It is important to monitor the prevalence of TB – and especially drug-resistant TB – within the population. Hana El Sahly, M.D. of the Department of Molecular Virology and Microbiology (MVM) and her colleagues at Baylor College of Medicine have studied a group of patients infected with drug-sensitive and drug-resistant TB over the course of about five years. Among these patients from the Houston area, they found a steady, low-level incidence of drug-resistant TB that disproportionately affected certain subpopulations. Those that were more likely to have drug-resistant TB included HIV-positive individuals, people of Hispanic or Asian ethnicity, and those with a history of past TB. There were 15 patients in their study who acquired drug resistance while on therapy; these patients were also more likely to be HIV-positive or of Asian ethnicity.
Dr. El Sahly has also been involved in a study that investigated whether TB isolated from patients in the Houston area is susceptible to moxifloxacin, one of a class of antibiotics called quinolones that are used as second-line anti-TB drugs. Patient samples were analyzed for reduced susceptibility to moxifloxacin and other quinolone antibiotics, as well as first-line antibiotics. They further examined the samples to identify mutations in genes associated with reduced susceptibility to the quinolone antibiotics. They found that there is a low incidence of moxifloxacin-resistant TB in this patient group, and it is associated with MDR-TB. Previous exposure to quinolones was common among these patients. This work should help in the design of better treatment regimens and provides a basis for further monitoring and research on TB drug resistance.
For More Information
- Basic information about TB from the CDC
- Information about drug-resistant TB from the CDC
- Information about TB, including research, from the National Institutes of Health
- Information about TB including estimated global and regional incidence from the World Health Organization
- Information about TB from the American Lung Association