2011 Surveillance Slides
Slide 19. Primary Anti-TB Drug Resistance, United States, 1993–2011. Primary drug resistance is shown for the past 19 years. The graph starts in 1993, the year in which the individual TB case reports submitted to the national surveillance system began collecting information on initial susceptibility test results for patients with culture-positive TB. Data were available for more than 85% of culture-positive cases for each year. Primary resistance was calculated by using data from persons with no reported prior TB episode. Resistance to at least isoniazid remained between 7.0% and 8.6% between 1993 and 2010, however in 2011, this increased to 9.2%. Resistance to at least isoniazid and rifampin, known as multidrug-resistant TB (MDR TB), decreased from 2.5% in 1993 to 1.1% in 1997, and remained at approximately 1.0 % until 2009 and 2010 when it increased to 1.1% and 1.2%, respectively. In 2011, it increased again to 1.3%.