Congenital TORCH infections

Toxoplasmosis - Cat, Cysts, & Calcifications

• Organism: Toxoplasma gondii (obligate intracellular protozoan).
• Source: Ingestion of oocysts from cat feces or tissue cysts in undercooked meat.
• Classic Triad (Sabin):
  • Chorioretinitis (most common finding)
  • Hydrocephalus
  • Diffuse intracranial calcifications
• Diagnosis: Serology (IgM, IgG), PCR of amniotic fluid.
• Treatment: Pyrimethamine + Sulfadiazine + Folinic acid for 1 year.

⭐ High-Yield: Chorioretinitis is the most frequent clinical finding in congenital toxoplasmosis, often presenting as bilateral macular lesions.

The 'O' Group - Syphilis & VZV

• Congenital Syphilis (T. pallidum)

  • Early (<2 yrs): Rhinitis ("snuffles"), maculopapular rash (palms/soles), osteochondritis (Wimberger's sign), Parrot's pseudoparalysis.
  • Late (>2 yrs): Hutchinson's triad (peg-shaped incisors, deafness, interstitial keratitis), mulberry molars, saber shins, Clutton's joints.
  • Rx: Penicillin G.

• Varicella Zoster Virus (VZV)

  • Congenital Varicella Syndrome (maternal infection <20 wks): Cicatricial (zig-zag) skin lesions, limb hypoplasia, chorioretinitis.
  • Neonatal Varicella (maternal rash 5d before to 2d after delivery): High mortality; give VZIG + Acyclovir.

⭐ Wimberger's sign: Symmetrical metaphyseal destruction of the proximal medial tibias, pathognomonic for congenital syphilis.

Rubella - Cataracts, Cardiac & Cochlear

• Classic presentation is Gregg's Triad: Eye, Ear, & Heart defects.
  • 📌 Mnemonic: "I (Eye) Heart (Heart) Ruby (Rubella) Earrings (Ears)".
• Ocular: Pearly nuclear cataracts (most common), salt-and-pepper retinopathy, microphthalmia.
• Cardiac: Patent Ductus Arteriosus (PDA) is most common, also Peripheral Pulmonary Stenosis (PPS).
• Auditory: Sensorineural hearing loss is the most frequent single defect.
• Timing: Highest risk with maternal infection in 1st trimester (<12 weeks).
• Other: "Blueberry muffin" rash (dermal erythropoiesis), IUGR, microcephaly.

⭐ Exam Favourite: X-ray of long bones may show a "celery stalk" or "celery stick" appearance at the metaphysis due to alternating linear densities.

CMV - Most Common Mayhem

• Most common congenital infection; highest transmission risk with primary maternal infection.
• Clinical Features (10% symptomatic):
  • IUGR, hepatosplenomegaly, petechial “blueberry muffin” rash.
  • Classic Triad: Chorioretinitis, periventricular calcifications, and sensorineural hearing loss (SNHL).
• Diagnosis:
  • Best test: CMV DNA PCR in urine or saliva within 3 weeks of birth.
  • Imaging: USG/CT shows characteristic intracranial periventricular calcifications.
• Treatment: IV Ganciclovir or Oral Valganciclovir for symptomatic neonates.

⭐ Sensorineural hearing loss (SNHL) is the single most common sequela of congenital CMV, even in infants asymptomatic at birth.

HSV - Skin, Eyes, Mouth Mayhem

• Transmission: Primarily intrapartum (85%) during passage through infected maternal genital tract.
• Presentation (SEM Disease): Typically at 10-12 days of life. Confined to:
  • Skin: Grouped vesicular lesions on an erythematous base.
  • Eyes: Keratoconjunctivitis, corneal ulcers.
  • Mouth: Ulcers on tongue, palate.
• Diagnosis: HSV PCR from swabs (skin, conjunctiva, mouth) is the gold standard.
• Treatment: IV Acyclovir 60 mg/kg/day for 14 days for SEM disease.

⭐ Even with SEM-only presentation, a full septic workup including LP for CSF PCR is crucial, as CNS involvement can be asymptomatic initially.

High‑Yield Points - ⚡ Biggest Takeaways

• Toxoplasmosis presents with the classic triad of chorioretinitis, hydrocephalus, and diffuse intracranial calcifications.
• Congenital Rubella Syndrome is defined by cataracts, congenital heart disease (PDA), and sensorineural deafness.
• CMV is the most common congenital infection, classically showing periventricular calcifications and causing sensorineural hearing loss.
• Congenital Syphilis has early signs like "snuffles" and rash, and late stigmata like Hutchinson's teeth and saber shins.
• Neonatal HSV manifests as skin-eye-mouth (SEM), CNS, or severe disseminated disease.