Mycobacterium tuberculosisAPHL develops, promotes, updates, and disseminates guidance related to Tuberculosis (TB) testing best practices nationwide in close collaboration with the Division of Tuberculosis Elimination (DTBE) at CDC. Commonly considered a disease of the past, TB is resurging in new and virtually untreatable forms that have the potential to cause debilitating disease in our nation's most vulnerable residents. Diagnostic laboratories play instrumental roles in fighting TB by identifying and isolating Mycobacterium tuberculosis, the causative agent of TB disease through the use and application of novel diagnostic techniques.​​

Education and Training  

A set of free and interactive training modules, the “Essentials for the Mycobacteriology Laboratory: Promoting Quality Practices” are an on-demand resource to promote competency, quality and safety in common mycobacteriology testing practices. Designed for laboratorians at all levels of experience, each module in the series is complemente​d by references and resources. This set of training modules were updated in 2020 with the most current information and recommendations.  

*Note: Due to the most recent update many of the modules are now eligible for continuing education credit.

Drug Susceptibility Testing

In 2015, APHL in collaboration with CDC established a National PHL Drug Susceptibility (DST) Reference Center for Mycobacterium tuberculosis to provide quality-assured drug susceptibility testing for eligible US public health laboratories. The reference center serves as an extension of CDC’s Division of TB Elimination Laboratory Branch providing services that are harmonized with and complementary to those available at CDC.

The TB subcommittee has developed and published white papers covering current guidelines, recommendations and research findings as well as issues in Mycobacterium tuberculosis Complex (MTBC) drug susceptibility testing.

Self-Assessment Tool

In 2019, APHL and CDC updated the Mycobacterium Tuberculosis: Assessing Your Laboratory, a tool designed originally in 1995, to assist laboratories in the assessment of the quality of their laboratory’s TB diagnostic practices. The most recent updates reflect changes to TB diagnostics over the last six years since the 2013 version was published. The 2019 version was updated to align with current guidelines and recommendations and includes additional questions to address safety considerations and inactivation for downstream applications as well as clearer items to assess employee competency. Learn more.

Advanced Molecular Detection

APHL has supported building and maintaining next generation sequencing capacity and capability at public health laboratories across the US since 2013 as well as created resources for Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF-MS) for Mycobacterium tuberculosis complex (MTBC). Whole genome sequencing (WGS) in particular can be an invaluable tool in both public health and clinical efforts to reduce the burden of tuberculosis. WGS of MTBC provides detailed genomic information that increases the accuracy of outbreak investigations and can be used to identify drug-resistant TB strains. In combination with epidemiologic data, WGS can help differentiate TB cases that may be part of an outbreak from unrelated sporadic TB cases. Thus, WGS data can be utilized to identify clusters of interest and focus intervention resources. APHL's support of advanced molecular detection efforts are described below:

Establishment of MTBC WGS Reference Cen​​ters

In 2015, APHL, in cooperation with CDC, conducted a small pilot study to establish the feasibility of having PHLs serve as TB WGS Reference Centers (RCs), sequencing TB isolates for DTBE and their own jurisdictions. With the success of the pilot, five additional laboratories were selected to serve as RCs. Between 2015 and 2019, five to six public health laboratories served as RCs each year and >6,700 MTBC isolates were sequenced. This project is ongoing, and the TB WGS Reference Centers continue to receive isolates to assist with surveillance and public health outbreak response. Learn more about this pilot study​.

WGS of MTBC Positive Primary MGIT Cul​ture

In 2019, APHL funded 13 public health laboratories to evaluate the performance of WGS from primary (i.e., diagnostic) BD BACTE MGIT cultures positive for MTBC. The 13 funded public health laboratories sequenced a total of 707 samples during the project, which was delayed due to the COVID-19 response. Further lessons learned will be summarized and shared for the broader public health laboratory community.​

TB NGS Fact Sheet​

​In 2022, APHL, in cooperation with the APHL TB Subcommittee​ and CDC developed TB: The Next Generation (Sequencing)—Applications for NGS Technologies in Tuberculosis Testing​​This fact sheet gives an overview of the differences between sequencing methods, resource requirements and considerations, and TB NGS workflow. ​​​

​NGS Testing for TB Drug Resistance Mutations

In 2023, APHL, in cooperation with the TB Subcommittee and CDC developed​​ TB: Next Generation Sequencing and Molecular Drug Susceptibility Testing​. This fact sheet highlights principles related to prediction of antimicrobial resistance and provides a summary of key genes and mutations that are associated with resistance to key anti-TB drugs. This resource builds on a prior NGS-related factsheet. ​

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