Infectious Mononucleosis (Mono)

What is mono?

Infectious mononucleosis (also called mono, glandular fever or kissing disease) is a disease caused by a human herpes virus, known as the Epstein-Barr virus (EBV). Mononucleosis refers to a relative increase in the number of lymphocytes in the blood, a characteristic of infection caused by EBV. The virus spreads through saliva, hence the term kissing disease, but can also be transmitted through blood transfusions.

Infectious mononucleosis can occur in a person of any age. The infection is usually not serious, but complications may arise sporadically. Infectious mononucleosis mostly resolves on its own. However, EBV infection may persist throughout life. Most adults seem to have antibodies against EBV in their blood, which suggests that it is a fairly common viral infection but most people do not experience symptoms as they develop immunity against it.

What are the symptoms of mono?

EBV infection usually does not show any symptoms in children. However, symptoms may appear in teenagers and young adults. It may take between one to two months after the infection for symptoms to appear. This is because of the long incubation period of EBV in the human host.

The following are the common symptoms of infectious mononucleosis:

  • Fever, which usually peaks during afternoons and early evenings
  • Sore throat (pharyngitis) that may cause severe pain
  • Swollen lymph glands (adenopathy) in the neck region
  • Fatigue that can last for many months
  • A general feeling of uneasiness (malaise)
  • Loss of appetite
  • Enlarged spleen
  • Mild enlargement of liver
  • Swollen or puffy eyelids
  • Small red eruptions on the palate inside the mouth
  • Jaundice may occur in rare cases

In some rare cases, severe complications may occur. These include neurologic complications (likeseizures, brain inflammation, palsies, and psychosis), hematologic complications (like hemolytic anemia and lowered counts of various types of blood cells), rupture of spleen, airway obstruction leading to difficulty in breathing, and inflammation of the liver.

Diagnosis of infectious mononucleosis requires blood tests to confirm the presence of antibodies against EBV. Blood of infected individuals also contain abnormally shaped white blood cells.

What causes mono?

The cause of infectious mononucleosis is infection by EBV – Epstein Barr Virus. It survives only in the human host. EBV infects the antibody-producing cells of the immune system (known as B-cells) and stays within these cells throughout life. The virus is shed intermittently in the saliva of the infected person. Kissing spreads the virus from an infected to an uninfected person. However, it may not be obvious because the infected person usually does not show any symptoms.

How is mono treated?

Infectious mononucleosis usually resolves on its own within a couple of weeks. However, fatigue may persist for many months. Treatment is usually supportive thereby allowing the body to heal itself. It involves complete bed rest (especially in the first couple of weeks) till the fever, sore throat and fatigue subside. The patients should also avoid lifting heavy weights or playing contact sports till the spleen returns to its normal size.

In cases where complications arise, corticosteroids are prescribed. The antiviral drug, acyclovir, helps in decreasing the shedding of the EBV in saliva. However, its clinical effectiveness is still questionable.

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