Congenital and Perinatal Infections Flashcards
What is perinatal infection?
Infectious during time of delivery
When is ascending infection most common?
When the placenta has ruptured
How does maternal infection lead to premature delivery or fetal death
Direct end-organ damage, chronic infection
non-specific effect. Mum is too weak to have baby
When is the Varicella virus vaccine given?
at 18 months, with the MMRV vaccine
Why is MMR given at 12 months?
Prevent cross reaction with maternal antibody
What is anthem and enanthem?
anthem = rash on surface of the body enanthem = rash on mouth
What are the common herpes virus that affect humans
CMV
HSV type 1 + 2
Varicella Zoster
EBV
What is chicken pox?
Primary VZV infection
Where does VZV become dormant? What is it called if it reactivates?
DRG
Shingles
What is the typical presentation of VZV?
fever, lethargy, rash in 24 hours
Pruritic vesicular rash with ulcerated areas
Vesicles shed virus
What are the complication of VZV infection?
Secondary bacterial infection due to skin lesions
Pneumonitis
Acute cerebellar ataxia
At what stage of pregnancy is immune-suppression most obvious?
third trimester, so primary infection here is most dangerous as baby is most unprotected
T/F Smoking is an independent variable to fetal defect
True, it increases the risk of pneumonitis specifically
When is the fetus most susceptible to mental retardation and developmental abnormalities if the mother gets infected by VZV?
Primary infection in the first trimester
When will VZV infection cause perinatal varicella
Primary infection within 7 days before delivery, as mum doesn’t have the time to mount immune response
What is VZIG?
Concentrated preformed immunoglobulin given prophylactically within 96 hours post-exposure
what is the management of acute chicken pox in mothers
Acyclovir + negative pressure chamber to limit the spread
T/F We can clear cytomegalovirus
False, the infection is life-long
What kind of cell is produced when infected with CMV?
multinuclear giant cell
Where does CMV stay latent in?
White blood cells
T/F Reactivated CMV is much more infectious
False, primary infection is more infectious
What is the mode of transmission for CMV?
via any body liquid
T/F Most of the CMV exposures occur in adults of the developed world
True, and most exposures in the developing world are in children
What are the common ways for babies to get CMV?
horizontal transmission (in day-care centre), or breast milk from mum postnatally
2% of the live births will have congenital CMV. How much of the infected will be symptomatic? What are the symptoms?
10%
calcification around brain, microcephaly, significant long term sequelae
Can asymptomatic babies develop long term sequelae
Yes, 10-15% will have long term sequelae such as unilateral sensory deafness
How do we determine whether CMV infection is early or late?
IgG avidity test for how strongly the antibody binds. Late infection will test for higher avidity
T/F IgM is a good diagnosis for acute CMV infection
False, IgM for CMV can persist for a long time, up to 18 months
Reactivated CMV can also cause rise of IgM
Why is it important to retest for infections
To detect for rising titres of antibody
How do we confirm fetal CMV infection?
amniotic fluid testing 6-8 weeks after primary infection, or at 20 weeks gestation
If the foetus is symptomatic, what is the management option?
ultrasound to check for microcephaly or calcification
Can we assume the baby is safe if the baby has asymptomatic congenital CMV?
No, we need to follow them up, as deafness can take five years to develop
What is the treatment of CMV?
Ganciclovir IV for 6 weeks to half the rate of deafness
Valganiciclovir can also be added
T/F Rubella viral infection can be infectious before symptoms are present
True, virus is shed is large amount in nasopharyngeal secretion
What are the typical signs of rubella?
fever, lymphadenopathy in the occipital nodes
What is the classic triad of congenital rubella syndrome?
ophthalmological,
cardiac and auditory abnormalities
T/F Rubella infection is linked to diabetes and thyroid illness
True, they are the rarer presentations
T/F Risk of congenital damage is highest in the third trimester
False, it’s in the first trimester when all the organs are forming
How do we diagnose congenital rubella syndrome?
fetal amniotic fluid test for rising IgG and IgM (acute infection)
Which virus causes “slapped cheek” syndrome?
Parvovirus
T/F Parvovirus is self-limiting
True
What are the presentations of parvovirus infection?
fine reticular rash on body, cheeck
circum-oral pallor
What is Hydrops foetalis?
Parvovirus with haematological abnormalities (sickled cell) that reduce RBC lifespan. HF is a significant anaemia
What is the treatment of Hydrops foetalis?
Intrauterine transfusion until the virus is cleared
T/F HSV-1 is genital specific
False, HSV-2 is typically genital specific
How will HSV be transmitted from the mother to baby?
perinatally during delivery if there is primary infection or reactivation
What are the symptoms of congenital HSV infection
skin-eye-mouth disease
skin vesicle
delayed encephalitis
disseminated intravascular coagulation
What is the management of herpes?
acyclovir
What is the causative agent of syphilis?
Treponema pallidum
What are the diagnostic tests for syphilis?
EIA and RPR
What symptom can the baby develop if there is congenital Toxoplasma gondii infection?
delayed retinopathy
