Abstract
BackgroundThe implementation of rapid drug susceptibility testing (DST) is a current global priority for TB control. However, data are scarce on patient-relevant outcomes for presumptive diagnosis of drug-resistant tuberculosis (pDR-TB) evaluated under field conditions in high burden countries.MethodsObservational study of pDR-TB patients referred by primary and secondary health units. TB reference centers addressing DR-TB in five cities in Brazil. Patients age 18 years and older were eligible if pDR-TB, culture positive results for Mycobacterium tuberculosis and, if no prior DST results from another laboratory were used by a physician to start anti-TB treatment. The outcome measures were median time from triage to initiating appropriate anti-TB treatment, empirical treatment and, the treatment outcomes.ResultsBetween February,16th, 2011 and February, 15th, 2012, among 175 pDR TB cases, 110 (63.0%) confirmed TB cases with DST results were enrolled. Among study participants, 72 (65.5%) were male and 62 (56.4%) aged 26 to 45 years. At triage, empirical treatment was given to 106 (96.0%) subjects. Among those, 85 were treated with first line drugs and 21 with second line. Median time for DST results was 69.5 [interquartile - IQR: 35.7–111.0] days and, for initiating appropriate anti-TB treatment, the median time was 1.0 (IQR: 0–41.2) days. Among 95 patients that were followed-up during the first 6 month period, 24 (25.3%; IC: 17.5%–34.9%) changed or initiated the treatment after DST results: 16/29 MDRTB, 5/21 DR-TB and 3/45 DS-TB cases. Comparing the treatment outcome to DS-TB cases, MDRTB had higher proportions changing or initiating treatment after DST results (p = 0.01) and favorable outcomes (p = 0.07).ConclusionsThis study shows a high rate of empirical treatment and long delay for DST results. Strategies to speed up the detection and early treatment of drug resistant TB should be prioritized.
Highlights
The implementation of rapid drug susceptibility testing (DST) is a current global priority for TB control
Only a handful studies of the clinical impact on adult patients with a presumed diagnosis of drugresistant tuberculosis (DR-TB) under field conditions in high burden countries have been published regarding the incorporation of new molecular technologies for TB diagnosis
RMP rifampicin, INH isoniazid, EMB ethambutol, SM streptomycin, PZA pyrazinamid, Confidence interval (CI) confidence intervals aAny resistance indicates resistance to the anti-tuberculosis medication tested, independent of resistance results to other medications. This is a descriptive study, in a high burden country, of the health system approach at reference center level to the investigation and management of patients suspected of having drug resistant TB. At triage in those centers, we observed a high rate (96.0%) of empirical treatment, similar to that reported (96.0%) by Theron et al [13] among presumed drug sensitive and drug resistant pulmonary TB cases detected by Xpert and higher than that (59.0%) described by Yacobson et al evaluating presumed drug resistant TB cases [15]
Summary
The implementation of rapid drug susceptibility testing (DST) is a current global priority for TB control. Data are scarce on patient-relevant outcomes for presumptive diagnosis of drug-resistant tuberculosis (pDR-TB) evaluated under field conditions in high burden countries. There are several reasons for this, including the fact that culture and DST results often take a long time and, sometimes, do not even become available at all. This tradition of empirical treatment has major implications on the impact of newer and more sensitive diagnostic tests with faster laboratory turnaround times [9,10,11,12,13,14,15,16,17,18,19]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
