Micro 2

Question 1

TORCH

Answer 1

led to use of poor test… “TORCH titer”

Question 2

serology IS the way to Dx:

Answer 2

syphilis, toxo

Question 3

serology CANNOT Dx:

Answer 3

HSV, CMV

Question 4

pyogenic bacterial infections

Answer 4

Group B strep, E. coli

Question 5

congenital and perinatal viral infections

Answer 5

CMV, HSV, parvovirus, HIV

Question 6

Frequency of congenital infections asymptomatic at birth

Answer 6

CMV >90%
Rubella 60-70%
Toxo 75%
syphilis 50% or more depending on definition
HIV >99% (may not manifest for 6mo-1yr b/c manifests as opportunistic infection)

HSV rarely asymptomatic!! <5%

Question 7

Common findings in congenital non-pyogenic infections

Answer 7

hepatosplenomegaly
jaundice
anemia
pneumonia
adenopathy
petechiae
meningioencephalitis

Question 8

Distinctive features of congenital non-pyogenic infections:

intracranial calcifications

Answer 8

toxo, CMV

Question 9

Distinctive features of congenital non-pyogenic infections:

cataracts

Answer 9

rubella, HSV

Question 10

Distinctive features of congenital non-pyogenic infections:

chorioretinitis

Answer 10

toxo, CMV

Question 11

Distinctive features of congenital non-pyogenic infections:

bone lesions

Answer 11

syphilis, rubella

Question 12

Distinctive features of congenital non-pyogenic infections:

congenital heart dz

Answer 12

rubella

Question 13

Distinctive features of congenital non-pyogenic infections:

microencephaly

Answer 13

CMV

Question 14

Distinctive features of congenital non-pyogenic infections:

hydrocephalus

Answer 14

toxo

Question 15

Distinctive features of congenital non-pyogenic infections:

vesicles

Answer 15

HSV, VZV, syphilis

Question 16

Syphilis

Answer 16

Treponema pallidum
difficult to culture… dark field microscopy!

Transmitted transplacentally: can be isolated (14 wks early in 74% women) from amniotic fluid; lack of pathological fetal changes before 5th month; hematogenous spread–> widespread problems in fetus

Risk to infant varies depending on mother’s stage of untreated syphilis:

• primary and secondary: 50% stillbirth, 50% infected
• Latent: 20-60% normal
• Late: 70% normal

Placenta:
pale, thick, and larger than normal
Focal villositis with endovascular and perivascular proliferation (hypercellular)
Treponema may be identified by silver stain

Question 17

Congenital syphilis presentation

Answer 17

asymptomatic usually at birth
w/in 2 yrs:
--multiorgan involvement
--non-immune hydrops
--hepatosplenomegaly
--bone involvement (periostitis)
--Cartilage involvement (snuffles)
--pneumonia
--derm changes (copper rash)
--desquamation? respiratory distress?

Question 18

Dx syphilis

Answer 18

Abs to cardiolipin (VDRL and RPR)
–can give false positives, so follow up w/…
detect Abs to T. pallidum
–i.e. MHA-TP microhemagglutination test

Question 19

Report of the Committee on Infectious Diseases (AAP) guidelines (for syphilis)

Answer 19

Mother’s serological status has to be determined prior to discharge

Question 20

prenatal management for syphilis

Answer 20

RPR screening during pregnancy at least once

twice at least in high risk populations

Question 21

prenatal Rx for syphilis

Answer 21

single dose of benzathine PCN
repeat wkly x2 for HIV concurrent

follow titers during pregnancy and document 4 fold drop in titers

re-treat any time 4-fold increase

Rx partner

Question 22

infant Rx for syphilis

Answer 22

procaine PCN
aqueous PCN
benzathine PCN IM if guaranteed F/U (inadequate CNS Rx w/ just one dose)

Question 23

HIV

Answer 23

maternal screening is key! (congenital HIV is preventable)

Dx w/ culture and PCR;
If mother HIV+ and infant asymptomatic: Rx w/ AZT until PCR neg. two different times 6 wks apart

Question 24

Rubella

Answer 24

Severe cases with mental retardation, microcephaly, cataracts, deafness, intradermal erythropoiesis (“blueberry muffin” appearance—not specific for rubella b/c can occur anytime anemia???)

stillbirth risk very high if first few wks of pregnancy

mother serology=key!

Dx viral culture and PCR

Question 25

Congenital toxo

Answer 25

more commonly transmitted later in pregnancy, but more of a problem if transmitted early Severe cases often with hydrocephalus, chorioretinitis, jaundice, splenomegaly, intracranial calcifications (diffuse) calcifications on CT are diffuse (b/c comes from blood stream?) Early Dx is essential for Rx 80-90% develop neuro sequelae, esp. eyes Dx w/ serology! (very sensitive, postitive titers require confirmation) Rx long and complicated (pyrimethamine and sulfadiazine)

Question 26

CMV

Answer 26

probably most common perinatal infection in utero, natally, or post-natally aquired congenital: smallest percentage of births, but bad and long term sequelae natal: 2-6% post-natal: 14-21%... natal and postnatal usually not severe (URI) unless immunosuppressed

Question 27

congenital CMV invections

Answer 27

most >90% asymptomatic primary maternal infection (gets CMV for first time while pregnant) causes more of the problems, but secondary can cause some! MC symptoms when symptomatic: jaundice, petechiae, hepatosplenomegaly, IUGR, preterm, microcephaly, etc. dilated ventricles, periventricular calcifications, w/ small head on CT Dx: Isolation of CMV from urine or other body fluid (CSF, blood, saliva) in the first 21 days of life is considered proof of congenital infection serology bad, PCR good

Question 28

Sequelae of congenital CMV

Answer 28

neuro=most common and most severe >90% of symptomatic have visual, audiologic, etc. 5-17% of ASYMPTOMATIC congenital CMV still develop neuro sequelae!!! i.e. hearing loss cranial CT is good predictor of sequelae

Question 29

HSV

Answer 29

primary infection>>>recurrent infection Skin-mouth-eye (SEM) dz 6-10 days old disseminated dz w/ or w/out CNS 5-7 days encephalitis alone presents days later 25% long-term CNS sequelae Dx: DFA testing of specimen from skin; culture=gold standard, but unhelpful for CNS involvement; PCR Rx: 14 days if SEM, 21 days if CNS

Question 30

Hep B

Answer 30

mother infectious if HepBsAg positive transmission at time of birth give HBIG and vaccine to newborn ASAP Risk of transmission is 5-20% (w/out Rx) Risk increases to 70-90% if mother HBeAg positive asymptomatic baby doesn't mean anything Hepatitis B acquired in childhood has higher chances of developing chronic hepatitis and ultimately Hepatocellular carcinoma and cirrhosis

Question 31

early onset bacterial infections in newborn

Answer 31

<72 hrs Group B strep, E. coli, Listeria monocytogenes, proteus, klebsiella, Staph

Question 32

late onset

Answer 32

>72 hrs

Question 33

empiric antibiotics

Answer 33

Ampicillin/PCN w/ aminoglycoside discontinue after 48hrs if asymptomatic 10-14 days for sepsis 14-21 days for meningitis