The International Circumpolar Surveillance interlaboratory quality control program for Streptococcus pneumoniae, 1999...

Area of Science:

• Microbiology
• Public Health
• Epidemiology

Background:

• The International Circumpolar Surveillance (ICS) Program monitors invasive pneumococcal disease in Arctic regions.
• An interlaboratory quality control (QC) program is crucial for ensuring reliable data from participating reference laboratories.

Purpose of the Study:

• To assess the concordance of pneumococcal serotyping and antibiotic susceptibility testing (AST) among participating laboratories in the ICS program.
• To evaluate the quality and consistency of diagnostic testing for invasive pneumococcal disease in the Arctic.

Main Methods:

• Four laboratories (AIP, NCS, LSPQ, SSI) participated in an interlaboratory QC program from 1999-2008.
• 190 pneumococcal isolates were tested for serotyping and antibiotic susceptibility using methods including broth microdilution (BMD) and Etest.
• Concordance rates for serotyping, serogrouping, and minimum inhibitory concentration (MIC) were calculated.

Main Results:

• Overall serotype and serogroup concordance were high at 95.8% and 97.4%, respectively.
• Modal MIC concordance for BMD and agar dilution was >96% for most antibiotics, with slightly lower rates for erythromycin and clindamycin.
• Categorical concordance for AST between Etest and BMD remained high, exceeding 89% for key antibiotics.

Conclusions:

• The study demonstrates a high degree of correlation in serotyping and AST results among the participating laboratories.
• The findings support the reliability of the ICS QC program for invasive pneumococcal disease surveillance in the Arctic.
• Consistent laboratory testing is vital for effective public health interventions against pneumococcal infections.