Neonatal sepsis of vertical transmission: an epidemiological study from the "Grupo de Hospitales Castrillo".

A prospective multicenter study was designed to assess the epidemiology of neonatal sepsis of vertical transmission in Spain. The study was carried out by the "Grupo de Hospitales Castrillo" that included the neonatal services of 19 tertiary care (reference) hospitals and 9 secondary care hospitals. Prospective data from infants with culture-proved neonatal sepsis, clinical sepsis and bacteremia were recorded for 1995 to 1997. In a total of 203,288 neonates, proven sepsis was diagnosed in 515 (rate of 2.5 per 1000 live births), clinical sepsis in 724 (rate of 3.6 per 1000 live births), and bacteremia of vertical transmission in 155 (rate of 0.76 per 1000 live births). Very low birth weight (VLBW) infants (< or = 1500 g) showed a significantly higher incidence of confirmed sepsis (26.5 per 1000 live births) and clinical sepsis (32.4 per 1000 live births) than infants weighing > 1500 g. Streptococcus agalactiae was the most frequent causative pathogen in cases of proven sepsis (51%) and bacteremia (33%), but Escherichia coli was the most frequently recovered organism in the VLBW group. The mortality rate of proven sepsis was significantly higher than that of clinical sepsis (8.7% versus 4.3%) (P < 0.01). In the VLBW cohort, there were no significant differences in the mortality rate between proven sepsis and clinical sepsis. In conclusion, clinical sepsis was the most frequent diagnosis, probably related to intrapartum chemoprophylaxis. Streptococcus agalactiae was the most frequent causative pathogen of culture-positive sepsis and bacteremia, whereas E. coli was the most significant in VLBW infants.