3rd Nordic distribution of external quality assessment samples in medical mycology: do we still need to improve?

Abstract number: P1349

Mortensen K.L., Fernandez V., Gaustad P., Chryssanthou E., Sandven P., Arendrup M.C.

Objectives: A Nordic External Quality Assessment program in medical mycology was established in 2005. In order to monitor the level of routine diagnostics, not ``best practice'', the specimens were designed to resemble clinical samples and the laboratories were asked to handle the samples like routine samples.

Methods: Five simulated clinical samples were distributed at no cost to 63 Nordic laboratories of clinical microbiology of whom 54 submitted results. The specimens contained the following microorganisms: (1) Fusarium solani (corneal scraping), (2) Candida (C.) albicans and C. krusei in a ratio of 10:1 (blood culture), (3) C. glabrata and Stenotrophomonas maltophilia (tracheal aspirate), (4) Aspergillus (A.) fumigatus and C. dubliniensis (BAL), and (5) C. inconspicua (vaginal secretion). A brief clinical information was given for each specimen.

Results: Specimen 1: 48% (26/54) of the laboratories detected the mould, of whom 6 correctly identified it to the species level (23%). Specimen 2: 83% (45/54) reported the presence of the C. krusei isolate, but only 57% (31/54) also reported the C. albicans isolate even though the ratio was in favour of C. albicans. Specimen 3: 94% (51/54) detected the yeast, of whom 86% (44/51) correctly identified it as C. glabrata. Specimen 4: The presence of A. fumigatus was correctly reported by 59% (32/54) of the laboratories while 6% (three laboratories) did not report growth of a mould at all. Specimen 5: 17% (9/54) correctly reported the isolate as C. inconspicua, and 35% of the laboratories reported either the closely related C. norvegensis or non-albicans yeast. Thirty-four laboratories reported 528 susceptibility results. 22% (5/22) incorrectly reported the C. glabrata-isolate as fluconazole-susceptible. One laboratory incorrectly reported the C. albicans-isolate in specimen 2 as fluconazole-resistant.

Conclusion: The results of this third distribution of simulated clinical samples emphasise that mycological diagnosis is difficult especially in the routine and polymicrobial setting and that there is a need for the continuous training of laboratory technicians and clinical microbiologists. However, a higher proportion of laboratories succeeded this year detecting the polymicrobial nature of the blood culture and the Aspergillus-isolate in the presence of yeast. This suggests that quality assessment programmes including simulated clinical samples are valuable for the improvement of mycological skills in clinical laboratories.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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