HIV2 Flashcards
How many lineages are there of HIV2?
9
Lettered a-I
Only a and b endemic
Testing for HIV2
Three CE marked serology tests performed in an ISO 15189 accredited lab - reactivity on 2 CE marked 4th gen tests for hiv1 and hiv2 then differention of hiv2 on a ce marked antibody only test
Not confirmed until second sample with consistent reactive results (poct can be first sample)
Hiv 2 window period
90 days from exposure because only an antibody test as p24 specific for hiv1
A negative test should be repeated at 6 weeks and 3/12 post exposure with parallel testing for hiv2 viral rna and if necessary proviral dna
What should you do with serology results that don’t fit into a clear pattern of confirmed lab diagnosis? Hiv2
Fully investigate for presence or abscence oh HIV2 - PCR for HIV2 proviral dna
When to measure viral load in PLW HIV2?
Baseline and appropriate intervals - 6 monthly for those not on treatment
Detectable pre treatment / 1,3,6 months then 6 monthly
Undetectable pre tx 1, 6 months then 6/12ly
How is HIV2 resistance testing performed?
Genotypic only method
Must have at least 500cp/ml
When to start ARV? HIV2
Minimal evidence for correlating viral load with treatment benefit but is evidence correlating cd4 cell count with treatment response.
Benefits of initiating treatment will outweigh risk in majority of people
Suggest all people with hiv2 start ARVs
Strong suggest if -
Dual hiv1/2 infection
Pregnancy
Coinfection with hep b
Diagnosis made during primary hiv2 injection
Detectable hiv2 viraemia
Cd4 <500
Advanced disease/opportunistic infection
Symptoms or an indicator condition of hiv 1 or 2 regardless of cd4 or VL
What ARV to use if uncertainty about whether there might be dual hiv 1 and 2 infection?
Something that is active against both viruses - resistance may be more
Likely to develop in HIV2
How to manage PHIV2?
Start ARV
From TEMPRANO/START/HPTN052 improved morbidity and mortality following ART initiation regardless of CD4 count
Reduces risk onward transmission
Possible limitation of viral reservoir
How to manage HBV/HIV2 coinfection?
As per HIV1 - tx with tdf containing ARV
How does VL differ in HIV2?
More elite controllers
Most people still go on to have disease progression and CD4 drops even if VL levels low
Does u=u apply in hiv2?
Yes but can only say this for those on treatment
What ARVs to start in HIV2?
TDF/FTC preferred backbone
TAF/FTC also suitable
ABC/3TC 2nd line - likely to be greater TDF activity in presence of viral resistance
What ARVs are not recommended in HIV2?
NNRTI no activity against HIV2
AZT, stavudine not recommended due to mitochondrial toxicity
atazanavir, fosamprenavir, tipranavir
No clinical experience of MVC in tx naive individuals
Which third agent to use in HIV2?
DTG BD or DRV/r Bd
unless consistently aviraemic before tx then can have OD
Alternatives if appropriate but minimal data
Bictegravir
Cobicistat as booster
RAL BD but more resistance emerging than with DTG
Elv/c
