External quality assurance scheme for Streptococcus pneumoniae – 2012
The 2012 external quality assurance scheme for Streptococcus pneumoniae shows that European pneumococcal reference laboratories vary in the level to which they characterise strains referred to them, ranging from full speciation and serogrouping to full serotyping and sequence typing.
Overall, the results show a significant improvement from the previous EQA, which was conducted in 2010. Errors in speciation and serotyping were down to 1.7%, compared with 13.2% in the previous distribution.
The EQA distribution has again indicated that some laboratories lack the necessary reagents to fully serotype isolates, and this renders surveillance of invasive pneumococcal disease difficult. Comprehensive data on serotype distribution are essential in order to establish the impact of the use of pneumococcal vaccines.
The antimicrobial susceptibility testing results indicate that the majority of the laboratories have little difficulty in performing susceptibility testing. The major discrepancy was in the interpretation of the results because of the use of different interpretative guidelines. Some laboratories are using EUCAST guidelines while others are still using CLSI guidelines. All EU reference laboratories should be moving towards using EUCAST guidelines.
