Microbiological external quality assurance program (MEQAP)--evaluation of results obtained in sanitary epidemiological laboratories in 2002

The aim of this study was to evaluate reliability of identification and determination of sensitivity to antibiotics and chemotherapeutics of some Gram positive cocci strains in 34 sanitary-epidemiological stations. All laboratories engaged in this study received 3 strains: S. aureus (S. aureus SC+ CF+, resistant to methicillin., or S. aureus SC - CF+, sensitive to methicillin), coagulase-negative staphylococci (S. epidermidis or S. haemolyticus or S. saprophyticus) and Enterococcus sp. (E. faecalis HLAR-positive or E. faecalis HLAR-negative or E. faecium or E. gallinarum). All these strains previously were identified in Department of Bacteriology of National Institute of Hygiene. Of the 68 staphylococci strains tested, 66 isolates were correctly identified. Among the 34 enterococcal strains studied the greatest difficulty in identification was caused by E. gallinarum strain--(8 out of 13 strains were incorrectly recognised). The determination of the sensitivity of the control strains to antibiotics and chemotherapeutic agents, generally was performed correctly in accordance with to the NCCLS and national recommendations. Some incorrect results of the antibiograms were caused by an erroneous interpretation of the zones of inhibition.     

Decentralization of Acid Fast Bacilli(AFB) External Quality Assurance Using Blind Rechecking for Sputum Smear Microscopy in Ethiopia

Introduction

Ethiopia achieved a rapid expansion of TB microscopic centers for acid fast bacilli (AFB). However, external quality assurance (EQA) services were, until recently, limited to few regional and sub-regional laboratories. In this paper, we describe the decentralization experience and the result of EQA using random blinded rechecking.

Materials and Methods

The routine EQA quarterly report was compiled and analyzed. A positive result by the microscopic center while the EQA center reported negative result is categorized as false positive (FP). A negative result by the microscopic center while the EQA center reported positive is considered false negative (FN). The reading of EQA centers was considered a gold standard to compute the sensitivity, specificity, positive predictive (PPV) and negative predictive values (NPV) of the readings of microscopic centers.

Results

We decentralized sputum smear AFB EQA from 4 Regional Laboratories (RRLs) to 82 EQA centers and enrolled 956 health facilities in EQA schemes. Enrollment of HFs in EQA was gradual because it required training and mentoring laboratory professionals, institutionalizing internal QA measures, equipping all HFs to perform diagnosis, and establishing more EQA centers. From 2012 to 2014 (Phase I), the FP rate declined from 0.6% to 0.2% and FN fell from as high as 7.6% to 1.6% in supported health facilities (HFs). In HFs that joined in Phase II, FN rates ranged from 5.6 to 7.3%. The proportion of HFs without errors has increased from 77.9% to 90.5% in Phase I HFs and from 82.9% to 86.9% in Phase II HFs. Overall sensitivity and specificity were 95.0% and 99.7%, respectively. PPV and NPV were 93.3% and 99.7%, respectively.

Conclusion

Decentralizing blinded rechecking of sputum smear microscopy is feasible in low-income settings. While a comprehensive laboratory improvement strategy enhanced the quality of microscopy, laboratory professionals’ capacity in slide reading and smear quality requires continued support.     

Reliability of results evaluation for the passive hemagglutination test in pertussis obtained from WSSE laboratories

This study was undertaken for assessing of the reliability of the passive haemagglutination test with B. pertussis endotoxin in 18 laboratories of the Sanitary Epidemiological Stations. Each laboratory determined the level of pertussis antibodies in three serum samples twice, at interval of two weeks. The correct results were obtained in 7 laboratories (38.9%). The results of pertussis antibodies determination in only one or two samples were differed more than twice from correct in 5 additional laboratories; in this way the test was carried out satisfactorily in 12 laboratories (66.7%). Reproducibility of the results was good in 12 laboratories (66.7%). The study showed the necessity of repeated interlaboratory controls and periodic training of laboratory workers for raising of the quality and reliability of serological investigations for pertussis.     

Quality control of CD4+ T-lymphocyte enumeration: results from the last 9 years of the United Kingdom National External Quality Assessment Scheme for Immune Monitoring (1993-2001)

The human immunodeficiency virus (HIV) global epidemic has necessitated the routine enumeration of T-lymphocyte subsets, which has created a need for external quality assurance (EQA). The United Kingdom National External Quality Assessment Scheme (UK NEQAS) for Immune Monitoring provides EQA for 296 laboratories in 40 countries. In 1993, UK NEQAS developed and incorporated into its program stabilized whole blood that enables the accurate monitoring of laboratory performance. Overall, the mean interlaboratory coefficient of variation (CV) for percentage CD4(+) T-lymphocyte subset enumeration has fallen from 15% to less than 5%, as a direct result of the increased use of CD45/ side scatter (SSC) gating. Laboratories using alternative gating strategies (i.e., CD45/CD14 or forward scatter [FSC]/SSC) were about 7.4 times more likely to fail an EQA exercise. Furthermore, the adoption of single-platform technology resulted in a reduction of the overall mean interlaboratory CV for absolute CD4(+) T lymphocytes from 56% (prior to the widespread use of single-platform technology) to 9.7%. Individual laboratory deficiencies were also identified using a performance monitoring system and, through re-education by collaboration with the coordinating center, satisfactorily resolved. In conclusion, during the last 9 years, the UK NEQAS for Immune Monitoring program has highlighted the significant technological advances made by laboratories worldwide that undertake lymphocyte subset enumeration.     

Comparison of Cervical Cytology Reporting Rates: A Useful Adjunct to External Quality Assurance

Reporting rates for abnormal and inadequate cervical smears have been compared during a 5-year period in nine laboratories and related to targets and achievable ranges recently recommended by the National Health Service Cervical Screening Programme (NHSCSP). There was improved consistency in rates for all grades of abnormality as well as inadequate smears. the average rate for moderate and severe dyskaryosis combined increased to 1.6%, which is the target recommended by the NHSCSP, and the standard deviation fell from 0.52 to 0.27. Although average rates for mild dyskaryosis and borderline nuclear change combined and inadequate smears both remained within the achievable range recommended by the NHSCSP, four laboratories were above the upper limit for each of those categories in the final year. During the 5 years of the study there was a fall in the number of ‘inflammatory’smears coded as negative with a recommendation for early repeat. Only one laboratory still uses that category. the challenge for the future lies in controlling high rates for minor abnormalities and inadequate smears while maintaining acceptable rates for moderate and severe dyskaryosis. Comparison of reporting rates is regarded by the participating laboratories as a useful adjunct to external quality assurance. Les taux des frottis cervico-utérins anormaux et inadéquats ont été comparés sur une période de cinq ans pour neuf laboratoires et évalues par rapport aux objectifs et aux intervalles de valeur récemment publiés dans les recommandations du programme de dépistage cervico-utérin du NHS (NHSCSP). Une amélioration de l'homogenéïté des taux de tous les grades d'anomalies aussi bien que celui des frottis inadéquats a été observée. Les taux moyens de toutes les catégories ont augmentés. Le taux moyen de I'ensemble des dyscaryoses modérées et sévères, a augmenté pour atteindre 1,6%, ce qui est I'objectif recommandé par le NHSCSP, et I'ecart type est passé de 0,52 à 0,27. Bien que les taux moyens de l'ensemble des dyscaryoses légéres et des modifications nucléaires “borderline” (BNC) sgient restés dans l'intervalle recommandé par le NHSCSP, quatre laboratoires étaient audessus de la limite supérieure pour chacune de ces catégories, au cours de la derniére année. Au cours des cinq années de cette étude, il y a eu une chute du nombre des “frottis inflammatoires” codés comme négatifs mais où un contrôle rapproaché avait été recommandé. Un seul laboratoire utilise encore cette catégorie. Pour le futur, le challenge se situe au nivau du contrôle des taux élevés d'anomalies mineures et de frottis inadéquats tout en maintenant des taux acceptables de lésions de dyscaryoses moyennes à sévères. La comparaison des taux des différentes catégories de frottis est considérée comme une aide très utile pour I'assurance de qualité externe pour les différents laboratoires participants. Der Anteil abnormer und nicht verwertbarer Abstriche wurde über einen Zeitraum von fünf Jahren zwischen neun Labors und den Empfehlungen des National, Health Service Cervical Screening Programme (NHSCSP) verglichen. Es ergab sich eine bessere Übereinstimmung für alle Anomalien sowie die Rate nichtauswertbarer Abstriche. Der Anteil mässinger und schwerer Dysplasien zusammengefasst stieg auf 1,6% und entsprach damit der Vorgabe des NHSCSP. Die Standardab-weichung sank von 0,52 auf 0,27. Obgleich auch der Anteil der leichten Dysplasien und borderline-Fälle im Bereich der NHSCSP-Empfehlungen blieben lagen dennoch vier Labors auch im letzten Jahr oberhalb der Grenzwerte. Im Untersuchungszeitraum sank die Zahl der als enzündlich beurteilten und zur Kontrolle empfohlenen Fälle. Nur eines der Labors benützt diese Beurteilung noch. Die Forderung der Zukunft wird die Senkung der nichtauswertbaren Präparate und leichten Dysplasien unter Beibehaltung des Standards für mässige und schwere Dysplasien sein. Der Vergleich der Beurteilungen zwischen Labors wird als nützliche Ergänzung der externen Qualitätssicherung angesehen.     

External Quality Assurance of Malaria Nucleic Acid Testing for Clinical Trials and Eradication Surveillance

Nucleic acid testing (NAT) for malaria parasites is an increasingly recommended diagnostic endpoint in clinical trials of vaccine and drug candidates and is also important in surveillance of malaria control and elimination efforts. A variety of reported NAT assays have been described, yet no formal external quality assurance (EQA) program provides validation for the assays in use. Here, we report results of an EQA exercise for malaria NAT assays. Among five centers conducting controlled human malaria infection trials, all centers achieved 100% specificity and demonstrated limits of detection consistent with each laboratory''s pre-stated expectations. Quantitative bias of reported results compared to expected results was generally <0.5 log₁₀ parasites/mL except for one laboratory where the EQA effort identified likely reasons for a general quantitative shift. The within-laboratory variation for all assays was low at <10% coefficient of variation across a range of parasite densities. Based on this study, we propose to create a Molecular Malaria Quality Assessment program that fulfills the need for EQA of malaria NAT assays worldwide.     

Frequent major errors in antimicrobial susceptibility testing of bacterial strains distributed under the Deutsches Krebsforschungszentrum Quality Assurance Program

The Quality Assurance Program (QAP) of the Deutsches Krebsforschungszentrum (DKFZ) was a proficiency testing system developed to service the laboratory animal discipline. The QAP comprised the distribution of bacterial strains from various species of animals for identification to species level and antibiotic susceptibility testing (AST). Identification capabilities were below acceptable standards. This study evaluated AST results using the DKFZ compilations of test results for all bacterial strains showing the number of participants reporting the strain as resistant (R), sensitive (S) or intermediate susceptible (I) to each antibiotic substance used. Due to lack of information about methods used, it was assumed that what the majority of the participants reported (R or S) was the correct test result and that an opposite result was a major error (ME). MEs occurred in 1375 of 14,258 (9.7%) of test results and ME% ranged from 0% to 23.2% per bacterial group-agent group combination. Considerable variation in MEs was found within groups of bacteria and within groups of agents. In addition to poor performance in proper species classification, the quality of AST in laboratory animal diagnostic laboratories seems far below standards considered acceptable in human diagnostic microbiology.     

Quality of semen obtained by electroejaculation from chacma baboons (Papio ursinus)

Fifty-four baboons (Papio ursinus) were subjected to an electro-ejaculation procedure that yielded 683 usable ejaculates in 705 attempts. Quality evaluations by usual human spermiogram methods were applicable with only minor modifications to the procedures. By human criteria these wild baboons remained fertile after capture, and their use as a fertility model in pharmacological studies appeared to be appropriate.     

Bone marrow histopathology in chronic myelogenous leukemia (CML)--evaluation of distinctive features with clinical impact.

Bone marrow features in stable-phase chronic myelogenous leukemia (CML) are characterized by a striking heterogeneity which is determinable by appropriate means including representative pre-treatment trephine biopsies, immunohistochemistry and morphometry. Cell lineages involved to a variable extent consist not only of neutrophil granulopoiesis, but include also megakaryocytes, erythroid precursors, resident macrophages and lymphocytes. Moreover, the stromal compartment, in particular reticulin and collagen fibers, plays a pivotal role in the disease process. Following morphometric analysis significant correlations may be calculated between histological parameters and clinical-laboratory findings. Relevant interactions are detectable between number of megakaryocytes and their precursors with fiber density. This findings is in line with the close functional relationships between megakaryopoiesis and fibroblasts regarding the complex pathomechanisms of myelofibrosis. Moreover, other correlations are observable between reduction of erythropoiesis or increase in fibers with clinical features like anemia, percentages of myelo- and erythroblasts in the peripheral blood, spleen size or LDH level. These variables are in keeping with more advanced stages of CML which indicate a transition to myeloid metaplasia and thus exert a significant impact on survival. Consequently, the different risk profiles of patients are determined by both clinical and morphological parameters of predictive value. Regarding the latter, extent of myelofibrosis, amount of erythroid precursors and numbers of myeloerythroblasts in the peripheral blood are significantly associated with prognosis. For this reason, it should be mandatory to enter morphological criteria into prospective clinical trials on CML, not only for diagnostic purpose, but also for a proper evaluation of different survival patterns.     

Requirements for reference (calibration) laboratories in laboratory medicine

In addition to reference measurement procedures and reference materials, reference or calibration laboratories play an integral role in the implementation of measurement traceability in routine laboratories. They provide results of measurements using higher-order methods, e.g. isotope dilution mass spectrometry and may assign values to materials to be used for external quality assessment programs and to secondary reference materials. The requirements for listing of laboratories that provide reference measurement services include a statement of the metrological level or principle of measurement, accreditation as a calibration laboratory according to ISO 15195 and the participation in a proficiency testing system (regular inter-laboratory comparisons) for reference laboratories. Ring trials are currently conducted for thirty well-defined measurands and the results are made available to all laboratories. Through the use of reference laboratory services that are listed by the Joint Committee for Traceability in Laboratory Medicine there is the opportunity to further promote traceability and standardisation of laboratory measurements.     

Microbiological Evaluation of Cold-Water Shrimp (Pandalus borealis)

A bacteriological survey of the Maine shrimp industry was conducted to investigate the conditions associated with the production of frozen, raw, peeled shrimp. In-plant samples and finished product units were collected from seven plants. The most probable number of Escherichia coli, coliforms, and coagulase-positive staphylococci, as well as aerobic plate counts (APC), were determined. Freshly harvested shrimp collected from fishing vessels had an APC geometric mean of 510/g, and E. coli, coliforms, and coagulase-positive staphylococci were absent. Subsequent storage and insanitary practices during processing increased the APC and introduced coliforms. However, the low air temperatures (18 to 45 F) in the plants and the large volumes of cold water (34 F) used during processing inhibited significant bacterial buildup in the finished product.     

Evaluation of LiF:Mg,Ti (TLD-100) for Intraoperative Electron Radiation Therapy Quality Assurance

Background

Purpose of the present work was to investigate thermoluminescent dosimeters (TLDs) response to intraoperative electron radiation therapy (IOERT) beams. In an IOERT treatment, a large single radiation dose is delivered with a high dose-per-pulse electron beam (2–12 cGy/pulse) during surgery. To verify and to record the delivered dose, in vivo dosimetry is a mandatory procedure for quality assurance. The TLDs feature many advantages such as a small detector size and close tissue equivalence that make them attractive for IOERT as in vivo dosimeters.

Methods

LiF:Mg,Ti dosimeters (TLD-100) were irradiated with different IOERT electron beam energies (5, 7 and 9 MeV) and with a 6 MV conventional photon beam. For each energy, the TLDs were irradiated in the dose range of 0–10 Gy in step of 2Gy. Regression analysis was performed to establish the response variation of thermoluminescent signals with dose and energy.

Results

The TLD-100 dose-response curves were obtained. In the dose range of 0–10 Gy, the calibration curve was confirmed to be linear for the conventional photon beam. In the same dose region, the quadratic model performs better than the linear model when high dose-per-pulse electron beams were used (F test; p<0.05).

Conclusions

This study demonstrates that the TLD dose response, for doses ≤10Gy, has a parabolic behavior in high dose-per-pulse electron beams. TLD-100 can be useful detectors for IOERT patient dosimetry if a proper calibration is provided.     

The Effectiveness of Internet Cognitive Behavioural Therapy (iCBT) for Depression in Primary Care: A Quality Assurance Study

Background

Depression is a common, recurrent, and debilitating problem and Internet delivered cognitive behaviour therapy (iCBT) could offer one solution. There are at least 25 controlled trials that demonstrate the efficacy of iCBT. The aim of the current paper was to evaluate the effectiveness of an iCBT Program in primary care that had been demonstrated to be efficacious in two randomized controlled trials (RCTs).

Method

Quality assurance data from 359 patients prescribed the Sadness Program in Australia from October 2010 to November 2011 were included.

Results

Intent-to-treat marginal model analyses demonstrated significant reductions in depressive symptoms (PHQ9), distress (K10), and impairment (WHODAS-II) with medium-large effect sizes (Cohen''s d = .51–1.13.), even in severe and/or suicidal patients (Cohen''s d = .50–1.49.) Secondary analyses on patients who completed all 6 lessons showed levels of clinically significant change as indexed by established criteria for remission, recovery, and reliable change.

Conclusions

The Sadness Program is effective when prescribed by primary care practitioners and is consistent with a cost-effective stepped-care framework.