HSV

Question 1

Incidence of neonatal HSV disease in Australia

Answer 1

very low (3 per 100,000 live births)

Question 2

Modes of transmission of HSV

Answer 2

1. Intrapartum (most)
2. True intrauterine infection (<5%)
3. Postnatal from infected care giver (10%)

Question 3

Major type of neonatal HSV infection

Answer 3

HSV-1 (>65%)
Risk of MTCT with HSV-1 greater than from HSV-2 (OR 16.5)

Question 4

Risk of MTCT of HSV:
Past history, no clinical recurrence in pregnancy or labour

Answer 4

Very low (<0.04%)

Question 5

Risk of MTCT of HSV:
Past history, clinical recurrence in pregnancy or delivery

Answer 5

Active lesions at delivery: 2%
(Likely lower in immunocompetent women in Australia)

Question 6

Risk of MTCT of HSV:
No past history, primary first episode (sero-neg for both HSV 1&2 and genital swab +ve)

Answer 6

High risk (25-50%)
- However if type specific sero-conversion occurs well before delivery (<30/40) = risk same as for recurrent herpes

Question 7

Risk of MTCT of HSV:
Non-primary first episode (i.e. positive serology but for the other type than current infection)

Answer 7

High risk (25-50%)
- Unless sero-conversion well before delivery in which case risk same as for recurrent herpes

Question 8

Antenatal Management of women with a history of genital HSV (laboratory confirmed)

Answer 8

Consider suppressive antiviral therapy from 36 weeks’ if:
- multiple recurrent overt lesions
- frequent symptomatic recurrences

Question 9

Suppressive antiviral therapy what and why?

Answer 9

Aciclovir 400mg TDS or valaciclovir 500mg BD reduces
1. Clinical recurrences
2. Asymptomatic shedding
3. Caesarean section
4. Virus in genital tract
*Underpowered to evaluate efficacy of preventing transmission to newborn

Question 10

Intra-partum management of women with a history of genital HSV and no active lesions

Answer 10

1. Proceed with vaginal delivery
2. Avoid FSE, FBS, OVD if possible

Question 11

Who to examine for genital herpes

Answer 11

All women admitted in labour (RANZCOG)

Question 12

Intra-partum management of women with a history of genital HSV and active lesions

Answer 12

1. Balance low risk of MTCT in vaginal delivery of women with recurrent disease, with risks of caesarean section
2. CS reduces risk of HSV transmission at birth, but does not provide complete protection

Question 13

Antenatal Management of primary genital HSV

Answer 13

1. If diagnosis in early pregnancy, suppressive therapy from 36/40
2. If diagnosis in third trimester
   - suppressive therapy from 36/40
   - delivery via CS (regardless of timing of ROM)

Question 14

Scenarios with very low risk of neonatal HSV exposure and disease

Answer 14

1. Mother with active recurrent genital herpes due to HSV2 at delivery
2. Mother who had primary genital HSV2 and how has now developed HSV type specific IgG

No need to do neonatal surface swabs on these babies in Australia. Monitor for clinical disease.

Question 15

Scenarios with possible high risk of neonatal HSV exposure and disease

Answer 15

1. Mother with primary genital or sstemic infection close to delivery
2. Infant born to mother with active genital herpes and no known past history of genital HSV
3. Preterm infant born to mother with active genital herpes
4. Infant born to immunocompromised mother with active genital herpes

Perform Ix including swabs, bloods, LP and commence IV aciclovir immediately