September 4, 2012
DNA Tracking Could ‘Solve’ TB Outbreaks
Reconstructing the spread of killer diseases such as tuberculosis (TB) from person to person using DNA sequencing quickly identifies the origin and movement of pathogens. This approach is directly informing public health strategies to control infectious disease outbreaks, says a scientist speaking at the Society for General Microbiology's Autumn Conference at the University of Warwick.
A team from the British Columbia Centre for Disease Control in Vancouver, Canada used whole-genome sequencing to analyze the bacterial DNA in samples from 36 of 41 infected individuals in a TB outbreak. They were able to track the pathogen's movements through the community in British Columbia, including where it started and who infected whom. From this they could identify key persons, places, and behaviors that contributed to the spread of disease. They showed how the social structure of a community contributed to the rapid spread of TB and that a rise in crack cocaine use in the area may have triggered the outbreak.
The group is currently applying the same reconstruction technique to a different TB outbreak in a different social setting. "We are discovering how important location-based transmission is, and that identifying and screening individuals who visited these locations are integral to outbreak management," explained Dr Gardy. Other research groups are applying this genome-based approach for outbreak reconstruction to other micro-organisms. "We hope to build a 'pathogen knowledge base' that describes how different communicable diseases spread in different social and environmental settings. From this we will be able to identify commonalities that can be targeted in global public health interventions."
The work is directly informing public health policy and practice, said Dr Gardy. "As frontline public health practitioners we are using whole-genome sequencing to answer pressing questions. We are able to take our research findings and translate them into clinical action in the short term. With better control and prevention programs, we can ultimately reduce the burden of certain infectious diseases," she said.
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