TORONTO - As swine flu teeters on the verge of becoming a pandemic, Canada is at the forefront in testing for the respiratory illness.
Mexican health officials have sent their Canadian counterparts pleas for assistance, first asking for help in determining the nature of the illness in the early stages of the outbreak and now asking Canada to help test their viral samples.
"Overall I think in Canada we're doing pretty well," said Dr. Michael Gardam, the director of infectious diseases at the Ontario Agency for Health Protection and Promotion.
"Despite the initial scrambling that happens with something like this...we have come so far in a week, it is really remarkable."
The National Microbiology Laboratory in Winnipeg is at the helm of testing in Canada as the country's leading public health infectious disease laboratory. The scientists are testing samples from across the country, as well as those from Mexico.
But with Canadian cases of swine flu popping up from coast to coast, provincial public health laboratories are also involved in the urgent effort to identify swine flu cases.
When someone visits their doctor or a hospital complaining of flu-like symptoms and they have been to Mexico in the last seven days or if they have been in contact with a person with a confirmed case of swine flu, the doctor will take a respiratory specimen.
Doctors may also use their discretion to test someone who appears to have a particularly nasty bout of the flu.
A swab is taken through the nose from the nasopharynx, the area of the upper throat behind the nose. It is then shipped off to a lab.
The whole process from swab to swine flu diagnosis can take anywhere from one to five days, according to officials in several provinces.
The results of the first tests sent from Nova Scotia to Winnipeg were available within a day, said the province's medical officer of health.
However, as more swine flu cases pop up and the Winnipeg lab becomes busier, Dr. Robert Strang expects that time frame to lengthen.
Saskatchewan is also sending its samples directly to Winnipeg for testing, though the province is working toward confirming the presence of the H1N1 virus itself.
"We have to get the specific test from Winnipeg and we have to train people to use those tests," said Saskatchewan's chief medical officer of health, Dr. Moira McKinnon.
That process is expected to be up and running in Saskatchewan within days.
In British Columbia a local lab runs a preliminary test and if that is positive for influenza it is sent to a provincial lab, arriving within about one day.
Dr. David Patrick, director of epidemiology services at the B.C. Centre for Disease Control, said their lab can then run a PCR test in about four hours.
PCR stands for polymerase chain reaction and is a technique to amplify DNA, generating millions or more copies of a particular DNA sequence to identify the virus.
If that test is positive for influenza A, then it might take another eight to 12 hours to determine if it is seasonal flu or not, Patrick said.
After that it would take four to eight hours to do the sequencing to find out if it is indeed the H1N1 swine flu.
Officials in Ontario are asking doctors and hospitals to send swabs directly to the provincial lab.
The PCR test that the Ontario lab is currently using can show if the virus is influenza A, but not if it is the H1N1 strain.
"If we get an influenza A that's non-typeable that's the first clue that this probably is swine flu, because regular seasonal flu should be easily typeable," said Gardam.
Those initial results are sent to Winnipeg, where the national lab performs a further PCR test to confirm the presence of swine flu. Gardam said the whole process from swab to confirmation from Winnipeg can take up to five days.
The lab in Ontario is processing about 80 specimens a day, but is hoping to increase that capacity shortly to several hundred a day.
The B.C. lab is also sending confirmed samples to Winnipeg so the National Microbiology Laboratory can perform further research.
Patrick said B.C. officials intend to continue sequencing their results, which could show if there is an ongoing pattern of mutation with the virus. Ontario health officials are also trying to determine if the virus is changing.
"It is evolving, as the flu virus does evolve, and it will be very important to track it over time, particularly in terms of drug resistance, and that's going to be a very important part of our surveillance activity going forward," said Dr. Vivek Goel, president and CEO for the Ontario Agency for Health Protection and Promotion.
