You've heard it time and time again. Wash your hands to prevent disease.
But research done in 2007 and presented by the Canadian Medical Association Journal Thursday found there is no evidence that hand washing prevents the flu.
The report, commissioned by the Public Health Agency of Canada and described in a news article on the CMAJ's website, stated that current evidence shows flu is primarily spread through the air.
Despite the results, the Public Health Agency of Canada continues to recommend handwashing to prevent the flu because there is "substantial evidence" to support washing to prevent infection.
"We really do think handwashing is a safeguard," Dr. Donald Low, microbiologist-in-chief at Mount Sinai Hospital in Toronto told 愛污传媒 Channel. He chaired the handwashing study.
Infectious disease specialist Dr. Neil Rau, who was not involved in the study, explained to 愛污传媒 Channel the information that flu is spread mostly through the air is not altogether new.
"There's a small portion of flu that can be transmitted by shaking hands with someone who has it and then touching your eye or your mouth... or touching an inanimate surface like a bus pole," he said. "But most flu is transmitted through cough and sneezing.
Low said further study is needed to prove whether handwashing does prevent respiratory illnesses from spreading. He explained that once anyone puts their contaminated hand into their mouth, they increase their chances of becoming infected.
"If you wash that hand, (infection) won't be happening," he said.
Sneezing and coughing can shoot viruses through the air and can be transmitted to people as far as two metres away. Low says surgical masks provide some protection, but air seeps in through the sides, so they are not enough.
The skinny on masks
New research from McMaster University in Hamilton also released Thursday finds that cheaper surgical masks, which were used during Toronto's SARS outbreak, are just as effective in protecting health-care workers as N95 respirators.
The N95 masks were originally designed to protect construction workers from breathing in particles, so they fit closer to the face. They are thicker, and cost about five times more than surgical masks.
The study was published in JAMA, the Journal American Medical Association Thursday.
More than 400 nurses participated in the study. Half wore one type of mask, and half wore the other while dealing with patients with respiratory illness. Both groups got sick about 23 per cent of the time.
That's contradictory to a Chinese study released in September that found surgical masks don't protect health-care workers from flu.
Nineteen-hundred health-care workers took part in that study. It found workers who wore N95 masks were 75 per cent less likely to get sick than people who wore surgical masks. That study prompted the U.S. government to change its recommendations on the use of surgical masks.
At least one doctor admits all the contradictory information about the flu is confusing.
"The average family physician is confused and that's partly because there is a lot of conflicting evidence and things change day by day," College of Family Physicians of Canada President Dr. Sarah Kredentser told the CMAJ.
She said the College is working with the Public Health Agency to come up with a uniform guideline for Canadian doctors.
