HIV and other STIs

Question 1

HIV
a) CD4 counts for AIDS diagnosis
b) Normal CD4 count
c) Effect of HAART on CD4 count
d) What infections do not present until count is <50

Answer 1

a) <200
Or infection with AIDS-defining opportunistic pathogens

b) Normal CD4 count >500

c) HAART leads to increases in CD4 count over time, if treatment started early enough

d) - CMV choroidoretinitis
- Mycobacterium avian complex (MAC) pneumonia

Question 2

LGV
a) Cause
b) Presentation
c) Diagnosis
d) Management

Answer 2

a) Chlamydia trachomatis serovars L1-L3

b) Primary - ulcer
Secondary - painful enlarged LNs that often discharge; may also have HSM, conjunctivitis
Tertiary (20 years later) - procto-colitis

c) - Chlamydia screen (including rectal swab)
- Sample from ulcer/enlarged LN

d) Doxycycline 21 days

Question 3

HSV
a) Most common cause of genital herpes in UK
b) Who is offered prophylaxis

Answer 3

a) HSV-1 (although HSV-2 is the “classical” cause)

b) >6 episodes per year - give 1 year of prophylactic aciclovir

Question 4

PEP
a) Needlestick injury with HIV positive person

Answer 4

a) 3 anti-retrovirals for 1 month
(if they have detectable viral load)

Question 5

Syphilis
a) Skin manifestations
b) Neurosyphilis
c) Cardio-syphilis

Answer 5

a) - Rash involving palms and soles
- Condylomata lata

b) Asymptomatic
Meningeal - meningism
Meningovascular - meningism + strokes
Paresis
Tabes dorsalis - dorsal columns
Argyll Robertson pupils

c) Aortitis with aneurysm, AR

Question 6

Kaposi sarcoma
a) Virus associated
b) Causes other than HIV/AIDS
c) Risk with HAART

Answer 6

a) HHV-8

b) Endemic in African populations, elderly Jewish men

c) Risk increases in first 6 months of therapy
- may be due to Immune Reconstitution Inflammatory Syndrome (IRIS), whereby treatment leads to over-activation of immune system to infection and worsening infection (this may be how PML presents in HIV also - PML-IRIS)

Question 7

PML
a) What is it?
b) Cause and risk factors
c) Presentation
d) Diagnosis and differentials
e) Treatment

Answer 7

a) Demyelinating disease affecting the brain (spares the optic nerve and spinal cord) triggered by JC virus activation

b) John Cunningham (JC) virus
- Naturally found in 80% individuals
- PML only affects immunocompromised patients:
HIV/AIDS with CD4 <200 (40%), haematological malignancy (30%), drug immunosuppression* (30%)

*Chemotherapy, steroids, calcineurin inhibitors, natalizumab, etc.

c) - Subacute progressive onset
- UMN weakness, ataxia, CN palsies, confusion, etc.

d) CT/MRI brain - multifocal hypodense areas (hyperdense on T2) with no enhancement (vs toxoplasmosis) and no mass effect

Differentials:
- HIV encephalopathy/dementia - slower onset, JC antibody negative
- Cryptococcal/TB meningitis - more acute, meningism, CN palsies, CSF analysis
- Toxoplasmosis - more acute, multiple ring enhancing lesions, mass effect

e) No specific treatment
- In HIV/AIDS, optimisation of HAART to improve CD4 count is advised

Question 8

Trichomonas vaginalis.
a) Characteristic sign on colposcopy

Answer 8

a) Strawberry cervix

Question 9

Hep C
a) needlestick injury with infected person - management
b) Side effects of treatment
c) Majority of transmission is via…?

Answer 9

a) Monthtly Hep C RNA PCR testing
- If positive at any stage (seroconversion), treat with 6 months of interferon + ribavirin

b) - Ribavirin - haemolytic anaemia (avoid in the elderly, cardiac failure, haematological disorders)
- Interferon - flu-like illness, mood/emotional changes, thyroiditis

c) Needle sharing - IVDUs (rare for sexual transmission though does happen)

Question 10

Causes of diarrhoea in HIV/AIDS
a) Watery, profuse, stool samples show oocytes on modified ZN staining
b) Bloody diarrhoea in AIDS patient

Answer 10

a) Crytosporidiosis

b) CMV

Question 11

Toxoplasmosis
a) Presentation
b) Diagnosis
c) vs PML

Answer 11

a) Acute (2 weeks) history of neurological deficit, raised ICP

b) Multiple ring enhancing lesions on MRI with mass effect

c) Toxoplasmosis tends to be more acute, mass effect/ring enhancing cortical lesions vs periventricular/subcortical lesions in PML

Question 12

Hep B
a) HBeAg antibodies
b) Route of infection

Answer 12

HBeAg indicates :
- seroconversion and carries higher risk of HCC
- higher infectivity
- higher risk of vertical transmission in pregnancy

b) Sexual, IVDUs, blood

Question 13

Post-needlestick risk of infections

Answer 13

HIV - 0.3%
Hep C - 3%
Hep B - 30% +

Question 14

HAART
a) What is a risk of AZT?

Answer 14

a) Dilated cardiomyopathy

Question 15

HIV skin eruption - follicular papules or pustules, predominantly located on the scalp, face, neck, and upper chest

Answer 15

Eosinophilic folliculitis

Question 16

Non-gonococcal urethritis
a) Causes
b) Presentation
c) Management

Answer 16

a) 60% chlamydia, other organisms also

b) May present like UTI, but beware in young males who are sexually promiscuous

c) Doxycycline, or azithromycin

Question 17

Bacterial vaginosis
a) Sign on microscopy
b) Treatment

Answer 17

a) Clue cells

b) Metronidazole

Question 18

Which vaccines are avoided in HIV with low CD4 count?

Answer 18

Live vaccines (due to immunosuppression):
- MMR
- Typhoid
- oral polio
- BCG
- Yellow fever
- Varicella

Question 19

CMV infection
a) CD4 count
b) Presentation
c) diagnosis
d) management

Answer 19

a) Usually <50

b) Pneumonitis
Hepatitis
Retinitis
Colitis

c) serum PCR for CMV
Transbronchial biopsy may show “owl” cells

d) IV ganciclovir

Question 20

Mycobacterium associated with low CD4 count and affecting chest, hilum and abdomen

Answer 20

Mycobacterium avium intracellulare

Question 21

HAART
a) Nucleoside reverse transcriptase inhibitors (NRTI); one also used to treat Hep B
b) Non-nucleoside reverse transcriptase inhibitors (NNRTI)
c) Protease inhibitors
d) Integrase inhibitors
e) Pill that combines 3 drugs
f) If presenting with fever, night sweats and weight loss 3-6 weeks post- initiation of HAART -?

Answer 21

a) Tenofovir (used also to treat Hep B), emtricitabine, zidovudine (AZT)
- Note: often given as one Truvada® tablet (245 mg tenofovir and 200 mg emtricitabine)

b) Efavirenz

c) Darunavir

d) raltegravir (inTEGgrase - ralTEGravir)

e) Atripla® (efavirenz/emtricitabine/tenofovir disoproxil)

f) IRIS
Screen for infection
Treat with steroids, but continue HAART

Question 22

Hep A - transmission

Answer 22

Faecal oral route
- may be from contaminated food
- also in anal sex if doing oral after (especially MSM)

Question 23

Seroconversion
- diagnosis

Answer 23

Elevated HIV viral load