Evaluation Results of 21th Iranian External Quality Assessment Schemes (EQAS) of Microbiology laboratories in 2007

摘要

The aim of this study was to determine ability of Iranian microbiology laboratories for identification and susceptibility testing of two unknown microorganisms. In Feb 2007 21st run of proficiency testing of Iranian microbiology laboratories carried out by Iranian reference health laboratories. In this survey two unknown microorganisms including Salmonella paratyphi B and Staphylococcus aureus were submitted to 1305 microbiology laboratories. Of 1305 laboratories, 1122(.86%) laboratories participated in our survey and 183 (14%) laboratories did not participated in our program. Of 1122 laboratories, 523(46.6%) laboratories identified S.paratyphi B correctly. The results of susceptibility testing of S.paratyphi B were relatively satisfied for nalidixic acid, ciprofloxacin and trimethoprim-sulfamethoxazole. However the results of susceptibility testing for tetracycline and ampicillin were unsatisfied and only 578 (52.5%) and 558 (49.7%) Of laboratories reported correct answer for tetracycline and ampicillin respectively. Regarding to identification Staphylococus aureus of 1122 laboratories 767 (68.4%) identified this organism correctly It is concluded that the majority of microbiology laboratories were able for identification of S.parathyphi B and S.aureus. Nearly 50% of laboratories produced incorrect susceptibility testing answer according to S.paratyphi B for tetracycline and ampicillin. Introduction Blind retesting of previously analyzed specimens can be used an assessment in number of different areas of the microbiology laboratory, such as appropriate setup based on the source of the unknown organism ,correct identification of unknown organism, appropriate titters of infectious disease of serologies testing and reporting of antimicrobial susceptibility testing results and many more. (1,2,3,4,5).This processes called external quality assessment scheme (EQAS), competency assessment or proficiency testing. There are many benefits for participation in the EQAS for laboratories.(i) participating laboratories are able to assess whether their results are comparable with those of other laboratories. (ii) EQAS can provide a valuable educational stimulates to laboratory staff. (iii) It provides credibility to the participating laboratory by providing evidence that the participating laboratory has a responsible attitude towards quality issues (evidence of participation is required by some acceding agencies); (iv) EQA provides an insight into national performance levels; and (v) EQAS improves national performance levels. (1,5) The Iranian national external quality assessment scheme for microbiology laboratories were introduced in 1994 for evaluation of performance and competency testing of microbiology laboratories in both governmental and private sectors. The scheme covers a wide range of clinical microbiology activities including identification and susceptibility testing. We annually perform three run of EQAS programs .In microbiology laboratories various steps have been taken to upgrade the EQAS programs. In recent years, the scheme has been actively promoted throughout country resulting increased participation. In spite of regular performance of EQAS by reference laboratory of Iran, many microbiology laboratories are not able for identification and performance of correct susceptibility testing of some microorganisms. Our recent studies showed that nearly one third of microbiology laboratories in Tehran were not able to identify three unknown microorganisms such as Acinetobacter baumannii, Enerococcus faecalis and Enterobacter agglomerans.(6) The aim of this study was to determine ability of Iranian microbiology laboratories for identification and susceptibility testing of three unknown microorganisms. Methods In Feb 2007 21st run of proficiency testing of Iranian microbiology laboratories carried out by research center and reference laboratories of Iran. In this survey two unknown microorganisms including Salmonella Paratyphi B and