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Molecular testing reduces time in respiratory isolation

A sputum molecular testing algorithm resulted in less time spent in respiratory isolation among patients with possible tuberculosis, according to research published in JAMA Internal Medicine.

“New guidelines recommend that molecular testing replace sputum-smear microscopy to guide discontinuation of respiratory isolation in patients undergoing evaluation for active tuberculosis (TB) in health care settings,” Lelia H. Chaisson, MSc, Johns Hopkins Bloomberg School of Public Health, and colleagues wrote.

Chaisson and colleagues conducted a prospective cohort study to investigate the feasibility of implementing sputum molecular testing strategies using an assay called GeneXpert MTB/RIF (Xpert; Cepheid) to guide discontinuation of respiratory isolation. The researchers enrolled 621 hospitalized patients undergoing evaluation for active pulmonary TB.

During the preimplementation period, clinicians ordered at least one sputum microscopy and culture for 301 patients and completed the rapid TB testing evaluation process for 77% of those patients (n = 233). During the postimplementation period, 302 molecular tests were ordered for 234 of 320 patients (73%) and results were received for 295 (98%) tests.

All patients with culture-confirmed TB (n = 7) were accurately diagnosed with the molecular testing algorithm. The algorithm excluded TB in all patients with Mycobacterium tuberculosis (MTB) culture-negative results (n = 251).

The molecular testing strategy and the assay were associated with substantial reductions in median times to final rapid test result (39.1 vs. 22.4 hours), discontinuation of isolation (2.9 vs. 2.5 days) and hospital discharge (6 vs. 4.9 days). The strategy and assay saved $13,347 per isolated TB-negative patient on average.

“Routine use of molecular assay testing should be strongly considered to provide faster, more patient-centered care to hospitalized patients undergoing evaluation for TB in the United States and other low TB-burden settings,” Chaisson and colleagues concluded. – by Alaina Tedesco

Disclosure: The authors report no relevant financial disclosures.