A 6-week-old male infant was admitted to the nursery with a three-day history of fever, lethargy, and regurgitation of feedings. The infant had been full-term at birth. A detailed history of the family and social circumstances yielded no information to suggest child abuse or accidental trauma.
On physical examination, the infant was febrile (temperature, 40°C) and had generalized muscular hypertonicity and a bulging anterior fontanelle. Cerebrospinal fluid (CSF) examination showed a white blood cell count of 1.5× 109/L (1500/mm3), a glucose level of 1.7 mmol/L (30 mg/dL), and a protein level of 2.15 g/L (215 mg/dL). The CSF culture yielded Klebsiella pneumoniae. The infant was administered parenteral gentamicin and chloromycetin. Ten days later, he had a tender swelling of the left shoulder. His white blood cell count was 37.2×109/L (37.2× 103/mm3) with 0.50 (50%) band cells and an erythrocyte sedimentation rate of