Infectious mononucleosis ("mono")
is caused by a virus
The Epstein-Barr virus (EBV) that causes mononucleosis
is a type of herpes virus. The virus infects a certain
type of white blood cell called “B lymphocytes.”
The virus is shed in saliva and spreads through
direct contact
EBV spreads through contact with the saliva of another
person who has the virus. Kissing and contact with hands
or toys soiled with infected saliva are common ways to
spread the virus. EBV is shed in the saliva during the
illness and for many months after infection. The virus
can reactivate later and be shed again from the mouth
and throat.
Symptoms to look for may include:
- Fever
- Sore throat
- Swollen glands (especially in the back of the neck)
- Tiredness
Symptoms start 30 to 50 days after exposure. Many people
(especially infants and young children) catch mononucleosis
and only have mild symptoms similar to the common cold.
Older children and young adults are more likely to have
worse symptoms. For this reason, "mono" is more
often recognized in high school and college-age students.
Symptoms can last from one to several weeks.
Almost everyone catches mononucleosis during
their life
As many as 95% of adults in the United States have been
infected by the time they are 35 or 40 years old.
No treatment other than rest is needed for most people
with mononucleosis
You can prevent EBV infection
Avoid contact with the saliva of someone who has mononucleosis
or who recently had it. Keep children's toys clean and
out of the mouths of others. Persons with a recent EBV
infection should not donate blood.
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Maryland Department of Health & Mental
Hygiene
Office of Epidemiology and Disease Control Programs
May 2000 |
