Clinical microbiology quality assurance program: a Taiwan experience

Quality assurance programs have been established during the last two decades in developed countries to promote high quality performance in clinical laboratories. In Taiwan, such a program for clinical microbiology laboratories has been in place since July 1987. It has been supported by the Department of Health, Executive Yuan, R.O.C. and was set up by the authors. The manpower status, facilities and equipment, and performance of clinical laboratories were investigated during the first year and standards of laboratory quality were recommended. Since then, under a continuing education program, we have conducted seminars, symposia, workshops, short-courses or panel discussions approximately 4 times a year. There have been about 150 participants per session and they have come from local hospitals (primary care hospitals), regional hospitals (secondary care hospitals) and medical centers (tertiary care hospitals). Proficiency test specimens or external unknown specimens were sent to all the laboratories twice a year and approximately 3 specimens were used each time for the evaluation of each laboratory's diagnostic capability and quality of service. Results indicated that there were tremendous improvements in the quality of laboratory performance. At the same time, several laboratory manuals describing the methods of quality control of clinical specimens, test procedures, media and reagents, personnel management and a compilation of reports etc. were published as guidelines of basic requirements for each level of the laboratories. For local hospital laboratories in remote areas, several regional hospitals or medical centers with high quality laboratories were selected to serve as back-ups. Our evaluation has shown that the performance and quality of service provided by most clinical microbiology laboratories in Taiwan have now reached nearly the level of those found in the so-called "developed countries".     

Special considerations for the clinical microbiology laboratory in the diagnosis of infections in the cancer patient

The clinical microbiology laboratory faces enormous challenges in diagnosing infections that cause morbidity and mortality in cancer patients. Such laboratories face several issues that surpass those faced by laboratories that perform more routine work. Issues such as sources of clinical specimens, need for correlation and interaction between laboratory and clinical services, blood cultures, susceptibility testing, and the role of new molecular diagnostic techniques are considered in this article.     

Impact of quality control on accuracy in enzyme immunoassay testing for human immunodeficiency virus type 1 antibodies

OBJECTIVE: To assess use of quality control (QC) material, supplemental to internal kit controls (calibrators), as protection against errors in enzyme immunoassay testing for human immunodeficiency virus type 1 antibodies. DESIGN: From August 1994 to January 1996, enzyme immunoassay testing accuracy was assessed for laboratories participating in the Centers for Disease Control and Prevention Model Performance Evaluation Program that provided information regarding their use of QC material. Error rates were examined for human immunodeficiency virus type 1 antibody-negative, strongly positive, and weakly positive samples. RESULTS: The overall error rate with QC (2.20%) was significantly (P = .0023) lower than the error rate without QC (2.90%). With QC use there was a significant reduction in the relative risk of error for negative (P = .014) and weakly positive (P = .0067) samples. After multivariate analysis, use of QC lowered overall error rate by 29% (P = .0009). Laboratories not using QC were at increased risk of systematic error. Following the Clinical Laboratory Improvement Amendments of 1988 guidelines for QC material was relatively more protective against error than lower frequencies/number of levels. CONCLUSIONS: Using QC protected against errors in enzyme immunoassay testing for human immunodeficiency virus type 1 antibodies. Two levels of QC should be used with each run as mandated by the Clinical Laboratory Improvement Amendments of 1988.     

Variants of squamous cell carcinoma of the anal canal and perianal skin and their relation to human papillomaviruses

Investigators participating in the Epidemiologic Study of Cystic Fibrosis project began to collect microbiological, pulmonary, and nutritional data on cystic fibrosis (CF) patients at 180 North American sites in 1994. Part of this study was a survey undertaken in August 1995 to determine microbiology laboratory practices with regard to pulmonary specimens from CF patients. The survey included a section on test ordering, completed by a site clinician, and a section on test performance and reporting, completed by each site's clinical microbiology laboratory staff. Seventy-nine percent of the surveys were returned. There was intersite consistency of microbiology laboratory practices in most cases. The majority of sites follow most of the CF Foundation consensus conference recommendations. There were differences in the frequency at which specimens for culture were obtained, in the use of selective media for Staphylococcus aureus and Haemophilus influenzae, and in the use of a prolonged incubation for Burkholderia cepacia. These variations in practice contribute to prevalence differences among sites and may result in differences in clinical care.     

Matrix effects and the performance and selection of quality-control procedures to monitor PO2 measurements

We have assessed how variation in the matrix of control materials would affect error detection and false-rejection characteristics of quality-control (QC) procedures used to monitor PO2 in blood gas measurements. To determine the expected QC performance, we generated power curves for S(mat)/S(meas) ratios of 0.0-4.0. These curves were used to estimate the probabilities of rejecting analytical runs having medically important errors, calculated from the quality required by the CLIA '88 proficiency testing criterion and the precision and accuracy expected for a typical analytical system. When S(mat)/S(meas) ratios are low, the effects of matrix on QC performance are not serious, permitting selections of QC procedures based on simple power curves for a single component of variation. As S(mat)/S(meas) ratios increase, single-rule procedures generally show a loss in error detection, whereas multirule procedures, including the 3(1)s control rule, show an increase in false rejections. An optimized QC design is presented.     

Aspects of epidemiology of Campylobacter in poultry

The CPS ID 2 (CPS) chromogenic agar was compared to routine media for use in the isolation, enumeration, identification, and susceptibility testing of bacteria recovered from urine specimens. Of 487 urine specimens, 318 were culture negative, 12 were positive on CPS only, 16 positive on routine only, and 141 positive on both. The enumeration of microorganisms agreed for 96 of the 141 cultures. Fewer organisms were recovered on CPS for 25 cultures, more for 20 cultures. The identification of bacteria from CPS and routine media agreed for all isolates. Susceptibility testing was performed for 100 isolates. The categorical susceptibility test results from isolates grown on CPS agreed with results from routine media for 77 isolates. For the remaining 23 isolates, one or more discrepancies were seen involving 16 different antimicrobial agents; 27 minor, 1 major, and 6 very major errors. After additional testing, there were 10 confirmed errors, 7 minor and 3 very major errors. This study demonstrates that CPS agar is a reliable medium for culturing urine. Susceptibility testing directly from this medium resulted in low error rates for all antimicrobial agents tested.     

General principles of specimen collection and transport

In this issue of Clinical Infectious Diseases, we present the first article in a series entitled "Diagnostic Microbiology Updates." Although clinical microbiology is included in the curricula of virtually all infectious disease fellowships, the degree of emphasis on this subject varies considerably. Infectious disease physicians--even those who have direct responsibilities or consulting responsibilities for the microbiology laboratories of the institutions in which they practice--may be hard pressed to keep up with the rapidly changing content of the primary literature in clinical microbiology. The purpose of this series, therefore, is at least in part to fill this void and to provide concise updates for clinicians. The first article, written by Dr. Michael L. Wilson, reviews current concepts in specimen collection and transport. A key issue for all clinicians (which is not always sufficiently emphasized) is the quality of the specimen submitted to the laboratory. It is an axiom that if specimens of poor quality are submitted, the results generated by the laboratory will have little or no clinical utility. Dr. Wilson's article describes some of the methods available to assure that only specimens of good quality, i.e., those most likely to be useful clinically, are processed in the microbiology laboratory. Future articles will address specific types of specimens, groups of pathogens, and diagnostic techniques, including molecular methods. We hope this series will be informative and valuable to the readers of Clinical Infectious Diseases, and we look forward to your comments.     

Fallibility of urine drug screens in monitoring methadone programs

Urine specimens containing five different drugs, each at three levels of concentration with zero to five drugs in a specimen, were sent to two "approved" laboratories. In only 46.9% and 13.8%, respectively, were all drugs present correctly identified and no false-positive results reported. With some allowances, the results improved to 53.8% and 49.4%. If these tests are to be continued then (1) the fallibility of these tests should be known by all treatment personnel, (2) laboratories should be licensed rather than merely approved, and (3) maintenance of the license should be made contingent on passing "blind" proficiency tests.     

Direct diagnosis of Chlamydia trachomatis genital infections: culture or PCR?

PCR and culturing were compared for the routine diagnosis of Chlamydia trachomatis infections. Two laboratories experienced in both techniques participated in the study, which included 513 specimens. Both techniques were performed on each specimen; the portion of the specimen used for PCR was divided in two, and each half was sent to one of the two laboratories, where the tests were run in a blinded fashion. The PCR primers used by the two laboratories matched different parts of the bacterial genome. PCR inhibitors were looked for in all specimens. Overall, PCR was more sensitive than culturing; the difference was marked for sperm and endopelvic specimens and nonsignificant for urethral and cervical specimens. False-positive PCR results were few in number; there were no consistent false-positive results when each specimen was amplified twice. PCR inhibitors were rarely present in urethral and cervical specimens but were found in 7% of sperm and endopelvic specimens. PCR inhibitors should be looked for routinely during PCR testing of sperm or endopelvic specimens.     

Effect of analytical run length on quality-control (QC) performance and the QC planning process

The performance measure traditionally used in the quality-control (QC) planning process is the probability of rejecting an analytical run when an out-of-control error condition exists. A shortcoming of this performance measure is that it doesn't allow comparison of QC strategies that define analytical runs differently. Accommodating different analytical run definitions is straightforward if QC performance is measured in terms of the average number of patient samples to error detection, or the average number of patient samples containing an analytical error that exceeds total allowable error. By using these performance measures to investigate the impact of different analytical run definitions on QC performance demonstrates that during routine QC monitoring, the length of the interval between QC tests can have a major influence on the expected number of unacceptable results produced during the existence of an out-of-control error condition.     

Improvement in mammography quality control: 1987-1995

PURPOSE: To assess possible changes in quality control (QC) practices at mammography sites in the United States. MATERIALS AND METHODS: Mammography site surveys were conducted in 1990, 1992, and 1995 through the Colorado Mammography Advocacy Project (CMAP). Data from mammography sites applying for American College of Radiology (ACR) accreditation were collected between August 1987 and August 1993 through the ACR Mammography Accreditation Program. Data from both of these surveys were analyzed to assess temporal changes in mammography QC practices in the United States between 1987 and 1995. RESULTS: CMAP results indicated statistically significant improvement in medical physicist QC practices between 1990 and 1992 and in technologist QC practices between 1990 and 1995. Improvements in radiologic technologist QC practices coincided with increases in radiologic technologist continuing education in mammography. ACR results indicated statistically significant improvement in technologist QC practices between 1988 and 1992. CONCLUSION: There have been substantial improvements in QC practices at mammography sites in the United States during the past decade.     

Genetic algorithms-based design and optimization of statistical quality-control procedures

In general, one cannot use algebraic or enumerative methods to optimize a quality-control (QC) procedure for detecting the total allowable analytical error with a stated probability with the minimum probability for false rejection. Genetic algorithms (GAs) offer an alternative, as they do not require knowledge of the objective function to be optimized and can search through large parameter spaces quickly. To explore the application of GAs in statistical QC, I developed two interactive computer programs based on the deterministic crowding genetic algorithm. Given an analytical process, the program "Optimize" optimizes a user-defined QC procedure, whereas the program "Design" designs a novel optimized QC procedure. The programs search through the parameter space and find the optimal or near-optimal solution. The possible solutions of the optimization problem are evaluated with computer simulation.     

The effects of orientation and thickness on the notch-tensile creep strength of single crystals of a nickel-base superalloy

The effects of crystallographic orientation and thickness of specimen on the notch-tensile creep strength of single crystals of a nickel-base superalloy UDIMET∗520 has been examined at 700°, 850°, and 900 °C. It was found that the notch-tensile creep strength of thin specimens depended on the crystallographic orientations not only in the tensile direction but also in the normal direction of the specimens, and that the creep strength was superior in the thin specimens with the [011] tensile and the [011] normal orientations or the [001] tensile and the [110] normal orientations. The thick-notched specimens exhibited great creep resistance regardless of the crystallographic orientations. Formerly Graduate Student Formerly Graduate Student, Tokyo Metropolitan University     

Cognitive performance, mood and experimental pain before and during morphine-induced analgesia in patients with chronic non-malignant pain

OBJECTIVE: To determine the ability of simple, rapid tests to identify HIV-1 antibody-positive specimens in field settings using the World Health Organization's (WHO) alternative testing strategies. DESIGN: Three-phase evaluation of simple, rapid assays using banked specimens and prospectively collected serum specimens at regional hospitals and rural clinics. METHODS: Seven test (Retrocell, Genie, HIVCHEK, SUDS HIV-1, Testpack, Serodia HIV-1, and HIV-1/2 RTD) were evaluated and results compared with standard enzyme immunoassay (EIA) and Western blot results (phase 1). Further evaluation consisted of prospective testing of routine specimens at regional (phase 2; n = 900) and rural, peripheral laboratories (phase 3; n = 1266) throughout Honduras with selected assays. RESULTS: Sensitivity and specificity were calculated for each assay and combination of assays for each phase to evaluate the effectiveness of the WHO alternative testing strategies. All tests in all phases were > 99% sensitive after correcting for technical errors, with two exceptions (SUDS, phase 1; HIVCHEK, phase 3). In phase 3, where the testing algorithm was diagnostic, several combinations of assays were 100% sensitive and specific using WHO strategy II or III. For the Honduras Ministry of Health, the combination of Retrocell and Genie was found to be equally sensitive, more specific (no indeterminate results), and less expensive than EIA/Western blot. CONCLUSION: Combinations of rapid, simple HIV antibody assays provide sensitivity and specificity performance comparable to EIA/Western blot. Application of these combinations in the WHO alternative testing strategies provides an inexpensive and effective method of determining HIV status. Assay combinations using these strategies can be easily performed in small, rural laboratories and have been implemented in routine HIV screening in Honduras.     

Detection and identification of mycobacteria in formalin-fixed, paraffin-embedded tissues by nested PCR and restriction enzyme analysis

A novel assay based on a nested PCR and restriction enzyme analysis of the PCR products was developed for the rapid detection and identification of Mycobacterium bovis and M. avium-M. intracellulare species in formalin-fixed, paraffin-embedded tissue (PET) specimens. On the basis of the nucleotide sequence data obtained in the present study, general nested primers were constructed to amplify a 424-bp segment of the gene encoding the 65-kDa surface antigen of mycobacteria. The nested PCR assay proved to be highly sensitive, since as little as 5 to 10 fg of extracted mycobacterial DNA was detected. The safety of the assay as a routine method for the diagnosis of M. bovis and M. avium-M. intracellulare in PET specimens was provided by taking various precautions. In order to prevent false positivity, specific tools and procedures were applied. To detect false-negative results and assess the efficiency of the PCR, an internal standard molecule of amplification was constructed. The digestion of the amplicons with the restriction endonuclease Sau96-I allowed the identification of M. bovis and M. avium-M. intracellulare in a large number of clinical specimens. The present results indicate that PCR combined with an internal control of amplification and restriction enzyme analysis of the amplicons provides a rapid, sensitive, and reliable method for routine diagnostic laboratories to detect and identify M. bovis and M. avium-M. intracellulare in PET specimens.     

Electronic data processing system for clinical microbiology

A computerized clinical microbiology data storage and retrieval system, which was introduced at the Institute of Medical Microbiology 14 month ago, is described. This institute has to perform routine diagnostic microbiology for hospitals in the Kanton of Zuerich including the university hospital. In addition, it serves as a public health laboratory for Zuerich and adjacent districts. Patient and physician data are entered into a data station IBM 3741 and stored on discettes. Each afternoon, these data are printed on special report forms, which then are transferred to the diagnostic laboratories. After completion of the investigation, a copy of this form containing the results is sent to the physician. Every two weeks, the information stored on the discettes are converted onto the magnetic tape "discette". In addition, the original report form, containing the codified results and the fees, are read by an optic reader, which transfers the information onto the tape "report". Both tapes then serve the computer to print the accounts as well as to summarize the results monthly in form of the medical statistics. These provide valuable information to enhance patient care. All data are stored in a cumalative microbiology data bank for later retrieval.     

Psychiatric disorder onset and first treatment contact in the United States and Ontario

The aim of the study was to evaluate the quality of routine brain perfusion single-photon emission tomography (SPET) images in Finnish nuclear medicine laboratories. Twelve laboratories participated in the study. A three-dimensional high resolution brain phantom (Data Spectrum's 3D Hoffman Brain Phantom) was filled with a well-mixed solution of technetium-99m (110 MBq), water and detergent. Acquisition, reconstruction and printing were performed according to the clinical routine in each centre. Three nuclear medicine specialists blindly evaluated all image sets. The results were ranked from 1 to 5 (poor quality-high quality). Also a SPET performance phantom (Nuclear Associates' PET/SPECT Performance Phantom PS 101) was filled with the same radioactivity concentration as the brain phantom. The parameters for the acquisition, the reconstruction and the printing were exactly the same as with the brain phantom. The number of detected "hot" (from 0 to 8) and "cold" lesions (from 0 to 7) was visually evaluated from hard copies. Resolution and contrast were quantified from digital images. Average score for brain phantom images was 2.7 +/- 0.8 (range 1.5-4.5). The average diameter of the "hot" cylinders detected was 16 mm (range 9.2-20.0 mm) and that of the "cold" cylinders detected, 11 mm (5.9-14.3 mm) according to visual evaluation. Quantification of digital images showed that the hard copy was one reason for low-quality images. The quality of the hard copies was good only in four laboratories and was amazingly low in the others when comparing it with the actual structure of the brain phantom. The described quantification method is suitable for optimizing resolution and contrast detectability of hard copies. This study revealed the urgent need for external quality assurance of clinical brain perfusion SPET images.     

Cigarette smoking and other risk factors for silent cerebral infarction in the general population

Control dried organisms as lenticules are a dependable and convenient alternative to wet cultures for quality assurance and process controls in routine food microbiology. Lenticules are designed to give a fixed, reproducible inoculum over an extended period of time without loss of cultural characteristics or viability. During a period of 23 months, 596 paired counts were performed by both Miles and Misra and spiral plating techniques on lenticule controls. Correlation between the two methods and within batches was excellent. Only 14 counts (2.5%) fell outside the standard operating limit of 0.5 log10. All were within 1.0 log10. On two separate occasions, replicate runs were performed on five reconstituted lenticules from a batch. The counts obtained showed variation within and between lenticules only slightly in excess of what is expected by chance. Lenticule replicates performed by three other laboratories also produced satisfactory results. It is thought that lenticules could improve the accuracy of total plate counts and lead to a better standardization of quantitative methods in food microbiology within and between laboratories.     

Developing a VA counselling psychology training program: a case history of university-hospital cooperation.

"… APA-approved training programs have been organized in an increasing number of universities in cooperation with nearby VA training hospitals." The first such university-VA hospital training program involved Columbia University's Teachers College and the VA training unit for Metropolitan New York. The selection of trainees, the integration of university training and VA traineeships, the success of the training, and the role, responsibilities, and privileges of consultants in this particular program are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical evaluation of the automated COBAS AMPLICOR MTB assay for testing respiratory and nonrespiratory specimens

We evaluated the COBAS AMPLICOR PCR system (Roche Diagnostics) for the routine detection of Mycobacterium tuberculosis complex (MTBC) in clinical specimens. Diagnostic culture, considered as the reference method, was performed with BACTEC, L?wenstein-Jensen, Stonebrink, and Kirchner media. Occasionally MB-Redox, ESP, or MGIT medium was also used. A total of 643 respiratory and 506 nonrespiratory specimens collected from 807 patients were investigated. Of the 95 culture-positive specimens, 80 were COBAS AMPLICOR MTB positive, and of the 1,054 culture-negative specimens, 1,044 were COBAS AMPLICOR MTB negative. After resolving discrepancies by review of the medical history, the overall sensitivity, specificity, and positive and negative predictive values for the COBAS AMPLICOR MTB assay, respectively, were 83.5, 98.8, 86.7, and 98.6% compared to those of diagnostic culture. In smear-positive specimens, the sensitivity of the COBAS AMPLICOR MTB assay was 96%, versus 48% for smear-negative specimens. No significant differences in the test performance between respiratory and nonrespiratory specimens were observed. The overall inhibition rate was less than 2%, excluding stool specimens. The clear advantages of the COBAS AMPLICOR PCR system are standardized procedures and reagents for specimen processing as well as an internal control for reliable monitoring of PCR inhibitors. By simplifying the work flow through a completely automated amplification and amplicon detection procedure, the COBAS AMPLICOR PCR system proved itself as a very useful component for routine diagnostic procedures.