An Ottawa senior is dead and dozens more are ill following a flu outbreak that is mystifying doctors.

"I don't think we've ever had Influenza A that early before. Not that I can remember," Liz Palmer, director of care for the Starwood nursing home, told CJOH News. "We'd like to know exactly what's happening."

It isn't just a problem at Starwood.

"We've got four clusters of flu at four different long-term care facilities," said Dr. David Salisbury, associate medical officer of health.

"One of the people who is sick has the Fujian subtype ... so there's a bit of question as to hangover from last year," he said.

Globally, the Fujian strain of the Influenza A virus was the most common cause of flu in the 2003-04 flu season.

Other experts say that's not likely. They think it's probably the start of an unusually early flu season.

Flu doesn't usually start up until the weather turns cold. Depending on where you live in Canada, that could mean starting in October or November, and running until March or April.

Actually, the 2003-04 flu season got off to an early start last year, with the first cases detected in late September and early October in Alberta and Saskatchewan, according to a Health Canada article on its website.

As a result, there is no flu vaccine even ready yet -- although the formulation for the 2004-05 flu season was announced in mid-June.

The vaccine isn't expected to be available until early October.

When it is available, the vaccine will contain the A/New Caledonia/20/99 (H1N1), A/Wyoming/3/2003 (H3N2) and B/Jiangsu/10/2003 virus antigens.

Health Canada recommends October to mid-November as the best time to be immunized. It also notes that people must be vaccinated every year, as the flu threat changes.

Since there's no vaccine available yet, the experts recommend people in Ottawa washing their hands thoroughly and often.

"The virus spreads through mucus," said Dr. Earl Brown, a University of Ottawa virologist. "So you touch friends, handrails -- people are always touching their nose. That's where the virus ends up and that's how you get infected."

It's also recommended that those Ottawa residents with loved ones in nursing homes check first before visiting and to delay any visits to a flu-affected facility.

With a report from CJOH's Kim Brunhuber