Congenital/Perinatal Infections Flashcards
Why is the TORCH acronym not a good acronym? What is the acronym
T=toxo
O=other, mostly syphilis
R=rubella
C=CMV
H=herpes
What is the difference between a congenital and perinatal infection?
Congenital = acquired during pregnancy (CMV, rubella, toxo, Listeria, Syphilis, HSV, Malaria, etc.)
Perinatal = acquired around or during time of birth (GBS, Listeria, HIV, Gonorrhea/chlamydia, syphilis, HSV, etc)
Where can the infection cross the placenta?
Which types of pathogens do this best
Placenta is covered by synctiotrophoblast which is basically ONE BIG CELL – impermeable
There are spots where the placenta doens’t have this– that’s where pathogens can get through
Intracellular pathogens are the rule for congenital infections
What is Listeria monocytogenes?
What disease does it cause in adults?
catalase positive, gram positive rod
Found on contaminated food
causes GI symptoms in healthy adult, more severe symptoms in preg women- bacteremia /immunocompromised - meningitis
How does Listeria get across placenta? what makes it good at this?
Inhaves GI epithelial cells –> lymph noddes
Once intracellular can pss cell to cell without exposure to outside environment - can avoid detection by antibodies
Toxin listeriolysin O = pore forming, initiates polymerization of host actin on its butt, which propels it through a neighboring cell
What is the manifestation of Listeria in pregnant women?
In newborn?
Nonspecific symptoms, premature labor, fetal mortality (placental, fetal lung/GI involvement), bacteremia
Early onset disease: <1 week of age: bacteremia
Late onset: after day 7 - meningitis
How can you treat Listeria infection? Prevent it?
Treat: IV ampicillin during pregnancy
Neonates: ampicillin + an aminoglycoside
Prevent by washing and cooking raw food, don’t eat unpasteurized dairy (raw cheese)
What is the most common congenital infection?
CMV: 1/100 of births have it
What is CMV?
Herpes family virus
DNA genome
Causes mono-like syndrome or can be asymptomatic in adults
Acute infection followed by latency – can be reactivated
Does CMV more commonly come from primary or reactivation disease?
Primary disease is rare but almost always leads to disease
Reactivation is more common but rarely leads to disease
*most cases are due to reactivation because seropostive rate is high
What are the symptoms of congenital CMV?
Most are asymptomatic! Especially when mother had reactivation. But can have sequalae later in life– hearing loss, low IQ
Symptoms: prematurity, SGA, jaundice, hepatosplenomegaly, neuro (hearing loss, low IQ), calficications in baby’s head (seen with ultrasounds), blueberry muffin rash, retinitis
How is congenital CMV diagnosed?
Amniotic fluid PCR
Postnatally: detect virus in first 2-3 weeks of life via urine
You can also check dried blood spt PCR which has lots of false neg’s but can be useful if it’s positive
How do you treat CMV?
There aren’t great treamtnets
CMV hyperimmune globulin prenatally
Neonatal: ganciclovir slows hearing loss
Valganciclovir= its oral version but unclear if helpful
What is rubella?
Enveloped ssRNA (+ sense) genome
Transmission by resp tract secretions/drolets
Acquired rubella causes self-limited fever, rash (face to trunk)
Dangerous if congenital
Why do we vaccinate against Rubella if it’s not that serious of a disease?
Because we don’t want pregnant women to get it – very dangerous when congenital infection
When during pregnancy is the highest risk of congenital infection by rubella?
1st trimester is highest risk - nearly 100% if exposed, high rates of fetal death
2nd trimester= lowest risk
3rd trimester risk rises but not as bad as first trimester
What is the clinical manifestation of congenital rubella?
Deafness
Cataracts/glaucoma
Neurological deficits
Cardiac abnormalities
Blueberry muffin rash
How do you diagnose congenital rubella?
RTPCR in mom of pharyngeal swab
Postnatally: viral isolatino or RTPCR of nasopharnyx, CSF, urine
How do you treat rubella? Prevent?
No treatment
Prevent by vaccinating everyone– but don’t give the vaccine during pregnancy because it’s live viral
What is toxoplasmosis?
Parasite, asymptomatic in adults but can reactivate during pregnancy and cause congenital toxoplasmosis
More severe infection if earlier in pregnancy, but more common to get infection later in pregnancy
What are the symptoms of congenital toxo?
Chorioretinitis, hydrocephalus, intracranial calcifications
How do you diagnose congenital toxo?
Amniotic fluid PCR or IgG avidity in pregnant mother
Postnatal placental culture, histopathology, serology, imaging
How do you treat congenital toxo during pregnancy? In affected newborn?
Preg: spiramicin if <18 wks or pyramethamine+ sulfadiazine +leukovorin
Newborn gets the same 3 drug regimen for 12 weeks
How do neonates get GBS?
Vaginal colonization in mom (25% of women hav eit) –> severe disease in 1% of their newborns
What’s the clinical manifestation of GBS in new born?
Early onset: mostly bacteremia
Late onset: bacteremia, meningitis, skin/bone/soft tissue infections
How do you prevent perinatal GBS?
Screen moms before they give birth & then give IV penicillin every 4 hours during labor
How do you treat newborns with GBS?
If you suspect invasive bacterial disease, cover a variety of pathogens including Listeria, E. coli, etc.
Once you have a diagnosis, treat with penicillin +/- aminogylcoside for synergy
How do you diagnose GBS?
Culture
