Infectious mononucleosis and Epstein-Barr Virus
drsuryabrata@gmail.comCause:
- Commonest cause – EBV.
- Other causes of mononucleosis-like syndrome – CMV, HIV (during seroconversion), Toxoplasma, Hepatitis virus, Adenovirus etc
Epidemiology:
- Primary EBV infection and infectious mononucleosis are common in children, teenagers and young adults.
- 95% of healthy individuals are infected with EBV.
- In children, infection is usually mild or even asymptomatic.
- Symptomatic disease is common in teenagers and young adults (15-24 years).
- In adults, the infection is less common but often severe.
Transmission:
- It is transmitted via body fluid. Saliva is the commonest mode.
- Once infected, an individual can shed the virus in the saliva for approx—6 months, and intermittently, lifelong.
- It is called kissing disease but can be transmitted via less intimate contact than this.
- Other modes are – sexual contact and breastfeeding.
Signs and symptoms:
- Triad of – Fever, tonsillar pharyngitis and lymphadenopathy.
- Other common features are – fatigue, splenomegaly (up to 60% cases) and low mood.
- You may also find – hepatomegaly, rash, headache and body ache.
Complications
- Usually self-limiting disease.
- Neurological complications – meningoencephalitis, transverse myelitis, optic neuritis, Cranial nerve palsy, Guillain–Barré syndrome.
- Haematological complications – aplastic anaemia, thrombocytopenia and related complications.
- Other complications – Splenic rupture, airway obstruction, myocarditis, hepatitis, and renal failure.
Diagnosis
- Typical clinical features
- Haematology – increased white cell count, atypical lymphocytes, anaemia, thrombocytopenia.
- Heterophile antibody test – e.g. Paul Bunnel test or monospot test
- EBV serology
- EBV PCR
If you want to know about a heterophile antibody, see this video.
- Heterophile antibody test should not be done in children <4 years or immunocompromised patients (risk of false-negative result)
- False-positive results can be seen in – rheumatoid disease, SLE, leukaemia, lymphoma, infections including malaria, HIV, CMV, rubella, viral hepatitis, tularaemia etc.
- 90% of patients are expected to be positive heterophil antibodies by 3 weeks, and they disappear at approximately three months.
Atypical lymphocytes can also be seen in CMV, HIV, HHV6, rubella, mumps, viral hepatitis, toxoplasmosis, typhus, lead poisoning etc.
Differential diagnosis:
- Streptococcal sore throat (Group A Streptococcus)
- Mononucleosis-like syndrome – CMV, HIV seroconversion, Toxoplasma infection, Viral hepatitis, Adenovirus etc.
- Leukaemia
- Drugs – phenytoin, carbamazepine
Treatment:
- Usually, self-limiting.
- Supporting treatment – nutrition, hydration
- Paracetamol, NSAIDs
- Steroids and acyclovir – selected cases
- Avoid sports for 4 weeks (risk of splenic rupture).
