Measles outbreak traced to China
NORTHERN B.C.: Researchers link cases from 2010 to single visitor
An outbreak of measles in northern B.C. in 2010 can be traced to a single visitor from China, according to research from scientists at the B.C. Centre for Disease Control and the University of B.C.
The study is billed as the largest using whole-genome-sequencing techniques to identify the genetic code of a measles virus and chart its spread.
“In the past when we wanted to reconstruct an outbreak, we’d have to talk to patients and ask: ‘Who do you know? Who are your contacts? Where do you go?’ And we try to make a best guess about how a disease spreads based on our interviews,” said Jennifer Gardy, a senior scientist with the Centre for Disease Control and lead author of the study published online Monday by the Journal of Infectious Diseases. “In this case, it’s almost like we interviewed the virus and asked: ‘Where did you go?’ ”
Researchers tracked 82 cases of measles after three people fell ill at the 2010 Olympics in Vancouver, obtaining samples of blood, urine or cells from mouth swabs that contained enough of the virus for complete genome sequencing in 27 cases. That allowed them to connect the dots in the 61 northern B.C. patients.
Six other cases in Metro Vancouver were linked to a single carrier of a strain called D8, which is normally found in the U.S., Italy and India. Another 15 cases couldn’t be definitively linked to either carrier.
The single H1 strain of measles virus traced to China moved with the visitor up Highway 97 — from the U.S. border to Prince George and beyond — causing 61 cases of measles.