Population-Based Surveillance in San Francisco and Atlanta Trends in Incidence and Antimicrobial Resistance of Early-Onset Sepsis:

Objective. Although increased use of intrapartum antibiotics caused significant declines in early-onset group B Streptococcus (GBS) infection, the effect on infections caused by other pathogens is not clear. The objective of this study was to determine trends in the incidence of early-onset sepsis caused by organisms other than group B streptococcus in the era of antimicrobial prophylaxis. Methods. We conducted surveillance for early-onset sepsis as part of the Active Bacterial Core surveillance. A case was defined as isolation of bacteria from blood or cerebrospinal fluid from an infant who was 0 to 6 days of age and born in the surveillance area during 1998 through 2000 (248 184 births). Results. We identified 408 cases of early-onset infection. GBS caused 166 (40.7%) cases (52 in 1998, 51 in 1999, and 63 in 2000 for incidences 0.62, 0.62, and 0.76 cases per 1000 live births, respectively). Other bacterial pathogens were identified in 242 cases (82 in 1998, 79 in 1999, and 81 in 2000 for incidences 0.99, 0.95, and 0.98 per 1000 live births, respectively) of early-onset sepsis. Escherichia coli caused 70 cases (0.25, 0.28, and 0.31 cases per 1000 live births, respectively, in 1998–2000). The proportion of E coli infections that were resistant to ampicillin increased significantly among preterm infants from 29% (2 of 7) in 1998 to 84% (16 of 18) in 2000 but not in full-term infants: 50% (4 of 8) in 1998 and 25% (1 of 4) in 2000. Conclusions. Whereas rates of early-onset sepsis caused by GBS and other pathogens were low and did not change significantly during the study period, antibiotic-resistant E coli infections among preterm infants increased. Overall, these trends are reassuring, but careful evaluation of the increase in resistant infections in very young infants is critical in the future. Pediatrics 2002;110:690–695; neonatal sepsis, group B Streptococcus, guidelines, surveillance, Escherichia coli, antimicrobial resistance. ABBREVIATIONS. GBS, group B Streptococcus; CSF, cerebrospinal fluid. Bacterial infection during the first 7 days of life, or early-onset infection, places an infant at risk for death or long-term disability.1–3 Group B Streptococcus (GBS) is the leading cause of early-onset sepsis. Because intrapartum antibiotic prophylaxis has been shown to reduce early-onset GBS disease,4 in 1996 consensus guidelines were issued recommending the use of intrapartum antibiotic prophylaxis for women who are at risk of transmitting GBS to their infants during labor.5–7 Strategies were recommended to identify these women, and penicillin G, a narrow-spectrum antibiotic, was designated as the prophylaxis agent of choice. We estimate that the use of intrapartum antibiotics has doubled since the release of the consensus guidelines.8,9 The Centers for Disease Control and Prevention’s Active Bacterial Core surveillance has documented a 70% decline in the incidence of early-onset GBS disease from 1993 to 1999.10,11 Although the decline in GBS disease has been attributed to the use of prophylactic antibiotics during labor, the effect of the increased use of intrapartum antibiotics on pathogens other than GBS that cause early-onset disease is unknown. A few studies have evaluated trends in early-onset sepsis caused by organisms other than GBS.12–15 Multicenter surveillance in Australia between 1991 and 1997 of 180 000 births compared infections in the first 48 hours of life caused by GBS with those caused by other organisms.15 The incidence rates for early-onset disease caused by GBS and by other bacterial pathogens decreased significantly between 1991 and 1997. A second study, including nearly 47 000 births at a single hospital, looked at infection during the first week of life from 1991 to 1996.14 The GBS infections decreased from 5 cases in 1991 to 1 case in 1996 at the hospital, whereas the number of infections caused by other organisms increased from 3 to 8 in the same time period. A study in Connecticut showed a decrease in GBS infections from 0.61/ 1000 in 1996 to 0.23/1000 in 1999, whereas non-GBS causes of infection did not change (0.65/1000 in 1996 and 0.68/1000 in 1999).16 We conducted surveillance From the *Active Bacterial Core surveillance (ABCs) of the Emerging Infections Program Network, Respiratory Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, and the ‡Epidemic Intelligence Service, Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, Georgia; §Emerging Infections Program, San Francisco, California, and the School of Public Health, University of California, Berkeley, California; and the Emerging Infections Program, Veterans Affairs Medical Center and Emory University School of Medicine, Atlanta, Georgia. Received for publication Jan 17, 2002; accepted Apr 26, 2002. Dr O’Brien’s current affiliation is the Center for American Indian and Alaskan Native Health, the Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland. Reprint requests to (A.S.) Respiratory Diseases Branch, Division of Bacterial and Mycotic Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd, MS C-23, Atlanta, GA 30333. E-mail: aschuchat@cdc.gov PEDIATRICS (ISSN 0031 4005). Copyright © 2002 by the American Acad-