Infectious mononucleosis: what is this disease, symptoms and causes

What is Mononucleosis?

Infectious mononucleosis, also called kissing disease or Filatov's disease, is an infectious viral disease caused by Epstein-Barr virus (VEB).

The disease can occur at any age, but is especially common in children and adolescents and has an incubation period of about 6 weeks.

The characteristic symptoms of mononucleosis are:

• sore throat;
• fever;
• fatigue;
• inflammation of the lymph nodes.

Although the symptoms can be quite unpleasant, they generally do not last longer than 2-3 weeks without complications, even if in adults fatigue may persist for several months.

Infection occurs mainly through saliva; the length of time a patient remains infectious has not yet been precisely determined, although it is believed that the virus can persist in saliva for at least 6 months after the onset of the disease; from an absolute point of view, mononucleosis, however, is not considered a highly contagious disease.

Diagnosis is usually made with special blood tests, and treatment only includes symptomatic therapy, since drugs that could act directly on the responsible virus is not.

The prognosis is excellent, so much so that most patients with EBV infection recover without complications and develop permanent immunity to fight the virus; in rare cases, some cancers have been associated with infection, but there is still no definite evidence of a causal relationship.

Can mononucleosis come back? Relapses

In most cases, mononucleosis occurs only once in a lifetime, acquiring immunity. However, in rare cases, symptoms of the disease can recur after months or even years.

Most cases of mononucleosis are associated with the Epstein-Barr virus (EBV). After infection, a person becomes a carrier of the virus, usually in a latent state, throughout his life. Periodically, the virus can reactivate. When this happens, the virus can be excreted in the saliva, although its symptoms no longer appear.

In rare cases, reactivated EBV can cause symptoms in people with fragile immune systems, such as those with AIDSohm.

Only rarely does mononucleosis lead to a serious condition known as active chronic infection Epstein-Barr virus, characterized by persistent illness for 6 months after the initial diagnosis.

In case of recurring signs and symptoms of mononucleosis, the person experiences:

• fatigue;
• asthenia;
• fever;
• sore throat;
• inflammation of the lymph nodes.

To determine the origin of your current symptoms, consult your doctor. Remember that many other conditions, from hepatitis to toxoplasmosis, can cause symptoms similar to infectious mononucleosis.

Causes mononucleosis

Infectious mononucleosis is caused by infection with the Epstein-Barr virus, which belongs to the herpes virus family. (which also includes herpes simplex viruses types 1 and 2, and human herpesvirus type 3, responsible for varicella smallpox and shingles).

An estimated 95% of the world's adult population carries the virus.

It is transmitted through the saliva of the host, for example, when:

• deep kiss (this is why the disease is called "kissing disease");
• the use of food and drinks of the patient;
• using a patient's toothbrush;
• sneezing, coughing.

Small children can also become infected indirectly, for example, if contaminated toys come into contact with mouth (the virus is believed to survive on objects, at least as long as it remains wet).

Epstein-Barr virus (EBV) is mainly transmitted through body fluids, especially saliva, but it can technically also be spread through blood and semen through intercourse, blood transfusion, and organ transplant.

Not everyone who transmits the infection has symptoms of the disease, i.e. those who are able to infect without showing symptoms are called "healthy carriers." Some patients may also spread the virus through saliva for several months after they recover, and periodically, at different stages, they can infect other people, because the virus can recur even without symptoms.

This is because the virus remains inactive in the body for the rest of its life after infection, but in most cases it does not cause any complications or symptoms. Only in rare cases and under certain conditions can symptoms appear for a short time.

When a person first becomes infected with the virus (primary EBV infection), a person can become infected for weeks without symptoms. Once the virus has entered the body, it remains in a latent (inactive) state. If the virus reactivates, EBV can be transmitted to others, regardless of the time that has passed since the initial infection.

Symptoms of mononucleosis

The mononucleosis virus has an incubation period of about 4-8 weeks, but in young children this period may be shorter.

The initial symptoms of mononucleosis typically include:

• fever (fever):
• headaches;
• muscle pain;
• inflammation of the lymph nodes in the neck (cervical lymphadenitis) and in the armpits;
• severe fatigue.

After a few days, you may experience:

• sore throat, such as tonsillitis that does not get better with antibiotics
• generalized malaise;
• chills;
• excessive sweating;
• loss of appetite (slight weight loss is possible);
• pain and swelling around the eyes;
• tonsillitis;
• whitish products on the tonsils, resembling bacterial plaques;
• arthralgia (joint pain);
• enlargement of the spleen.

Rarely, but may appear:

• nausea and vomiting;
• jaundice (yellowness of the skin and sclera of the eyes);
• labored breathing (dyspnea);
• anemia;
• change in heart rate (tachycardia, atrial fibrillation).

Signs and symptoms such as fever and sore throat usually disappear almost completely within 2-3 weeks, however, fatigue and swelling of the lymph nodes and spleen may also persist for several weeks. When symptoms develop in adulthood, they can be especially severe, and feelings of fatigue and malaise can last for many months.

Almost all patients with mononucleosis for whom doctors prescribe amoxicillin or ampicillin if they are misdiagnosed develop maculopapular rash (rash and itching over the body), which, however, does not present any future complications (antibiotic allergies does not arise).

Mononucleosis in children

In small age groups, infection can also occur through the exchange of contaminated objects (such as toys) that children usually put in their mouths; very often the infection is asymptomatic or very mild.

Recovering is just as quick; for adolescents, it can take a few weeks at the most.

In some cases, it is recommended to avoid sports for a month, or only in the case of an enlarged spleen.

When to see a doctor?

If you are experiencing the symptoms listed above, you may be suffering from mononucleosis; a doctor should be consulted to confirm the diagnosis, and in the meantime, it is recommended to rest and eat properly.

It is recommended that you go to the emergency room if:

• shortness of breath or hoarse breathing;
• difficulty swallowing fluids;
• severe abdominal pain.

Complications of mononucleosis

The infection usually clears up spontaneously without any particular consequences, but the rare complications of mononucleosis can be more serious than the disease itself.

Chronic fatigue syndrome.

About 1 in 10 patients will feel very tired for 6 months or more after the initial infection. Some experts believe it may be a form of chronic fatigue syndrome, poorly understood conditions that cause constant fatigue and many other symptoms, such as headaches and pain in joints.

Exercise to restore strength and energy levels can help prevent and reduce long-term fatigue.

Effect on blood.

In some cases, the infection can lead to a decrease in the number of certain blood cells:

• red blood cells (anemia): may make you feel short of breath and tired;
• leukocytes (neutropenia): may contribute to the development of a secondary infection;
• platelets: May cause bruising and hemorrhage.

In most cases, these side effects of the disease are limited and resolve after a few weeks or months.

Spleen ruptured.

About half of people who develop mononucleosis also experience an enlarged spleen; this is not a problem in itself, but there is a small risk that the organ will burst. The main sign of a ruptured spleen is severe pain in the left side of the abdomen. The situation requires immediate medical attention.

The risk of ruptured spleen is low, estimated at about 1 in every 500-1000 cases, but the condition can be fatal because it causes severe internal bleeding. A ruptured spleen usually occurs as a result of damage caused by exercise such as contact sports, so it is very important to avoid these activities for at least a month after the appearance symptoms.

Neurological complications.

In less than 1 in 100 cases, Epstein-Barr virus can affect the nervous system and cause a range of neurological complications, including:

• Guillain-Barré syndromewhere the nerves become inflamed, causing symptoms such as numbness, weakness, and temporary paralysis
• Bell's palsywhen the muscles on one side of the face temporarily weaken or become paralyzed;
• viral meningitis, inflammation of the protective membranes surrounding the brain and spinal cord; although viral meningitis unpleasant, it is much less serious than the bacterial form, which can be fatal;
• encephalitis, brain inflammation.

These complications often require special treatment, but more than four out of five patients make a full recovery.

Secondary infection.

In a small number of cases, the primary infection weakens the immune system and allows several bacteria to infect other parts of the body (secondary bacterial infection).

Possible secondary infections that can develop during mononucleosis include serious conditions such as pneumonia and pericarditis (inflammatory lesion of the serous membrane of the heart).

Secondary infections are more common in people with very weak immune systems, such as AIDS or those undergoing chemotherapy.

Lymphoma.

Persons with lifelong mononucleosis are at slightly higher risk of developing Hodgkin's lymphomas compared to the general population, but the likelihood in the absence of other risk factors remains low.

The link between infection and cancer has not yet been fully elucidated.

During pregnancy:

Women with symptoms similar to those of mononucleosis should see a gynecologist immediately, because in some cases it is actually scary cytomegalovirus.

When mononucleosis is detected, it is considered that there is no particular risk to the fetus.

Diagnostics

A doctor may suspect mononucleosis after a physical examination, observation of symptoms, and a medical history. During the visit, the doctor checks if the lymph nodes, tonsils, liver and the spleen, and checks if these signs are related to the symptoms described by the patient.

Blood tests.

Laboratory tests can help you understand whether a subject has EBV infection or has been infected in the past.

The following EBV-associated antigens can be used to detect antibodies:

• Capsid antigen antibodies (VCA)
  • Anti-VCA IgM antibodies appear early and usually disappear within 4-6 weeks.
  • Anti-VCA IgGs appear in the acute phase of infection, peak 2-4 weeks after onset, decrease slightly and therefore persist throughout life.
• Early antigen (EA)
  • Anti-EA IgG appears in the acute phase of the disease and usually becomes immeasurable after 3-6 months. In many people, detection of antibodies is a sign of active infection. However, 20% of healthy people can have anti-EA antibodies for many years.
• Antibodies to nuclear antigen (EBNA)
  • Anti-EBNA antibodies are not detectable in the acute phase of infection, although they develop gradually 2–4 months after symptom onset and persist throughout life. Other EBNA enzyme immunoassays can give false positive results.

Interpretation of analyzes of antibodies to EBV.

EBV antibody tests are usually not needed to diagnose infectious mononucleosis, but may be required for identifying the cause of the disease in people with atypical symptoms or other medical conditions that may be caused by EBV infection. Mononucleosis symptoms usually resolve within 4 weeks. If a person has been experiencing symptoms for more than 6 months and there is no laboratory confirmation of infection, other chronic conditions or chronic fatigue syndrome should be considered.

Interpretation of antibodies to EBV requires a good knowledge of the analyzes and clinical data of the patient, and diagnoses of EBV infection are schematized as follows:

• Susceptibility to infection: a subject is considered susceptible to infection if it does not have antibodies against VCA.
• Primary infection (new or recent). A subject is considered to have primary EBV infection if they have anti-VCA IgM but no anti-EBNA antibodies. Other results clearly indicative of primary infection are high or increased levels of anti-VCA IgG without anti-EBNA antibodies after at least 4 weeks of illness. The disease may go away before diagnostic antibody levels appear. Rarely, a person with an active infection may not have measurable levels of specific antibodies against EBV.
• Previous infection: the simultaneous presence of antibodies against VCA and anti-EBNA indicates a previous infection (occurred several months or years earlier). Since more than 90% of the world's adults are infected with EBV, antibodies against EBV from past infections will be detectable in most people. Elevated or high antibody levels can persist for years and are not a sign of recent infection.

Antibody	The moment when found in blood
VCA-IgM	It appears for the first time after exposure to the virus and then disappears after about 4-6 weeks.
VCA-IgG	It appears during an acute infection and reaches a maximum after 2-4 weeks, then decreases slightly, stabilizes and remains detectable throughout the patient's life.
Antibody Against Early Antigen (EA-D)	Appears during the acute phase and then tends to disappear; approximately 20% of infected patients will have detectable amounts of this antibody in their blood even for several years after recovery.
EBNA	Usually does not appear until the acute infection has resolved; it develops 2–4 months after the first infection and is then present throughout life.

Combined examination of serum samples representing acute phase and recovery does not distinguish between recent and past infections. In many cases, the antibody response is rapid during the primary infection. Clinical signs of infectious mononucleosis appear along with the appearance of anti-VCA IgG and IgM. However, the antibody pattern is not stable until symptoms appear.

Mononucleosis treatment

Symptoms rarely last longer than a few months, but especially in younger patients, complete recovery is observed within 2-4 weeks.

However, even after recovery, the virus will remain dormant in the body for the rest of its life. sometimes reactivating itself without significant symptoms (but becoming contagious again for some time).

There is no specific therapy for infectious mononucleosis because antibiotics are useless in the fight against viral infections. The basis of therapy is, first of all, bed rest and replacement of lost fluid.

Alcohol, which can damage the liver, already weakened by infection, should be avoided.

Recreation.

Rest is often underestimated and is an integral part of the recovery from mononucleosis during the first symptoms; then gradually resume normal activities at the first sign of recovery to reduce the risk of fatigue and fatigue in the months that follow.

In the first month, avoid contact sports or activities that could lead to a fall, as the spleen can be enlarged and therefore more vulnerable and at risk break. Ask your doctor when it is safe to resume normal activities. Your doctor may advise you to follow a gradual exercise program to help you regain strength during your recovery.

Medications.

Pain relievers such as paracetamol or ibuprofencan help relieve pain and fever. It is recommended to avoid taking aspirin in children or adolescents as it is associated with Reye's syndrome (acute liver failure and encephalopathy), a rare but potentially life-threatening complication.

Antibiotics are not effective in the treatment of mononucleosis, because they do not affect viruses, but can be prescribed if a bacterial infection of the throat or lungs (pneumonia) also develops.

Short course corticosteroids can be appointed if:

• the tonsils are especially swollen and cause breathing difficulties;
• severe anemia occurs (deficiency of oxygen-carrying red blood cells);
• heart problems such as pericarditis (inflammation of the serous membrane of the heart) develop;
• problems affecting the brain and nervous system arise (for example, encephalitis).

Preventing the spread of infection.

A person affected by an infection does not need isolation, as most adults are immune to it.

Mononucleosis is contagious, especially during the acute phase when fever is still present, so you can return to work, university or school as soon as you feel ready. The risk of spreading infection to others is reasonably low if basic hygiene practices are followed (in it is recommended for some time, for example, to avoid sharing food, liquids and utensils devices).

Prevention of mononucleosis

The infection spreads through saliva. If you are infected, you can try not to spread the virus by kissing anyone or sharing food, dishes, glasses and cutlery for a few days after the fever (temperature) disappears and, if possible, even longer.

The Epstein-Barr virus can persist in the patient's saliva even for several months after infection; it should also be noted that the virus remains inactive in the body until the end of life, sometimes reactivating even without the appearance of obvious symptoms (provided that the person has a healthy immune system).

There is no vaccination that could prevent the infection.