Neonatal meningitis. Epidemiological study of the Grupo de Hospitales Castrillo

Objective: A prospective multicenter study was designed to assess the incidence, etiology, risk factors and outcomes of vertically transmitted and nosocomial meningitis in neonates over a two-year period.

Methods: Cases of neonatal meningitis diagnosed between January 1, 1997 and December 31, 1998 in the neonatology departments of 28 acute-care hospitals in Spain ("Grupo de Hospitales Castrillo") were prospectively studied. Bacteriological meningitis was considered confirmed when cerebrospinal fluid culture (CSF) was positive for bacteria, virus or fungi, probable when CSF culture was negative but blood culture was positive, and unconfirmed when both cultures were negative.

Results: During the study period, 151 cases of meningitis were diagnosed. Transmission was vertical in 84 cases and nosocomial in 67. The incidence of vertically transmitted meningitis was 0.51 of live births, and was significantly higher in very low birth weight (VLBW) infants. Confirmed bacteriological meningitis was diagnosed in 66 patients (78.6 %). No risk factors were identified in 46.4 % of the patients. Group B Streptococcus (agalactiae) was isolated in 48.5 % of cases of confirmed meningitis and Escherichia coli was isolated in 18.2 %. In 69.7 % of cases the results of blood culture were in agreement with those of CSF culture. The overall mortality rate was 8.3 %; mortality was significantly higher in VLBW infants (33.3 % vs 4.2 % in infants weighing 1,500 g). Thirteen percent of survivors had sequelae. The incidence of meningitis of nosocomial transmission was 0.2 % of admissions and was more frequent in VLBW infants. Confirmed bacteriological meningitis was diagnosed in 49 patients (73.1 %). Two or more risk factors were present in 62.7 % of patients. E. coli was isolated in 26.5 % of cases of nosocomial meningitis and Staphylococcus epidermidis was isolated in 24.5 %. In 55 % of patients the results of blood culture agreed with those of CSF culture. The overall mortality rate was 19.4 %. Mortality was significantly higher in VLBW infants and 18.5 % of survivors showed sequelae.

Conclusions: The incidence, mortality and sequelae of neonatal meningitis in Spain were similar to those reported in recent studies. The most commonly isolated pathogens were group B Streptococcus in vertically transmitted meningitis and E. coli and S. epidermidis in nosocomial meningitis. We believe the distinction between vertical and nosocomial meningitis to be appropriate because the epidemiology of these diseases is different, which implies a different therapeutic approach. The high percentage of positive blood cultures indicates the need to include lumbar puncture whenever systemic infection is suspected in the neonatal period.