Dr. Rubin -- Congenital/Perinatal Infections

Question 1

3 protective immunity mechanisms for fetus and neonate

Answer 1

• Placenta (filter microorganisms)
• Maternal Ab (mostly 3rd term)
• Breast milk (secretory IgA)

Question 2

Time of fetal infection that produces the most devastating effects

Answer 2

1st trimester

Question 3

3 types of effects of fetal infection

Answer 3

• Interference with normal development
• Inflammatory reaction to the infection
• Placental insufficiency leading to poor growth

Question 4

How to recognize exposure of a pregnant woman

Answer 4

• Usually asymptomatic
• Detection of specific IgM Ab to an offending agent or rising titer of IgG helpful to assess risk
• Baseline immunity will help to excluse dx (i.e. immunity against Rubella, CMV, parvo, etc)

Question 5

Ig findings that indicate fetal infection

Answer 5

Presence of specific IgM or rising IgG titre

Question 6

4 ways to isolate offending agents to diagnose infant

Answer 6

• Viral cultures of urine and other body secretions for CMV, Rubella, HSV
• PCR amplification if possible (i.e. Toxo)
• Pathology of placenta
• Darkfield microscopy from lesions for *T. pallidum *(syphillis)

Question 7

4 fetal infections that you absolutely cannot miss (important to treat)

Answer 7

• Toxoplasmosis
• Syphilis
• HSV
• HIV

Question 8

Fetal infection with no effective treatment

Answer 8

Rubella

Question 9

Fetal infection with which there is only a possibility of treatment benefit

Answer 9

CMV (partial and transient improvement)

Question 10

9 examples of organisms that are included in the O (other) of TORCH screen

Answer 10

• Syphilis
• TB
• Listeria
• Leptospirosis
• Hepatitis B
• Enteroviruses
• Varicella
• Parvovirus
• HIV

etc

Question 11

Common misconception about TORCH

Answer 11

• There is no one test that will screen for congenital infections
• Nothing replaces a good clinical accumen and directed specific testing

Question 12

11 common features associated with TORCH agents

Answer 12

• Prematurity
• IUGR
• Congenital defects
• Abnormal head size
• Intracranial Ca++
  
  • Periventricular
  • Diffuse
• Eye abormalities
• Earing loss
• Hepatosplenomegaly
• Hematologic AbN
• Bone lesions
• Inflammtion of CSF

Question 13

2 conditions of adnormal head size associated with TORCH agents

Answer 13

• Microcephaly
• Hydrocephaly

Question 14

3 eye abnormalities associated with TORCH agents

Answer 14

• Chorioretinitis
• Cataracts
• Micophthalmia

Question 15

Define TORCH

Answer 15

• Toxoplasma
• Other (covered in another card)
• Rubella
• Cytomegalovirus
• Herpes

Question 16

Classic triad of congenital toxoplasmosis

Answer 16

• Hydrocephaly
• Diffuse intracranial calcifications
• Chorioretinitis

Question 17

Approach to congenital toxoplasmosis

Answer 17

1. Refer to maternal serology
2. If not done, start with Toxo IgG and then Toxo IgM
   
   1. NEG
   2. POS
3. Ophthalmology assessment for chorioretinitis
4. Head imaging (CT vs. US vs Xray)

Question 18

Use of NEG in congenital toxoplasmosis diagnosis

Answer 18

• Toxo IgG = excludes Congenital Toxoplasmosis
• Toxo IgM = does not totally exclude

Question 19

Describe the use of POS in congenital toxoplasmosis

Answer 19

• Look at titre and avidity –> strong avidity = more remote infection
• Toxo IgM = increases the likelihood, but + for >6 months

Question 20

Approach to toxoplasmosis during pregnancy

Answer 20

• Seruconversion documents
• Positive IgM
  
  • PCR on amniotic fluid
  • Serial ultrasounds, looking for ventricular dilatation
  • Placental histology

Question 21

Treatment for positive aminiotic fluid PCR in event of suspected toxoplasmosis during pregnancy

Answer 21

Pyramethamine and sulfadiazine and folinic acid supplements

Question 22

Treatment for negative amniotic fluid PCR in event of suspected toxoplasmosis

Answer 22

Spiramycin

Question 23

Approach to suspected congenital rubella (7)

Answer 23

1. Check mom’s rubella status prior to the current pregnancy
   
   1. If positive = excludes rubella
   2. If negative or unknown, check Rubella IgG on Mom or baby
      
      1. If negative = excludes Rubella –> immunize Mom
      2. If positive –> rubella IgM
         
         1. If positive = Congenital Rubella
         2. If Negative –> Rubella Viral Cultures

Question 24

Approach to suspected congenital CMV

Answer 24

• Urine viral culture for CMV
  
  • POSITIVE = if done within first 2 - 3 weeks of birth –> CMV
  • NEGATIVE = exclude CMV
• No need for serology

Question 25

3 potential manifestations of congenital herpes

Answer 25

* Skin, eye, mucous membrane ("SEM") * Encephalitis * Disseminated

Question 26

Approach to suspected congenital herpes

Answer 26

* Lesion --\> viral cultures * POSITIVE = herpes * No lesions * Culture mouth, NP, eyes, urine ,rectum * POSITIVE \> 48 hours after birth = viral replication vs. colonization after intrapartum exposure * CSF and blood HSV PCR * Tissue diagnosis NOTE: HSV IgG and IgM not very helpful

Question 27

Approach to suspected congenital syphillis

Answer 27

Check naternal serology and recheck at time of delivery, or thereafter * NEGATIVE = exclude * POSITIVE = review history, prior treatment

Question 28

3 of the only congenital infections that are treatable

Answer 28

* Syphillis * Toxoplasmosis * HSV

Question 29

2 sequelae of maternal primary CMV in pregnancy

Answer 29

* Severe psychomotor delay (50 - 60%) * Hearing loss (30 - 60%)

Question 30

Primary etilogy of Fifth Disease (erythema infectiousum)

Answer 30

Parvovirus B19

Question 31

Effect of parvovirus in hemoglobinopathy patietns

Answer 31

Aplastic crisis

Question 32

Effects of parvovirus B19 in pregnancy

Answer 32

* ?Spontaneous abortion in 1st trimester * Fetal anemia nad hydrops in 2nd and 3rd trimester * ?Stillbirth

Question 33

3 general effects of parvovirus B19

Answer 33

Bone marrow aplasia (hemolysis) --\> severe anemia and CHF

Question 34

4 other infectious causes of nonimmune hydrops

Answer 34

* Toxoplasmosis * Rubella * CMV * Syphillis

Question 35

Diagnosis of parvovirus B19

Answer 35

Serology on mom at time of exposure * If IgG positive = immune * If IgG negative = check and follow IgM and IgG

Question 36

Why is elevated alpha-fetoprotein a potential marker for adverse outcome

Answer 36

Produced in fetal liver, which is the major site for fetal erythropoiesis and major site of infection for B19

Question 37

Approach to a mother who is sAg and eAg positive for hepatitis B

Answer 37

High transmission and risk for infant to become chronic carrier = give HBIG and first dose of vaccine **at birth** (then at 1, 6 months)

Question 38

Describe perinatal HCV transmission

Answer 38

* Low (\<5%) * Increased if co-infected iwth HIV (18-20%)

Question 39

HCV diagnosis in infant

Answer 39

Follow serology at 6, 12, 18 months PCR potentially

Question 40

When to give prophylactic antiviral to infants exposed to HSV at birth (4)

Answer 40

* Eyes, NPA and urine cultures are positive * Primary infection in mother * Premature with limited transfer of maternal Ab * Instrumentation

Question 41

5 situations that cause higher risk of HSV to infant

Answer 41

* First episode of maternal infection in pregnancy (i.e. versus recurrent) * Multiple cervial lesions * Rupture of membranes \> 6 hours * Instrumentation, scalp electrodes * Prematurity, no maternal antibody

Question 42

4 manifestations of VZV embryopathy

Answer 42

* Limb scarring and atrophy * Bony defects * CNS abnormalitis * Eye, chorioretinitis

Question 43

3 potential manifestations of Varicella Zoster infection in newborn

Answer 43

* VZV embryopathy * Development of Zoster early in life * Congenital vericella syndrome

Question 44

Approach to suspected congenital varicella zoster infection

Answer 44

* Unlikely that VZIG is protective in fetus * Give VZIG to newborn in maternal varicella 5 days before to 2 days after delivery