The potential impact of up-front drug sensitivity testing on India’s epidemic of multidrug-resistant tuberculosis
Abstract
Background
In India as elsewhere,
multidrug-resistance (MDR) poses a serious challenge in the
control of tuberculosis (TB). The End TB strategy, recently
approved by the world health assembly, aims to reduce TB deaths
by 95% and new cases by 90% between 2015 and 2035. A key pillar
of this approach is early diagnosis of tuberculosis, including
use of higher-sensitivity diagnostic testing and universal rapid
drug susceptibility testing (DST). Despite limitations of
current laboratory assays, universal access to rapid DST could
become more feasible with the advent of new and emerging
technologies. Here we use a mathematical model of TB
transmission, calibrated to the TB epidemic in India, to explore
the potential impact of a major national scale-up of rapid DST.
To inform key parameters in a clinical setting, we take
GeneXpert as an example of a technology that could enable such
scale-up. We draw from a recent multi-centric demonstration
study conducted in India that involved upfront Xpert MTB/RIF
testing of all TB suspects.
Results
We find that widespread,
public-sector deployment of high-sensitivity diagnostic testing
and universal DST appropriately linked with treatment could
substantially impact MDR-TB in India. Achieving 75% access over
3 years amongst all cases being diagnosed for TB in the public
sector alone could avert over 180,000 cases of MDR-TB (95% CI
44187 – 317077 cases) between 2015 and 2025. Sufficiently
wide deployment of Xpert could, moreover, turn an increasing MDR
epidemic into a diminishing one. Synergistic effects were
observed with assumptions of simultaneously improving MDR-TB
treatment outcomes. Our results illustrate the potential impact
of new and emerging technologies that enable widespread, timely
DST, and the important effect that universal rapid DST in the
public sector can have on the MDR-TB epidemic in India.
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Source:
PLOS ONE
