Ability of Iranian Microbiology Laboratories for Detection and Susceptibility Testing of Unknown Microorganisms: Survey of 2149 Laboratories
M Rahbar, M Saremi, R Sabourian, S Yazdi
M Rahbar, M Saremi, R Sabourian, S Yazdi. Ability of Iranian Microbiology Laboratories for Detection and Susceptibility Testing of Unknown Microorganisms: Survey of 2149 Laboratories. The Internet Journal of Laboratory Medicine. 2008 Volume 3 Number 2.
The Iranian 18th national external quality assessment scheme(EQAS)for microbiology laboratories were carried out in Feb 2005.In this survey we distributed three unknown microorganism among 2149 microbiology laboratories( each laboratory two microorganism) Of 2149 microbiology laboratory,1493 laboratory (69.5%) participated in our survey. Of 1493 laboratory, 512(34.3%) identified
Blind retesting of previously analyzed specimens can be used an assessment in number of different areas of the 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. ( Mahon et al 2007, Washington Wet al 2006., Sarp et al 2004 . Isenberg 2004, Vandepitte et al. 1991 ) This processes called external quality assessment scheme (EQAS) or competency assessment Sandle (2005) has described the benefits of 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.
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
Material and Methods
In Feb 2005, 18th run of proficiency testing of Iranian microbiology laboratories carried out by research center and reference laboratories of Iran. In this survey three unknown microorganisms including
We asked all laboratories to identify each microorganism and performance of susceptibility testing just for
Of 2149 laboratories only 1493(69.5%) laboratories participated in our survey and 656 (30.5%) did not participated in this study. Of 1493 laboratories 512(34.3%) laboratories identified
The main goal of EQAS is to improve the quality and strengthen the capabilities of laboratories. In evaluating the microbiology laboratories in Islamic Republic of Iran it was presumed beforehand that the laboratories were functioning within an acceptable range. Unfortunately our results did not confirm this assumption, and there was a wide range of capabilities of the laboratories for identification different species of microorganisms . In a previous study by Abbassi et al (2006) they evaluated the results of 10th external quality control assessment results which carried out in reference laboratory of Iran in summer of 2002. They distributed five species bacteria (each laboratories two unknown organism )among 487 microbiology laboratories in Tehran and districts. Of 487 laboratories received answers from 437 (89.7%) laboratories. Of 291 laboratories 224 (77%) produced correct answer for
In another study (Tenover et al , 2001) to evaluate bacterial resistance, the Centres for Disease Control and Prevention (CDC) and WHO distributed 6 different strains of bacteria among 130 laboratories in the United States and other countries. Most of the laboratories were able to identify
The microbiology laboratory serves as the first steep in identification and performing of susceptibility testing of microorganisms isolated from patients specimens The main goal of EQAS is to improve the quality and strengthen the capabilities of laboratories for correct identification and susceptibility testing The experiences of error as reported for the various groups of laboratories in our programs in the different microbiology EQAS programs was relative and may not represent the exact rate of error experienced in actual practice. Because of following(i)the generally accepted opinion that external proficiency testing results represent the best effort of some laboratories ,and it has been reported that the proficiency of laboratories as measured in blinded studies ,in which laboratories did not know they were being tested ,was lower than their proficiency testing under condition when the laboratories knew they were being tested, (ii) The differences among the laboratories in the extent of identification reported for certain types of samples;(iii)the variation in occurrence of microbial species in different patients population ,(iv)the differences in frequency with which various microbial; species encountered by individual laboratories and the difference in the types and quality of patients specimens tested by individual laboratories.
Many laboratories were restructured so that they no longer had experienced medical technologist or pathologist /or medical microbiologist dedicated to the performance of microbiology testing. However, they still chose to perform all levels of laboratory testing for diagnosis of infectious disease .The laboratories that were not restructured and that maintained testing done by experienced, dedicated personnel continued to show improvement in performance on the proficiency tests samples, by the end of the observation period, they made errors in bacterial identification and susceptibility testing <5% of the time. Those laboratories that were restructured and staffed with generalists as well as increased the variety of what they offered continued to make many serious errors in identification and susceptibility testing .This finding is likely because they down-graded their technical expertise by employing less- experienced personnel ,in contrast to the laboratories that maintained staff with focused expertise . In doing some the restructured laboratories double the number of errors made in bacterial identification. ( Peterson et 2001)
There are other factors that may affected the identification and susceptibility tests and standardized methods are more likely to be reproducible than unstandardized methods. Quality assurance is the overall process by which the quality results can be guaranteed. A major part of this process is the internal quality control testing which is routinely undertaken to monitor the precision and accuracy of the test procedures, the performance of regents, and the performance of the person carry out the tests. However, there are additional aspects that contribute to quality assurance, including regular participation in external quality assessment schemes, internal quality assessment and the validation process, in which atypical or contradictory results can be detected. Education is an important part of the quality assurance process as an understanding of the techniques, together with their limitations and pitfalls, contributes significantly to the recognition, resolution and avoidance of errors (Sharp et al., 2004.Brown et al et al., 2001 ) Unfortunately many of laboratories in our county do not have material and reagents for performance these tests and internal quality controls are very poor. For this reason the majority of laboratories have problems for identification of unusual microorganisms.
Conclusion .The results of this and other EQAS shows that many microbiology laboratories very poor proficiency testing results for identification unknown microorganisms. We are planning to establish a proper policy for manufacturers (or importers) to produce the necessary and important media and reagents. In addition, adding special postgraduate training courses and distribution of scientific guidelines will be helpful. With these new policies, we hope in future to upgrade the capabilities of the microbiology laboratories in our country.