HIV Flashcards
Define
Aetiology: present in vaginal fluid, semen, blood, breast milk -> transmission through sexual contact, BB, vertical
Less transmission through vaginal mucosa than through anal mucosa
Decision to treat with PEP based on guidelines (i.e. only ‘considered’ if penetrative vaginal intercourse)
- HIGHEST risk of transmission if mother is newly diagnosed at the beginning of pregnancy or near delivery (as viral load is extremely high in acute phase of infection)
Risk factors
Risk factors:
- vertical risk if high viral load
- low CD4 count
- prolonged rupture of membranes (>4h)
- breastfeeding
- chorioamnionitis
- preterm delivery
Reduced transmission risk: low/ undetectable viral load at the time of delivery, ART, C-section delivery, XS formula feeding
Epidemiology: increasing prevalence as people are living longer, most prev in black-African heterosexual women in the UK
Signs and symptoms
Asymptomatic: 1-4 weeks for seroconversion (from primary infection)
General S/S of HIV/AIDS – fever, rash, lethargy, oral ulcers, lymphadenopathy, sore throat, etc.
AIDs-defining diseases – PCP, Kaposi’s sarcoma, MAC, oesophageal candidiasis, CMV retinitis
Investigations
BLOOD testing;
Routine HIV testing in antenatal booking regular viral load, CD4 count
Baseline indication tests – FBC, UE, LFT, lactate, blood glucose
- WANT TO CHECK FOR HAEMOGLOBINOPATHY
Do a full STI screen
Full Hep Screen needed
- Hep C and HIV together
Additional blood tests
- Varicella zoster
- Measles
- Toxoplasmosis
- (Parvo virus and rubella)
Neonates test +ve for HIV antibodies due to passive transfer from mother -> diagnosis of HIV in the neonate requires direct viral amplification by PCR (carried out at birth, on discharge, 6 weeks, 12 weeks and 18 weeks)
Management
Monitoring:
- 2x CD4 counts (at baseline and at delivery)
- 8x Viral load (measured every 2-4 weeks, at 36 weeks and after delivery)
- Check LFTs when starting at with each routine blood test
- Check for co-infection with HBV and HCV
The risk of vertical transmission is affected by maternal viral load, obstetric factors and infant feeding
Management of mother:
ART:
- Maternal = continual (do not stop)
- Zidovudine if uncomplicated/NO SYMP women
HAART has slightly tetragenic but allows for vaginal delivery if the viral load is low
cART - 2 x NRTI, 1 x NNRTI
Integrase inhib is used when above doesn’t suppress high viral load
SHOULD HAVE COMMENSED BY 24 WEEKS
Neonate = first 2-4 weeks of life for the baby – see below
Delivery (different for PROM/PPROM, but this is too in-depth to be important here):
Undetectable (<50 copies/mL) at 36 weeks -> vaginal delivery
Detectable viral load (>50 copies/mL) at 36 weeks -> ELCS at 38w
ELCS at 38w if… HIV/HCV co-infection, >50 HIV/mL OR on zidovudine monotherapy
If pre-labour SROM (>34wks) –> IOL (<50 copies/mL) or Emergency CS (>50 copies/ml)
If SROM <34 wks –> IM steroids, optimise viral load, MDT discussion about timing and mode of delivery
[Intrapartum zidovudine – only if detectable viral load]
Avoidance of breastfeeding (+ offer cabergoline to women to supress lactation + free formula)
Invasive prenatal diagnostic testing should be deferred until HIV viral load suppressed to < 50 RNA copies/mL
If not on cART and invasive diagnostic test cannot be delayed, women should commence ART (including raltegravir) and be given a single dose of nevirapine 2-4 hours prior to procedure
Foetal blood sampling is contraindicated (even if undetectable)
Do NOT stop ART post-partum
Management of infants:
- Cord clamped as soon as possible and baby bathed immediately after birth
- Zidovudine monotherapy for 2-4w (low/medium risk) OR 4w PEP combination (high risk)
- Women not to breastfeed
- Give all immunisations including BCG (unless a moderate-high risk of transmission)
- Confirm or deny diagnosis of HIV in the neonate with direct viral amplification by PCR
- (normally carried out at birth, on discharge, 6 weeks, and 6 months) and antibody test at 18m
Summary
Summary:
ART: all women should be offered ART regardless of whether they were previously taking it - joint HIV and obs referral (or HIV specialist clinic)
Delivery: vaginal delivery is recommended if viral load <50/mL at 36 weeks, otherwise C-section
Neonatal ART: zidovudine (oral or IV) is usually administered orally to the neonate if maternal viral load is <50/mL; otherwise, triple ART should be used. Continue therapy for 2-4 weeks
Breastfeeding: all women in the UK should be advised NOT to breastfeed
Suppress lactation with cabergoline
Complications
Complications and Prognosis
- Transmission to baby (depending on viral load)
- HIV-related infections and complications
- Progression to AIDS
- GOOD prognosis if viral load is suppressed
PACES
PACES Counselling:
Refer them to an HIV/obs clinic where you will see them every 2 weeks
Stress the importance of good compliance with HAART (want to start by 24 wks)
- Risk of vertical transmission is greatly reduced if the viral load remains low
Viral load measurement every 2-4 weeks and at 36 weeks
Viral load <50 copies/mL at 36 weeks -> safe vaginal delivery
Viral load >50 copies/mL at 36 weeks -> ELCS
Explain neonatal treatment with oral zidovudine for 2-4w if viral load is <50 otherwise triple ART
No breastfeeding in the UK
Will check HIV diagnosis in neonate by PCR at birth, discharge, 6 wks and 6 months
MDT imp
- Test partner if they are HIV positive
https: //www.hiv-druginteractions.org/checker
PrEP and PEP:
PrEP = two-drug ART (i.e. 2x NRTI)
PEP = three-drug ART for 1 month (i.e. HAART for 1 month; 2x NRTI + 1x INI)