The disease, which is caused by the Epstein-Barr virus (EBV), is considered benign though serious complications can occur, especially in older individuals.

The EBV belongs to the same virus family as the herpes and varicella (chicken pox) viruses. It is widespread, with statistics showing that as many as 90 per cent of middle-aged adults have been exposed to the disease. In young children, the disease is often unnoticed and leads to lifetime immunity that protects the individual from a second infection.

Symptoms are thus more prevalent among adolescents and adults. Following an incubation period that varies from two weeks to several months, the early manifestations mimic flu, with extreme fatigue, high fever around 38.5 to 40 degrees Celsius, muscle pain, headache and sore throat with swollen tonsils.

A clinical exam will reveal multiple swollen lymph nodes, especially in the neck as well as an enlarged spleen, both as a result of the virus’s significant immunologic reaction within the body. Similarly, this reaction may also trigger disorders of blood cell formation with low red blood cells, abnormal white blood cells and low platelets or clot forming cells.

In the majority of the cases, recovery happens spontaneously after two to three weeks but marked fatigue often persists for several weeks and even months.

Complications are infrequent and mainly occur in teenagers and young adults. The enlarged spleen might become more vulnerable to abdominal trauma and could lead, although rarely, to a life-threatening rupture of the spleen requiring emergency surgery. In addition, the dissemination of the virus in the body can lead to significant inflammation of major organs. Among these are the liver with hepatitis that may result in a jaundice, the heart with myocarditis or inflammation of heart muscle, and the nervous system with meningitis and the Guillain-Barr syndrome, the latter an autoimmune disorder attacking the nerve cells.

As the symptoms are not specific to the disease, diagnosis is usually not made solely on the clinical exam and blood tests are needed to confirm the infection. The complete blood count (CBC) often reveals the presence of an abnormally high proportion of one type of white blood cells known as monocytes, which is suggestive of mononucleosis and from which disease gets it name. More importantly, immunologic tests that can detect the antibodies to the EBV, such as the monospot test, finally confirm the diagnosis of mononucleosis.

Currently, there is no anti-viral therapy nor vaccine effective against the EBV. Treatment simply aims at alleviating high fever and muscle pain with paracetamol or ibuprofen.

 Aspirin is contraindicated among children younger than 16 years of age because its use has been associated with a higher risk of Reye’s syndrome, a rare but severe complication of viral infection. Antibiotics are not indicated unless there is a patent bacterial infection on the tonsils or sinuses. Complications are dealt with according to the site of viral inflammation.

If you are suffering from mononucleosis, prolonged rest, proper nutrition and good hydration are essential elements of recovery. It is essential to avoid vigorous exercise due to the risk of spleen rupture and wise to only progressively resume normal daily activities.

You are likely to remain contagious for several weeks after the fever has disappeared so you should refrain from kissing people and sharing cutlery and flatware during this period to avoid spreading the infection.

DR GERARD LALANDE is managing director of CEO-Health, |which provides medical referrals for expatriates and customised |executive medical check-ups in Thailand. He can be contacted at gerard.lalande@ceo-health.com