Using genomics to diagnose and control TB

While tuberculous, or TB, is often considered a disease of the past, the reality is that the bacterial infection still has an impact on segments of the population in BC, and more significantly, around the world.

While tuberculous, or TB, is often considered a disease of the past, the reality is that the bacterial infection still has an impact on segments of the population in BC, and more significantly, around the world. A TB infection is diagnosed in a British Columbian once every day and a half — about 250 cases each year — costing the health care system nearly $13 million annually to treat. And while rates of TB have been declining slightly over the last few years, the rates of non-tuberculosis mycobacteria infections (NTMs) are increasing, with almost twice the number of cases diagnosed than TB.

2016 MSFHR Scholar Award recipient, Dr. Jennifer Gardy wants to drive down those numbers.  As an assistant professor in the School of Population and Public Health, Canada Research Chair in Public Health Genomics, and a senior scientist at the BC Centre for Disease Control, she is leading a genomic epidemiology project called “BRIDGE-MTB: Bringing Integrated Data, Genomics, and Evaluation to Mycobacteria and Tuberculosis”.

Gardy’s research program will look at ways to change how TB and NTMs are diagnosed in BC, with broader implications for the treatment of these organisms and understanding their epidemiology — the clusters or outbreaks of disease — to help control their spread. Both TB and NTMs are a threat to the most vulnerable members of society particularly immunocompromised individuals such as seniors, as well as new immigrants.

BRIDGE-MTB is a five-year, province-wide program that expands on previous research conducted by Gardy. BRIDGE-MTB will use whole genome sequencing to diagnose the DNA profile of tuberculosis and NTM bacteria strains. Armed with this information, Gardy and her team will be able to reduce the time it would take to accurately diagnose the disease using traditional lab analyses — currently four to six weeks and up to several months — to a single analysis, available in a matter of days.

Genomics also provide valuable information on the type of strain to assist physicians in identifying the most effective antibiotic treatment. A faster and more accurate diagnosis means patients will have access to the right treatment earlier and conceivably, improved outcomes.

Using genomic data to understand how infectious diseases like TB “behave” will also help determine the epidemiology of the diseases identifying where, how and why they are transmitted. Also, whether the strain is part of an outbreak and aid in identifying how to prevent transmission and control outbreaks faster.

The research conducted by Gardy also has applications for addressing the incidence of TB worldwide, identified by the World Health Organization as rivalling AIDS as a leading cause of death, particularly in the developing world. Gardy has been collaborating with Oxford University and TB labs around the world exchanging data and ideas on using genomics as a tool to diagnose and manage the disease. “It has loads of exciting potential,” says Gardy. “Now the public health agencies in those settings — from Public Health England to here at BCCDC — are saying ‘wow, this is a technology that we can really use to change our clinical practice.’ And it’s happening, so we’re making a real difference in the public health system.”