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NOTE: A surveillance case definition is a set of uniform criteria used to define a disease for public health surveillance. Surveillance case definitions enable public health officials to classify and count cases consistently across reporting jurisdictions. Surveillance case definitions are not intended to be used by healthcare providers for making a clinical diagnosis or determining how to meet an individual patient’s health needs.

CSTE Position Statement(s)

  • 09-ID-06

Clinical Description

Streptococcus pneumoniae causes many clinical syndromes, depending on the site of infection (e.g., acute otitis media, pneumonia, bacteremia, or meningitis).

Laboratory Criteria For Diagnosis

Isolation of S. pneumoniae from a normally sterile body site (e.g., blood, cerebrospinal fluid, or, less commonly, joint, pleural or pericardial fluid)

Case Classification


Any reported case lacking confirmation of isolation of Streptococcus pneumoniae from a normally sterile body site.


Isolation of Streptococcus pneumoniae from a normally sterile body site in a person of any age.


Notification to CDC of confirmed cases of invasive pneumococcal disease (IPD) is recommended by CSTE.

The licensure of a new 13-valent pneumococcal conjugate vaccine (PCV13) is expected in late 2009 or early 2010. Surveillance should be enhanced to provide baseline and ongoing data for the assessment of disease burden and immunization program effects.

In January 2008, the Clinical and Laboratory Standards Institute published new Minimum Inhibitory Concentration (MIC) breakpoints for defining susceptibility of S. pneumoniae isolates to penicillin.1 The new breakpoints are estimated to decrease the number of isolates classified as antibiotic-resistant by approximately 5%.2 The changes in breakpoints will likely result in a surveillance artifact in drug resistant S. pneumoniae reporting and further complicate interpretation of the reported data.


  1. Clinical and Laboratory Standards Institute. Performance Standards for Antimicrobial Susceptibility Testing; Eighteenth Informational Supplement. CLSI document M100-S18 (ISBN 1-56238-653-0). Clinical and Laboratory Standards Institute, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania. 19087-1898 USA, 2008.
  2. Centers for Disease Control and Prevention. Effect of New Penicillin Susceptibility Breakpoints for Streptococcus pneumoniae—United States, 2006-2007. MMWR 2008;57:1353-5.

Related Case Definition(s)