Multidrug resistance among persons with tuberculosis in California, 1994-2003

Context Between 1994 and 2003, tuberculosis (TB) cases in California declined 33% (4834 to 3224). However, in 2003 California reported the largest number of cases in the nation, and over the past decade the proportion of cases with multidrug-resistant tuberculosis (MDR-TB) has not decreased. Objective To describe the magnitude, trends, geographic distribution, clinical characteristics, risk factors, and outcomes of MDR-TB cases reported to the California registry of Reports of Verified Cases of TB. Design, Setting, and Cases Analysis of 38 291 TB cases reported from all 61 local health jurisdictions in California during 1994-2003. Multidrug-resistant TB was defined as resistance to at least isoniazid and rifampin. Main Outcome Measures Results of univariate and multivariable analyses of MDR-TB magnitude, trends, geographic distribution, clinical characteristics, associated factors, and outcomes. Results Of 38 291 reported TB cases, 28 712 (75%) were tested for resistance to at least isoniazid and rifampin; of these, 407 MDR-TB cases (1.4%) were reported from 38 of 61 California health jurisdictions (62%); the proportion of MDR-TB cases did not significantly change over the study period (P=.87). Cases of MDR-TB were twice as likely to have cavitary lesions compared with non-MDR-TB cases (P<.001) and were 7 times more likely to have reported previous treatment for TB (P<.001). Of MDR-TB cases with outcomes, 231 (67%) completed therapy, and those with MDR-TB were significantly less likely to complete therapy than those without MDR-TB (P<.001). Multivariate analysis identified previous TB diagnosis, positive acid-fast bacilli sputum smear results, Asian/Pacific Islander ethnicity, time in the United States less than 5 years at the time of diagnosis, and outcomes of "died" and "moved" as factors associated with MDR-TB. Conclusions Multidrug-resistant TB, an airborne disease with limited, costly treatment options, persists in 1% to 2 % of all cases despite California's control efforts. Local and global TB control efforts are needed to prevent the further development and spread of MDR-TB.