5/26- Congenital Infections Flashcards
Viruses that cause congenital infections
- Cytomegalovirus (CMV)
- Rubella
- Herpes simplex (HSV)
- Varicella-zoster (VZV)
- Enteroviruses
- HIV
- Parvovivrus B19
Bacteria that cause congenital infections
- Treponema pallidum
- Mycobacterium tuberculosis
Protozoa that cause congenital infection
- Toxoplasma gondii
- Trypanosoma cruzi
TORCH infections
- Toxoplasmosis
- Other: syphilis
- Rubella
- CMV
- Herpes, HIV
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)
Congenital infections are usually associated with what stage of infection in the mother?
(e.g. primary, recurrent, latent)
Primary infections
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
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
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
What is the most common congenital viral infection? Stats?
Cytomegalovirus
~1% of al lnewborns
commonly asymptomatic; may develop later
How is CMV transmitted congenitally?
- Transplacental
- Intrapartum (during delivery)
Infection of CMV when results in the most severe sequelae?
Primary infection in 1st half of gestation
How many infants are symptomatic for CMV at birth?
10% symptomatic at birth
Do mother Abs protect fetus from CMV infection?
Not really
- Infection can occur with recurrent disease (can be infected with new strain during pregnancy)
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
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)
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
How many infants with herpes of asymptomatic mothers?
2/3
(history absent in 2/3 of mothers of infected infants)
What is herpes’s risk of infection from mother to child?
Primary infxn: 25-60%
Reactivated: 2%
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
Key symptoms of congenital herpes? (since it is so rare)
- Cutaneous findings (scarring from previous vesicles, )
- CNS abnormalities
- Eye abnormalities
Incidence of congenital Varicella (broadly speaking)?
- Rare because most moms in US are immunized
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%
Method of varicella transmission?
Transplacental
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)
How is congenital Rubella transmitted?
Transplacental
When during pregancy is congenital Rubella infection most common?
Risk is limited almost exclusively to the 1st trimester
What is the underlying mechanism of congenital Rubella symptoms?
Defects due to cytopathic damage to vessels and organ ischemia
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)
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
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)
What causes syphilis?
Treponema pallidum
Transmission of congenital syphilis?
Transplacental
Rates of transmission of the different stages of syphilis during pregnancy?
- 1/2’: 50%
- Early latent: 40%
- Late latent: 10%
- 3’: 10%
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)
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
Hutchinson’s triad
Triad of manifestations for late syphilis:
- Interstitial keratitis
- Sensorineural hearing deafness
- Hutchinson teeth
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
What causes toxoplasmosis?
Toxoplasma gondii (a parasite)
Incidence of congenital toxoplasmosis?
- 1-5 cases per 10,000 live births (0.01 - 0.05%)
Transmission of toxoplasma?
Transplacental
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)
How is toxoplasmosis acquired?
Acquired via:
- Undercooked meat
- Soil, water, food contaminated with cat feces
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
How many infants or asymptomatic with toxoplasmosis at birth?
70-90%
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
Sequelae of congenital toxo?
- Chorioretinitis (retinal lesions in 85% of untreated congenital infxns)
- Mental retardation
- Motor deficits
- Hearing loss
- Seizures
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
What dz is associated with pneumonia alba?
Syphilis
What dz is associated with limb hypoplasia?
Varicella
What dz is associated with cataracts?
Rubella
What dz associated with cutaneous scars?
Herpes
(but also Varicella)
What dz is associated with CNS calcifications?
Toxoplasmosis
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
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
Question:
The most common congenital infection is?
A. Toxoplasmosis
B. Syphilis
C. Cytomegalovirus
D. Rubella
E. Herpes
C. Cytomegalovirus
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
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
