STEPTRACKERMICROBIOLOGY + PEDIATRICS + OBSTETRICS | INFECTIONS BY SYSTEM | HIGH-YIELD REVIEW

TORCH & Neonatal Infections

Infections passed from mother to fetus or newborn — each congenital infection leaves a signature (eyes, ears, heart, brain calcifications, bones, skin), and neonatal sepsis has its own short list of organisms.

FOCUS ON

Shared TORCH features: growth restriction, hepatosplenomegaly, jaundice, thrombocytopenia, "blueberry muffin" rash (extramedullary hematopoiesis). Toxoplasma: chorioretinitis, hydrocephalus, diffuse calcifications. Rubella: cataracts, deafness, PDA. CMV (most common): periventricular calcifications, microcephaly, sensorineural hearing loss. HSV: vesicles, keratoconjunctivitis, encephalitis in weeks 1–3. Syphilis: snuffles, rash on palms/soles, osteochondritis → Hutchinson teeth, saddle nose, saber shins. Others: VZV (limb hypoplasia, scars), parvovirus B19 (hydrops), Zika (severe microcephaly), HIV, HBV. Neonatal sepsis/meningitis: GBS, E coli, Listeria.

INFECTION

TRANSMISSION · TIMING

SIGNATURE FINDINGS

PREVENTION · TREATMENT

Toxoplasmosis

Primary maternal infection (cats, raw meat); risk of transmission ↑ later, severity ↑ earlier

Chorioretinitis, hydrocephalus, diffuse intracranial calcifications, seizures

Avoid litter and raw meat · spiramycin; pyrimethamine-sulfadiazine

Rubella

First-trimester maternal infection (unvaccinated)

Cataracts, sensorineural deafness, PDA/pulmonary stenosis, blueberry muffin rash

Check immunity before pregnancy; MMR postpartum

Cytomegalovirus

Primary or reactivated maternal infection; daycare workers

Periventricular calcifications, microcephaly, chorioretinitis, hearing loss (most common nongenetic cause); most newborns asymptomatic

Hygiene · valganciclovir for symptomatic newborns

Herpes simplex

Mostly during delivery (primary maternal genital HSV highest risk)

Skin-eye-mouth vesicles, encephalitis, disseminated disease in weeks 1–3

Acyclovir from 36 weeks · C-section with lesions · IV acyclovir

Syphilis

Transplacental, any trimester

Early: stillbirth, hydrops, snuffles, maculopapular rash incl. palms/soles, hepatosplenomegaly, periostitis · late: Hutchinson teeth, mulberry molars, saddle nose, saber shins, interstitial keratitis, CN VIII deafness

Screen each pregnancy · penicillin

Varicella

Maternal chickenpox < 20 weeks · or 5 days before to 2 days after delivery

Limb hypoplasia, cicatricial scars, cataracts, cortical atrophy · or severe neonatal varicella

VZIG for exposed newborn/mother

Parvovirus B19

Maternal fifth disease

Fetal anemia → high-output heart failure → hydrops fetalis

Fetal MCA Doppler · intrauterine transfusion

Zika

Mosquito or sexual exposure in pregnancy

Severe microcephaly, collapsed skull, subcortical calcifications, eye lesions, contractures

Travel advice

HIV · HBV · HCV

Mostly at delivery or breastfeeding (HIV)

Usually no findings at birth

Maternal ART + infant zidovudine · HBV vaccine + HBIG ≤ 12 h

Group B strep

Vaginal colonization; early onset (< 7 days) or late (to 3 months)

Sepsis, pneumonia, meningitis

Screen at 36–37 weeks · intrapartum penicillin

E coli · Listeria

Birth canal · transplacental (deli meat, soft cheese)

Sepsis, meningitis · granulomatosis infantiseptica, preterm birth

Ampicillin + gentamicin

Neonatal conjunctivitis

Chemical (day 1), N gonorrhoeae (2–5), C trachomatis (5–14)

Hyperpurulent vs watery-then-purulent

Erythromycin prophylaxis · ceftriaxone vs oral azithromycin

Mechanism — why timing matters

Early pregnancyOrganogenesis

→

Structural defectsRubella heart and eye, varicella limbs

Later pregnancyPlacenta more permeable

→

More transmission, milder diseaseToxoplasma

At delivery

→

HSV, GBS, HBV, HIV, gonorrhea, chlamydia

Telling TORCH apart

INFECTION

BRAIN

SIGNATURE

Toxoplasma

Diffuse calcifications, hydrocephalus

Chorioretinitis

Rubella

Microcephaly

Cataracts, PDA, deafness

CMV

Periventricular calcifications

Hearing loss

HSV

Encephalitis

Vesicles

Syphilis

—

Snuffles, bone, teeth

How it's tested

COMMON CONFUSIONCalcifications hugging the ventricles point to CMV; calcifications scattered through the brain with hydrocephalus point to Toxoplasma.

THE TRAPMost congenitally infected CMV babies look normal at birth — hearing loss may appear later, so screen.

YOUR APPROACHSignature finding (eye, ear, heart, brain pattern, skin, bone) → infection → maternal exposure and timing → prevention step.

If you see… think…

Newborn with cataracts, PDA and deafness → congenital rubella

Periventricular calcifications and failed hearing screen → congenital CMV

Hydrocephalus, chorioretinitis, scattered calcifications → congenital toxoplasmosis

Blueberry muffin rash → TORCH (rubella, CMV) — extramedullary hematopoiesis

Rhinorrhea, palm/sole rash and periostitis in an infant → congenital syphilis

Notched incisors and saddle nose in a child → late congenital syphilis

Vesicles and seizures at 10 days of life → neonatal HSV

Fetal hydrops after maternal slapped-cheek exposure → parvovirus B19

Limb hypoplasia and zigzag scars → congenital varicella

Intrapartum penicillin prevents → early-onset GBS disease