Oxford-Nanopore eBook - 12

TB or Not TB?
Using Advanced
Methods to
Track Infectious
Diseases

Professor Justin O'Grady on
using a targeted nanopore
sequencing-based method
to rapidly detect drugresistant tuberculosis

Drug resistance is a huge hurdle to
reducing the spread of tuberculosis
(TB), the world's deadliest infectious
disease. An estimated 10 million cases and
more than 1.6 million deaths are attributed
to TB each year. The greatest impediment
to treatment and prevention efforts is drug
resistant TB (DR-TB).

There are half-a-million cases of multi-drug resistant TB (MDR-TB)
annually, and more than 6% of these cases are now classified as
extremely drug resistant (XDR-TB). All of them are very difficult
to cure. TB is most prevalent in middle- and Southern-Africa, but
most instances of new TB cases with drug resistance, including
XDR-TB, occur in Russia, China and India.
Justin O'Grady, a senior lecturer at University of East Anglia,
UK, is using nanopore sequencing to develop new ways to
identify and track TB and has been able to develop a rapid

clinicalomics.com

and accurate test to detect DR-TB. He says that nanopore
sequencing using Oxford Nanopore's MinION platform is
"flexible and cost-effective and very easily deployable."

Seq & Treat
Next-generation sequencing (NGS) has great potential for
rapidly diagnosing DR-TB. "TB takes a long time to grow," in
culture, O'Grady says, and that process doesn't always result
in an accurate means of determining resistance to antibiotics.
NGS is more comprehensive than current rapid tests, which
only look at a limited set of targets across the genome. Nonetheless, uptake of sequencing can be hindered by concerns
regarding its cost, integration into existing lab workflows,
skills required for using the technology, and management
and interpretation of the sequencing data.
A world map of MDR/DR-TB cases tested for susceptibility to
second-line drugs, O'Grady points out, shows how well-financed places are performing tests for TB identification, but
they aren't doing enough testing for second-line resistance
in locations with MDR-TB or XDR-TB. To address this issue,

http://www.clinicalomics.com

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