Doctors across Canada are reporting that there has been an unexpectedly low number of flu cases this season.

Experts don't have an explanation for why the number has been so low.

"It's a little bit odd that we haven't seen any other flu in Canada," Dr. Michael Gardam, director of infection prevention and control at Ontario's Agency for Health Protection and Promotion, told CBC News. "There really aren't any great solid explanations as to why that is."

Schools in particular have noticed a drop in the number of students off sick.

"Normally this time of the year ... there are fewer students rushing out to play. Not this year," said Lori Nagy, manager of media and community relations with Edmonton's Catholic Schools District. "As we head into March, we're pleased to have very low absenteeism throughout the district. So it is a very unique and very different year."

Some flu experts theorize that perhaps the H1N1 virus that was rampant last year has replaced the seasonal flu as the dominant virus. Or perhaps people who were sick from H1N1 last fall, or those who got the vaccine for it, are protected from other flu strains.

Gardam said experts will take time to study what's been happening before coming to any conclusions.