IC18 HIV Flashcards
mode of transmission for HIV
HIV is transmitted from one person to another through specific body fluids — blood, semen, genital fluids, and breast milk. These happens through:
- Unprotected sexual intercourse with an infected person
- Sharing infected syringes and needles (e.g.between intravenous drug users)
- Mother-to-child transmission during pregnancy, at birth or through breast-feeding
- Transfusion with contaminated blood and blood products
who should be tested for HIV?
- Intravenous drug users
- Person who have unprotected sex with multiple partners
- Man who have sex with man
- Commercial sex workers
- Persons treated for STDs
- Recipients of multiple blood transfusion
- Persons who have been sexually assaulted
- Pregnant women (compulsory)
Diagnosis of HIV infection
- serum antibody detection (HIV EIA test, western blot)
- HIV RNA detection/ quantification (viral load) using PCR
Presentation of HIV (different stages)
- Acute (primary) HIV infection
- flu like illness - asymptomatic stage
- no S/S, persist for many years - persistent generalised lymphadenopathy
- lymph node enlargement in the neck, underarms, groins for more than 3 mths - AIDS (CD4 <200/mm3)
- advanced stage many organs involved, systemic sx
- even with normal CD4 count, can still have AIDS if have any opportunistic infection
- Rare cancer: Lymphoma and Kaposi sarcoma
Goals of ART
- Reduce HIV-associated morbidity and mortality
- Prolong the duration and quality of survival
- Restore and preserve immunologic function
- Maximally and durably suppress plasma HIV viral load
- Prevent HIV transmission
Surrogate markers in HIV - CD4
- normal: 500-1200 cells/mm3
- strongest indicator of immune function and disease progression
- use to determine urgency for initiation
- use to assess response of ART
-> take at baseline
-> every 3-6mths after tx initiation
-> every 12 mths after adequate responses
=> adequate CD4 cells response = CD4 50-150 during first year of tx
- used to assess the need for initiating or discontinuing prophylaxis for opportunistic infections
at what CD4 cell count should prophylaxis abx for pnuemocystis pneumonia be started?
<200 cells/mm3
surrogate markers in HIV - viral load
amt of virus in the plasma
- most important indicator of response to ART
- measured
-> before initiation
-> within 2 to 4 weeks (no later than 8 weeks) after initiation/ modification
-> every 4-8 weeks until viral load suppressed
-> stable regimen 3-6mths (or every 12mths)
effective regimen generally achieve viral suppression by… (HIV)
8 to 24 weeks
when to start ART for HIV? for who?
advice to pt
when to defer tx
start ASAP for all HIV infected individuals regardless of CD4 cell count
- to prevent HIV transmission
- educate pt on the benefits and consideration for ART
- strategies to optimise adherence
- may be deferred due to clinical and/or psychosocial factors
ASAP if possible!!
Benefits of earlier ART initiation
- maintenance of higher CD4 count, prevent irreversible damage
- decrease risk for HIV associated complications
- decreased risk of non opportunistic conditions (CVD, renal, liver, non AIDS diseases)
- decrease risk of HIV transmission
Limitations of earlier initiation (ART)
- SE and toxicities
- drug resistance
- transmission of drug resistant virus
- less time to prepare, non-adherence
- treatment fatigue
- increased cost
list of common ART
- NRTI - nucleoside reverse transcriptase inhibitors
- INSTI - integrase strand transfer inhibitor
- NNRTI - non-nucleoside reverse transcriptase inhibitors
- PI - protease inhibitors
- Fusion inhibitors
- CCR5 antagonist
NRTI drugs
Tenofovir
Emtricitabine
Abacavir
Lamivudine
Zidovudine
advantage of NRTI
backbone of combination ART
renal elimination (less concern for DDI)
