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Active Bacterial Core Surveillance


ABCS is an active laboratory- and population-based surveillance system for invasive bacterial pathogens of public health importance. For each case of invasive disease in the surveillance population, a case report is completed and bacterial isolates are sent to CDC and other reference laboratories for additional laboratory evaluation. Currently, ABCs conducts surveillance for 6 pathogens: group A and Group B Streptococcus, Haemophilus influenzae, Neisseria meningitidis, and methicillin-resistant Staphylococcus aureus (MRSA). ABCs currently operates in 10 Emerging Infections Programs (EIP) sites across the U.S., representing a population of approximately 41 million. Most areas restrict the population to certain pathogens to ensure complete reporting and good audit data. National estimates of cases, disease rates, and deaths are calculated from these data.

Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases
Data Years Available: 
Mode of Collection: 
Standardized case reports and laboratory specimens.
Selected Content: 
Data collected include disease pathogen, basic demographics, underlying conditions, vaccinations and risk factors for infection.
Population Covered: 
10 EIP surveillance sites (states and metropolitan areas) : California (3 county San Francisco Bay area); Colorado (5 county Denver area); Connecticut; Georgia (20 county Atlanta area); Maryland (6 county Baltimore area); Minnesota; New Mexico; New York (15 county Rochester and Albany areas); Oregon (3 county Portland area); Tennessee (11 urban counties)

A standardized case report is completed on all identified cases. Laboratory information is complemented by data collected from patient medical records obtained through the cooperation of on-site hospital personnel or through medical records review by county health department personnel or ABCs surveillance personnel. Surveillance areas regularly assess the completeness of information collected through the system and make adjustments as needed. Sterile site isolates are collected for each identified case of group A Streptococcus, Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae when available. Some sites collect group B Streptococcus isolates. Isolates are sent to CDC, the University of Texas Health Science Center at San Antonio, or the Minnesota Department of Health for further testing and characterization. National estimates of cases are calculated by applying race and age specific rates of disease for the aggregate surveillance area to the age and racial distribution of the U.S. population.

Response Rates and Sample Size: 
Interpretation Issues: