5/26- Congenital Infections Flashcards Preview

Term 5: Infectious Disease > 5/26- Congenital Infections > Flashcards

Flashcards in 5/26- Congenital Infections Deck (58):
1

Viruses that cause congenital infections

- Cytomegalovirus (CMV)

- Rubella

- Herpes simplex (HSV)

- Varicella-zoster (VZV)

- Enteroviruses

- HIV

- Parvovivrus B19

2

Bacteria that cause congenital infections

- Treponema pallidum

- Mycobacterium tuberculosis

 

3

Protozoa that cause congenital infection

- Toxoplasma gondii

- Trypanosoma cruzi

4

TORCH infections

- Toxoplasmosis

- Other: syphilis

- Rubella

- CMV

- Herpes, HIV

5

US Screening during pregnancy

- Rubella

- Syphilis (early and near delivery)

- Hepatitis B

- HIV

 

- Testing for CMV immunity is not routine (some obstetricians will do, some don't)

- Some states screen for toxoplasma in newborns (not TX)

6

Congenital infections are usually associated with what stage of infection in the mother?

(e.g. primary, recurrent, latent)

Primary infections

7

What factors play a role in the manifestations of infection in infants?

- More severe with infection earlier in gestation 

- Many infected infants asymptomatic at birth; must be screened

8

Pathogenesis of congenital infections

- Maternal infection, then

- Bloostream invasion, then

- Fetal infxn, placental infxn, or both

(placental may lead to infecting fetus or not), then

- Intrauterine death OR

   premature infant OR

   term infant

Outcomes:

- Intrauterine growth retardation (IUGR)

- Developmental anomalies

- Congenital disease

- Normal infant

 

9

Case

- A term female infant born by precipitous NSVD to an 18 y/o woman who received no prenatal care

- Mother reports using marijuana and alcohol early in pregnancy and was daignosed with 2 UTIs; had several "colds" late in pregnancy

- Lives with boyfriend, 2 dogs, cat, and turtle

- Infant is 2 kg, lethargic, jaundice, weak cry, microcephaly, distended abdomen, hepatosplenomegaly, diffuse petechial rash with areas of purpura on extremities

- Elevated liver enzymes

- Scattered intracerebral calcifications on head US

Most likely etiology?

Cytomegalovirus

10

What is the most common congenital viral infection? Stats?

Cytomegalovirus

~1% of al lnewborns 

commonly asymptomatic; may develop later

11

How is CMV transmitted congenitally?

- Transplacental

- Intrapartum (during delivery)

12

Infection of CMV when results in the most severe sequelae?

Primary infection in 1st half of gestation

13

How many infants are symptomatic for CMV at birth?

10% symptomatic at birth

14

Do mother Abs protect fetus from CMV infection?

Not really

- Infection can occur with recurrent disease (can be infected with new strain during pregnancy)

15

Symptoms of congenital CMV (7)?

- Intrauterine growth restriction (small for age)

- Jaundice

- Skin: purpura, petechiae, blueberry muffin

- Hepatosplenomegaly

- Microcephaly

- CNS calcifications

- Retinitis

- Sensorineural hearing loss

16

What is a blueberry muffin rash?

Sites of erythropoesis is neonate, possibly because virus invades bone marrow and kicks out the RBC-producing cells

(it is palpable)

17

What is the most common sequelae of congenital CMV?

Stats (number affected, timeframe)?

Sensorineural hearing loss

(more common sequelae if symptomatic at birth)

- causes 21% of hearing loss at birth

- 1/3 to 1/2 of hearing loss due to CMV is late-onset

18

How many infants with herpes of asymptomatic mothers?

2/3

(history absent in 2/3 of mothers of infected infants)

19

What is herpes's risk of infection from mother to child?

Primary infxn: 25-60%

Reactivated: 2%

20

Transmission of congenital herpes?

Other methods of vertical transmission (not truly congenital)?

Congenital:

-  Transplacental

- Ascending (rupture of membranes while mom has active outbreak)

Neonatal:

- Intrapartum (86%)

- Postnatal (10%)

- Intrauterine/congenital (4-5%)-- so this one is actually pretty rare

21

Key symptoms of congenital herpes? (since it is so rare)

- Cutaneous findings (scarring from previous vesicles, )

- CNS abnormalities

- Eye abnormalities

22

Incidence of congenital Varicella (broadly speaking)?

- Rare because most moms in US are immunized

23

When is a varicella infection most likely to be transmitted to the infant?

What is the percentage of infection during this time frame?

- before 20 wks of gestation 

- 1-2%

24

Method of varicella transmission?

Transplacental

25

Symptoms of congenital varicella?

- Possibly associated w/ abortion and prematurity

- Scars

- Cataracts, retinitis, microphthalmos

- Hypoplastic limbs (lesions as limbs develop)

- Seizures and other nervous system abnormalities

- At autopsy, skin, lung, and liver uniformly involved (it's everywhere)

26

How is congenital Rubella transmitted?

Transplacental

27

When during pregancy is congenital Rubella infection most common?

Risk is limited almost exclusively to the 1st trimester

28

What is the underlying mechanism of congenital Rubella symptoms?

Defects due to cytopathic damage to vessels and organ ischemia

29

Incidence of congenital Rubella in US?

- Very low (3 in 2012, none in 2009-2011)

- This has occurred in mothers who have been in endemic areas (like mom contracting Rubella in Africa)

30

Symptoms of Rubella?

- Cataracts (can happen with others, but key for Rubella!), microphthalmos, glaucoma

- Auditory: sensorineural loss

- Neurologic: meningoencephalitis, microcephaly, retardation

- Cardiac: PDA, peripheral pulmonary stenosis

Other manifestations:

- Blueberry muffin rash

- Intratuterine growth retardation

- Pneumonitis

- Bone dz

- Hepatosplenomegaly

- Thrombocytopenia

31

Case

- 2.52 kg, AGA, male infant born at 37 wks gestation via a stat C/S

- At delivery thick meconium, poor tone, respiratory effort

- Apgars are 3/6/8

- Promptly intubated

- Born to 30 yo G2P1 mom with cocaine addiction and Hx of herpes, syphilis, and gonorrhea; mother did not receive prenatal care

- Multiple petechiae, round lesions on palms/soles with desquamation, distended abdomen, hepatosplenomegaly, bilateral axillary lymphadenopathy, decreased tone

Diagnosis?

Syphilis 

(rash on palms/soles is key)

32

What causes syphilis?

Treponema pallidum

33

Transmission of congenital syphilis?

Transplacental

34

Rates of transmission of the different stages of syphilis during pregnancy?

- 1/2': 50%

- Early latent: 40%

- Late latent: 10%

- 3': 10%

35

Clinical manifestations of congenital syphilis?

- Stillbirth, prematurity, hydrops fetalis (edematous)

- Hepatosplenomegaly, lymphadenopathy

- "Snuffles" (profuse runny nose)

- Rash, condyloma lata, gumma, desquamation

- Anemia, thrombocytopenia

- Osteochondritis, pseudoparalysis (since so painful)

- Meningitis

- Pneumonia alba (can look totally white on CXR)

36

Late manifestations for congenital syphilis

(even up to 9+ yrs later!)

- Frontal bossing (enlarged frontal lobe), saddle nose

- Keratitis, glaucoma, retinitis

- Sensorineurla hearing loss

- Hutchinson teeth (notched incisers), mulberry molars (outgrowths)

- Rhagades (cracking of sides of mouth), gummas

- Saber shins, clutton joints

37

Hutchinson's triad

Triad of manifestations for late syphilis:

- Interstitial keratitis

- Sensorineural hearing deafness

- Hutchinson teeth

38

Case:

- 2 yo infant born at 37 wks gestation to a 33 yo G5 P3 Ab1 mother. RPR, HepB, and HIV negative, Rubella nonimmune

- Mom exposed to mice, cats, and kittens while cleaning houses; ill in 2nd and 3rd month of pregnancy with "flu-like" illness, sore throat, and lymphadenopathy

- US at 29 wks gestation revealed hydrocephalus and hepatosplenomegaly

- Repeat US 1 wk prior to delivery was improved but persistent hydrocephalus

- Weight and height 50%, no microcephaly

- Split sutures

- Pupils sluggish, retinal exam abnl

- Hepatomegaly, but no jaundice

- Decreased tone

- No rash

Cause?

Toxoplasmosis

39

What causes toxoplasmosis?

Toxoplasma gondii (a parasite)

40

Incidence of congenital toxoplasmosis?

- 1-5 cases per 10,000 live births (0.01 - 0.05%)

41

Transmission of toxoplasma?

Transplacental

42

When during pregnancy is transmission of toxoplasma most common?

- When mom is parasitemic (primary infxn with parasites in blood)

- Reactivation in immunocompromised mother (e.g. HIV)

43

How is toxoplasmosis acquired?

Acquired via:

- Undercooked meat

- Soil, water, food contaminated with cat feces

44

Life cycle of Toxoplasma?

- Excreted in feces of cats

- Oocytes may be ingested by many different animals and spread via their undercooked meat

- Thus contaminated soil, kitty litter or undercooked food

45

How many infants or asymptomatic with toxoplasmosis at birth?

70-90%

46

Symptoms of congenital toxoplasmosis?

Classic triad?

- Rash

- Lymphadenopathy

- Hepatosplenomegaly

- Jaundice

- Pneumonitis

- Thrombocytopenia

- CNS abnls: hydrocephalus, calcifications, microcephaly, seizures

- Chorioretinitis, retinal scarring

- Deafness

Classic triad:

- Calcifications

- Chorioretinitis

- Hydrocephalus

47

Sequelae of congenital toxo?

- Chorioretinitis (retinal lesions in 85% of untreated congenital infxns)

- Mental retardation

- Motor deficits

- Hearing loss

- Seizures

48

General evaluation for congenital infections?

- Hearing evaluation (hearing screen mandated in US before leaving hospital, but may need something more sophisticated like ABR)

- Ophthalmologic exam

- Labs; CBC d/p (for anemia or thrombocytopenia), LFTs, specific serologies (Rubella IgM, toxoplasma...)

- Lumbar puncture

- CNS imaging (typ CT or MRI of brain; US may be useful)

- Bone radiographs

 

49

What dz is associated with pneumonia alba?

Syphilis

50

What dz is associated with limb hypoplasia?

Varicella

51

What dz is associated with cataracts?

Rubella

52

What dz associated with cutaneous scars?

Herpes

(but also Varicella)

53

What dz is associated with CNS calcifications?

Toxoplasmosis

54

Question:

An infant is born small for gestational age, jaundiced, and is microcephalic. Another common physical exam finding is:

A. Dysmorphic features

B. Extra digits

C. Hepatosplenomegaly

D. Rales on auscultation of chest

C. Hepatosplenomegaly

55

Question:

An essential test to establish the diagnosis for this infant (last ?) would be:

A. TORCH titers

B. Viral cultures

C. Otolaryngology evaluation

D. EKG

B. Viral cultures

56

Question:

The most common congenital infection is?

A. Toxoplasmosis

B. Syphilis

C. Cytomegalovirus

D. Rubella

E. Herpes

C. Cytomegalovirus

57

Question:

An infant is born with a congenital infxn transmitted to his mother by contact with cat feces. The pathogen is a:

A. Virus

B. Bacteria

C. Fungus

D. Parasite

D. Parasite

58

Question:

Congenital infxns are associated with damage to the following organ systems:

A. Central Nervous System

B. Reticuloendothelial System

C. Cardiovascular System

D. Musculoskeletal System

E. All of the above

E. All of the above