Late-onset meningitis in sick, very-low-birth-weight infants. Clinical and sonographic observations

To determine the clinical and sonographic features of late-onset meningitis (after 7 days of life) in sick, very-low-birth-weight infants.

Retrospective study of a patient series.

Neonatal intensive care nursery at Parkland Memorial Hospital in Dallas, Tex.

Ten preterm infants with birth weights of more than 1750 g who developed late-onset meningitis during a 42-month study period.

None.

Ten preterm infants developed meningitis at a mean (+/- SD) postnatal age of 20 +/- 14 days. Eight of the infants survived. Initial clinical signs were nonspecific, eg, apnea and bradycardia (eight infants), abdominal distention (five infants), hyponatremia (serum sodium level, < 130 mmol/L), and a decrease in urine output with an increase in weight (three infants). Specific neurologic signs occurred in three infants (seizures [n = 2] and third-nerve palsy [n = 1]). Sonographic abnormalities noted in seven (70%) of the 10 infants included progressive ventriculomegaly (n = 6), thalamic echodensities (n = 3), ventriculitis (n = 4), and cystic leukomalacia (n = 1). The progressive ventriculomegaly developed from 1 to 2 weeks after diagnosis; permanent shunting was required in all six infants. The thalamic echodensities were linear or punctate and developed from 1 to 2 weeks after diagnosis in two infants.

The data indicate the need for a high index of suspicion of meningitis in very-low-birth-weight infants suspected of having sepsis because of the nonspecific clinical presentation of meningitis. Because both progressive ventriculomegaly and thalamic echodensities are late and frequent findings, serial sonograms are essential for careful monitoring of sequelae of disease.