Patti Benson

The Vaccine Safety Datalink: A Model for Monitoring Immunization Safety

The Vaccine Safety Datalink (VSD) project is a collaborative project between the Centers for Disease Control and Prevention and 8 managed care organizations (MCOs) in the United States. Established in 1990 to conduct postmarketing evaluations of vaccine safety, the project has created an infrastructure that allows for high-quality research and surveillance. The 8 participating MCOs comprise a large population of 8.8 million members annually (3% of the US population), which enables researchers to conduct studies that assess adverse events after immunization. Each MCO prepares computerized data files by using a standardized data dictionary containing demographic and medical information on its members, such as age and gender, health plan enrollment, vaccinations, hospitalizations, outpatient clinic visits, emergency department visits, urgent care visits, and mortality data, as well as additional birth information (eg, birth weight) when available. Other information sources, such as medical chart review, member surveys, and pharmacy, laboratory, and radiology data, are often used in VSD studies to validate outcomes and vaccination data. Since 2000, the VSD has undergone significant changes including an increase in the number of participating MCOs and enrolled population, changes in data-collection procedures, the creation of near real-time data files, and the development of near real-time postmarketing surveillance for newly licensed vaccines or changes in vaccine recommendations. Recognized as an important resource in vaccine safety, the VSD is working toward increasing transparency through data-sharing and external input. With its recent enhancements, the VSD provides scientific expertise, continues to develop innovative approaches for vaccine-safety research, and may serve as a model for other patient safety collaborative research projects.

Burden of Community-Onset Escherichia coli Bacteremia in Seniors

BACKGROUND Although Escherichia coli is a well-recognized cause of urinary tract infection in seniors, little is known about the burden of invasive E. coli infection in this population. METHODS We conducted a population-based cohort study of 46,238 noninstitutionalized Group Health Cooperative members>or=65 years of age to ascertain incidences of community-onset E. coli bacteremia and, for comparison, pneumococcal bacteremia, and we then performed a case-control study to identify risk factors for community-onset E. coli bacteremia. RESULTS The overall rate of community-onset E. coli bacteremia in the study cohort was 150 cases/100,000 person-years, which was approximately 3 times higher than the rate of pneumococcal bacteremia. In the case-control study, urinary catheterization and urinary incontinence were the only factors associated with an increased risk of E. coli bacteremia in men (62 cases), whereas cancer, renal failure, congestive heart failure, coronary artery disease, and urinary incontinence were associated with an increased risk of E. coli bacteremia in women (119 cases). CONCLUSIONS E. coli appears to be the leading cause of community-onset bacteremia in seniors, and, on the basis of these rates, we estimate that 53,476 cases occur in noninstitutionalized seniors each year in the United States. Community-onset E. coli bacteremia in seniors is, therefore, an infection of public health importance.