TY - JOUR
T1 - Time to Sputum Culture Conversion and Treatment Outcomes among Patients with Isoniazid-Resistant Tuberculosis in Atlanta, Georgia
AU - Schechter, Marcos C.
AU - Bizune, Destani
AU - Kagei, Michelle
AU - Machaidze, Mamuka
AU - Holland, David P.
AU - Oladele, Alawode
AU - Wang, Yun F.
AU - Rebolledo, Paulina A.
AU - Ray, Susan M.
AU - Kempker, Russell R.
N1 - Funding Information:
Financial support. The study was funded in part by the National Institutes of Health National Institute of Allergy and Infectious Diseases (K23AI103044 to R. R. K.), and the Atlanta Clinical and Translational Science Institute (UL1TR000454).
Publisher Copyright:
© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Background Although isoniazid-resistant tuberculosis is more common than multidrug-resistant tuberculosis, it has been much less studied. We examined the impact of isoniazid resistance and treatment regimen, including use of a fluoroquinolone, on clinical outcomes. Methods A retrospective cohort study among patients with sputum culture-positive tuberculosis was performed. Early fluoroquinolone (FQ) use was defined as receiving ≥5 doses during the first month of treatment. The primary outcome was time to sputum culture conversion (tSCC). A multivariate proportional hazards model was used to determine the association of isoniazid resistance with tSCC. Results Among 236 patients with pulmonary tuberculosis, 59 (25%) had isoniazid resistance. The median tSCC was similar for isoniazid-resistant and -susceptible cases (35 vs 29 days; P =.39), and isoniazid resistance was not associated with tSCC in multivariate analysis (adjusted hazard ratio = 0.83; 95% confidence interval [CI],.59-1.17). Early FQ use was higher in isoniazid-resistant than -susceptible cases (20% vs 10%; P =.05); however, it was not significantly associated with tSCC in univariate analysis (hazard ratio = 1.48; 95% CI,.95-2.28). Patients with isoniazid-resistant tuberculosis were treated with regimens containing rifampin, pyrazinamide, and ethambutol + a FQ for a median of 9.7 months. Overall, 191 (83%) patients were cured. There was no difference in initial treatment outcomes; however, all cases of acquired-drug resistance (n = 1) and recurrence (n = 3) occurred among patients with isoniazid-resistant tuberculosis. Conclusions There was no significant association with isoniazid resistance and tSCC or initial treatment outcomes. Although patients with isoniazid-resistant tuberculosis had a high cure rate, the cases of recurrence and acquired drug resistance are concerning and highlight the need for longer-term follow-up studies.
AB - Background Although isoniazid-resistant tuberculosis is more common than multidrug-resistant tuberculosis, it has been much less studied. We examined the impact of isoniazid resistance and treatment regimen, including use of a fluoroquinolone, on clinical outcomes. Methods A retrospective cohort study among patients with sputum culture-positive tuberculosis was performed. Early fluoroquinolone (FQ) use was defined as receiving ≥5 doses during the first month of treatment. The primary outcome was time to sputum culture conversion (tSCC). A multivariate proportional hazards model was used to determine the association of isoniazid resistance with tSCC. Results Among 236 patients with pulmonary tuberculosis, 59 (25%) had isoniazid resistance. The median tSCC was similar for isoniazid-resistant and -susceptible cases (35 vs 29 days; P =.39), and isoniazid resistance was not associated with tSCC in multivariate analysis (adjusted hazard ratio = 0.83; 95% confidence interval [CI],.59-1.17). Early FQ use was higher in isoniazid-resistant than -susceptible cases (20% vs 10%; P =.05); however, it was not significantly associated with tSCC in univariate analysis (hazard ratio = 1.48; 95% CI,.95-2.28). Patients with isoniazid-resistant tuberculosis were treated with regimens containing rifampin, pyrazinamide, and ethambutol + a FQ for a median of 9.7 months. Overall, 191 (83%) patients were cured. There was no difference in initial treatment outcomes; however, all cases of acquired-drug resistance (n = 1) and recurrence (n = 3) occurred among patients with isoniazid-resistant tuberculosis. Conclusions There was no significant association with isoniazid resistance and tSCC or initial treatment outcomes. Although patients with isoniazid-resistant tuberculosis had a high cure rate, the cases of recurrence and acquired drug resistance are concerning and highlight the need for longer-term follow-up studies.
KW - fluoroquinolones
KW - isoniazid resistance
KW - time to sputum culture conversion
KW - tuberculosis
UR - http://www.scopus.com/inward/record.url?scp=85034816379&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85034816379&partnerID=8YFLogxK
U2 - 10.1093/cid/cix686
DO - 10.1093/cid/cix686
M3 - Article
C2 - 29020173
AN - SCOPUS:85034816379
SN - 1058-4838
VL - 65
SP - 1762
EP - 1771
JO - Clinical Infectious Diseases
JF - Clinical Infectious Diseases
IS - 11
ER -