FEDERAL PUBLIC SERVICE, HEALTH, FOOD CHAIN SECURITY AND ENVIRONMENT CLINICAL BIOLOGY COMMISSION CLINICAL BIOLOGY SECTION

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1 IPH J. Wytsmanstreet 14 B-1050 Brussels FEDERAL PUBLIC SERVICE, HEALTH, FOOD CHAIN SECURITY AND ENVIRONMENT CLINICAL BIOLOGY COMMISSION CLINICAL BIOLOGY SECTION External Quality Assessment for Molecular Microbiology Survey 2008/02 Herpes Simplex Virus This report is available on our webpage: This report may not be reproduced, published or distributed without permission of IPH

2 QUALITY CONTROL for MOLECULAR DIAGNOSTICS Block 4, Kelvin Campus, West of Scotland Science Park, Glasgow, G20 0SP Scotland Tel: +44 (0) Fax: +44 (0) BEIPH Final Report QCMD 2008 Herpes Simplex Virus (HSVDNA08) EQA Programme William G MacKay on behalf of QCMD and its Scientific Advisory Board June 2008 Not to be reproduced or quoted without permission of QCMD. Any queries about this report should be addressed to the QCMD Neutral Office. The QCMD programme is organised in collaboration with the European Society for Clinical Virology and the European Society for Clinical Microbiology & Infectious Diseases. Registered in Scotland Reg No: SC Registered Office: 39 Castle Street, Edinburgh EH2 3BH

3 1. Programme aims The primary aim of this External Quality Assessment Programme was to allow participants to test their nucleic acid testing technologies with respect to sensitivity, specificity (negative controls and specificity controls) and reproducibility (duplicate samples) for herpes simplex virus type 1 and herpes simplex virus type Programme details Table 1: Programme details HSVDNA08 Date of panel distribution 19/02/2008 Number of participants 25 Number of countries 1 Number of respondents 20 (80%) Number of datasets submitted 24 Number of qualitative datasets submitted 23 (96%) Number of qualitative and quantitative datasets submitted 1 (4%) Five participants did not return results. Of these, three withdrew officially citing 'assay under validation' (n=2) and 'technical issues' (n=1). 3. Panel composition This EQA panel for the detection of herpes simplex virus (HSV) consisted of nine samples containing various concentrations of herpes simplex viruses, one sample containing Varicella-Zoster virus (VZV) and two samples negative for both. All panel materials were subjected to independent testing by laboratories recognised as expert in the detection of these targets. The strains used in the panel were HSV-1 MacIntyre (ATCC VR-539) and HSV-2 MS (ATCC VR-540). Table 2: Panel composition Sample Sample Sample Stock Sample content matrix * dilution status HSV08-01 HSV Type 1 DMM/BSA 1.0x10-4 Strong Positive HSV08-02 HSV Type 2 DMM/BSA 1.0x Positive HSV08-03 HSV Type 1 DMM/BSA 1.0x10-2 Strong Positive HSV08-04 HSV Type 2 DMM/BSA 1.0x10-5 Strong Positive HSV08-05 HSV Neg Medium DMM/BSA Negative HSV08-06 VZV (Ellen) DMM/BSA Negative HSV08-07 HSV Type 1 DMM/BSA 1.0x10-3 Strong Positive HSV08-08 HSV Type 2 DMM/BSA 1.0x Positive HSV08-09 HSV Type 1 DMM/BSA 1.0x Positive HSV08-10 HSV Type 2 DMM/BSA 1.0x Positive HSV08-11 HSV Neg Medium DMM/BSA Negative HSV08-12 HSV Type 2 DMM/BSA 1.0x10-2 Strong Positive * Dulbecco s Modified Medium / Bovine serum albumin. A sample status was assigned to each panel sample and consisted of 'Strong positive', 'Positive', 'Weak positive' and 'Negative'. 2

4 4. Programme results 4a. Qualitative analysis of the EQA data The number (percentage) of correct qualitative results is presented in Table 3. Qualitative data was returned by participants as 'positive', 'negative' or 'not determined'. Not detemined results were counted as incorrect for all panel samples (positive or negative). QCMD organises datasets according to commercial and in-house technology groups, which are Conventional PCR, Real time PCR, NASBA, SDA, TMA and bdna. Where datasets were reported as other for a technology or kit method this was reviewed by the QCMD Neutral Office and assigned to an appropriate group where possible. Table 3: Number of correct qualitative results per panel member and technology type Sample Sample Stock content dilution PCR Total Conventional Real time datasets In-house b Commercial c In-house d NASBA e n=24 n=3 n=3 n=16 n=2 n % n % n % n % n % HSV08-03 HSV Type 1 1.0x HSV08-07 HSV Type 1 1.0x HSV08-01 HSV Type 1 1.0x HSV08-09 HSV Type 1 1.0x HSV08-12 HSV Type 2 1.0x HSV08-04 HSV Type 2 1.0x HSV08-08 HSV Type 2 1.0x HSV08-10 HSV Type 2 1.0x HSV08-02 HSV Type 2 1.0x HSV08-06 VZV (Ellen) HSV08-05 HSV Neg Medium HSV08-11 HSV Neg Medium c: Argene HSV R-gene (n=2), Roche LightCycler HSV 1/2 Detection Kit (n=1). e: biomerieux NucliSENS EasyQ HSV 1/2 (n=2). In-house details are not presented (b and d). QCMD uses a colour-coded scheme for scoring based on the classification of results in relation to expected or consensus results. A more detailed explanation of the scoring system is provided in the appendix to this report and on the QCMD website ( 3

5 4b. Qualitative performance scores Table 4: Qualitative performance scores per technology type Total PCR NASBA e Sample Sample All technologies Conventional Real time Status In-house b Commercial c In-house d n=24 n=3 n=3 n=16 n= HSV08-03 Strong Positive HSV08-07 Strong Positive HSV08-01 Strong Positive HSV08-09 Positive HSV08-12 Strong Positive HSV08-04 Strong Positive HSV08-08 Positive HSV08-10 Positive HSV08-02 Positive HSV08-06 Negative HSV08-05 Negative HSV08-11 Negative c: Argene HSV R-gene (n=2), Roche LightCycler HSV 1/2 Detection Kit (n=1). e: biomerieux NucliSENS EasyQ HSV 1/2 (n=2). In-house details are not presented (b and d). Figure 1: Percentage of qualitative performance scores per technology type % b c d e b c d e b c d e b c d e b c d e b c d e b c d e b c d e b c d e b c d e b c d e b c d e HSV08-03 HSV08-07 HSV08-01 HSV08-09 HSV08-12 HSV08-04 HSV08-08 HSV08-10 HSV08-02 HSV08-06 HSV08-05 HSV08-11 Technology group per panel sample a: b: Conventional in-house PCR, c: Real time commercial PCR, d: Real time in-house PCR, e: NASBA. 4

6 Acknowledgements QCMD wishes to acknowledge the support of the Derriford Hospital (Derriford, UK) and St Elisabeth Ziekenhuis (Tilburg, The Netherlands) for performing independent testing. QCMD The data and report documents provided are intended for the sole use of the participant. It is based on material in our possession or supplied to us, which we believe to be reliable. Whilst every effort has been made to ensure its accuracy, we cannot offer any warranty that factual errors have not occurred. We therefore take no responsibility for any damage or loss that may be suffered by reason of any such inaccuracies. 5

7 Appendix A Scoring system for qualitative EQA data The scores awarded for qualitative EQA data were based on the sample status (see Section 3). The scoring system is represented in the following table, where 0 is 'highly satisfactory' and 3 is 'highly unsatisfactory'. Colour has been included as an extra visual aid. Scoring system based on the assigned sample status Sample status Participant's result Negative Not determined Positive Strong Positive Positive Weak Positive Negative