Varicella Zoster Flashcards
Significant exposure to varicella zoster
- Living in the same household as a person with active chickenpox or herpes zoster
- Face-to-face contact with a case of chickenpox or zoster for at least 5 minutes or being in the same rom for at least one hour
When is chickenpox infectious
2 days before rash until lesions crusted
VZV vaccine in pregnancy
Not recommended
Delay pregnancy 28 days post
No fetal infections have been associated with VZV vaccine
Management for VZV if significant exposure and non-immune
- Passive immunisation with ZIG
- preferably within 96 hours
- still recommended if exposure within 10 days - Consider aciclovir PEP if ZIG not given and at risk
- e.g. second half of pregnancy, immunocompromised, lung disease smoker
Maternal complications of chickenpox
- Respiratory symptoms
- Haemorrhagic rash or bleeding
- New lesions developing >6 days
- Persistent fever >6 days
- Neurological symptoms
Management for confirmed uncomplicated maternal VZV
- Oral aciclovir 800mg five times per day if ≤24 hours from onset of rash
- Monitor at home
- Fetal medicine counselling when recovered
Management for confirmed complicated / immunocompromised maternal VZV
- IV aciclovir 10mg/kg IV 8hrly
- Inpatient supportive therapy
- CS if fetal compromise, maternal respiratory failure exacerbated by advanced pregnancy
Risk of fetal varicella syndrome following maternal chickenpox:
<12 weeks’
0.55%
Risk of fetal varicella syndrome following maternal chickenpox:
12-28 weeks
1.4%
Risk of fetal varicella syndrome following maternal chickenpox:
>28 weeks
No cases reported
MFM Management of chickenpox in pregnancy (counselling + diagnosis)
- Detailed fetal US at least five weeks after primary infection
- Repeat ultrasounds until delivery. If abn consider MRI
- VZV fetal serology unhelpful
- Amnio for PCR not usually recommended if US normal as risk of FVS is low
Risk of FVS if amnio VZV PCR neg and US normal at 23 weeks
Negligible
Risk of FBS if amnio VZV PCR positive and US features of FVS
Very high
Varicella Syndrome Manifestations
- Skin scars 78%
- Eye abnormalities 60%
- Limb abnormalities 68%
- Prematurity, LBW 50%
- Cortical atrophy, intellectual disability 46%
- Poor sphincter control 32%
- Early death 29%
Microcephaly, low IQ, convulsions, skin scarring , ipsilateral limb hypoplasia
Neonatal management if maternal chickenpox 7 days before to 2 days post delivery
- ZIG <24 hours post-partum (up to 72 hours)
- Discharge term infants as soon as possible
- Breastfeeding encouraged
No ZIG if maternal infection <7 days before delivery unless preterm <28/40 or <1000g BW
