HIV-2 Flashcards
1
Q
Which HIV type is most common HIV-1 or HIV-2?
A
HIV-1
2
Q
What is the relationship between HIV-2 and simian immunodeficiency virus (SIV)?
A
Closely related to SIV in sooty mangabeys
3
Q
What is the difference in the relationship between HIV-1, HIV-2 and SIV?
A
HIV-1 related to SIV in chimpanzees
HIV-2 related to SIV in sooty mangabeys
4
Q
What is the prevalence worldwide of HIV-2?
A
1-2 million
5
Q
Where is HIV-2 endemic?
A
West Africa
6
Q
How many subtypes of HIV-2?
A
NINE (9)
Only A & B epidemic
7
Q
Describe the limitations of evidence in HIV-2 prevalence and natural course.
A
Cohort and treatment studies - group A only
Small worldwide number
Rapid HIV test often does not differentiate
8
Q
What is the the pathogenicity of HIV-2?
A
Most untreated individuals will have disease progression
Slower progression than HIV-1
9
Q
Describe limitations of evidence for treatment of HIV-2
A
ART developed for HIV-1 group M
Limited in vitro evidence
Evidence based on cohort and observational studies only
10
Q
What is the difference between HIV-1 and HIV-2 and transmission?
A
HIV-2 lower risk of horizontal and vertical transmission
11
Q
Why is transmission less likely with HIV-2 vs HIV-1?
A
Lower plasma viral load, often undetectable
12
Q
What is the relationship between CD4 and AIDS in HIV-2?
A
AIDS defining illness can occur at higher CD4 count
13
Q
What is the progression of CD4 in HIV-2 vs HIV-1?
A
CD4 count in HIV-2 slower decline
14
Q
What is the disease trajectory in HIV-2 vs HIV-1?
A
HIV-2 progresses at half the rate of HIV-1
15
Q
Is there any difference in clinical disease/AIDS-defining illness due to HIV-2 vs HIV-1?
A
No
16
Q
Which TWO class of ART can resistance more easily develop?
A
NRTI
PI
17
Q
Does HIV-2 protect against HIV-1?
A
No but may delay clinical progression of HIV-1
18
Q
What type of animal SIV is the HIV-2 origin?
A
SIV smm
19
Q
What human contact is there with sooty mangabeys in West Africa?
A
Hunted for FOOD
Kept as PETS
20
Q
When did SIVsmm likely jump from sooty mangabey to human?
A
1905-1945
21
Q
What was the prevalence of HIV-2 in West Africa in 1980s?
A
> 1% in some parts
22
Q
Where in West Africa reported the highest prevalence of HIV-2?
A
Guinea-Bissau
23
Q
What is the prevalence of HIV-2 in GUinea Bissau?
A
8%
24
Q
What is the prevalence of HIV-2 in over 40 year olds in GUinea Bissau?
A
20%
25
Dissemination of HIV-2 outwith West Africa is attributed to which event and which country?
War of Independence (1963-1974)
| Portugal
26
Which countries in Europe have the highest prevalence of HIV-2?
FRANCE
| PORTUGAL
27
What is the number of people living with HIV 2 in FRANCE?
1000
28
What is the number of people living with HIV 2 in PORTUGAL?
2000
29
What are the possible reasons for decreasing prevalence of HIV-2?
lower transmission rate
change in risk behaviour
reduced healthcare associated infection
competition with HIV-1
30
When should ART be started in HIV-2?
At new diagnosis
| evidence to support limited
31
Why is adherence so important in ART for HIV-2?
INTRINSIC resistance therefore less options
LOWER THRESHOLD for resistance
LIMITED SWITCH options
32
Why is regular CD4 monitoring encouraged for HIV-2?
VL is often undetectable and therefore does not help with monitoring of therapy efficacy and health status
33
What is general pathway of testing and confirming HIV-2 infection?
4th generation Ag/Ab SCREENING
at least 2 CONFIRMATORY tests
1 test that can DIFFERENTIATE between HIV1 and HIV2
34
What is the limitation of the 4th generation Ag/Ab test for HIV in context of HIV-2?
p24 antigen detective designed towards HIV-1
| therefore this test is only ANTIBODY test for HIV-2 and has no utility in early infection
35
Is there an avidity test of HIV-2?
No
36
What is the limitation of the HIV-2 RNA viral load test?
often undetectable therefore no use if trying to confirm HIV-2 infection
37
What additional test can be used to confirm HIV-2, if screen is indeterminate and viral load undetectable?
measure HIV-2 PROVIRAL DNA
38
What is the proportion of PLW HIV-2 who have undetectable viral load and are ART naive?
25-40%
39
Can PLW HIV-2 progress even if viral load undetectable?
Yes
40
What is the relationship between HIV-2 detectable viral load and clinical progression?
Higher risk or rate of progression c/w undetectable
41
Which HIV-2 subtype is harder to measure viral load for?
B
42
What is the discordance observed between viral load and clinical progression in subtype B HIV-2?
Clinical progression more regularly observed with undetectable VL c/w subtype A
43
Why might clinical progression be more likely in subtype B HIV-2 and undetectable VL?
Harder to test for VL for subtype B therefore may be incorrectly measured as undetectable
44
What type of resistance testing if available for HIV-2?
Genotypic
45
At what viral load level can resistance testing be performed on HIV-2?
>500copies/ml
46
What 2 classes of ART is HIV-2 naturally resistant?
```
NNRTIs
Fusion inhibitors (enfuvirtide)
```
47
Describe the method of genotypic HIV-2 resistance testing.
- EXTRACTION viral RNA
- REVERSE TRANSCRIPTION of RNA to complementary DNA
- PCR AMPLIFICATION of cDNA
- ANALYSED for mutations
48
Sanger resistance method is used for HIV-2, what level do mutations have to be present in the viral population to be detected?
>15% of viral population
49
Why should ART be given to PLW HIV-2?
Overall evidence suggests, without ART:
- HIV-2 will progress to AIDS
- Life expectancy reduced by 10 years
50
Is ART recommended in HIV-2 infection?
YES
| Although no consensus across world
51
When monitoring dual HIV-1 and 2 infection what is essential to check?
viral load and resistance of EACH virus
52
What is the definition of primary HIV infection?
HIV infection within maximum of 6 months from estimated time of HIV transmission
53
What is the rationale for immediate ART start in primary HIV-2 infection?
Improved mortality and morbidity regardless of CD4 (HIV-1 trials)
Reduce transmission
Limit viral reservoir
54
When should ART be started in HIV-2 and hepatitis B co-infection?
Either as HIV-2 start
or
if independent HBV treatment criteria is met
ART should cover both viruses
55
Should ART be started in HIV-2 with detectable VL?
YES
| detectable VL strong indication for ART start
56
Why is low level viraemia in HIV-2 of concern?
VL HIV-2 shown to be 10 to 100 times lower than HIV-1 when matched for CD4 cell count, ie impact of CD4 even at low level
57
What is the definition of Advanced HIV disease in adults?
CD4<200
| Stage 3 or 4 at presentation
58
When should ART be started in HIV-2 with current or past history of an indicator condition?
IMMEDIATE start, regardless of VL
59
HIV-2 infection + MALE sex is associated with increased risk of what?
AIDS
Loss to follow up
Mortality
60
At what age is there an higher overall mortality in HIV-2?
>45 years
61
What EIGHT specific settings is ART recommended in HIV-2?
1) PRIMARY infection
2) CO-INFECTION with HBV
3) DETECTABLE viral load
4) CD4 <500
5) ADVANCED HIV (CD4 <200)
6) OPPORTUNISTIC infection
7) INDICATOR condition
8) COMORBIDITY - esp cardio, renal, hepatic
62
What is the recommended combination ART for HIV-2?
```
2x NRTI
+
1x 2nd generation INSTI
or
1x ritonavir-boosted PI
```
63
What is the first line NRTI regimen for HIV-2?
Tenofovir disoproxil
+
Emtricitibine
64
Can TAF be used instead of TDF for HIV-2?
YES
65
Why is tenofovir preferred over abacavir for HIV-2?
TDF great activity in presence of resistance
66
Studies of abacavir use in HIV-2 are generally in the context of what combination therapy?
Triple NRTI with zidovudine + lamivudine
67
Why are zidovudine and stavudine not recommended as first line treatment of HIV-2?
MITOCHONDRIAL toxicity
68
Why are didanosine not recommended as first line treatment of HIV-2?
MITOCHONDRIAL toxicity
| HEPATIC toxicity
69
What are the TWO preferred 3rd agents that can be considered for HIV-2?
DOLUTEGRAVIR
| DARUNAVIR/ritonavir
70
What 3 INSTIs can be alternative to DTG for HIV-2?
BICTEGRAVIR
RALTEGRAVIR
ELVITEGRAVIR/cobicistat
71
Can cobicistat be used as an alternative pharmacokinetic enhancer to ritonavir for HIV-2?
YES
72
What is the recommended DOSE of DOLUTEGRAVIR for HIV-2?
50mg TWICE daily
73
When might DOLUTEGRAVIR ONCE daily be used for HIV-2?
If undetectable viral load prior to starting ART
74
Why is dolutegravir generally preferred over darunavir/r for HIV-2?
Better TOLERABILITY
| REDUCED drug-drug interaction
75
Why is darunavir the preferred PI in HIV-2?
Better TOLERABILITY and TOXICITY profile
76
What is the recommended DOSE of DARUNAVIR/r for HIV-2?
600mg/100mg TWICE daily
77
When might DARUNAVIR/r ONCE daily be used for HIV-2?
If undetectable viral load prior to starting ART
78
What is the potential disadvantage of using bictegravir for HIV-2?
available only as combination SINGLE TABLET REGIMEN
| Unable to increase dose
79
What are the disadvantages of not being able to increase dose of bictegravir for HIV-2?
May be less effective if detectable viral load
or
past history of treatment failure on 1st gen INSTI
80
What evidence of INSTI resistance from RALTEGRAVIR use is there for HIV-2?
ONE RETROSPECTIVE study
| relatively FREQUENT emergence
81
How should RALTEGRAVIR be dosed for HIV-2?
TWICE daily
82
Other than darunavir, what other PIs can be used for HIV-2?
LOPINAVIR/ritonavir
| SAQUINAVIR/ritonavir
83
To which PIs is there reduced phenotypic sensitivity and therefore should not be used for HIV-2?
ATAZANAVIR
FOSAMPRENAVIR
TIPRANAVIR
84
Through what mechanism is HIV-2 intrinsically resistant to NNRTIs?
DIFFERENT STRUCTURE of NNRTI-binding pocket in HIV-2 c/w HIV-1
85
Other than NNRTI what other ART is HIV-2 INTRINSICALLY resistant too?
FUSION inhibitor
| ENFUVIRITIDE
86
Can MARAVIROC be used for HIV-2?
MAYBE
Evidence IN VITRO
No clinical experience
87
How often should CD4 count be checked in HIV-2 infection for those NOT on ART and those ON ART?
```
BASELINE
AFTER START:
1 month
3 month
6 month
THEN
3-6 monthly thereafter
```
88
What resistance testing should be performed at baseline on HIV-2?
NRTI
PI
INSTI
89
How often should VIRAL LOAD be checked in HIV-2 infection for those NOT on ART?
SIX (6) monthly
90
How often should CD4 count be checked in HIV-2 infection for those NOT on ART?
Baseline
| 3-6 months
91
How often should VIRAL LOAD be checked in HIV-2 infection if DETECTABLE prior to ART start?
```
1 month
3 month
6 month
then
3-6 monthly
```
92
How often should VIRAL LOAD be checked in HIV-2 infection if UNDETECTABLE prior to ART start?
1 month
| 6 month
93
When should resistance be checked in HIV-2 outwith baseline?
if previously undetectable and becomes repeatedly detectable
94
What is the annual average CD4 cell loss in HIV-2 c/w HIV-1?
HIV-2 ELEVEN (11) cells/mm3/year
| HIV-1 FORTY NINE (49) cells/mm3/year
95
Is the CD4 cell count more rapid for HIV-2 or HIV-1?
HIV-2
96
Is CD4 cell count response to ART poorer in HIV-2 or HIV-1?
HIV-2
97
What factor makes CD4 cell count response poorer in HIV-2 after starting ART?
LOW nadir CD4 cell count
98
Why is CD4 cell count monitoring potentially more important in HIV-2 than HIV-1 even if on treatment?
HIV-2 viral load often UNDETECTABLE at start of ART but can still result in CD4 loss
99
Is virological response to ART SLOWER in HIV-2 or HIV-1?
HIV-2
100
In PREGNANCY, what is the preferred 3RD agent for ART in HIV-2?
DARUNAVIR/r
101
Why is DARUNAVIR preferred 3rd agent in PREGNANCY?
more clinical experience
102
What ART typically consider safe in pregnancy + HIV-1 cannot be used in HIV-2?
EFAVIRENZ
| ATAZANAVIR
103
Why can atazanavir and efavirenz NOT be used in pregnancy + HIV-2?
Resistance (not suitable in any clinical scenario as Rx for ART)
104
What is the risk of VERTICAL transmission for UNTREATED HIV-2?
0.6-4%
105
Is VERTICAL transmission rate lower or higher for HIV-2 vs HIV-1?
LOWER
106
What are the BENEFITS of starting ART in PREGNANCY for HIV-2?
avoid detectable viral load in pregnancy
potentially reduce risk of vertical transmission
improve retention of care post party
107
What PEP should be given to the NEONATE if VERY LOW or LOW risk of HIV-2 tranmission?
ZIDOVUDINE
108
What PEP should be given to the NEONATE if HIGH risk of HIV-2 tranmission?
```
TRIPLE THERAPY:
ZIDOVUDINE
+
LAMIVUDINE
+
RALTEGRAVIR
```
109
What alternative 3rd agent can be used as PEP for neonate at high risk of HIV-2 transmission?
LOPINAVIR/ritonavir (with caution)
110
What THREE measures can be used to define HIV-2 treatment failure?
1) DETECTABLE viral load (2 consecutive samples)
2) DECLINE CD4 count
3) HIV/AIDS specific symptoms
111
Is PEP and PrEP available for HIV-2?
YES
Use same as for HIV-1
No evidence
