Perinatal infections Flashcards
Maternal symptoms of toxoplasmosis
often asymptomatic. malaise, fever, lymphadenopathy.
Maternal complications of CMV in pregnancy?
Maternal infection: febrile illness, myocarditis, pneumonitis, hepatitis, retinitis, gastroenteritis, or meningoencephalitis
Symptoms of rubella infection
- maculopapular rash
- fever
- myalgia
- lymphadenopathy
antenatal obstetric complications from rubella infection?
miscarriage
preterm birth
What is the incidence in Australia (general population) of listeria?
1:100,000
15% of annual cases are pregnant women
Describe secondary syphilis timing?
Systemic dissemination 2-8 weeks after resolution of chancre
Symptoms of secondary syphilis?
50% asymptomatic
Systemic illness
Condyloma lata
During what time period does early latent phase of syphilis develop?
Within 2 years of acquisition
During what stages is syphilis infectious?
primary, secondary and early latent phases only
Not infectious to sexual contacts during latent and tertiary stages. No longer infectious 48 hours after antibiotic
Complication of syphilis treatment in pregnancy?
Jarisch Herxheimer reaction (40%)
Incidence of congenital CMV?
0.2-2% neonates show signs of infection
primary = 30% fetal infection secondary = 1% fetal infection
Describe pathogen causing CMV?
herpes type DNA virus
multiple strains
Serological signs recent CMV
elevated aminotransferases lymphocytosis IgM + IgG +/- low IgG avidity
Toxoplasmosis epidemiology
- NZ pregnancy cases/yr
- fetus/yr
NZ pregnancy cases per year = 164
foetuses affected per year = 66
Neonatal sequelae of congenital CMV infection?
- IUGR 50%
- petechiae 76%
- purpura 13%
- jaundice 67%
- hepatosplenomegaly 60^
- microcephaly 53%
- chorioretinitis/optic atrophy 20%
- seizures 7%
mortality <3mo = 10%
Sequelae of neonatal rubella syndrome (6)?
- heart defects
- cataracts/retinopathy
- SNHL
- anaemia
- hepatosplenomegaly
- meningoencephalitis
What do non-treponema tests defect?
non specific
RPR and VRDL give indication of infectivity, response to treatment or reinfection.
False negatives in early infection, HIV or immunosuppression.
Maternal investigations for listeria?
blood cultures
MSU
vaginal swabs
Pregnancy/fetal complications of listeria infection?
miscarriage
preterm birth
high risk IUFD (40-50%)
Neonatal sequelae of listeria infection?
early onset disease: <7 days 20-60% mortality
Conjunctivitis, pneumonitis, meconium, granulomatosis infantiseptica (skin granuloma, papular or pustular rash)
placental and cord granuloma
late onset disease (7d-6w). 10-20% mortality.
Vertical transmission rate of parvovirus once mother infected?
50%
Aspects of history which influence risk of maternal parvovirus infection?
maternal susceptibility = 40%
exposure at home (50% risk of transmission) = 20% infected
exposure at school = 20-30% transmission
10-15% infected
exposure in community = 20% risk transmission
10% infected.
maternal symptoms parvovirus
asymptomatic slapped cheeck arthropathy aplasia myocarditis
If parvovirus suspected by IgG and IgM negative, when would you repeat serology?
2-4 weeks after exposure
Recommended fetal monitoring in pregnancy following parvovirus infection?
2w USS with MCA PSV for 12 weeks
When should IVIG be given in pregnancy after varicella exposure?
non immune
<96 hours after exposure
exposure <7 days prior to delivery, until 2 days postnatal
Within what time Fram can VZIG be given after exposure to varicella?
<96 hours
some effect demonstrated up to 10 days
What is the risk of fetal disease after infection with toxoplasmosis in pregnancy in first trimester?
10% fetal infection
85% fetal damage (severe)
SYPHILIS Epidemiology (NZ cases/yr + CS cases/yr)
2018 NZ 500 infectious cases. Between 2016 and 2020, 14 congenital syphilis reported cases
(>100/year cases, >4 CS cases/year)
What is the initial screening test for syphilis (1)?
Enzyme immunoassay (EIA) in guidelines. VRDL NZ
Syphilis treatment in pregnancy
Benzathine benzylpenicillin tetrahydrate. 1 dose 1st and 2nd trimester. Two doses third trimester. Daily if neurosyphilis.
Antenatal complications of syphilis in pregnancy
Mid-trimester miscarriage
Stillbirth
Congenital anomalies caused by syphilis evident on fetal USS
Small bowel dilatation PolYhydramnios Placentamegaly Hydrocephalus/hydrops IUGR Lower limb abnormalities IUFD S
Neonatal abnormalities caused by syphilis?
KISS DR: keratitis, illness (jaundice, anaemia, low plt) saber shins saddle nose Deafness Rhagades (perioral lesions) Other: cerebral palsy, hepatosplenomegaly.
Diagnosis of CMV
Serum IgM and IgG positive with low (<65%) IgG avidity (<3mo since infection)
TOXOPLASMOSIS Transmission
Transmission: raw or undercooked meat, not washing hands or veges, contact with cat faeces
Treatment of toxoplasmosis <18 weeks
spiramycin
Treatment of toxoplasmosis >18 weeks
pyrimethamine, sulfadiazine and folonic acid (latter two teratogenic in 1st trimester)
Sensitivity and specificity of amniotic fluid PCR for toxoplasmosis?
high sensitivity between 17-21 weeks (90-100%)
Ultrasound findings with congenital toxoplasmosis?
hydrocephalus,
brain or hepatic calcifications,
ascites,
splenomegaly
(CASH)
Rubella virology
Rna togavirus
Mode of transmission rubella (2)?
droplet and vertical
Highest risk gestation of contracting congenital rubella syndrome?
<12w = 85% CRS, 80% maternal infection
From what gestation is there minimal risk of congenital defects secondary to fetal infection with rubella?
17 weeks
Neonatal specialist assessments recommended with congenital rubella syndrome?
Ophthalmology
Hearing screening
Cardiac screening
List trepononemal and non-treponemal investigations?
non-treponemal: RPR, VDRL
treponema = TPPA, TPHA, EIA
What do treponemal tests detect?
Antibodies to T. pallidum
Will demonstrate if someone has ever had syphilis, whether or not they were treated. Does not indicate when infection occurred. Small false positive rate.
If someone is at increased risk of syphilis infection in pregnancy, when would you screen them?
Booking, 28w, 36w, birth, 6w PP.
What are the microbial features of listeria?
Gram positive rod, facultative anaerobe.
flagellated
Antenatal complications of listeria infection (4)?
miscarriage
IUFD 19%
NND 60%
For what congenital infections would you not perform amniocentesis for diagnostic purposes?
parvovirus
listeria
COVID-19
Syphilis
Prevalence of parvovirus in pregnancy?
1:400 pregnancies
Risk of parvovirus fetal infection and loss after exposure at home?
40% susceptible
50% fetal infection
10% miscarriage
< 10% fetal hydrops
Risk of parvovirus fetal infection and loss after exposure in community?
40% susceptible (20% transmission mum) = 8% maternal infection = 4% fetal infection = 0.4% fetal loss
What infections may cause fetal anaemia?
parvovirus, syphilis, rubella
When would one expect onset of hydrops after parvovirus infection?
2-17 weeks
Maternal investigations parvovirus?
Paired parvovirus IgG and IgM.
Can compare to booking screening.
If both negative repeat in 2w for seroconversion
What tests can be performed for rubella with invasive fetal testing?
PCR
culture
fetal IgM
can be performed after CVS and amniocentesis
Describe fetal varicella syndrome (5 systems).
Rash/scar (80%)
Limb hypoplasia (70%)
Cataracts (60%)
Microcephaly, ventriculomegaly. Neurodevelopmental delay (50%)
mortality (30%)
Hydrops
IUGR
Hyperechoic bowel and hepatic calcifications. Hepatosplenomegaly.
What are some maternal complications of varicella?
Severe maternal disease: pneumonia, hepatitis, encephalitis, death.
What is a significant exposure to chickenpox?
5 minutes face to face, 1 hour same room.
What are the obstetric complications of varicella?
no increased risk of miscarriage
PTB
What risk factors would prompt you to consider PEP with PO valaciclovir after varicella exposure after 20 weeks?
immunocompromised
lung disease
smoker
<24hrs of symptoms
Highest risk gestation of FVS?
Highest risk between 12-28 weeks (1.4%)
What is the prevalence of varicella infection in pregnancy?
3:1000
Maternal symptoms of varicella virus?
Rash: papules, vesicles + crusts.
Pneumonia 5%
Encephalitis rare
Fetal investigations for CMV infection
Amniocentesis with CMV NAAT. Perform >6w after infection and after 22/40 if possible for best sensitivity.
What are the classic fetal complications of toxoplasmosis in pregnancy?
hydrocephalus
chorioretinitis
intracranial arteriosclerosis
+/- hydrops, deafness, blindness, neurodevelopment delay, seizures.
Highest risk gestation for infection causing congenital toxoplasmosis?
> 27 weeks gestation
What is the risk of fetal disease after infection with toxoplasmosis in the third trimester?
30-75% fetal infection
10% fetal damage (mild)
For what congenital infection should termination not be offered?
Parvovirus
Malaria
What are the maternal/antenatal implications of toxoplasmosis infection?
miscarriage
IUFD.
Usually maternal disease is mild, with fever malaise and lymphadenopathy.
What is the risk of perinatal transmission at vaginal delivery with previous HSV-1 or 2 with no lesions?
<1%
What is the risk of perinatal transmission with recurrent genital HSV-1 at time of vaginal delivery?
15%
What is the risk of perinatal transmission with vaginal delivery after primary HSV at 36 weeks?
25-50% transmission risk
What is the risk of perinatal transmission of HSV to the neonate?
HSV encephalitis
Discuss increase risks associated with HSV and scalp electrodes
OR 6.8 if virus present.
Discuss evidence around maternal antiviral suppression of HSV for vaginal delivery.
Reduces risk of clinical recurrence and asymptomatic shedding.
Clinical trials underpowered to evaluate efficacy of preventing transmission to newborn.
What are signs of neonatal HSV infection?
vesicular skin lesions, seizures, unexplained sepsis, low platelets, elevated LFTs, DIC, respiratory distress, corneal ulcer/keratitis
After an HIV +ve screening result, what further testing should be done?
Vaginal swabs
VRDL, HCV, HBV
HIV RNA viral load, HIV resistance testing, CD4+lymphocytes, FBC, LFT, UEC
If HIV+, when would vaginal delivery be suitable?
on HAART from at least 24 weeks, viral load <50copies/mL at 36 weeks.
If HIV+ with viral load 50-399 copies/mL @36 weeks, what mode of delivery would be recommended?
+/- intrapartum zidovudine
planned CS 38-39w
formula fed
What is the risk of HIV transmission without modern therapy +/- breastfeeding?
20% no modern therapy
40% no modern therapy + breastfeeding.
HIV-What are the criteria to be fulfilled for low risk of MTCT <2%.
maternal viral load undetectale
appropriate mode of delivery
formula fed baby
baby received PEP
What is the MTCT risk of a women on HAART breastfeeding?
1-5%
Risk vertical transmission of syphilis if
- primary
- secondary
- early latent
- 70%
- 70%
- 40%
Implications of symptomatic congenital infection CMV (occurring in 10% of infected fetus’)?
50% will have long term sequelae.
early mortality <3mo = 5-10%
neurodevelopmental and sensory deficits (eyes, hearing)
Risk of ‘symptomatic’ CMV infection after fetal transmission?
10%
50% of those will have long term sequelae.
Only 10% of asymptomatic foetuses/neonates have long term sequelae.
Investigations after delivery for toxoplasmosis infection?
placenta- histo and PCR
neonate: whole blood PCR, cerebral USS, CSF for PCR
Trend for vertical transmission of toxo in pregnancy?
Increasing incidence of infection with GA (10–>30—>50%)
Decreasing proportion of fetal damage (85–>20–>10%)
Trends in rubella infection with advancing GA
rUbella- u shape fetal infection
<12-36+ (80–>50–>30–>60–>100%) with GA
fetal disease most likely <12w 85%
Then decreases with time (35%@13-16, rare after)
Incubation and infectious period of varicella?
incubation 10-21 days
infectious 2 days prior to rash
rash lasts 6 days
infectious until two days after lesions crusted
Testing for neonate after delivery at risk of congenital parvovirus?
FBC and plt check on day 1