HIV Flashcards
What are the initial investigations after a person has been diagnosed with HIV?
Viral load
CD4 T cell count
HIV genotype
When should treatment be started after the diagnosis of HIV?
Straight away
What is the composition of combined therapies for HIV?
Have at least 2 classes, and 3 drugs
All in 1 tablet
What are the classes of antiretroviral drugs?
Nucleoside reverse transcriptate inhibitors (NRTIs)
Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
Protease inhibitors (PIs)
Integrase inhibitors (INSTIs)
Fusion inhibitors (FIs)
Chemokine receptor antagonists (CCR5 antagonists)
What parameters are monitored in a person with HIV?
Viral load
- Decreases in weeks-months after treatment commenced
Other STIs
What is the most common reason that viral load does not decreases after treatment is started?
Patient not taking medications
What is the biggest risk factor for contracting HIV in Australia?
MSM
What is the biggest risk factor for contracting HIV in sub-Saharan Africa?
Sex
What is the biggest risk factor for contracting HIV in East and South-East Asia?
IVDU
What is the risk of contracting HIV from a needle-stick injury, if the patient has HIV?
1 in 300
What is the risk of contracting hepatitis C from a needle-stick injury, if the patient has hepatitis C?
1 in 30
What is the risk of contracting hepatitis B from a needle-stick injury, if the patient has hepatitis B?
If vaccinated, vanishingly small
If unvaccinated, 1 in 3
Why does treatment equal cure in hepatitis C?
No reservoir
What is the reservoir for HIV?
CD4 cells
What is the reservoir for hepatitis B?
DNA of hepatocytes
Is there treatment for hepatitis B? Is there a cure?
Treatment, yes
No cure
Who gets pre-exposure prophylaxis (PrEP)?
Partner has HIV
Person/partner has significant risk
Within 72 hours of risky sex
Along with HIV, what else do you test for?
Hepatitis B Hepatitis C Combined PCR on urine - Chlamydia - Gonorrhoea Syphilis
What are the symptoms of initial infection with HIV?
Often asymptomatic Flu-like illness - Fever - Lymphadenopathy - Rash (uncommon)
What does HIV serology involve?
Dual testing for Ag and Ab
When does HIV antigen become positive in a serology test?
Within 10-14 days
If the combined HIV serology is negative, when is the patient out of the woods?
Test remains -ve after 6 weeks
In what cases is PCR testing for HIV used?
When concerned about vertical transfer
Is specific consent required for HIV testing?
Yes
Why is it important to test for chlamydia?
Largely asymptomatic
Which populations are at higher risk of contracting gonorrhoea and syphilis?
MSM
Indigenous Australians
From where are swabs taken for gonorrhoea testing?
Throat
Anal
What are classical infections of AIDS?
Cerebral toxoplasmosis CMV retinitis Crytococcal meningitis Pneumocystis pneumonia Mycobacterium avium complex (MAC) infection
What are some atypical, or severe skin or oral infections that suggest impaired cell-mediated immunity, especially if risk factors are present?
Shingles in young person Warts - Intra-oral - Widespread facial - Severe anogenital Severe/widespread herpes simplex Facial molluscum contagiosum Oral candidiasis Oral hairy luekoplakia Necrotising gingivitis TB
What are some cancers that are more common in HIV?
Lymphomas
Kaposi’s sarcoma
Anal cancer
What are the key messages to convey to a patient at diagnosis with HIV?
Readily treatable
Shouldn’t interfere greatly with life plans - will need regular medical checks
Use condoms
Treatment prevents transmission
What are the key questions to ask a patient at diagnosis with HIV?
Have donated blood/semen in last year?
Any sexual partners from last year contactable? Could you call them and recommend a test?
Who can you talk to for support?
What is seroconversion?
HIV Ab test converts from -ve to +ve 3-5 weeks after transmission
What is seroconversion illness?
Febrile illness around time of seroconversion
Sometimes severe enough to present to hospital
What is seroconversion illness often assumed to be?
Flu
Glandular fever
What are the possible symptoms of seroconversion illness?
Fever Sore throat Rash Diarrhoea Weight loss
What are the parameters for CD4 cells?
More than 500 = normal
500-200 = mild immunosuppression
Less than 200 = risk of AIDS
What are the principles of antiretroviral therapy (ART)?
Suppress viral replication to
- Prevent viral infection of CD4 cells
- Allow reconstitution of cell-mediated immunity
- Stop reverse transcriptase making random drug-resistant mutations
Can patients go on drug holidays on ART?
No, unless essential
Continuous viral suppression better than intermittent therapy, even at high CD4 counts
What is immune reconstitution inflammatory syndrome?
When cell-mediated immunity improves, some weeks after starting ART, asymptomatic infections may suddenly present with inflammation
Symptoms occurring some weeks after starting ART, in someone with initially low CD4 count, consider possibility of T cell-mediated immune flare in existing infection
