A newborn is diagnosed with congenital infection. Cranial ultrasound shows periventricular calcifications, and ophthalmic examination reveals chorioretinitis. Hearing assessment shows sensorineural hearing loss. The mother had a flu-like illness in the first trimester with contact with cat litter. Which organism is most likely responsible?
- A Rubella virus
- B Toxoplasma gondii ✓
- C Cytomegalovirus
- D Treponema pallidum
Correct answer: B. Toxoplasma gondii
Explanation
Congenital toxoplasmosis classically presents with the triad of chorioretinitis, hydrocephalus, and intracranial calcifications (diffuse, scattered). Maternal exposure to cat feces (oocysts) or undercooked meat in the first trimester is the risk factor. CMV causes periventricular calcifications but the cat litter exposure points to Toxoplasma. Rubella causes cataracts and deafness; syphilis causes rhagades and periostitis.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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