What is it?

It´s a clinical syndrome characterized by discomfort, headache, fever, a sore throat, enlarged lymph glands located in the neck or widespreading and mild, transient liver inflammation (hepatitis). Most of the time (79% of the cases) it has as its causative agent a virus called Epstein-Barr (EBV), but it also can be caused by the Cytomegalovirus (CMV) in approximately 21% of the cases. It affects more often teenagers and young adults, but it may affect the elderly and pre-teenage children. For its frequency and by tradition we´re going to address only the infection by the Epstein-Barr virus, leaving the Cytomegalovirus infection to another chapter.

The disease has achieved greater importance because several tumors involve a type of white blood cell, the B lymphocytes, which are cells that house the virus during the infection and present in their genetic code the same code of the virus, raising the suspicion, today confirmed, that those infections contribute to the cause of the tumors. This greater relevance has been achieved in the new setting of increasing “immunosuppressed” populations (people whose immune defenses are decreased), whether as a result of infection (AIDS) or anti-rejection treatment (in the case of transplant patients), or as a result of cancer treatment.

How is it acquired?

More often, the infection is acquired by the contact of saliva contaminated by the virus with the mouth and throat mucosa of an individual that hasn´t previously been in contact with this germ. It can also be acquired, albeit seldom, by blood transfusion, by other organs and sexual intercourse. For being little resistant, the virus needs direct contact between the contaminated saliva and the mucosa. This characteristic along with the age group during the infection is more usually the reason why it´s been nicknamed “ kissing disease” .

What does one experience?

The classic triad comprises a sore throat, fever and lymph nodes across the body (lymphadenomegaly in medical language) especially in the neck, but further symptoms such as discomfort, headache, lack of appetite, sore muscles, chills, nausea, abdominal discomfort, cough, vomiting and joint pain can also be present in this order of frequency.

After the contact, the disease takes on average 2 to 3 weeks to manifest itself (incubation period), the most common manifestations being a sore throat and fever on a daily basis in the afternoon which may reach up to 40°C. In 5% of the cases occur rashes, skin patches that resemble urticaria, a manifestation common to other infectious diseases that physicians call exanthematous viral infectious (rubella, measles, etc). These symptoms, in most cases, take 1 to 4 months to go away.

The non-teenage and non-young adult populations are less likely to develop a complete clinical picture, many cases going on unnoticed, the so-called asymptomatic cases. Another relevant finding is the enlargement of the liver (10 to 15% of the cases) and spleen (50% of the cases). The latter appears at the beginning of the second week of clinical manifestations and lasts 7 to 10 days, being a potential factor for complications, since the spleen becomes quite brittle and may rupture upon small traumas, causing a life-threatening internal hemorrhage.

How is the diagnosis made?

By the symptoms and findings that the doctor discovers during the clinical exam in addition to the data they collect during the patient´s interview. An accurate diagnosis is made by blood tests in which the presence of antibodies is detected in the sick individual´s blood.

How is it treated?

As in most diseases caused by viruses, there´s no treatment available, nor is it necessary since most often the disease is self-limiting. Drugs are used for the symptoms, such as analgesics, antithermal agents, and, if necessary, drugs for nausea. Those presenting an enlarged spleen are recommended not to practice sports or activities that may pose risk for spleen rupture.

How to prevent it?

The disease confers permanent immunity and seldom can present manifestations in a second infection. There´s no need for patient insulation, as the infection occurs only with very close or intimate contact. Although vaccination has a range that goes beyond the infection, as theoretically it could prevent even some lymphocyte tumors (lymphomas), it doesn´t present recommendable efficiency and safety yet.

What should I ask my doctor ?

What diseases am I exposed to after having had infectious mononucleosis and what measures should I take in order to prevent these?