HIV 2

Question 1

HIV2 epidemiology

Answer 1

Epicentre - west Africa and its colonies
Incidence falling
Dual HIV1 and 2 infection has been observed

UK - 137 HIV2, 35 dual

Question 2

HIV 2 transmission

Answer 2

Heterosexual sex most common
Less infectious in early stages- lower level of viraemia than with HIV 1
Rate increased with concurrent STI especially ulcerative conditions

Vertical transmission possible also blood transfusion, probably also homosexual sex, injecting drug use

Question 3

HIV2 natural history

Answer 3

Less pathogenic than HIV1 (2-3x increased mortality to non hiv population, 10x in HIV1)

Longer asymptomatic phase - can go 10-20 years asymptomatic
Less incidence of AIDS defining illness

Lower viral loads than HIV1 - ? Produces less RNA

Less infectious than HIV1

Question 4

HIV2 diagnosis

Answer 4

All confirmatory lab tests for HIV should be for 1 and 2
If any queries from these tests should be sent to Colindale for further inv

If lab doesn’t have HIV 2 testing need to re test anyone who is undetectable while not on tx

Dual infection can only be proved by having both HIV 1 and 2 DNA by PCR
HIV2 RNA may be neg so non diagnostic

Question 5

HIV 2 RNA VL

Answer 5

30 fold lower than HIV1 VL
No commercial assays available therefore limited access to testing in UK
If detectable - predicts rate of progression
Low or undetectable - slow rate

Only detectable in 8% with CD4>500, 53% in those with AIDS defining illnesses

Difficult to interpret as variation between labs

Treatment response may be poorer than in HIV infected individuals

Question 6

CD4 count

Answer 6

Only way to identify if tx needed and monitor tx/progress if VL undetectable

If VL undetectable CD4 can stay stable for many years
Like in HIV1 high VL can lead to rapid CD4 decline

Rises with ARVs but not as significantly as in HIV1

Question 7

HIV2 genotype

Answer 7

Should be done for all patients (BHH)
Can have baseline or secondary mutations

Pathways of resistance differ to HIV1

Question 8

Treatment HIV 2 - when to start

Answer 8

Based on CD4 and clinical status

Treat when If VL> 1000 even if CD4 >500

If dual infection consider HIV1 to be dominant but need agent active against both

Question 9

What to treat HIV2 with

Answer 9

First like - TDF or AZT with 3TC or FTC PLUS LPV/r or DRV/r
Truvada Kaletra - published data showing efficacy

Second line - 2 NRTIs plus kaletra
Can consider adding Raltegravir to the above

NNRTIs not effective along with some PIs and t20
Efficacy of MVC unknown but could be considered