Culture and drug sensitivity testing among patients with pulmonary tuberculosis in Mexico: National data for 2009-2013

This study documented the number and results of mycobacterial culture and drug sensitivity testing (CDST) in Mexico from 2009-2013 and assessed whether states with a higher risk of multidrug-resistant tuberculosis (MDR-TB) performed more CDST and had more cultures showing MDR-TB. Data for this longitudinal, descriptive, operational research study came from the electronic records of 31 state public health laboratories in Mexico. The total number of CDSTs was 6 470, increasing from 2 143 in the first 2 years to 4 327 in the latter 3 years. There was a significant increase in the proportion of cultures showing sensitivity to all drugs, from 53.1% to 60.9% in 2011-2013 (P < 0.001) and a significant decrease in the proportion showing MDR-TB, from 28.2% in 2009 to 19.8% in 2013 (P < 0.001). Cases of extensively drug resistant tuberculosis were < 1% per year. In the 12 states with higher risk for MDR-TB, significantly more CDSTs (2 382 test) were done in 2011-2013 than in the other 19 states (1 945 tests). Also, for each year the proportion of cultures showing MDR-TB was significantly higher in high risk MDR-TB states than in lower risk ones (P < 0.001). During the 5-year study period, CDST was scaled up in Mexico, particularly in high-risk MDR-TB states where a higher proportion of cultures showed MDR-TB. Scale up and wider coverage of CDST should continue.