Perinatal Infections Flashcards
Which infections are relevant?
Bacterial
-GUT CS
Gonnor/Clamyd, UTI, TB, Chorioaminionitis, Syphilus
Viral
CMV, Herpes, HepB, Rubella
Other
toxoplas
Why do these infections matter?
Sustained maternal pyrexia (38.8) can cause problems.
- 1st trimester (ntd, miscarriage)
- 2/3rd trimester(preterm labour, fetal death)
PTL is commonest cause of fetal/neonatal death
What is the commonest bacterial infection?
UTI
What us commenest cause of PTL?
Chorioamnionitis
What is perinatal?
Pregnancy + first week of life
What are causes of Chorioaminionitis?
- low path anaerobic commensal vaginal/bowel bacteria
- bacterial vaginosis
- group b strep(rare in sa but occurs 1st world.
Why is chorioamnionitis NB?
Comments cause of PTL AND PTL is commenest cause of fetal or neonatal death therefore…chorio commoemst cause of fetal/neonatal death
How does chorioamnionitis cause PTL?
Mom is often asymptomatic
Infection will set up inflammation in baby which affects the PG pathway and causes PTL
Effects of Choriomanionitis to mom
PPROM
PTL
endometritis
Septicaemia
Effects of chorioamnionitis on baby?
Septic shock
Pneumonia
How to manage chorioamnitis?
Mom and/or baby
- iv ampicillian (crosses placenta)
- genta/metronida if septicaemia
What to do if group B strep detected?
Common cause of puerpural sepsis.
If mom is well and baby is sick and proved to have GBS then mom is carrier.
Mom must be given prohylactic Ab next preg and notify obstetrician.
What does Clamydia and Gonorrhoea cause in baby?
Clamydia- eye infevtion and pneumonia
Gon- eye inf
Treat mom + partner
TB in babys?
No diff in presentation/management for 1st TB epsiode.
The main challenge is to avoid extrapulmonary TB.
Mom is not infectiius after 2weeks therapy.
INH prohkyaxis given to baby if mum less than 2 weeks treatment or active TB
Cant use streptomycin in treatment
Effect of TB on pregnancy?
Impaired fetal growth if mum ill and wasted.
Previous tb with bad lungs and pulm hpt may cause maternal mortality
How to identify primary syphilus?
Chancre
Painless Regional Lymphadenopathy
What are signs of secondary syphilus?
Rash on palms and soles Alopecia Snail track ulcers in mouth Generalised adenopathy Malaise
Latent Syph still affects fetus
How to dx syphilus?
Primary screening
-VDRL(lab test, not on CSF, expresed at titre >1/16 treat for syph,
Management of Syphilus
Primary
-benzathine penicil 2.4mu IMI x3 1 week apart. Crosses placenta.
Secondary l/early latent
-same treatment
Pen allergy
- doxy
- erythro
What are the consequences of congenital syphilus?
LBW- preterm or UGA
Hepatosplenomeg Blisters on palms and soles Peeling skin Oedema Osteitis in 70% Jaundice Purpura Anaemia Rds
What is Rx for neonatal syphilus?
Procaine penicill 50 000 iU/kg IMI for 10days if baby symptomatic or xray sign.
Baby asympto but mother has
- asymtp but untreated (latent)
- partial rx
- rx completed in last 4 weeks preg
- treated with erythromycin
Baby will get benzathine penicill 50 000iU/kg IMI STAT
If mom has Acute hepatitis in preg?
Baby gets extra vaccine at birth +hep B IgG if avail.
What does CMV look like under microscope?
Infected and swollen cells
Multinucleate giant cells.
What are effects of CMV on baby?
Brain
- seizures
- microcephaly
Ears and Eyes
- late onset neural deafness
- micropthalmia
- chorioretinitis
Blueberrry muff
HSM
Clinical features of Rubella in mother?
German Measles Flu like symptoms Red maculopap rash face + extremeties Post auricular, sub occip and cervical lymphadenopathy No encephalitis Self limiting arthrits in young women
Clinical features of rubella in baby?
Cataracts, glaucoma , PDA, VSD, microcephaly, deafness, extramedullary haematopoiesis (blueberry muf rash)
How can infants contract herpes?
If mom haw active herpes baby is at high risk.
Infant exposed to infected maternal secretions at delivery or PROM.
If mum has 48hr acyclovir baby can safely delivered
Why does recurrent herpes infection confer less risk to fetus?
Mother can transfer protective Ab across placenta.
- mum infected 1st time during preg means no Ab=higher risk.
Viral shedding can happen up to 6weeks post infection.
HIV Infection = more viral rep and shedding
How to make Dx of herpes?
Pcr
Culture
Serology
Clinical features in mom and baby?
Mother
- painful vesicles on vulva or vagina and persist for 2-3weeks.
Congenital Infection
-microcephaly HSM jaundice pneumonitis
Neonatal Infection
- local skin lesion eye mouth involvement
- cns involvement (encephalitis)
How to dx hsv?
Viral pcr or culture from fluid in vesicles
What clues in state sector can indicate possible infection antenatally?
Syphilis signs and symp
Rubella- rash and post auric/subocip nodes
Herpes- vesicles
Aids - suspect toxo and cmv
What would raise suspicion in congen infection antenatally?
Ultrasound changes in baby such as:
- symm iugr
- big placenta
- hydrops fetalis
- big liver/spleen
- brain calcifications
What will raise suspcion of congen infection post delivery?
SGA baby Flat,unwell, poor feeding Mom rpr pos and untreated - always check rpr. Heavy placenta >1/7 of baby weight Any specific signs or sympt
