HIV

Question 1

Define

Answer 1

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)

Question 2

Risk factors

Answer 2

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

Question 3

Signs and symptoms

Answer 3

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

 

Question 4

Investigations

Answer 4

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)

 

Question 5

Management

Answer 5

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

Question 6

Summary

Answer 6

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

Question 7

Complications

Answer 7

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

Question 8

PACES

Answer 8

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)