Influence of antibiotics during delivery work on early onset sepsis

Abstract number: P2220

Aguilar A., Juncosa T., Gené A., Iriondo M., Alarcón A., Thió M.

Objectives: 1. To assess the incidence of early onset sepsis with positive culture during the period 1996–2006 compared to a historic period previous to implementation of prophylaxis during delivery in women carrying S. agalactiae (1988–1994). 2. To know the aetiology and the mortality in these patients during the period of study.

Methods: Retrospective study of newborn less than seven days old, attended in the Neonatology Unit during the period 1996–2006 with a diagnosis of sepsis/meningitis and a positive culture of blood and/or CSF. The isolated microorganism, pregnancy week of the mother at delivery and evolution of illness were recorded.

Results: Twenty-nine newborns with early onset sepsis and positive culture (22 of them born in our own hospital and seven coming from other centres) were attended in the Neonatal Unit. Isolated microorganisms were: 15 S. agalactiae, 8 E. coli, 2 L.monocitogenes, 1 C. albicans, 1 E. faecalis, 1 P. aeruginosa and 1 S. pneumoniae. Eleven of the 29 newborn were preterm (38%), less than 37 weeks of pregnancy. In 10 cases, mothers had received antibiotics during delivery work. Onset of clinical illness was detected during the first day of life in 65.5% of cases. Mortality was due to infection in 17.2% of cases (five babies, all of them less than 31 weeks of pregnancy) and the remaining 24 children had a good evolution without sequelae. During the historic period, the incidence of early onset sepsis with positive culture was of 2.2/1000 live births (43 internal cases per 19453 live births) and that due to S. agalactiae was of 1.3/1000 live births (26 internal cases). In contrast, during the studied period the global incidence was of 0.5/1000 live births, with 22 internal cases per 40129 live births (P < 0.001) and that due to S. agalactiae was of 0.27/1000 live births, with 11 internal cases (P < 0.001).

Discussion: The use of prevention strategies against neonatal sepsis during the last years has lead to a significant reduction (P < 0.001) of early onset sepsis both as a global fact (from 2.2 to 0.5/1000 live births) and as that due to S. agalactiae (from 1.3/1000 to 0.27/1000 live births). The two predominant infectious agents during the studied period were S. agalactiae (51%) and E. coli (27%). Mortality has been related to extreme prematurity.