Epstein-Barr Virus, Mumps & HIV Flashcards
What is infectious mononucleosis (IM)?
A viral infection caused by the Epstein-Barr virus (EBV).
Also known as ‘mono’ or ‘glandular fever’.
What triad of features characterises (IM)?
1) fever
2) pharyngitis
3) lymphadenopathy
How is EBV spread?
This virus is found in the saliva of infected individuals.
Infection may be spread by kissing or by sharing cups, toothbrushes and other equipment that transmits saliva.
Typical exam scenario for IM:
An adolescent with a sore throat, who develops an itchy rash after taking amoxicillin.
Mononucleosis causes an intensely itchy maculopapular rash in response to amoxicillin or cefalosporins.
Clinical features of IM?
- Prodromal phase: malaise, fatigue, headache, and low-grade fever
- Classic triad: sore throat, fever, lymphadenopathy
- Splenomegaly (may rarely predispose to splenic rupture)
- Hepatitis: transient rise in ALT
- Palatal petechiae
What is effect of taking amoxicillin whilst having infectious mononucleosis?
Development of a maculopapular, pruritic rash.
Lymphadenopathy in IM vs tonsillitis?
IM - lymphadenopathy may be present in the anterior and posterior triangles of the neck
Tonsillitis - typically only results in the upper anterior cervical chain being enlarged
Prognosis of IM?
Symptoms typically resolve after 2-4 weeks.
In certain diseases (such as HIV) we can test for specific antibodies to infectious mononucleosis.
In IM, what antibodies does the body produce?
Heterophile antibodies (these are more multipurpose and not specific to the EBV antigens).
It takes up to 6 weeks for these antibodies to be produced.
What 2 tests can be used to test for heterophile antibodies?
1) Monospot test
2) Paul-Bunnell test
What is the monospot test?
This introduces the patient’s blood to RBCs from HORSES.
Heterophile antibodies (if present) will react to the horse RBCs and give a positive result.
What is the Paul-Bunnell test?
This is similar to the monospot test but uses red blood cells from sheep.
It is possible to test for specific EBV antibodies in IM.
What do these antibodies target?
Viral capsid antigen (VCA)
IgM vs IgG antibody?
The IgM antibody rises early and suggests acute infection.
The IgG antibody persists after the condition and suggests immunity.
What are patients advised to avoid in EBV?
1) Alcohol - EBV impacts the ability of the liver to process the alcohol.
2) Contact sport - due to the risk of splenic rupture.
Management of IM?
Supportive:
1) Rest during the early stages, drink plenty of fluid, avoid alcohol
2) Simple analgesia for any aches or pains
3) Consensus guidance in the UK is to avoid playing contact sports for 8 weeks after having glandular fever to reduce the risk of splenic rupture
What are some complications of IM?
1) Haemolytic anaemia
2) Thrombocytopenia
3) Splenic rupture
4) Hepatitis
5) Cholestastic hepatitis
6) Chronic fatigue
7) Glomerulonephritis
EBV infection is associated with certain cancers, notably which one?
Burkitt’s lymphoma
What is mumps?
Mumps is an acute viral illness caused by the Paramyxovirus, primarily affecting the salivary glands, particularly the parotid glands.
Which salivary glands does mumps particuarly affect?
Parotid glands
How is mumps transmitted?
Through respiratory droplets and direct contact with infected individuals.
What is the pathognomonic sign of mumps infection?
Swelling of the parotid gland (parotitis) –> presents as tenderness and erythema overlying the angle of the mandible.
Which vaccine protects against mumps?
MMR vaccine offers around 80% protection against mumps.
Presentation of mumps?
- Prodrome: flu-like symptoms e.g. fever, myalgia, lethargy, reduced appetite
- Parotid gland swelling with associated pain: unilateral or bilateral
- Fever
Can present with symptoms of the complications:
- Abdominal pain (pancreatitis)
- Testicular pain and orchitis (orchitis)
- Confusion, neck stiffness & headache (meningitis or encephalitis)
What is the infective period of mumps in relation to parotid swelling?
infective 7 days before and 9 days after parotid swelling starts
What is the incubation period of mumps?
14-21 days
Describe characteristics of of parotitis in mumps
Swelling over the angle of the jaw, which may result in the earlobe being elevated and the jaw angle becoming obscured.
Tenderness, pain exacerbated by chewing, fever, malaise, anorexia, and headache.
What is a key complication of mumps in postpubertal males?
Orchitis
Describe orchitis
Testicular inflammation presenting with pain, erythema, warmth, and tenderness; primarily unilateral.
This is generally within a week post-paroritis.
Give 5 complications of mumps
1) Orchitis
2) Oophoritis
3) Meningitis
4) Encephalitis
5) Acute pancreatitis
6) Sensorineural hearing loss - usually unilateral and transient
How can a diagnosis of mumps be made?
1) PCR testing on a saliva swab
2) Blood or saliva can also be tested for antibodies to the mumps virus
Management of mumps?
Supportive: rest, fluids and analgesia.
Mumps is a notifiable disease –> need to notify public health of any suspected and confirmed cases.
What virus causes mumps?
paramyxovirus
What is HIV?
An RNA retrovirus
What are the 2 types of HIV?
HIV-1
HIV-2
What is the most common type of HIV?
HIV-1
HIV enters and destroys which cells?
CD4 T helper cells
Stepwise progression of HIV?
1) An initial seroconversion flu like illness within a few weeks of infection.
2) Infection is then asymptomatic until it progresses
3) Patient becomes immunocompromised and beings developing AIDS defining illnesses and opportunistic infections, potentially years later.
How is HIV spread (3 routes)?
1) Unprotected anal, vaginal or oral sexual activity
2) Mother to child at any stage of pregnancy, birth or breastfeeding (vertical transmission)
3) Mucous membrane, blood or open wound exposure to infected blood or bodily fluids e.g. sharing needles, needle-stick injuries or blood splashed in an eye.
What is mode of delivery determined by in a pregnant woman with HIV?
Determined by the mother viral load
What viral load indicates a normal vaginal delivery in HIV?
< 50 copies / ml
What should be given during the c-section if the viral load of HIV is unknown?
IV zidovudine
What viral load indicates a c-section in HIV?
> 50 copies/ml –> c-section is considered
> 400 copies/ml –> ALL women given c-section
What should be given during the c-section if the viral load of HIV is >10000 copies/ml?
IV zidovudine
What HIV viral load indicates the need for IV zidovudine during c-section?
1) Unknown viral load
2) >10000 copies/ml
Prophylaxis treatment may be given to the baby depending on the mothers HIV viral load.
What is a ‘low risk baby’? What is a ‘high risk baby’?
Low risk –> mothers viral load is <50 copies/ml
High risk –> mothers viral load is >50 copies/ml
What HIV prophylaxis is given to low risk babies (i.e. mothers viral load is <50 copies/ml)?
Zidovudine for 4 weeks
What HIV prophylaxis is given to high risk babies (i.e. mothers viral load is >50 copies/ml)?
Zidovudine, lamivudine and nevirapine for 4 weeks
Can HIV be transmitted in breastfeeding>
Yes, even if the mother’s viral load is undetectable.
Is breastfeeding recommended in HIV?
No - however if the mum is adamant and the viral load is undetectable, sometimes it is attempted with close monitoring by the HIV team.
What can cause a positive HIV result in children <18 months?
Positive results may be due to maternal antibodies in children aged under 18 months.
This does not necessarily mean they are HIV positive.
What 2 options exist for HIV testing?
1) HIV antibody screen
2) HIV viral load
What does the HIV antibody screen involve?
This tests whether the immune system has created antibodies due to exposure to HIV.
This is the standard screening test, but it can give false positive in babies of HIV positive mums, due to maternal antibodies that cross the placenta.
It can take up to 3 months for antibodies to develop after exposure to the virus.
What is the standard screening test for HIV?
HIV antibody screen
Why should you be cautious in using the HIV antibody screen in young children?
It can give false positive in babies of HIV positive mums, due to maternal antibodies that cross the placenta.
What is the HIV viral load test?
This tests directly for viruses in the blood.
This will never be falsely positive, but may come back as “undetectable” in patients on antiretroviral therapy.
Which HIV test can given false positives?
HIV antibody screen
Which HIV test can come back as “undetectable” in patients on antiretroviral therapy?
HIV viral load
When should you test for HIV (4 scenarios)?
1) Babies to HIV positive parents
2) When immunodeficiency is suspected e.g. unusual, severe or frequent infections
3) Young people who are sexually active can be offered testing if there are concerns
4) Risk factors such as needle stick injuries, sexual abuse or IV drug use
How many times are babies to HIV positive parents tested?
Twice
When are babies to HIV positive parents tested?
1) HIV viral load test at 3 months –> if this is negative, the child has not contracted HIV during birth and will not develop HIV unless they have further exposure.
2) HIV antibody test at 24 months –> to assess whether they have contracted HIV since their 3 month viral load e.g. through breast feeding.
What are the key principes of medical care in HIV?
1) Antiretroviral therapy (ART)
2) Normal childhood vaccines (avoiding or delaying live vaccines if severely immunosuppressed)
3) Prophylactic co-trimoxazole (Septrin)
4) Treatment of opportunistic infections
Why is prophylactic co-trimoxazole (Septrin) given to children with HIV?
Given for children with low CD4 counts, to protect against pneumocystis jirovecii pneumonia (PCP)
What is the aim of antiretroviral therapy (ART) in HIV?
To achieve a normal CD4 count and undetectable viral load.
