development of nasopharyngeal cancer in the Chinese population who have
a genetic weakness for this type of rare cancer. Epstein-Barr
virus (EBV), the cause of infectious mononucleosis,
is also a triggering agent for the 20 to 30 fold higher incidence of nasopharyngeal
cancer in the Chinese when compared to the low rates of North Americans and Europeans
(Ref. 4, p. 1774). Signs and symptoms: The symptoms
of EBV infection (= infectious mononucleosis) are as varied as the age
group that gets affected by it. The most severe infections occur in the age group
of 15 to 25. It was originally among a group of college students that the disease
was investigated in the U.S. and this was where the terminology of "kissing
disease" came from as this can be a source of transmission, although most
of the time simple droplet infection like in any other respiratory infection is
the common mode of transmission. In children the symptoms can be very mild like
a cold of 1 or 2 weeks. In young adults, however, it can be a severe infection
with a high fever, severe
throat pain with lymph node swelling in the neck region, a viral
tonsillitis and pharyngitis. The infected person may also suffer from a complete
loss of appetite, nausea, abdominal pain, headaches, chills and muscle pains.
In 30 % of patients there is swelling around the eyes ("periorbital edema").
When antibodies appear in the blood in the second week there can be sometimes
a skin rash that can look quite varied. Sometimes it looks like the measles, particularly
when the person was put on amoxicillin. At other times it looks like a rash with
a multitude of pin sized red spots (petechial rash). The spleen is enlarged in
50% of cases, the liver only in 10% . At the end of the first week or in the second
week there is a risk that the enlarged spleen could rupture with sudden jarring
motions. This is why contact sports should be avoided for at least 3 weeks. The
player would not perform well anyways because the EBV infection is taking a lot
of energy away from the person. Viral shedding from the pharynx goes on for up
to 18 months following infection with EBV! This is the case, even when the person
feels recovered after 3 or 4 weeks. The reason why EBV is so common, is the fact
that there are many asymptomatic carriers in the population all the time, who
shed the virus by droplet tansmission. Diagnostic tests: The
diagnosis is made mainly on clinical grounds, by history and examination. The
blood tests confirm some typical changes such as a moderately elevated white blood
cell count with 50% lymphocytes and 10% or more "atypical lymphocytes"
(=the "mononucleosis cells"). By the end of the 3rd week the monospot
blood test is positive in about 90% of patients (Ref. 4, p.268). This is not too
specific as chickenpox, lymphomas and influenza can lead to a falsely positive
monospot test as well. In these cases a EBV antibody level can be ordered, which
is specific for EBV infection. After 3 months the monospot test returns to normal
whereas the EBV antibody test stays positive for the rest of the life of the individual.
Treatment: Most patients recover spontaneously
from EBV infection in a course of 3 to 4 weeks. There is no vaccination for it.
In 1% or less of cases there can be neurological complications like seizures or
aseptic meningitis. Hemolytic anemia, kidney failure, myocarditis or splenic
rupture in the 2nd or 3rd week of the disease are other rare complications. If
the tonsils are so large that there is a danger of airway obstruction and in cases
where the blood is thinned too much (low platelet count) a course of corticosteroids
for 1 or 2 weeks is usually given (Ref. 4, p. 268). It is wise to do a throat
swab, if there is a change in the clinical presentation (more of a sore throat,
worsening of the condition) to rule out a bacterial uperinfection with group A
beta-hemolytic streptococcus, which would need to be treated with antibiotics.
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