HIV

Question 0

5 maternal infectious contraindications to BF (western)

Answer 0

HIV

Human T-cell leukaemia virus

Active TB

Hep B (until immunoglob and vaccine given)

CMV (prem only)

Question 1

What are the risk factors for maternal-infant transmission of HIV (7) and how can this be prevented?

Answer 1

Viral load = most predictive RF

ROM >4/24

Increased exposure to maternal blood- instrumentation/ scalp electrodes, episiotomy & vag tear, vag delivery (esp w high viral load)

Concurrent HSV infection- increased shedding of HIV in genital secretions

Prem/ LBW- likely impaired foetal/ placental membranes

AZT monotherapy rather than combined

BF

mother- combo antiretroviral therapy esp late antepartum & intrapartum (most risky period)

baby- zidovudine 2mg/kg PO QID for 6/52

ELUSCS for high viral load

Question 2

HIV confirmation in infant born to HIV mother -how and when

Answer 2

Viral PCR (HIV-1 NAAT)

First checked in first few days if mother didn’t have antiretrovirals or at 2/52 if she did. Rechecked regularly. Need 2 +ve tests to confirm dx

Question 3

What are the clinical manifestations of congenital HIV

Answer 3

Usually asymp in neonatal period.

25% have early onset AIDS-defining symp- few months old

75% occur at about 8yo

Infants- FTT, thrush, hepatosplenomeg, interstitial pneumonitis

Older- generalised LN, recurrent bac inf, parotitis, encephalopathy with developmental regression

Question 4

Pneumocystis -clinical picture -need for prophylaxis in neonates

Answer 4

Hypoxia > chest findings

Non-productive cough

CXR- butterfly/ ground glass pattern Babies born to HIV mothers need to start prophylaxis (cotrimoxazole PO or pentamidine nebs) at 4/6/52 old. Peak age in neonates = 3/12. This is usually BEFORE dx of HIV confirmed.

Question 5

4 classes of antiretrovirals to treat HIV

Answer 5

1) Nucleoside reverse transcriptase inhibitors (zidovudine) stop conversion of HIV RNA to DNA. Need phosphorylation for activation.
2) Nonnucleoside reverse transcriptase inibitors (efavirenz)- similar to above, but don’t need activation.
3) Protease inhibitors (-avirs)- prevents processing of polyprotein precursers
4) other

Question 6

How do antiretrovirals effect bone marrow.

Answer 6

Decreased Hb & WCC

Decreased platelets- secondary to HIV rather than therapy

Lipodystrophy (fat redistrobution)

Question 7

What are the RF for contracting HIV after needlestick (3) and when should prophylaxis be given?

Answer 7

RF- high viral load, large vol of blood, deep penetration. Risk 0.3% from contaminated needle.

Prophylaxis- most effective if commenced within 2/24. Poor efficacy if given >24-72 hours post injury. Continued for 4/52.