HIV Flashcards
Basic concepts HIV and ART
What are the 3 main types of HIV tests? (3)
- Antibody tests
- Antigen antibody tests
- NATs (nucleic acid tests) or PCR
What are the advantages and disadvantages of antibody tests for HIV?
- Can take 23-90 days to detect HIV antibodies.
- Results 5-10 days
What are the advantages and disadvantages of antigen/antibody test for HIV?
- p24 antigen produced before antibodies develop thus earlier detection 18-45 days
- in general note blood from vein better than skin prick etc
- can do rapid test 20 min
What is the issue of doing HIV serological tests on newborns?
HIV specific maternal antibodies cross placenta. Can have maternal antibodies up to 18m even if uninfected.
Need PCR
What are the advantages and disadvantages of HIV PCR testing?
- Look for actual virus in blood
- Good for people recent exposure and early sx of HIV with neg antigen/antibody test
- a NAT detect HIV 10-33 days post exposure
- Difficult in low resource settings!!!
What is the western blot test?
Can be used confirm an HIV diagnosis.
Detects HIV ANTIBODIES.
Describe the ELISA test in the context of HIV
Enzyme linked immunosorbent assay - detects ANTIBODIES.
Very accurate when combined with western blot
What is stage 1 HIV? (3)
Acute HIV infection
- Sore throat
- Maculopapular rash
- Persistant lymphadenopathy
What is involved in stage 2 HIV? (general points no specific diseases) (3)
- Moderate unexplained weight loss (<10%)
- Recurrent URTIs, sinusitis, tonsilitis, otitis media, pharyngitis
- Various conditions affecting skin, nails, mucous membranes
What stage of HIV - papular pruritic eruptions?
Stage 2
What stage of HIV - Herpes zoster/complications?
Stage 2
What stage of HIV - Seborrhoeic dermatitis?
Stage 2
Treat with ketoconozole - improves on ART
What is the treatment for localised (dermatomal HSV)
Acyclovir 800mg 5x day for 7-10 days
Other - Valacyclovir/famcyclovir
What stage of HIV - fungal nail infections?
Stage 2
What stage of HIV - oral hairy leukoplakia?
Stage 3
EBV associated - membranes cannot be scraped off –> improves on ART
What stage of HIV? Oral candidiasis and oesophageal candidiasis?
Stage 3
Stage 4
Oral anti fungal - Fluconazole
What stage of HIV? Pulmonary TB
Stage 3
Note as CD4 count drops - less likely to see granulomas as very limited immune response.
What stage of HIV - disseminated TB?
Stage 4
Describe the clinical picture of Tb in high CD4 count HIV?
a) symptoms
b) Imaging
c) sputum smear
d) Extra-pulmonary involvement?
a) severe cough + haemoptyiss
b) cavities - particularly upper lobe
c) positive
d) rare <20%
Describe the clinical picture of Tb in low CD4 count HIV?
a) symptoms
b) Imaging
c) sputum smear
d) Extra-pulmonary involvement?
a) minimal cough ,rare hamoptysis
b) No cavities - hilarious lymphadenopathy, miliary pattern - can be normal
c) often negative
d) common >50% disseminated disease
Describe what conditions are in WHO stage 3 (general themes, not specific diseases)? (5)
- Severe weight loss
- Chronic diarrhoea ( >1 month)
- Persistent fever (intermittent or constant for >1 month)
- Severe bacterial infections
- Unexplained aanemia +/- chronic thrombocytopenia (plts <50)
What is the viral cause of kaposis sarcoma?
HHV8
Human Herpesvirus-8
What stage of HIV is kaposis sarcoma?
stage 4 - AIDS defining
What is the treatment of kaposis sarcoma?
Mainstay - ART and analgesia
Consider chemo - mucosal/internal organ involvement, nodular involvement, assoc oedema, kids
Tricky - chemo in rural sub saharan Africa??
Give some examples of kaposis sarcoma supportive care? (4)
Analgesia
Topical salycic acid - itching
Crushed metronidazole to reduce smell
K+ permanganate to dry excess oozing
What stage of HIV - Pnumocystitis jirovecii pneumonia?
stage 4
Most common AIDS defining condition in UK/USA
What is the serum B glucan test and its use in PJP?
Detects fungal antigens in bodily fluid
High levels suggest PJP
PJP work up in low resource setting? (one key diagnostic test) (3)
- O2 desaturated test
- CXR
- Blood tests - Investigations for HIV and Tb
- Low threshold for TB tx if unsure
Treatment for pneumocystitis jirovecci?
Co trimoxazole IV or PO for 21/7
Severe cases IV plus pred
CPT - lifelong co-trimox preventative therapy
What is the most common form of adult meningitis in Southern Africa?
Cryptococcal meningitis
What stage of HIV - cryptococcal meningitis?
Stage 4
Syndromic diagnosis - HIV +ve, CN6 palsy, headache?
Cryptococcal meningitis
ddx Tb meningitis
What are the 3 phases of treatment in cryptococcal meningitis (general phases)
- Induction Phase
- Consolidation phase
- Maintenance Phase
What is the treatment guideline of cryptococcal meningitis in resource rich settings?
2 weeks Amp B and Flucytosin
8 weeks Fluconazole high dose
12 weeks Fluconozole normal dose
What is the treatment guideline of cryptococcal meningitis in a resource poor setting?
Lip Amp B (stat) + Flucytosin + Fluconozole 2 weeks
Fluconozole high dose 8 weeks
Normal dose fluconazole 12 weeks
WHO guidelines - until CD4 over 200 and viral loads supressed
When should you start ART in new HIV diagnosis and cryptococcal meningitis and why?
After 4-6 weeks
Risk of IRIS
As per WHO guidelines
Management of CM in HIV
What is IRIS in the context of HIV?
Immune reconstitution inflammatory syndrome
What are environmental risk factors for Talaromycosis?
- Areas of high rainfall
- The bamboo rat (only known animal reservoir)
- Endemic in Asia only
What is the treatment for Tararomycosis
Antifungal Tx
(Lip) Amp B 2 weeks
Itraconizole/voriconozole 10-12 weeks
What is someones CD4 count likely to be if you diagnose Talaromycosis?
Less than 100
What is the causative organism in Talaromycosis?
Talaromyces Marneffei - a dimorphic fungus
Do steroids have a role in the management of cryptococcal meningitis?
No. Charlie’s paper
Give differentials for SOL in HIV?
Pyogenic abcess
Cryptococcoma
Tuberculoma
Cerebral Toxoplasmosis
PML (progressive multifocal leukoencephalopathy
Primary CNS Lymphoma
Spot diagnosis:
Low CD4 count, CNS symptoms, ‘multiple ring enhancing lesions’ on CTB
Cerebral Toxoplasmosis
What is PML?
Progressive multifocal leuoencephalopathy
Severe demyelination disorder
Often insidious onset and progression of symptoms
Caused by a virus infection (polyomavirus JC)
- preferentially affects the CNS
- pathophysiology - reactivation due to poor immune system of HIV
- subacute focal neurology
What causes PML?
JC virus - Polyomavirus
Reactivation when CD4 is <200
What is the treatment for PML?
Antiretroviral treatment
What is the treatment for cerebral toxoplasmosis?
Pyrimethamine + sulfadiazine + folonic acid or cotrimoxazole