GP Infectious Disease Flashcards
What virus causes infectious mononucleosis (glandular fever)?
Epstein Barr Virus (EBV)
How is EBV spread?
Kissing, sharing cups, toothbrushes etc
(EBV = found in the saliva)
(Saliva transmission)
When is someone infectious with EBV?
Several weeks before the illness begins and intermittently for remainder of patient’s life
At what age do people normally get EBV and when is it more symptomatic?
- Childern → very few symptoms (most common)
- Teenagers + young adults → more severe symptoms
When is someone classed as having infectious mononucleosis?
When the have: EBV + symptomatic
Symptoms = sore throat, fever, fatigue
An adolescent has a sore throat and was given amoxicillin, she comes out in an intensely itchy maculopapular rash. What is the possible diagnosis?
Infectious mononucleosis
What happens if a patient with infectious mononucleosis takes amoxicillin or cefalosporins?
Patient develops an intensely itchy maculopapular rash
What are the signs and symptoms of infectious mononucleosis?
Symptoms:
* Sore throat
* Fatigue
Signs:
* Fever
* Lymphadenopathy
* Splenomegaly (splenic rupture in rare cases)
* Tonsillar enlargement
A teenage presents feeling tired and a sore throat. On examination she has lymphadenopathy, splenomegaly, tonsillar enlargement, and is warm to touch. Possible diagnosis?
Infectious mononucleosis
What antibodies do you produce in infectious mononucleousis?
Heterophile antibodies
(Multipurpose antibodies that are non-specific to EBV antigens)
Takes up to 6 weeks for these antibodies to be produced
What are the two tests for heterophile antibodies?
- Monospot test (patientts RBC to horses RBCs → heterophile Abx present → reaction to horse RBC → +ve result)
- Paul-Bunnell test (similar to monospot but sheep RBCs
What is the specificty and sensitivity of the monospot and Paul-Bunnell test for heterophile antibodies in reponse to EBV infection?
- 100% specificity
- 70-80% sensivity (not everyone who has IM produces heterophile antibodies - can take up to 6 weeks to produce them)
What are the specific antibody tests for EBV?
- The IgM antibody rises early → suggests acute infection
- The IgG antibody persists after the condition → suggests immunity
These antibodies target something called viral capsid antigen (VCA)
What is the management for infectious mononucleosis?
- Usually self-limiting (acute illness 2-3 weeks, fatigue can last several months after infection cleared)
- Avoid alcohol (EBV impacts the liver’s ability to process alcohol)
- Avoid contact sports (splenic rupture risk)
- Splenic rupture → emergency surgery
Name two complications of infectious mononucleosis
- Splenic rupture
- Glomerulonephritis
- Haemolytic anaemia
- Thrombocytopenia
- Chronic fatigue
EBV infection is associated with certain cancers, notable Burkitt’s lymphoma
What is Lyme disease?
Lyme disease = an infectious disease transmitted to humans through the bites of infected ticks
What is Lyme disease caused by?
Lyme disease = is a zoonotic infection caused by a spirochete of genus Borrelia
(transmitted to humans by ticks)