Extensively Drug-Resistant Tuberculosis in the United States, 1993-2007

Shah, N. Sarita MD, MPH
Pratt, Robert BS
Armstrong, Lori PhD
Robison, Valerie DDS, MPH, PhD
Castro, Kenneth G. MD
Cegielski, J. Peter MD, MPH

Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, Atlanta, Georgia. Dr Shah is now with the Department of Medicine, Albert Einstein College of Medicine, Bronx, New York.

Corresponding Author: J. Peter Cegielski, MD, MPH, Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, 1600 Clifton Rd, Mailstop E-10, Atlanta, GA 30333 ([email protected]).

Author Contributions: Mr Pratt and Drs Armstrong, Robison, and Cegielski had full access to all the data in the study. All authors take responsibility for the accuracy of the data analysis. The US National TB Surveillance System is responsible for the integrity of the data.

Financial Disclosures: None reported.

Funding/Support: No specific funding was provided for this analysis. The Division of Tuberculosis Elimination, CDC, employed all authors of this article and all other individuals acknowledged below who contributed to this report. In addition, the CDC provides funding to state and local departments of health to conduct TB surveillance. Dr Shah has received support from the Doris Duke Charitable Foundation while at Albert Einstein College of Medicine.

Role of the Sponsor: The Division of Tuberculosis Elimination, CDC, is responsible for the National Tuberculosis Surveillance System and for collecting and managing the data. The authors, not the agency, were solely responsible for the design and conduct of the study; analysis and interpretation of the data; and preparation, review, and approval of the manuscript.

Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent official views of the CDC.

Previous Presentation: These data were presented in part at the 2006 National TB Controllers Association Meeting, June 13, 2006, Atlanta, Georgia, but only included data through 2004.

Additional Contributions: We thank the city, county, and state TB controllers who contributed to this report through diligent recording and reporting of TB cases. We also thank Charles Wells, MD; Thomas Shinnick, PhD; Beverly Metchock, DrPH; Thomas Navin, MD; Jose Becerra, MD, MPH; and Phil LoBue, MD, Division of Tuberculosis Elimination, CDC, for their support of this work and critical review of the manuscript.

JAMA: The Journal of the American Medical Association 300(18):p 2153-2160, November 12, 2008.

Context

Worldwide emergence of extensively drug-resistant tuberculosis (XDR-TB) has raised global public health concern, given the limited therapy options and high mortality.

Objectives

To describe the epidemiology of XDR-TB in the United States and to identify unique characteristics of XDR-TB cases compared with multidrug-resistant TB (MDR-TB) and drug-susceptible TB cases.

Design, Setting, and Patients

Descriptive analysis of US TB cases reported from 1993 to 2007. Extensively drug-resistant TB was defined as resistance to isoniazid, a rifamycin, a fluoroquinolone, and at least 1 of amikacin, kanamycin, or capreomycin based on drug susceptibility test results from initial and follow-up specimens.

Main Outcome Measures

Extensively drug-resistant TB case counts and trends, risk factors for XDR-TB, and overall survival.

Results

A total of 83 cases of XDR-TB were reported in the United States from 1993 to 2007. The number of XDR-TB cases declined from 18 (0.07% of 25 107 TB cases) in 1993 to 2 (0.02% of 13 293 TB cases) in 2007, reported to date. Among those with known human immunodeficiency virus (HIV) test results, 31 (53%) were HIV-positive. Compared with MDR-TB cases, XDR-TB cases were more likely to have disseminated TB disease (prevalence ratio [PR], 2.06; 95% confidence interval [CI], 1.19–3.58), less likely to convert to a negative sputum culture (PR, 0.55; 95% CI, 0.33–0.94), and had a prolonged infectious period (median time to culture conversion, 183 days vs 93 days for MDR-TB; P < .001). Twenty-six XDR-TB cases (35%) died during treatment, of whom 21 (81%) were known to be HIV-infected. Mortality was higher among XDR-TB cases than among MDR-TB cases (PR, 1.82; 95% CI, 1.10–3.02) and drug-susceptible TB cases (PR, 6.10; 95% CI, 3.65–10.20).

Conclusion

Although the number of US XDR-TB cases has declined since 1993, coinciding with improved TB and HIV/AIDS control, cases continue to be reported each year.