A comparison of interview methods to ascertain fluoroquinolone exposure before tuberculosis diagnosis

Abstract

Summary Fluoroquinolone use before tuberculosis diagnosis delays the time to diagnosis and treatment, and increases the risk of fluoroquinolone-resistant tuberculosis and death. Ascertainment of fluoroquinolone exposure could identify such high-risk patients. We compared four methods of ascertaining fluoroquinolone exposure in the six months prior to tuberculosis diagnosis among culture-confirmed tuberculosis patients in Tennessee from January 2007 through December 2009. The four methods included a simple questionnaire administered to all tuberculosis suspects by health department personnel (FQ-Form), an in-home interview conducted by research staff, outpatient and inpatient medical record review, and TennCare pharmacy database review. Of 177 tuberculosis patients included, 72 (41%) received fluoroquinolones during the six months before tuberculosis diagnosis. Fluoroquinolone exposure determined by review of inpatient and outpatient medical records was considered the gold standard for comparison. The FQ-Form had 61% (95% Confidence Interval [CI] 48-73%) sensitivity and 93% (95% CI 85-98%) specificity (agreement 79%, kappa 0.56) while the in-home interview had 28% (95% CI 18-40%) sensitivity and 99% (94-100%) specificity (agreement 68%, kappa 0.29). A simple questionnaire administered by health department personnel identified fluoroquinolone exposure before tuberculosis diagnosis with moderate reliability.

Genomic Analysis of the Evolution of Fluoroquinolone Resistance in Mycobacterium tuberculosis Prior to Tuberculosis Diagnosis

“…A study conducted in Alberta, Canada, found that 17% of newly diagnosed TB patients had received one or more FQ prescriptions in the 6 months preceding their diagnoses (27). This likely led to periods of FQ monotherapy of their yet-undiagnosed TB, which can drive the emergence of FQ-resistant M. tuberculosis (28). Although previous reports, including this Canadian study, have shown that a single course of FQ is not associated with increased risk of FQresistant TB (26,27), our genomic study suggests that this observation may be ignoring the existence of undetected low-frequency resistant subpopulations that could lead to FQ treatment failure.…”

Genotypic and phenotypic characterization of Mycobacterium tuberculosis resistance against fluoroquinolones in the northeast of Iran

“…Three of these resistant isolates were among the 111 clinical isolates which were fully susceptible to the first-line anti-TB drugs isoniazid, rifampin, and ethambutol. This shows that FQ monoresistance is a problem in Iran that risks the efficient treatment of MDR-TB due to the overuse of this drug for the treatment of community-acquired pneumonia and other bacterial diseases, as well as the treatment of non-TB respiratory symptoms [21,22].…”

“…Since FQs have broadspectrum activity, they are usually overprescribed for various other bacterial infections, and they are easily accessible as over-the-counter medications in many resource-limited countries, exacerbating their misuse [18,20]. This has led to the increased emergence of FQresistant M. tuberculosis strains [21,22]. Resistance can also be developed due to the incomplete adherence to the TB treatment program, failure in previous treatment and contact with patients of resistant tuberculosis [18].…”