Canada is following the advice of the World Health Organization and has given up counting individual H1N1 flu cases, to focus instead on watching for disease patterns across the country.

Minister of Health Leona Aglukkaq announced Friday the federal government will no longer be releasing information three times weekly on individual confirmed cases.

"The Public Health Agency of Canada and provincial and territorial governments... are now focusing on measuring the community spread of H1N1, rather than individualized confirmed cases," she said.

"What this approach means is that we will be better able to identify trends in the spread of the illness, we will see who the virus is affecting most, and whether the virus is becoming more severe."

From now on, PHAC's long established FluWatch program will provide its usual weekly analysis of the extent and severity of the flu, and will include reports of unusual activity such as increased severity, increased hospitalizations and reports of antiviral resistance.

As well, PHAC will provide twice-weekly national updates on H1N1-associated deaths and will report regularly on any unusual outbreaks or clusters of illness.

Spread considered inevitable

On Thursday, the United Nations' WHO asked member nations not to send along any more H1N1 patient case counts. Instead, it asked countries to report clusters of severe cases or deaths caused by the virus, as well as unusual illness patterns.

"At this point, further spread of the pandemic, within affected countries and to new countries, is considered inevitable," the agency said in a briefing note, posted on its website.

The agency said it had become nearly impossible for national health authorities to keep count of cases, and the tracking has been eating away at precious laboratory and health services resources.

Infectious disease expert Dr. Donald Low of Toronto's Mount Sinai Hospital explained to CTV News Channel that infectious disease experts in Canada now have a good handle on how this virus spreads and who it infects, so to continue to record new cases isn't likely to add to that information.

Low said while it now appears that this virus causes mostly mild disease, it's still not clear who is most at risk of developing severe illness and why.

"What we have found that this is quite a different disease in that very small subgroup of patients who become quite ill. And we need to understand not only what is causing this more severe disease but is there any strategy that can better treat these patients?" Low said.

Aglukkaq said health authorities have found that about 35 per cent of those hospitalized with this flu have had underlying health conditions. As well, about 18 per cent of those hospitalized were admitted to intensive care.

CDC expects more cases in the fall

Meanwhile, the U.S. Centers for Disease Control and Prevention said Friday it expects the H1N1 virus will cause more disease as early as the fall, when schoolchildren return from summer break.

"We are expecting an increase in influenza or respiratory illness that could be earlier than what we see with seasonal influenza," the CDC's Dr. Anne Schuchat told reporters in a telephone briefing.

"This year, we've been seeing this 2009 H1N1 influenza virus circulating in the summer months. We've seen it in camps and military units. I'm just expecting when school reopens and kids get back together, we expect to see an increase."

Schuchat said the virus was thriving in spite of the heat and humidity of summer. Usually respiratory viruses such as flu do not circulate well in summer months.

Schuchat said this was likely because so many do not have immunity to H1N1, and not because the virus has some unusual properties.