TORCH infections

Background

• TORCH infections is an acronym for a group of congenital and perinatal infections that share overlapping clinical features in the newborn: Toxoplasmosis, Other (syphilis, varicella, parvovirus B19, Zika), Rubella, Cytomegalovirus (CMV), and Herpes simplex virus (HSV). These infections account for approximately 2-3% of all congenital anomalies and may cause fetal death, prematurity, growth restriction, and devastating multisystem disease. The emergency physician's role is to recognize the nonspecific clinical pattern that suggests congenital infection, initiate time-sensitive empiric treatment (especially acyclovir for HSV), and arrange appropriate confirmatory testing and specialist consultation.
• TORCH infections are transmitted from mother to fetus/neonate via:
  • Transplacental (during pregnancy) — most TORCH agents
  • Peripartum (during delivery) — HSV (~85% of neonatal HSV cases), HIV
  • Postpartum (breast milk, close contact) — CMV, HIV
• Earlier gestational infection generally causes more severe fetal damage; later infection causes higher transmission rates but often milder disease
• Neonatal cholestasis occurs in ~1 in 2,500 live births; infections account for ~11% of cases (see Neonatal hepatitis)

The "TORCH titer" — limitations

• A blanket "TORCH titer" panel (IgG screening) is of limited clinical utility and is not recommended as a primary diagnostic strategy
• Neonatal IgG largely reflects maternal antibodies transferred across the placenta and does not confirm neonatal infection
• Pathogen-specific testing (IgM, PCR) directed by clinical suspicion is far more useful
• If clinical syndrome suggests congenital infection, investigate each pathogen individually with the most appropriate rapid diagnostic test

Clinical features

Shared/overlapping features (the congenital infection pattern)

• Intrauterine growth restriction (IUGR)/small for gestational age
• Hepatosplenomegaly
• Jaundice (conjugated hyperbilirubinemia — see Neonatal hepatitis)
• Petechiae, purpura, or thrombocytopenia ("blueberry muffin" rash — dermal erythropoiesis)
• Microcephaly
• Chorioretinitis
• Sensorineural hearing loss
• Intracranial calcifications
• Anemia
• Seizures

Many neonates with congenital infection are asymptomatic at birth but develop sequelae (hearing loss, developmental delay, chorioretinitis) weeks to years later.

Pathogen-specific features

Toxoplasmosis (Toxoplasma gondii)

• Classic triad: chorioretinitis + hydrocephalus + diffuse intracranial calcifications
• Calcifications tend to be diffuse/scattered (compare CMV: periventricular)
• Chorioretinitis is the most common late finding — may appear months to years after birth
• Macrocephaly (from hydrocephalus) distinguishes from most other TORCH agents which cause microcephaly
• Most neonates are asymptomatic at birth; untreated disease leads to progressive neurologic and ocular damage
• Maternal risk: cat litter, undercooked meat, contaminated soil/water

Congenital syphilis (Treponema pallidum)

• Early (<2 years): hepatosplenomegaly, jaundice, rhinitis (snuffles — blood-tinged nasal discharge), maculopapular rash (palms/soles), osteochondritis/periostitis, generalized lymphadenopathy, funisitis (inflammation of umbilical cord), condylomata lata
• Late (>2 years): Hutchinson teeth (notched, peg-shaped incisors), saddle nose, frontal bossing, interstitial keratitis, saber shins, sensorineural deafness, high palatal arch
• Hydrops fetalis in severe cases
• Periostitis may be visible on skeletal X-rays (an important diagnostic clue)

Rubella (congenital rubella syndrome)

• Classic triad: sensorineural deafness + cataracts + congenital heart disease (especially patent ductus arteriosus, pulmonary artery stenosis)
• "Blueberry muffin" rash (dermal erythropoiesis)
• Hepatosplenomegaly, thrombocytopenic purpura
• Microcephaly, intellectual disability
• Deafness is the most common single manifestation
• Rare in countries with effective vaccination programs; consider in unvaccinated/immigrant populations

Cytomegalovirus (CMV) — the most common congenital infection

• Most common congenital infection worldwide (~0.2-2% of live births)
• ~90% are asymptomatic at birth — but asymptomatic infants can still develop late-onset hearing loss and developmental delay
• Symptomatic disease: petechiae, hepatosplenomegaly, jaundice, microcephaly, periventricular calcifications (compare toxoplasmosis: diffuse), chorioretinitis, seizures
• Sensorineural hearing loss is the most important late complication — leading infectious cause of childhood hearing loss worldwide
• "Blueberry muffin" rash

Herpes simplex virus (HSV) — the most acutely life-threatening

• Most EM-critical TORCH infection due to rapid progression and high mortality without treatment
• Incidence: ~1 in 2,000-3,200 live births in the US
• ~85% acquired peripartum (during delivery), ~10% postpartum, ~5% in utero
• Three clinical categories:

Category	Frequency	Typical onset	Key features	Mortality (with treatment)
SEM (skin, eyes, mouth)	~45%	Day 7-14	Vesicular rash (>80% have vesicles), keratoconjunctivitis, oral ulcers	<1%
CNS	~30%	Day 14-21	Seizures (often focal), irritability, lethargy, poor feeding, bulging fontanelle; vesicles in only ~60%	~4%
Disseminated	~25%	Day 7-14	Sepsis-like: DIC, hepatitis/liver failure, pneumonitis, shock; CNS involved in up to 75%; vesicles in only ~60%	~30%

• Critical pitfall: vesicular rash is absent in ~40% of CNS and disseminated disease — do not rely on vesicles to suspect HSV
• Fever is often absent at presentation
• Any ill neonate <42 days of age with sepsis-like picture, seizures, or liver failure should be empirically treated with acyclovir

Other "O" pathogens

• Parvovirus B19: severe fetal anemia → hydrops fetalis (nonimmune); aplastic crisis; usually self-limited if live-born; may require intrauterine transfusion
• Varicella (VZV): congenital varicella syndrome (limb hypoplasia, cicatricial skin lesions, microcephaly, cortical atrophy, chorioretinitis); very rare with maternal vaccination
• Zika virus: microcephaly (often severe), ocular defects, arthrogryposis; epidemic setting; no specific treatment
• HIV: usually asymptomatic at birth; testing and prophylaxis per neonatal protocols

Differential diagnosis

Neonate with the "congenital infection" pattern

• Other TORCH infections (always consider the full panel when one is suspected)
• Neonatal sepsis (bacterial — E. coli, GBS)
• Galactosemia (may mimic sepsis with liver failure; E. coli sepsis association)
• Tyrosinemia type 1 (liver failure + coagulopathy)
• Neonatal hemochromatosis (GALD)
• Biliary atresia (if jaundice is the presenting sign)
• Neonatal leukemia/neuroblastoma ("blueberry muffin" appearance)
• Hemophagocytic lymphohistiocytosis (HLH)
• Aicardi-Goutières syndrome (pseudo-TORCH — genetic condition mimicking congenital infection with calcifications + CSF lymphocytosis)

Evaluation

ED workup for suspected congenital infection

• CBC with differential: anemia, thrombocytopenia, atypical lymphocytes, neutropenia
• Hepatic panel: AST, ALT (may be markedly elevated in HSV hepatitis), bilirubin (fractionate)
• Coagulation studies: PT/INR, fibrinogen (DIC in disseminated HSV)
• Blood glucose: hypoglycemia (hepatic failure)
• BMP: electrolytes, renal function
• Blood culture (to exclude bacterial sepsis)
• Urinalysis and urine culture
• Lumbar puncture: CSF cell count, protein, glucose, HSV PCR, bacterial culture; HSV PCR on CSF is critical for diagnosis of CNS disease
• ALT specifically: markedly elevated ALT is a red flag for disseminated HSV (liver is a primary target organ)

Pathogen-specific testing (initiate from ED based on clinical suspicion)

Pathogen	Best diagnostic test	Key notes
HSV	HSV PCR (CSF, blood, surface swabs of mouth/eyes/nasopharynx/vesicles)	Start acyclovir empirically before results return; also send ALT, DIC labs
CMV	Urine CMV PCR or saliva CMV PCR	Must be collected within first 3 weeks of life to distinguish congenital from postnatal infection
Toxoplasmosis	Toxoplasma-specific IgM and IgA in infant serum; PCR	IgG alone reflects maternal antibodies; ophthalmology and neuroimaging needed
Syphilis	RPR/VDRL (quantitative) on infant AND mother; treponemal test (FTA-ABS IgM)	Compare infant to maternal RPR titers; skeletal survey; LP if neurosyphilis suspected
Rubella	Rubella-specific IgM in infant serum	Maternal vaccination history is critical; viral culture/PCR of nasopharyngeal secretions
Parvovirus B19	Parvovirus IgM; PCR on blood	Reticulocyte count (aplastic crisis); fetal ultrasound for hydrops

Imaging

• Cranial ultrasound (neonates): intracranial calcifications, ventriculomegaly, periventricular echogenicity
• CT head: more sensitive for calcifications; periventricular (CMV) vs diffuse (toxoplasmosis) distribution pattern
• MRI brain: most sensitive for cortical malformations (polymicrogyria in CMV), white matter disease
• Ophthalmologic examination: all suspected congenital infections require fundoscopic exam for chorioretinitis
• Skeletal survey: periostitis, osteochondritis (congenital syphilis)
• Audiology (ABR): arrange for all confirmed congenital infections, especially CMV

Management

HSV — the ED emergency

• Start IV acyclovir immediately in any neonate with suspected HSV — do not wait for PCR results
• Dose: acyclovir 20 mg/kg/dose IV every 8 hours (= 60 mg/kg/day)
• Duration:
  • SEM disease: 14 days IV
  • CNS or disseminated disease: 21 days IV
  • Repeat LP with CSF HSV PCR before stopping treatment in CNS disease; continue IV acyclovir until CSF PCR is negative
• After IV course: oral acyclovir suppressive therapy 300 mg/m²/dose TID for 6 months (reduces cutaneous recurrences and improves neurodevelopmental outcomes in CNS disease)
• Supportive care: IV fluids, correct DIC/coagulopathy (FFP, cryoprecipitate, platelets), respiratory support, seizure management, broad-spectrum antibiotics until bacterial sepsis excluded
• Monitor: CBC twice weekly (acyclovir-associated neutropenia in ~20%), daily creatinine (nephrotoxicity)
• Ophthalmology consult: herpetic keratoconjunctivitis requires topical trifluridine or ganciclovir in addition to systemic therapy

Congenital syphilis

• Aqueous penicillin G: 50,000 units/kg/dose IV every 12 hours (age <7 days) or every 8 hours (age ≥7 days) for 10 days
• Alternative: Procaine penicillin G 50,000 units/kg IM daily for 10 days (if IV not feasible)
• Normal neonate born to adequately treated mother (≥4 weeks before delivery): single dose benzathine penicillin G 50,000 units/kg IM may suffice
• No alternative to penicillin — penicillin-allergic infants require desensitization

Congenital toxoplasmosis

• Pyrimethamine (loading dose 2 mg/kg/day for 2 days, then 1 mg/kg/day) + sulfadiazine (50 mg/kg/dose BID) + leucovorin (10 mg 3 times weekly) for 12 months
• Leucovorin (folinic acid) is mandatory to prevent pyrimethamine-induced bone marrow suppression
• Do NOT substitute folic acid for leucovorin — folic acid antagonizes pyrimethamine's therapeutic effect while leucovorin selectively rescues marrow
• Add corticosteroids (prednisone 0.5 mg/kg BID) if CSF protein >1 g/dL or vision-threatening chorioretinitis
• Weekly CBC while on pyrimethamine (monitor for neutropenia, anemia, thrombocytopenia)

Congenital CMV

• Valganciclovir (oral) or ganciclovir (IV) for moderate-to-severe symptomatic congenital CMV
• Valganciclovir 16 mg/kg/dose BID orally for 6 months is current standard
• Goal is to preserve hearing and neurodevelopmental outcomes
• Not routinely initiated in the ED — refer to infectious disease/neonatology for treatment decisions
• Monitor for neutropenia, thrombocytopenia, hepatotoxicity

Congenital rubella

• No specific antiviral treatment
• Supportive management of cardiac defects, cataracts, hearing loss
• Infectious for up to 1 year — isolation precautions; notify public health

General supportive measures for all congenital infections

• Vitamin K (if cholestatic — fat-soluble vitamin malabsorption)
• Treat conjugated hyperbilirubinemia per workup
• Nutritional support (MCT-enriched formula if cholestatic)
• Seizure management
• Hearing evaluation (ABR) for all
• Ophthalmologic examination for all
• Developmental follow-up

Disposition

• All neonates with suspected congenital infection should be admitted — most will require NICU-level care
• HSV: start acyclovir in the ED; admit to NICU; infectious disease consultation
• Syphilis with positive RPR or symptomatic: admit; start IV penicillin after LP; involve infectious disease
• CMV, toxoplasmosis: admit for confirmatory testing, neuroimaging, ophthalmologic evaluation, and treatment initiation
• Well-appearing infant with isolated conjugated hyperbilirubinemia: may be evaluated urgently as outpatient (see Neonatal hepatitis) but ensure TORCH-specific testing is sent and follow-up is reliable
• Notify: congenital syphilis and rubella are reportable diseases — contact public health

See Also

• Neonatal hepatitis
• Neonatal jaundice
• Neonatal HSV
• Neonatal sepsis
• Biliary atresia
• Tyrosinemia
• Galactosemia
• Sensorineural hearing loss

External Links

• StatPearls — TORCH Complex
• CDC — Clinical Care of Toxoplasmosis
• PMC — Treatment of HSV Infections in Pediatric Patients
• Clin Microbiol Rev — Neonatal Herpes Simplex Infection
• Merck Manual — Neonatal HSV Infection
• NIH — Herpes Simplex Virus: Pediatric OIs