A whole-genome sequencing study traced the 2010 measles outbreak in British Columbia following the Winter Olympics back to a single visitor from China, the Vancouver Sun reports.
Researchers led by Jennifer Gardy at the BC Centre for Disease Control analyzed samples from 82 measles cases, about half of which were PCR-positive for the disease. They genotyped 45 samples and sequenced the full genomes of 27 measles viruses to generate a view of how the virus spread.
As Gardy and her colleagues report in the Journal of Infectious Diseases, they uncovered three lineages in Vancouver during the early days of the outbreak. Then one version of the virus — an H1 strain that could be traced to China — left the metro area to lead to the province-wide outbreak.
Indeed, the spread tracked with Highway 97, which runs from the US border north to the center of the province and beyond, as the visitor traveled, the Sun notes
"With the genomic analysis — the sort of forensic DNA investigation — we were able to determine that all cases in the north of British Columbia ... were the result of the single introduction of a virus," Gardy tells the Sun.