Mononucleosis (infectious mononucleosis)

Causes and transmission

EBV is the predominant cause and spreads mainly through saliva, which is why "kissing disease" is a familiar description. Transmission can also occur via shared utensils or transfusions in rare cases. Primary infection in childhood is often mild or asymptomatic, whereas adolescents and young adults more frequently develop the classic syndrome.

Clinical features and diagnosis

Typical symptoms include fever, sore throat, swollen cervical lymph nodes, pronounced fatigue and sometimes an enlarged spleen. Laboratory findings often show a lymphocytosis with atypical lymphocytes and positive heterophile antibody tests or specific EBV serology. A heterophile antibody (Monospot) test can be helpful but is not always sensitive early in illness; EBV-specific antibody testing clarifies uncertain cases.

Complications and differential diagnosis

• Potential complications: splenomegaly with rare risk of splenic rupture, transient hepatitis, airway compromise from severe tonsillar swelling, and secondary bacterial infections.
• Important differentials: streptococcal pharyngitis, CMV infection, toxoplasmosis, acute HIV seroconversion and other causes of febrile lymphadenopathy.
• Notable caution: some antibiotics such as ampicillin or amoxicillin commonly produce a generalized rash when given to patients with acute EBV infection.

Management, prognosis and prevention

Treatment is mainly supportive: rest, fluids, analgesics and throat care. Corticosteroids may be used for severe complications such as imminent airway obstruction. Most people recover over weeks to months, though fatigue can persist longer. There is no widely used vaccine against EBV at present; avoiding sharing saliva reduces transmission risk. While EBV infection is common and usually self-limited, the virus has been linked epidemiologically to certain uncommon malignancies and chronic conditions in which it plays a role.

Terminology and history

The illness is frequently called "glandular fever" in some countries (glandular fever) or abbreviated to "mono." EBV was identified as a human virus in the 1960s, which clarified the viral origin of the syndrome. Modern diagnostic tests and supportive care have improved recognition and management compared with earlier eras.