A balanced perspective is advocated for the assessment and application of the most recent and the oldest diagnostic methods for pulmonary tuberculosis (TB)—the molecular Xpert(®) MTB/RIF assay and microscopy for acid-fast bacilli. We discuss their respective merits and shortcomings and identify threats that may hamper their use in TB control. Neither test on its own provides all the information needed for diagnosis and treatment monitoring. Considering all aspects important for both individual patient care and disease control, neither seems ‘better' than the other. The required advancement of microscopy had already been hampered before the introduction of the GeneXpert technology by unsuccessful and probably misguided attempts to decentralise culture-based diagnosis and drug susceptibility testing. It seems evident that systematic replacement of microscopy by Xpert is not a viable option for the foreseeable future. Instead, the two methods should complement each other to arrive at a comprehensive, accessible and continuous service for a maximum number of patients. This will intrinsically prioritise targeting the most potent transmitters with the worst prognosis, simultaneously offering optimised prospects for efficient TB control. New microscopy and Xpert applications are expected to ultimately make control programmes independent of culture-based methods in diagnosis, treatment monitoring and outcome assessment.

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.

Quality laboratory services are essential for high quality, cost-effective health care. The need to use a laboratory systems approach, focusing on quality management systems (QMS) and accreditation standards, | is now well recognized,1 as it can provide vital information for proper planning and utilization of health | resources, which is critical in resource-limited settings. Accreditation also provides the credibility necessary to assure program investments in laboratory | strengthening. | The Global Laboratory Initiative (GLI) of the Stop | TB Partnership has developed a tool to assist laboratories in implementing a QMS that meets ISO15189 | Medical Laboratory–Requirements for Quality and | Competence, the most widely used standard for laboratory accreditation. This standard defi nes the requirements for a laboratory QMS, but provides no | guidance on how to implement processes and procedures to meet these requirements.

We present a statistical summary of results from the Model Performance Evaluation Program (MPEP) for Mycobacterium tuberculosis Drug Susceptibility Testing, 1994-2008 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 anti-tuberculosis 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-sq p<0.0001). For resistant strains, overall agreement by methods was: AP 91.3%; BACTEC 93.0%; and MGIT 82.6% and by drugs was: INH 92.2%; RMP 91.5%; EMB 79.0%; and PZA 97.5%. 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 inter-laboratory 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.