Intrauterine vs perinatal infection
before birth vs in 1w after birth
5 significant intrauterine infections
Rubella
CMV
VZV
Parvovirus B19
Zika
3 important perinatal infections
HSV1/2
Enterovirus
HPV
How many adults are immune to rubella?
90%
Transmission of rubella
Aerosol
Presentations of rubella (3)
morbilliform rash (face to trunk to limbs)
fever, malaise
small joint pain
Congenital infection of rubella and sequels on the foetus
<12w: congenital rubella syndrome (90%)
cataract, glaucoma, deafness, retardation, PDA, DM
12~16w: deafness (20%)
Diagnosis of rubella
Management for congenital rubella syndrome
<16w: counselling for termination of pregnancy
isolation
Vertical transmission rate of CMV
40% for primary infection
1-3% for activation / reinfection
Congenital infection of CMV (2)
Congenital cytomegalic disease (10-15%)
deafness (10%)
Diagnosis of CMV congenital infection
[before birth] amniotic fluid PCR
[after birth] urine / saliva PCR
Why CMV serology is not applicable in screening and diagnosis of congenital infection? (3)
What’s the difference between congenital and post-natal infection of CMV? How to determine which is which?
% of adults with VZV IgG +ve
90%
Congenital infection of VZV: timeframe
<20w: congenital varicella syndrome (1~2%)
>20w: zoster
perinatal (5d pre and 2d post): severe congenital varicella syndrome (fatal)
Diagnosis of VZV congenital infection
clinical (seldom do vesicular swab)
Management for risk of VZV congenital infection
Post-exposure prophylaxis by VZIG if the mother is susceptible
% of adults having Parvovirus B19 IgG
30%
Transmission of parvovirus B19
aerosol, blood products
Presentations of parvovirus B19 infection
Congenital infection of parvovirus B19
all or none
anaemia, hydrops fetalis (25~33%)
Transmission of Zika
vector borne, sexual, blood transfusion
intra-uterine, breast milk
Diagnosis of Zika congenital infection
[Before birth]
1. Serology: IgM (acute + convalescent)
2. PCR on urine & blood
(timing: within 14 days from onset / back from endemic areas)
3. PCR on aminotic fluid / cord blood
[After birth]
- <7d: PCR on CSF
- >7d: IgM