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How Soon Should Patients with Smear-Positive Tuberculosis Be Released from Inpatient Isolation?

Published online by Cambridge University Press:  02 January 2015

David J. Horne*
Affiliation:
Divisions of Pulmonary and Critical Care Medicine, Seattle, Washington
Catherine O. Johnson
Affiliation:
Department of Medicine, University of Washington School of Medicine; Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington
Eyal Oren
Affiliation:
Public Health-Seattle & King County, Tuberculosis Control Program, Seattle, Washington
Christopher Spitters
Affiliation:
Allergy and Infectious Diseases, Seattle, Washington Public Health-Seattle & King County, Tuberculosis Control Program, Seattle, Washington
Masahiro Narita
Affiliation:
Divisions of Pulmonary and Critical Care Medicine, Seattle, Washington Department of Medicine, University of Washington School of Medicine; Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington Public Health-Seattle & King County, Tuberculosis Control Program, Seattle, Washington
*
Harborview Medical Center, 325 9th Avenue, Box 359762, Seattle, WA 98104 (dhorne@u.washington.edu)

Extract

Objective.

In patients with smear-positive pulmonary tuberculosis who are hospitalized or reside in congregate settings, guidelines recommend airborne infection isolation until sputum smear results are negative. Studies have identified factors associated with delayed sputum smear and culture conversion in patients with tuberculosis. Because these studies did not use methods of survival analysis, estimates of time to sputum smear conversion that are based on initial patient characteristics are not available. The ability to predict time to sputum smear conversion could be useful for programmatic planning and patient counseling.

Methods.

We performed a cohort study using survival analysis to identify factors associated with time to sputum smear and culture conversion. We defined the time to sputum smear conversion as the time elapsed from the start of treatment to the first date of sustained conversion.

Results.

Ninety-eight patients had sputum smear samples positive for acid-fast bacilli. Lower initial smear grade (on 1+ to 4+ scale) and absence of cavitation on chest radiograph were associated with earlier sputum smear conversion in bivariate analysis. In multiple regression analysis, initial smear grade (hazard ratio, 0.45; 95% confidence interval, 0.35-0.57) and drug resistance (hazard ratio, 2.30; 95% confidence interval, 1.08-4.89) remained statistically significant; a model comprising only initial smear grade performed almost as well. Predictors of sputum culture conversion were similar.

Conclusions.

Initial smear grade was the strongest predictor of time to sputum smear and culture conversion in patients with pulmonary tuberculosis and may be a useful predictor for programmatic planning and patient counseling.

Type
Original Articles
Copyright
Copyright © The Society for Healthcare Epidemiology of America 2010

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References

1.American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America: controlling tuberculosis in the United States. Am J Respir Crit Care Med 2005;172:11691227.Google Scholar
2.Lienhardt, C, Manneh, K, Bouchier, V, et al. Factors determining the outcome of treatment of adult smear-positive tuberculosis cases in the Gambia. Int J Tubero Lung Dis 1998;2:712718.Google Scholar
3.Singla, R, Osman, MM, Khan, N, et al. Factors predicting persistent sputum smear positivity among pulmonary tuberculosis patients 2 months after treatment. Int J Tubero Lung Dis 2003;7:5864.Google Scholar
4.Dominguez-Castellano, A, Muniain, MA, Rodriguez-Bano, J, et al. Factors associated with time to sputum smear conversion in active pulmonary tuberculosis. Int J Tuberc Lung Dis 2003;7:432438.Google Scholar
5.Telzak, EE, Fazal, BA, Pollard, CL, et al. Factors influencing time to sputum conversion among patients with smear-positive pulmonary tuberculosis. Clin Infect Dis 1997;25:666670.Google Scholar
6.Guler, M, Unsal, E, Dursun, B, et al. Factors influencing sputum smear and culture conversion time among patients with new case pulmonary tuberculosis. Int J Clin Pract 2007;61:231235.CrossRefGoogle ScholarPubMed
7.Rieder, HL. Sputum smear conversion during directly observed treatment for tuberculosis. Tuber Lung Dis 1996;77:124129.CrossRefGoogle ScholarPubMed
8.Fortun, J, Martin-Davila, P, Molina, A, et al. Sputum conversion among patients with pulmonary tuberculosis: are there implications for removal of respiratory isolation? J Antimicrob Chemother 2007;59:794798.CrossRefGoogle ScholarPubMed
9.Kim, TC, Blackman, RS, Heatwole, KM, et al. Acid-fast bacilli in sputum smears of patients with pulmonary tuberculosis: prevalence and significance of negative smears pretreatment and positive smears post-treatment. Am Rev Respir Dis 1984;129:264268.Google ScholarPubMed
10.Horne, DJ, Johnson, CO, Oren, E, et al. Factors affecting time to sputum smear and culture conversion in patients with pulmonary tuberculosis. Am J Respir Crit Care Med 2008;177:A790.Google Scholar
11.Blumberg, HM, Burman, WJ, Chaisson, RE, et al. American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America: treatment of tuberculosis. Am J Respir Crit Care Med 2003;167:603662.Google Scholar
12.Diagnostic Standards and Classification of Tuberculosis in Adults and Children. This official statement of the American Thoracic Society and the Centers for Disease Control and Prevention was adopted by the ATS Board of Directors, July 1999. This statement was endorsed by the Council of the Infectious Disease Society of America, September 1999. Am J Respir Crit Care Med 2000;161:13761395.CrossRefGoogle Scholar
13. Report of Verified Case of Tuberculosis Manual. Available at: http://wonder.cdc.gov/wonder/help/TB/RVCTFormCompletion-Instructions.pdf. Accessed January 16, 2009.Google Scholar
14.Hosmer, DW, Lemeshow, S, May, S. Applied survival analysis: regression modeling of time-to-event data. 2nd ed. Hoboken, NJ: Wiley-Interscience, 2008.CrossRefGoogle Scholar
15.van Soolingen, D, Borgdorff, MW, de Haas, PE, et al. Molecular epidemiology of tuberculosis in the Netherlands: a nationwide study from 1993 through 1997. J Infect Dis 1999;180:726736.CrossRefGoogle ScholarPubMed
16.Mariam, DH, Mengistu, Y, Hoffner, SE, et al. Effect of rpoB mutations conferring rifampin resistance of fitness of Mycobacterium tuberculosis. Antimicrob Agents Chemother 2004;48:12891294.CrossRefGoogle ScholarPubMed
17.Garcia-Garcia, ML, Ponce de Leon, A, ME, Jimenez-Corona, et al. Clinical consequences and transmissibility of drug-resistant tuberculosis in southern Mexico. Arch Intern Med 2000;160:630636.CrossRefGoogle ScholarPubMed
18.Al-Moamary, MS, Black, W, Bessuille, E, et al. The significance of the persistent presence of acid-fast bacilli in sputum smears in pulmonary tuberculosis. Chest 1999;116:726731.CrossRefGoogle ScholarPubMed
19.Iseman, MD. An unholy trinity-three negative sputum smears and release from tuberculosis isolation. Clin Infect Dis 1997;25:671672.Google Scholar
20.Sepkowitz, KA. Tuberculosis control in the 21st century. Emerg Infect Dis 2001;7:259262.CrossRefGoogle Scholar