congenital infections Flashcards
how can we make a prenatal diagnosis of congenital infections ?
using amniocentesis
percutaneous umbilical cord sampling
when during the pregnancy is rubella most commonly seenn ?
first trimesteric infection n
what is the triad for congenital rubella ?
congenital heart disease ( PDA, PS)
cataract
deafness
how would a mother present with a rubella infection ?
at early pregnancy, 11 weeks or so , she presents with fever, rash and lymph node affection , with no findings on ultrasound
what is the pathogenesis of rubella infection /
virus induced tissue damage
virus induced retardation of cell division
how does the timing of infection affect the extent of damage in rubella ?
first trimester - severely damaged infant
11-20 weeks - risk of deafness only
after 20 weeks - risk of fetal damage is minimal
how is a diagnosis of rubella made ?
mother - seroconversion on screening fetus - amniocentesis, CVS , PCR infant - urinary PCR Blood or CSF culture Rubella specific IgM or persistently rising IgG
how are women with rubella treated ?
only given symptomatic treatment
how can rubella be prevented ?
MMR vaccine
what cells are targeted by the parvovirus B19 ?
erythroblastic red cell precursors
what is a common name for parvovirus B19 infection ?
slapped cheek disease
what is the mode of transmission of parvovirus ?
vertical transmission
how is a mother infected by parvovirus ?
through infected blood
respiratory secretions
how can parvovirus be diagnosed by lab investigations ?
findings will show
anemia
leukocytosis
reticulocytopenia
what is specifically found in fetal livers in parvovirus infectionn ?
inclusion bodies
how can i tell that the baby is anemic ?
severely edematous
has hepatosplenomegaly
( hydrops fetalis / buddha sign )
when is the risk of fetal loss the highest with parvovirus infections ?
in 2nd trimester
how can a diagnosis of parvo virus be made from the mother and the baby ?
B19 IgM
B19 IgG seroconversion
in the fetus :
B19 NAT , Hb
how can parvovirus infections be managed ?
no antiviral
regular screening
in cases of severe anemia intrauterine fetal blood transfusion can be done
what is the most common congenital infection ?
cytomegalovirus
what can CMV infection be confused with ?
EBV
what is the C/P of CMV in mnothers ?
may be asymptomatic
or
glandular fever like illness
how can CMV transmission occur ?
vertical transmission
during birth
through breast feeding
how does the risk of the fetus change in CMV ?
- primary infection - risk of fetal damage throughout pregnancy
- secondary infection - risk of damage is low
what is the presentation in CID ?
mental retardation
spastic diplegia
sensorineural hearing loss
epilepsy
what do the intracranial calcifications associated with CMV look like ?
railway calcifications
how can a diagnosis of CMV in the fetus be made ?
quantification of CMV but fetus must be at least 21 weeks
what is the management for CMV ?
no specific anti-viral
however ganciclovir can reduce the sensorineural hearing loss
what are the maternal consequences of varicella ?
varicella pneumonitis
what does fetal varicella syndrome look like ?
skin scarring in dermatomal distribution
eye defects
limb hypoplasia
neurological abnormalities
what are the fetal consequences if varicalla was acquired in :
1st and 2nd trimester
2nd and 3rd trimester
around delivery ?
1st and 2nd trimester - congenital varicella syndrome
2nd and 3rd - zoster in infancy
around delivery - neonatal varicella
what effect does maternal shingles have on the fetus ?
no risk unless the mother is immunosuppressed or the shingles is disseminated
what is the management and prevention for VZV ?
1.contact with shingles/chicken pox :
VZIG for susceptible within 10 days
2.Maternal chickenpox at birth:
VZIG for neonate
what is the treatment for chickenpox ?
acyclovir for shingles
zoster immunoglobulins for child
in neonatal HSV which types is relativley more common ?
HSV-2
what is the presentationn nof neonatal HSV ?
localized infection - eye, mouth and skin
widespread with severe CNS sequelae
what is toxoplasmosis infection ?
protozoal infection from cat faeces or undercooked meat
what is the infectious stage of toxoplasmosis ?
tachyzoite
what is the classical triad of congenital toxoplasmosis ?
intracranial calcifications
hydrocephalus
acute fundal chorioretinitis
what do the intracranial calcifications in CMV vs Toxoplasmosis look like ?
CMV - railway or peri-ventricular
Toxoplasmosis - dotted
what is the management of toxoplasmosis ?
termination treatment : sulphadiazine pyrimethamine folic acid alternating with spiramycin
what is the treatment of toxoplasmosis for the neonate ?
sulphadiazine
pyrimethamine
folic acid and must be continued for one year to avoid chorioretinitis
if a woman has toxoplasmosis and wants to get pregnant what should be advised ?
to delay pregnancy until her serology is clear
what are the manifestations of syphillus ?
interstitial keratitis
hutchinson’s teeth
clutton’s joint
how can screening for syphilis be done ?
through EIA , followed by a confirmatory test of TPPA and follow up can be achieved by RPR
what is the management of an neonate infected with syphilis ?
iv or IM penicillin for 10 days
what is the clinical neonatal presentation of CMV ?
petechia jaundice seizures hepatosplenomegaly small for gestational age
