TORONTO - Were you out of commission for most of the holidays? Laid low by some alien that invaded your throat and-or chest and-or sinuses and wouldn't let go?
Well, you weren't alone. There seems to be a whole lot of coughing, sneezing and nose-blowing going on.
But if you put it down to flu, you probably ought to think again. There's been very little influenza activity in Canada so far this year, though surveillance data suggests it is just now starting to pick up. If you've been sick already this winter, it likely wasn't with influenza — which means, unfortunately that there's still time to catch flu too.
So if it wasn't influenza, what did you have? Well, there are a bunch of viruses that cause what the medical world describes as an "ILI" or influenza-like illness.
Human metapneumoviruses, parainfluenza, respiratory syncytial virus (RSV for short), adenoviruses and rhinoviruses — the commonest cause of the common cold — can all trigger head colds or more severe cold- and flu-like symptoms.
But people rarely see doctors when they are suffering from uncomplicated colds or the flu, and when they do, doctors rarely run a test to identify the cause. Why bother? If it's a virus — and chances are good this time of year whatever is ailing you is viral — the medical arsenal has little to offer. The infection just has to run its course.
So there's no way for the average person to know what the culprit is. Heck, even the experts don't generally know.
Dr. Danuta Skowronski, an influenza specialist at the British Columbia Centre for Disease Control, was sick over the entire Christmas season. Two weeks later, her voice still sounds like it belongs to someone else. While she knows a lot about respiratory ailments, she can only make an informed guess about what it was that hit her.
"I'm quite sure it's not influenza. I didn't have the fever, the general aches," Skowronski says. "Whatever it is, it's hung on for a good long time, so I don't think it's a rhinovirus. RSV or human metapneumo are options ... but I've not been tested so I don't know."
Every Friday during the fall, winter and spring, the Public Health Agency of Canada publishes a report on influenza activity called FluWatch. It contains a graph showing the percentage of positive tests for a handful of respiratory viruses as well as flu.
The data present a national picture, which may not help you home in on what's going around in your particular community. But it does show that right around the end of the year there was a big surge in cases of RSV. Most of the activity has centred around New Brunswick, Nova Scotia, Quebec and Ontario.
The virus attacks the lungs and breathing passages, according to material on the website of the U.S. Centers for Disease Control. Most people recover within a week or two, though infection can be severe in premature infants, toddlers with heart or lung problems, children and adults with compromised immune systems and people over the age of 65.
RSV is the most common cause of pneumonia and bronchiolitis — inflammation of the small airways of the lung — in children under 12 months old in the U.S., the CDC says. That's probably true about Canada as well, says Dr. John Spika, director general of the Public Health Agency of Canada's centre for immunization and respiratory infectious diseases.
"We are hearing about more people being out ill. And it may well be that some of that illness may be due to RSV at this point in time," Spika says.
RSV circulates every year, though it doesn't sweep across the entire country in the way flu does, Spika says. He notes, though, that RSV causes a lot of problems in remote northern communities, where young kids who come down with it often have to be flown out for hospital care down south. "They develop an asthma-like illness."
While it might be interesting to know what to blame your illness on, from a public health or personal care point of view, it doesn't make a lot of difference.
The messaging from health professionals will be pretty much the same whether you have RSV or a rhinovirus, says Dr. Richard Rusk, the medical officer of health for communicable diseases with Manitoba Health.
Take care of yourself — get plenty of rest and drink plenty of fluids — and try to prevent spreading your bug to others by washing your hands, covering your cough and staying home if you can.
If your ailment left you speechless — in other words, laryngitis claimed your voice — you can also blame a virus.
"It's kind of a good news, bad news thing when people develop laryngitis," says Rusk. "I always tell my patients: 'Well, the good news is you don't have a severe bacterial infection that could end up hospitalizing you. You just have a virus. But the bad news is it could take you two weeks to get over it.'"
With reports of flu activity picking up, it's likely you'll be hearing more about sick friends, family members or colleagues in the next few weeks.
The proportion of infected people who are too sick to go to work or who need to go to hospital is much higher with influenza than with the other respiratory viruses, says Dr. Allison McGeer, an infectious diseases specialist at Toronto's Mount Sinai Hospital.
And McGeer says something else may be looming on the horizon, at least in some parts of the country. It's not a respiratory virus — it doesn't spread though coughing and sneezing. But it does make people miserable.
There have been 11 norovirus outbreaks in long-term care facilities in the Toronto area since Christmas, McGeer says, noting that could be a sign this may be an active norovirus year.
The Public Health Agency of Canada says that of the provinces and territories that report data to the National Enteric Surveillance Program, all have experienced norovirus outbreaks in long-term care and other institutions over the past few weeks.
Noroviruses attack the intestinal tract, triggering explosive diarrhea and vomiting. Like respiratory viruses, they also circulate during winter.