Understanding glandular fever - the basics

What is glandular fever?

Glandular fever (also known as infectious mononucleosis, sometimes referred to as ‘mono’) is a very common viral illness. About 90% of people over 35 have been infected with it, probably during early childhood, and have antibodies to the virus in their blood.

Glandular fever is caused by the Epstein-Barr virus, named after the two British researchers who first identified it in 1964, although the disease itself had been recognised many years earlier. A common member of the herpes family of viruses, the Epstein-Barr virus is spread primarily through the exchange of saliva, which is why glandular fever is sometimes known as ‘the kissing disease’. Coughing or other contact with infected saliva can also pass the virus from one person to another.

The glandular fever virus can stay active in a person weeks or months after all overt symptoms are gone, so close contact with someone who shows no sign of the disease can still put others at risk. On the other hand, not everyone who lives in close proximity to a person infected with glandular fever comes down with the illness. Scientists believe that a healthy immune system may make it possible to fight off the infection successfully.

When glandular fever strikes young children, the illness is usually so mild that it passes as a common cold or the flu. When it occurs during adolescence or adulthood, however, the disease can be much more serious.

Glandular fever comes on gradually. It begins with flu-like symptoms; fever, headache and a general malaise and lethargy. After a few days, the lymph glands begin to swell, although this symptom is not noticeable in everyone. Swollen glands in the back of the neck are especially typical of glandular fever. Most people develop a sore throat, which can be very severe, with inflamed tonsils. A fever, usually no higher than 40 degrees Celsius (104 degrees Fahrenheit), can also develop and may last up to three weeks.

Some people with glandular fever, particularly those who take the antibiotic amoxicillin, may develop a red rash all over the body. Others may notice red spots or darkened areas in the mouth that look like bruises. In about half of all cases, the spleen becomes enlarged, causing an area in the upper-left abdomen to become tender to the touch.

In most cases, glandular fever mildly affects the liver. Only a few individuals with glandular fever develop inflammation of the liver, causing jaundice, a yellowing of the skin and eyes caused by an increase of the liver's bile protein in the blood. In rare cases of glandular fever, the liver fails.

Other major complications that can develop from glandular fever include rupturing of the spleen, low blood platelet count, swelling of the covering of the brain or spinal cord and inflammation of the brain itself. But these complications are extremely rare.

Most people who come down with glandular fever feel much better within two or three weeks, although fatigue may last for two months or longer. Sometimes the disease lingers for a year or so, causing recurrent attacks that gradually become milder.

In the past, research suggested that the virus causing glandular fever might be linked to a persistent, debilitating illness known as chronic fatigue syndrome, which can last for years. Most recent research has shown no such link, however, and the cause of chronic fatigue syndrome remains unknown.