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??
