External quality assessment for the detection of HCV RNA, HIV RNA and HBV DNA in plasma by nucleic acid amplification technology: a novel approach.
ABSTRACT In this EQA study a novel approach was used to assess the performance of blood centres and blood product manufacturers in detecting the possible contamination of plasma with HCV, HIV and HBV by NAT.
A panel of 12 samples, three negative and three positive for each virus, was distributed to the EQA participants. The positive samples were prepared, using the respective WHO standards, in order to obtain a viral concentration of about three times the 95% DL of the methods most commonly used by laboratories involved in blood screening by NAT. Participants were requested to test each sample of the panel on different days, possibly by different operators using their routine NAT assay.
Overall, the participants' performance was satisfactory. In particular, 49 of the 59 participants (83%) were able to correctly identify all samples. Regarding the remaining 10 laboratories, in three cases a deviation from the laboratory's procedure that could be attributed to an operator's mistake was observed, in two cases a possible cross-contamination occurred while in the remaining five cases the failure to detect the positive samples couldn't be ascribed to any relevant deviation in the laboratory's procedure.
The novel design of this EQA study allowed participants to verify their day by day activity as the study was carried out in the context of their routine testing. Under these conditions, it was demonstrated that, despite the high level of automation reached by NAT assays, human errors can still occur.
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ABSTRACT: Three armored RNAs (virus-like particles [VLPs]) containing target sequences from enterovirus 71 (EV71) and coxsackievirus A16 (CA16) and a pan-enterovirus (pan-EV) sequence were constructed and used in an external quality assessment (EQA) to determine the performance of laboratories in the detection of EV71 and CA16. The EQA panel, which consisted of 20 samples, including 14 positive samples with different concentrations of EV and either EV71 or CA16 armored RNAs, 2 samples with all 3 armored RNAs, and 4 negative-control samples (NaN(3)-preserved minimal essential medium [MEM] without VLPs), was distributed to 54 laboratories that perform molecular diagnosis of hand, foot, and mouth disease (HFMD) virus infections. A total of 41 data sets from 41 participants were returned; 5 (12.2%) were generated using conventional in-house reverse transcription-PCR (RT-PCR) assays, and 36 (87.8%) were generated using commercial real-time RT-PCR assays. Performance assessments of laboratories differed; 12 (29.3%) showed a need for improvement. Surprisingly, 4 laboratories were unable to detect EV71 RNA in any samples, even those containing the highest concentration of 10(7) IU/ml. Furthermore, the detection sensitivity for EV71 among all laboratories (82.1%) was substantially lower than that for EV (97.4%) or CA16 (95.1%). Overall, the results of the present study indicate that EQA should be performed periodically to help laboratories monitor their ability to detect HFMD viruses and to improve the comparability of results from different laboratories.Journal of clinical microbiology 08/2011; 49(10):3591-5. · 4.16 Impact Factor
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ABSTRACT: Remarkable progress has been made in the quality assurance of Hepatitis B virus (HBV) DNA nucleic amplification techniques (NAT) during the past decade. And this report presents a 10-y external quality assessment (EQA) program performed by National Center for Clinical Laboratories in China since 2003. EQA panels were produced using freeze-dried HBV plasma or negative controls and then calibrated against the first International Standard for HBV DNA. By 2012, total 35,570 qualitative EQA reports and 56,826 quantitative reports have been collected. The overall correct recognition rate in qualitative test increased from 95.15% in 2003 to 97.99% in 2012. The proportion of participants with acceptable quantitative results also rose to 87.99% in 2012 compared with that of 27.53% in 2003. Besides, we observed a satisfactory reproducibility of <5% in all parallel samples. However, some laboratories still had difficulties in exact quantification of some low viral loads, which near to the limits of the dynamic range of the assays. Taking together, current EQA program showed an encouraging improvement of HBV DNA NAT in China. Distributing more challenging samples and increasing the subtypes are still needed in the future.Clinica chimica acta; international journal of clinical chemistry 08/2013; · 2.54 Impact Factor
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ABSTRACT: Two External Quality Assessment Programmes (EQAPs) were run in 2008 and 2009 to evaluate the proficiency of blood centres in detecting, by nucleic acid amplification techniques (NAT), the possible contamination of plasma with hepatitis C virus (HCV), human immunodeficiency virus (HIV) and hepatitis B virus (HBV). In the EQAP-2008, three customized panels were designed; each containing positive samples with a viral nominal concentration for the three viruses of about three times the 95% DL of the respective commercial NAT assay. In the EQAP-2009, the proficiency of the participants was evaluated with a single panel, independently on the NAT method used. While 84% (102/122) of the participants in the EQAP-2008 correctly identified the positive and negative samples of the panels, in the EQAP-2009 the percentage of proficient laboratories increased to 97% (118/122). Most importantly, in this 2-year experience, we observed a decrease in the number of pre-/postanalytical errors, from 14 in 2008 to two in 2009. The design of these two EQAPs allowed participants to assess the performance of the NAT methods applied in their routine screening of blood donations, not only with respect to analytical errors but also to human errors that, despite the high level of automation reached by NAT methods, can still occur.Vox Sanguinis 11/2010; 99(4):319-24. · 2.85 Impact Factor