Tuberculosis

APHL supports member laboratories in applying to the Laboratory Component of the CDC TB Elimination Cooperative Agreement. The goal of this cooperative agreement is to facilitate improvements in TB laboratory testing and performance. Cooperative Agreement laboratory funding is distributed to selected public health laboratories after application review using a predetermined (by CDC) funding formula. The TB Cooperative​ Agreement Toolkit consists of the TB Elimination Cooperative Agreement Checklist and How to Calculate Turnaround Times document designed to aid public health laboratories in the application process.

APHL in collaboration with DTBE supports member laboratories in the evaluation and implementation of new approaches or testing methods for tuberculosis testing through funding opportunities and pilot projects. Most recently APHL awarded more than ten laboratories funding to enhance their capacity for drug susceptibility testing (DST) of Mycobacterium tuberculosis (MTB), specifically with respect to fluoroquinolones (FQ) and rifampin (RIF).  Other past projects included:

• Pilot of MTBC WGS in Public Health Laboratories, 2015−2019
• Facilitating Test Verification and/or Modification of Algorithms for Interferon Gamma Release Assays, 2018-2019

• Mycobacterium tuberculosis: Assessing Your Laboratory
  A tool designed to assist laboratories with self-assessment of the quality of their laboratory’s TB diagnostic practices aligned with national guidelines and recommendations and includes questions to address safety considerations and inactivation for downstream applications.
  

• Suggested Standard Reporting Language for Molecular Detection of Mycobacterium tuberculosis Complex (MTBC) and Mutations Associated With Drug Resistance

• Guidelines for Submission of Sputum Specimens for TB Testing
  This document provides guidelines for obtaining and transporting high quality sputum specimens which are the most frequent specimen collected for laboratory diagnosis of TB. 

• Consensus Statement on the Use of Cepheid Xpert MTB/RIF Assay in Making Decisions to Discontinue Airborne Infection Isolation in Healthcare Settings
  This document provides guidance on the use of the Xpert MTB/RIF (Cepheid) Nucleic Acid Amplification test when making decisions to discontinue airborne infection isolation (AII) for persons with suspected, infectious pulmonary TB.

• Laboratory Considerations for Use of Cepheid Xpert® MTB/RIF Assay
  This document is intended to guide laboratories on integrating the Cepheid Xpert® MTB/RIF assay into existing TB testing practices.

Established in 2015, the National Public Health Laboratory Drug Susceptibility Testing (DST) Reference Center for MTBC provides quality-assured drug susceptibility testing at no cost for eligible 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. California Department of Public Health’s Microbial Diseases Laboratory serves as the Reference Center. 

• First-Line DST using MGIT with a panel of rifampin, isoniazid and ethambutol
• DST for 4-month rifapentine-moxifloxacin regimen using MGIT with a panel of rifampin, isoniazid and moxifloxacin
• Pyrazinamide DST using MGIT when a mutation with uncertain significance is detected via molecular methods and PZA resistance cannot be ruled out
• Second-Line DST using MGIT with a panel of ethionamide, capreomycin, amikacin, moxifloxacin, kanamycin and rifabutin
• Molecular detection of drug resistance performed by whole genome sequencing on submitted isolates and by targeted next generation sequencing on specimen sediments, mixed and non-viable cultures
• Whole genome sequencing data will be shared with the CDC for the purpose of national molecular surveillance 

• Lab Web Portal (v2.0) User Guide​​​ 
• Submission and Shipping Instructions
• Testing Algorithms and Workflows 
• tNGS and WGS Reporting ​Language and Bioinformatic Pipeline​​
• tNGS and WGS Performance Characteristics
• Frequently Asked Questions​ ​​
• PZA Workflow Changes and FAQ
• National PHL DST Reference Center WGS Webinar Video​ 

APHL’s TB Subcommittee has developed and published white papers covering current guidelines, recommendations and research findings and laboratory challenges for MTBC drug susceptibility testing. 

• Issues in Mycobacterium tuberculosis Complex Drug Susceptibility Testing: Fluoroquinolones
• Issues in Mycobacterium tuberculosis Complex Drug Susceptibility Testing: Rifampin 
• Issues in Mycobacterium tuberculosis Complex Drug Susceptibility Testing: Pyrazinamide 
• Issues in Mycobacterium tuberculosis Complex Drug Susceptibility Testing: Ethambutol 

Since 2024, BD has been investigating intermittent false resistance when testing for pyrazinamide resistance using the BD BACTEC^TM MGIT^TM 960 PZA kit. In November of 2025, BD announced that they had resumed production of a modified version of the kit which includes modified inoculation methods and reduced shelf-life. APHL has worked with DTBE and member labs to support pncA sequencing for prediction of PZA resistance and will continue to monitor the situation and provide updates as needed.

• BD Medical Device Correction-BACTEC MGIT 960 PZA Kit, November 5, 2025
• Letter to Customers-BD Bactec MGIT 960 PZA Kit, September 2024