Infectious mononucleosis is an infectious disease caused by the Epstein-Barr virus (EBV) in 90% of cases, while the remaining 10% is caused by cytomegalovirus (CMV). When children are infected with the virus, the infection usually resolves without symptoms. In adults, 25-75% will develop symptoms of the disease for which the typical three symptoms are: increased body temperature, enlarged lymph nodes and sore throat.
Pathogen
Epstein Barr virus (EBV) is a B lymphotropic (has distinct preference for attacking B lymphocytes) herpesvirus that is widespread throughout the world. In addition to causing infectious mononucleosis, the virus associated with cancer of the throat and certain B-cell lymphomas.
Transmission of the disease
EBV is primarily transmitted through saliva, and, rarely, blood transfusion. It is usually transmitted by kissing and touching of body parts and objects imbued with infected saliva. Since the transfer of droplets is unlikely, patients’ isolation is unnecessary. The virus remains in the host for a lifetime; after the first 18 months after infection it is secreted through saliva, and periodically thereafter. People with poorer immune status (virtually all patients with AIDS, 25-50% of people with transplanted organs) often spread the virus.
Symptoms
4-8 weeks after infection first symptoms appear: fatigue, loss of appetite and fever announce the start of a sore throat, temperature and enlargement the lymph nodes.
Severe sore throat usually forces the patients to seek medical help. Occasionally, patients will notice only fever and enlarged lymph nodes, or they will experience only one of these complications. Most patients complain on headache and malaise.
The course of the disease
Infectious mononucleosis in most cases is the disease with naturally limited duration.
Sore throat is intensive for 5-7 days, and then subsides during the following 7-10 days.
Elevated temperatures usually lasts 7-14 days, but sometimes it may last a little longer.
Lymph nodes are usually reduced after 3 weeks.
Fatigue is a persistent symptom. Most patients after 3-4 weeks feel well enough to return to school or work, but some patients may feel exhaustion for month, problems with concentration and inability to perform daily activities. Usually these are patients who have had a mild onset of the disease, no severe form of sore throat and high temperature.
Complications
Complications of infectious mononucleosis are uncommon, but can be very dramatic and become the dominant manifestation of the disease. These include:
- Autoimmune hemolytic anemia, which usually ends in 1-2 months
- Mild thrombocytopenia (low number of thrombocytes) in 50% of cases – ceases after 3-6 weeks
- Severe thrombocytopenia – very rare
- The mild granulocytopenia (reduction in granulocyte leukocytes) – usually subsides in 3-6 weeks
- Severe granulocytopenia – extremely rare, is associated with severe infection or death
- Burst spleen – a rare complication that occurs in the second or third week of illness, the symptoms are insidious or sudden stomach pain, rapid heartbeat, low blood pressure, cold sweat
- Neurological complications – brain nerve paralysis, inflammation of the brain and meninges (meningoencephalitis), Guillain-Barré syndrome, cerebral seizures, inflammation of the spinal cord, psychosis
- Hepatitis – a common component of infectious mononucleosis, almost 90% of patients had a slight increase in liver enzymes, but severe or persistent disorder of the liver is very rare
- Cardiac abnormalities – very rare (inflammation of the pericardium, inflammation of the heart muscle, constriction of the coronary arteries, changes in ECG)
- Obstruction of the airways due to enlarged lymph nodes
Can you die from infectious mononucleosis?
In more than 90% of cases, the disease has a benign and uncomplicated flow.
This disease is rarely fatal; neurological diseases, airway obstruction and burst spleen are the most common cause of death in previously healthy individuals.
Risky condition called sexually (X) linked lymphoproliferative syndrome (KSLP) or Duncan’s syndrome occurs in males. 40% of men affected by this condition die after EBV infection. This disease, of which not enough is known about, is characterized by enormous multiplication lymphoid tissue with possible severe immunological and hematological consequences such as agammaglobulinemia, aplastic anemia or lymphocytic lymphoma.
Diagnosis
In addition to the aforementioned symptoms, the diagnosis is confirmed by the following laboratory findings:
- An elevated white blood cell count
- Increased number of atypical lymphocytes (75% of patients). Lymphocytes are a type of white blood cells which are in this disease different from normal – enlarged and of altered nucleus
- The presence of heterophile antibodies (in 50% of children and 95% of adults). These are antibodies to sheep erythrocytes that are proved by the so-called monospot test.
- The mild granulocytopenia (granulocyte reduction in the number of leukocytes)
- Mild thrombocytopenia (low thrombocytes)
- Mild increase in immunoglobulin IgM, IgG and IgA
- Slight increase in liver enzymes
- The presence of EBV-specific antibodies – these serological tests diagnose EBV infection with certainty, and can be done immediately or if the above mentioned tests are contradictory
Distinguishing between CMV and EBV mononucleosis
Patients with mononucleosis caused by cytomegalovirus (CMV) on average are older and usually the disease is characterized by fever and inflammation of the throat. Sore throat and enlargement of the lymph nodes rarely occur. The disease occurs more insidiously and subsides at a slower rate than illness caused by the Epstein-Barr virus. Diagnosis is made by isolating the virus in the blood or specific antibodies against CMV.
Treatment
Treatment is symptomatic, because there are no drugs against pathogens. Patients are recommended to:
- rest. Patients need rest, which does not mean that they should strictly lie in bed because there is no evidence that strict rest accelerates recovery.
-increase intake of fluids while the disease lasts
- if necessary, take drugs for lowering high temperatures recommend by a doctor. Children under 12 should avoid acetylsalicylic acid (Aspirin, ) due to the risk of complications (Reye syndrome).
- the lozenge or hard candy can be taken with sore throats because their chewing accelerates the secretion of saliva and swallowing accumulated secretion
- avoid sports for 6-8 weeks – because of rare complications such as a ruptured spleen
Certain drugs are used in rare situations:
- Corticosteroids may relieve the symptoms of sore throat, but due to the side effects are usually given only if there are complications – obstruction of the respiratory tract and hematological disorders (anemia, granulocytopenia, thrombocytopenia)
- Alpha-interferon – has antiviral activity and can reduce the spread of EBV, but due to the high cost is usually applied in patients with immunity disorders
- Acyclovir - in high doses can block the spread of EBV in the throat, however, its clinical benefit is minimal or unnoticeable