HIV Flashcards
Antenatal testing for HIV
- Recommended for all women
- Screen with an enzyme immunoassay (EIA) test
- Confirm with Western blot (WB)
- Repeat testing in 3 weeks if recent exposure or re-exposure to HIV likely
Indeterminate Western blot
- Further testing needed
- Discuss with HIV reference laboratory
- Discuss with physician specialising in HIV infection
Additional Tests if HIV positive
- HIV RNA viral load
- HIV resistance testing
- CD4+ve lymphocyte subsets
- FBC, LFT, EUC etc
- Other infectious disease (syphillis, chlamydia/gonorrhoea, GBS screening)
Four components of prevention of MTCT of HIV
- Maternal viral load undetectable on effective cART
- Appropriate MOD
- Formula fed baby
- Baby PEP
Risk of HIV vertical transmission with optimal care
<1%
Risk of vertical transmission of HIV with no preventative strategies
-15-25% in non-breast fed infant, double that if breast fed
- Increasing rates of transmission with increasing viral load (strong correlation)
Risk of transmission of HIV whilst breast-feeding
i) Mothers on cART for 6 months and continued BF: overall r/o transmission at 6mths 1.08%, at 12 months 2.93%
ii) Mothers on cART throughout BF period: risk at 6mths 0.3%, risk at 12 months 0.6%
Management of pregnancy with conception on effective cART
Antenatal: continue current therapy (some exceptions)
Intrapartum: zidovudine not required
MOD: vaginal delivery if no obstetric contraindication
Management of new diagnosis of HIV in pregnancy, naiive to cART
- Start cART according to viral genotype results if available
- Informed counselling
Management of pregnancy with HIV viral load <50 copies/mL at ≥36 weeks’ gestation
Same as for conception of effective cART
Antenatal: continue current therapy (some exceptions)
Intrapartum: zidovudine not required
MOD: vaginal delivery if no obstetric contraindication
Management of pregnancy if HIV viral load >50 coplies/mL at ≥36 weeks’ gestation
Intrapartum: Consider intrapartum zidovudine / 3 hours prior to elective CS (esp. if VL >1000)
MOD: Planned CS at 38-39 weeks (esp. if VL >400 (UK) or 1000 (USA))
Management of late-booking, in labour, not on cART
- Stat dose of nevirapine
- Commence cART ASAP
- Add raltegravir or dolutegravir to regimen
- Intrapartum zidovudine
- CS (unless there’s no time)
Nevirapine, raltegravir, tenofovir
Readily cross the placenta and are added to ‘pre-load’ the fetus prior to delivery in late presenters
Management of late booking, not in labour, not on cART
Presents >28 weeks
- Commence cART ASAP
- Include dolutegravir or raltegravir in regimen
VL unknown or >100,000
- Commence cART ASAP
- Include dolutegravir or raltegravir
- Intrapartum zidovudine and planned CS
When should all women commence cART by and why?
By 24 weeks
Earlier virologic suppresion is associated with a lower risk of transmission
Recommended mode of feeding with HIV
Formula feeding
Optimal scenario for “safe breast-feeding” in HIV
- Strong engagement with health care
- Strong adherence to cART and continuation in BF
- Suppressed maternal VL
- Exclusive breast feeding ≤6 mths
- Avoiding mixed feeding or solids <6months
- Attention to breast health and avoiding breast milk from both breast during any episode of mastitis
- Suspending breast-feeding if maternal or infant gastro
- Do not recommence breast-feeding if formula feeding has been commenced
- HIV PCR test of baby 2 months after cessation of breast-feeding
- Mat VL monitoring 1-2 monthly while BF
Infant PEP: Very low risk category
- Maternal cART >10 weeks
- At least 2 maternal VL <50 during pregnancy, ≥4 wks apart
- One VL <50 at ≥36 weeks gestation
Rx: 2 weeks zidovudine monotherapy commencing within 4 hrs of birth
Infant PEP: Low risk category
- Maternal VL <50 at ≥36 weeks gestation
- Other ‘very low risk’ criteria not met OR
- Infant born <34 weeks’ and most recent VL <50
Rx: 4 weeks zidovudine
Infant PEP: High risk category
- Maternal VL at delivery anticipated / documented >50c/mL or unknown
- Uncertainty about maternal adherence to cART
Rx: Triple ARV (zidovudine + lamivudine (4 weeks) + 2 weeks nevirapine)
