Lab Test Details

Mycobacterium - AFB Smear and Culture
Updated	4/24/2023
Search Terms	Acid Fast Bacillus (AFB); GeneXpert; Mycobacteria; Mycobacterium tuberculosis (TB); M. tuberculosis; M. avium; NTM
How to Order	On the General Microbiology Test Request Form (OHA0060), in the “Mycobacteria” section, check the “AFB: Smear/Culture; sputum or primary specimen” box.
Availability	County and State Public Health entities
Performed	Daily on regular business days
Time to Reporting	Smear: within 2 working days after receipt of specimen. GeneXpert: within 3 working days after receipt of specimen or clinician request, whichever is later. Culture: up to 9 weeks after receipt of specimen.
CPT Code	87015, 87206, 87116, 87552

Specimen Collection Details
Collection	Collection kits available on request. Collect Sputum into 50ml tube provided Detailed instructions for collection, packaging, and submission of specimens (pdf)
Optimal Volume	5 ml - 10 ml (Not more than 10 ml)
Minimum Volume	0.5 ml (volumes under 1.0 ml processed with qualifier)
Handling	Store samples at refrigerated temperatures (2-8ºC) pending transport.
Transport	Package specimens with fully frozen ice packs to maintain refrigerated temperatures during transport. Receipt at the OSPHL within 24 hours of specimen collection is greatly preferred.
Rejection Criteria	Specimens are subject to the requirements of the OSPHL Specimen Submission Policy (pdf).
Comments	Original material submitted for testing is not retained after receipt and processing at the laboratory. Specimens received after 5 days of specimen collection may be contaminated with non-AFB organisms and will be processed with a qualifier. For additional information or assistance, please contact the laboratory at 503-693-4100
Method Details
Methodology	Standard reference methods for AFB smear and Culture
Performance Specifications	MTBC IS6110: Percent Accuracy - 100% Positive Predictive Value - 100% Negative Predictive Value - 100% Coefficient of Variation - 0.32 Misclassification Rate - 0% Limit of Detection - <1 CFU/50uL MTBC RD9: Percent Accuracy - 100% Positive Predictive Value - 100% Negative Predictive Value - 100% Coefficient of Variation - 0.31 Misclassification Rate - 0% Limit of Detection - <1 CFU/50uL MAC 15S-23S: Percent Accuracy - 100% Positive Predictive Value - 100% Negative Predictive Value - 100% Coefficient of Variation - 0.2 Misclassification Rate - 0% Limit of Detection - <2 CFU/uL
Change Log
4/24/2023	Updated Search Terms and How to Order
3/15/2021	Comprehensive changes to detailed instructions document, review as new; Edit Search Terms, Time to Reporting, Performance Specifications

Lab Test Details

Mycobacterium - AFB Smear and Culture

Specimen Collection Details

Method Details

Change Log