Canadian scientists have completed a genetic sequence of the H1N1 flu viruses that have appeared in Mexico and Canada and confirm that they are of the same strain, public health officials said Wednesday.
The sequencing took place at the National Microbiology Laboratory in Winnipeg was completed in less than a week.
The discovery that the viruses in both countries are the same eliminates the possibility that a genetic mutation might explain why Mexican cases of the virus have been more severe than in other countries, says the lab's Scientific Director General Dr. Frank Plummer.
"We are continuing our analysis, but, essentially, what it appears to suggest is that there is nothing at the genetic level that differentiates this virus that we've got from Mexico and those from Nova Scotia and Ontario that explains the apparent differences in disease severity between Mexico and Canada and the United States," Plummer told a news conference Wednesday.
"That's one of the big questions that everybody's been asking, so part of the answer is that it's likely not the virus itself that is explaining the differential and severity of disease between Mexico and the rest of North America."
Liberal Leader Michael Ignatieff issued a statement late Wednesday, congratulating the team.
"Like all Canadians, I am proud of the world-leading work done by Dr. Frank Plummer and his team at the National Microbiology Laboratory," he said. "By sequencing the H1N1 virus, Dr. Plummer and his colleagues have taken an immense step on behalf of the scientific community in understanding the H1N1 outbreak."
Scientists cannot yet say why the cases in Mexico have been much more severe than elsewhere, but one theory is that the patients had underlying medical conditions that increased their susceptibility to the virus.
There is also speculation that many in Mexico did not receive medical care quickly enough, whereas elsewhere, anyone with flu-like symptoms have been urged to seek care immediately.
The findings made at the Winnipeg lab will help scientists eventually understand how the virus originated, how it spreads and how it may change over time, Plummer said.
The lab has submitted the sequencing to GenBank, a public database where genetic sequencing information can be studied and compared by scientists around the world, Plummer said.
The work should also help with the development of a vaccine against this strain of H1N1.
Experts at the World Health Organization will meet next week to consider whether drug makers should switch from seasonal to pandemic flu production in response to the new H1N1 strain.
The confirmed global death toll from the H1N1 virus outbreak reached 44 on Tuesday, with the death of an American woman in her 30's who lived in Cameron County, Texas, along the U.S.-Mexico border.
Globally, the virus has infected nearly 1,900 people in 21 countries, according to the World Health Organization.
In Canada, the number of confirmed cases rose to 183 on Wednesday, with no deaths.
- Nova Scotia reported five new cases, bringing the province's total caseload to 53.
- Ontario confirmed 13 new cases, bringing its number of cases to 49.
- B.C. confirmed another eight cases, which brings the provincial total to 54.
All cases are said to be mild.
However, an Alberta girl was hospitalized in Edmonton earlier this week due to severe illness.
The WHO remains at pandemic alert Phase 5, indicating a pandemic is imminent.
With files from The Canadian Press
