A 3-day-old neonate presents with temperature instability, poor feeding, and abdominal distension. CBC shows WBC 3500/mm3, bands 25%, platelets 68,000/mm3, and CRP 32 mg/L. Blood culture grows Group B Streptococcus (GBS). The most reliable early diagnostic indicator that correctly triggered the workup was:
- A Absolute neutrophil count <1500/mm3
- B CRP >10 mg/L alone
- C Platelet count <100,000/mm3
- D Band to total neutrophil ratio (I:T ratio) >0.2 ✓
Explanation
The immature-to-total neutrophil ratio (I:T ratio) >0.2 is the single best hematologic parameter for early-onset neonatal sepsis screening, with sensitivity ~95% and a high negative predictive value when combined with CRP. It reflects the bone marrow's emergency release of immature forms. This child's I:T = 25/(total neutrophil count) must be assessed; a band count of 25% strongly suggests >0.2. An absolute neutrophil count <1000 (not 1500) is concerning; CRP alone lacks early sensitivity; thrombocytopenia is a consequence, not an early marker. Serial CRP at 12-24 hours is complementary.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.