Performance of tuberculosis drug susceptibility testing in U.S. laboratories from 1994 to 2008.

We present a statistical summary of results from the Model Performance Evaluation Program (MPEP) for Mycobacterium tuberculosis Drug Susceptibility Testing, 1994 to 2008, implemented by the U.S. Centers for Disease Control and Prevention (CDC). During that period, a total of 57,733 test results for culture isolates were reported by 216 participating laboratories for the first-line antituberculosis drugs used in the United States-isoniazid (INH), rifampin (RMP), ethambutol (EMB), and pyrazinamide (PZA). Using Clinical Laboratory and Standards Institute (CLSI)-recommended concentrations for one or more of three methods, agar proportion (AP), BACTEC460 (Bactec), and MGIT-960 (MGIT), yielded overall agreement of 97.0% for first-line drugs. For susceptible strains, agreement was 98.4%; for resistant strains, agreement was 91.0%, with significantly lower accuracy (chi-square test, P < 0.0001). For resistant strains, overall agreement by methods was 91.3% for AP, 93.0% for Bactec, and 82.6% for MGIT and by drugs was 92.2% for INH, 91.5% for RMP, 79.0% for EMB, and 97.5% for PZA. For some strains, performance by method varied significantly. Use of duplicate strains in the same shipment and repeat strains over time revealed consistent performance even for strains with higher levels of interlaboratory discordance. No overall differences in performance between laboratories were observed based on volume of testing or type of facility (e.g., health department, hospital, independent). By all methods, decreased performance was observed for strains with low-level INH resistance, RMP resistance, and EMB-resistant strains. These results demonstrate a high level of performance in detection of drug-resistant M. tuberculosis in U.S. laboratories.

National plan for reliable tuberculosis laboratory services using a systems approach. Recommendations from CDC and the Association of Public Health Laboratories Task Force on Tuberculosis Laboratory Services.

Since the mid-1990s, public health laboratories have improved tuberculosis (TB) test performance, which has contributed to the resumption of the decline in TB incidence in the United States. However, to eliminate TB in the United States, further improvements are needed in laboratory services to support TB treatment, prevention, and control. A critical step is the development of an integrated system that ensures prompt and reliable laboratory testing and flow of information among laboratorians, clinicians, and TB-control officials. Challenges to developing such a system include 1) establishing lines of communication among laboratorians, clinicians, and TB-control officials; 2) expediting reporting of laboratory results, which can avoid delayed or inappropriate treatment and missed opportunities to prevent transmission; 3) developing evidence-based recommendations for use of new laboratory technologies; 4) maintaining staff proficiency in light of declining numbers of specimens to test, workforce shortages, and loss of laboratory expertise; and 5) upgrading laboratory information systems and connecting all partners. The report of the Association of Public Health Laboratories Task Force presents a framework to improve the future of TB laboratory services and describes the role of the laboratory in TB treatment and control, Task Force processes, general principles and benchmarks, and steps for the dissemination of the Task Force recommendations. This MMWR expands on the Task Force report by describing specific actions and performance measures to guide development and implementation of an integrated system for providing TB laboratory services. CDC and the Association of Public Health Laboratories have developed these guidelines so that laboratorians, clinicians, public health officials, administrators, and funding entities can work together to ensure that health-care providers and TB-control officials have the information needed to treat TB patients, prevent TB transmission, and ultimately eliminate TB in the United States.

Implementation of a quality systems approach for laboratory practice in resource-constrained countries.

Under the direction of the US Global AIDS Coordinator's Office, Department of Health and Human Services, the CDC Global AIDS programme helps resource-constrained countries to address the global HIV/AIDS pandemic. Activities include laboratory capacity and laboratory infrastructure development in 25 resource-constrained countries. Medical practitioners and public health programme leaders in industrialized countries rely on the use of quality laboratory data for evidence-based medical decision-making to determine policy for the implementation of disease control measures, to monitor disease to determine the impact of control programmes, and to support surveillance activities. In these countries, laboratory data to support decision-making processes have a level of quality attributable to laws, regulations and guidelines developed over many years. However, resource-constrained countries have not had similar experiences. Few countries have developed laws, regulations or guidelines, nor is there a data-use culture (e.g. evidence-based medicine) for those in the decision-making environment in resource-constrained countries. The strengthening of laboratory capability and capacity in resource-constrained countries is an important goal to improve accurate and reliable data for the diagnosis, treatment and monitoring of disease.A process for the implementation of a quality systems approach for a laboratory is presented: (i) acknowledgement of the need to improve the laboratory programme in the country at the Ministry of Health and at all decision-making levels within the provinces/states of the country; (ii) assessment of capabilities, capacities, infrastructure, and training needs; (iii) implementation of a national meeting of laboratorians; (iv) designation of a national Quality Assurance Office and leadership within that office; (v) the development and provision of technical training.

Competency Guidelines for Public Health Laboratory Professionals: CDC and the Association of Public Health Laboratories.

These competency guidelines outline the knowledge, skills, and abilities necessary for public health laboratory (PHL) professionals to deliver the core services of PHLs efficiently and effectively. As part of a 2-year workforce project sponsored in 2012 by CDC and the Association of Public Health Laboratories (APHL), competencies for 15 domain areas were developed by experts representing state and local PHLs, clinical laboratories, academic institutions, laboratory professional organizations, CDC, and APHL. The competencies were developed and reviewed by approximately 170 subject matter experts with diverse backgrounds and experiences in laboratory science and public health. The guidelines comprise general, cross-cutting, and specialized domain areas and are divided into four levels of proficiency: beginner, competent, proficient, and expert. The 15 domain areas are 1) Quality Management System, 2) Ethics, 3) Management and Leadership, 4) Communication, 5) Security, 6) Emergency Management and Response, 7) Workforce Training, 8) General Laboratory Practice, 9) Safety, 10) Surveillance, 11) Informatics, 12) Microbiology, 13) Chemistry, 14) Bioinformatics, and 15) Research. These competency guidelines are targeted to scientists working in PHLs, defined as governmental public health, environmental, and agricultural laboratories that provide analytic biological and/or chemical testing and testing-related services that protect human populations against infectious diseases, foodborne and waterborne diseases, environmental hazards, treatable hereditary disorders, and natural and human-made public health emergencies. The competencies support certain PHL workforce needs such as identifying job responsibilities, assessing individual performance, and providing a guiding framework for producing education and training programs. Although these competencies were developed specifically for the PHL community, this does not preclude their broader application to other professionals in a variety of different work settings.

The laboratory efficiencies initiative: partnership for building a sustainable national public health laboratory system.

Beginning in early 2011, the Centers for Disease Control and Prevention and the Association of Public Health Laboratories launched the Laboratory Efficiencies Initiative (LEI) to help public health laboratories (PHLs) and the nation's entire PHL system achieve and maintain sustainability to continue to conduct vital services in the face of unprecedented financial and other pressures. The LEI focuses on stimulating substantial gains in laboratories' operating efficiency and cost efficiency through the adoption of proven and promising management practices. In its first year, the LEI generated a strategic plan and a number of resources that PHL directors can use toward achieving LEI goals. Additionally, the first year saw the formation of a dynamic community of practitioners committed to implementing the LEI strategic plan in coordination with state and local public health executives, program officials, foundations, and other key partners.

Roles of laboratories and laboratory systems in effective tuberculosis programmes.

Laboratories and laboratory networks are a fundamental component of tuberculosis (TB) control, providing testing for diagnosis, surveillance and treatment monitoring at every level of the health-care system. New initiatives and resources to strengthen laboratory capacity and implement rapid and new diagnostic tests for TB will require recognition that laboratories are systems that require quality standards, appropriate human resources, and attention to safety in addition to supplies and equipment. To prepare the laboratory networks for new diagnostics and expanded capacity, we need to focus efforts on strengthening quality management systems (QMS) through additional resources for external quality assessment programmes for microscopy, culture, drug susceptibility testing (DST) and molecular diagnostics. QMS should also promote development of accreditation programmes to ensure adherence to standards to improve both the quality and credibility of the laboratory system within TB programmes. Corresponding attention must be given to addressing human resources at every level of the laboratory, with special consideration being given to new programmes for laboratory management and leadership skills. Strengthening laboratory networks will also involve setting up partnerships between TB programmes and those seeking to control other diseases in order to pool resources and to promote advocacy for quality standards, to develop strategies to integrate laboratories functions and to extend control programme activities to the private sector. Improving the laboratory system will assure that increased resources, in the form of supplies, equipment and facilities, will be invested in networks that are capable of providing effective testing to meet the goals of the Global Plan to Stop TB.

Identification of a Mycobacterium tuberculosis strain with stable, low-level resistance to isoniazid.

We have identified a potential quality control strain of Mycobacterium tuberculosis to monitor isoniazid susceptibility testing. This strain (strain A) has a stable phenotypic low-level resistance to isoniazid, has a mutation of C (-15) --> T in the inhA promoter region, and gave consistent susceptibility test results in 141 laboratories.

Assessment of laboratory performance of nucleic acid amplification tests for detection of Mycobacterium tuberculosis.

During implementation of the Centers for Disease Control and Prevention's Mycobacterium tuberculosis nucleic acid amplification (NAA) evaluation program, 27.1% of participants used the same biological safety cabinet for NAA and specimen processing; 28.8% reported not using unidirectional workflow. An association between false positives and adverse responses to quality assurance questions (P = 0.04) illustrated the need for following NCCLS recommendations.

Core functions and capabilities of state public health laboratories: a report of the Association of Public Health Laboratories.

Emerging natural and man-made threats to the health of the nations population require development of a seamless laboratory network to address preventable health risks; this can be achieved only by defining the role of public health laboratories in public and private laboratory service delivery. Establishing defined core functions and capabilities for state public health laboratories will provide a basis for assessing and improving quality laboratory activities. Defining public health laboratory functions in support of public health programs is the beginning of the process of developing performance standards for laboratories, against which state public health laboratories, and eventually local public health and clinical laboratories, will establish and implement best laboratory practices. Public health is changing, and as apart of that change, public health laboratories must advocate for and implement improvements for public health testing and surveillance. These changes are outlined also in the Association of Public Health Laboratories consensus report (Association of Public Health Laboratories. Core functions and capabilities of state public health laboratories: a white paper for use in understanding the role and value of public health laboratories in protecting our nation's health. Washington, DC: Association of Public Health Laboratories, 2000).