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May 21, 2010 08:35  by Dr. Neil Rau

Health officials in Alberta are on the alert after five people there were recently diagnosed with measles. That follows an ongoing outbreak of the disease in B.C. that, as of May 17, had infected 87 people. Another probable case has been caught in Ontario.  

Why is measles continuing to reappear in Canada? 

Not that long ago, measles was commonplace. That was before 1970, when routine childhood vaccination programs were implemented. In fact, those who were born here in Canada before 1970 were immunized by naturally acquired infection.

But naturally acquired infections can be dangerous. Measles can cause anything from mild illness with a rash, to serious disease that may feature pneumonia (up to 6% of cases), a need for hospital admission (1%), swelling of the brain (0.1%) or death, especially in children (0.03%).

Given the global burden and impact of measles, a UN Millenium Development Goal was to reduce the number of children who continue to be killed by this disease in developing countries. Ultimately, the goal was only partly reached (annual deaths reduced from 733,000 in 2000 to 164,000 in 2008), mainly because of inability to vaccinate approximately 90% of the population in these resource-poor settings. 

Therefore, while effective measles vaccination programs have nearly eliminated the disease from developed countries, measles is repeatedly introduced to Canada from the developing world, where it remains commonplace.  

Indeed, the origins of many recent Canadian measles clusters can be traced to a visitor who unwittingly brought the disease here (as occurred in B.C. during the Winter Olympics while we were distracted by the medal haul.) 

Ultimately, vaccinating 80 - 90% of the population is the cornerstone of measles containment and elimination. That was achieved in Canada from the 1980s onward. The paradox is that we still see localized outbreaks of measles in Canada in the wake of cases introduced from abroad. Here are a few explanations:  

a)      Some Canadians continue to refuse the measles vaccine. The now debunked link between measles vaccination and autism has led to low vaccination rates in some communities in developed countries, especially the U.K.

b)      Those of us who were children in Canada during the 1970s received only one dose of the measles vaccine. Many new Canadians may have not been vaccinated at all. Beginning in 1996/1997, two doses of vaccine were routinely administered in childhood (at 12 months and again at ages 4 - 6) to provide longer lasting protection.

c)      Once a disease is almost eliminated from a community, the protection offered by vaccination may wane after 10 to 15 years. This is why a small percentage of cases are seen in Canadians who have been vaccinated with one or even two doses of vaccination.  These vaccinated patients typically get milder illness that those who have never been vaccinated.

Even though measles largely originates in the developing world, screening travelers is not the magic bullet that will keep Canada free of measles. This is because the majority of those who are contagious will not be "picked out" by a screening questionnaire or temperature scanning using costly thermal scanners. Moreover, contagiousness begins up to four days before any symptoms or signs develop. 

Measles is highly contagious, being spread to those sharing the same airspace. And when you consider that it takes anywhere from 9 to 21 days from exposure to the development of illness, it becomes evident that screening visitors and returning travellers from developing countries is a futile effort. 

Putting this all together, expect to see more news stories on localized measles outbreaks until global reduction -- and perhaps eradication -- of measles can be achieved through UN and WHO efforts. 

In the meantime, Canadians have a great vaccine at their disposal.

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Dr. Marla Shapiroclose [x]

Dr. Marla Shapiro, MDCM CCFP MHSc FRCP(C) FCFP, is a family physician and the Health and Medical Contributor for CTV's Canada AM as well as the editor of Parents Canada magazine, launched in March 2007.

She completed medical school at McGill University and trained at the University of Toronto for her Masters of Health Science in Community Health and Epidemiology. She holds a Fellowship in Family Medicine and is a NAMS credentialed menopause specialist. She is an associate professor in the Department of Family and Community Medicine at the University of Toronto, where she recently won an award for Creative Professional Activity.

Dr. Shapiro won the Society of Obstetricians and Gynaecologists of Canada/Canadian Foundation for Women's Health Award for Excellence in Women's Health Journalism in 2006 for her documentary "Run Your Own Race." Her book, "Life in the Balance: My Journey with Breast Cancer" was released in the fall of 2006 and is a national bestseller.

For her lifelong commitment to family medicine, Shapiro was awarded the College of Family Physicians of Canada's Award of Excellence for 2008.

Angela Mulhollandclose [x]

Angela Mulholland is the editor of CTV News' semi-weekly health newsletter MedNews Express as well as the MedNews Express Blog.

She has been a journalist for CTV News since 2000, covering current affairs, health and entertainment for CTV.ca. Before CTV, she worked for CBC.ca for two years.

She has a degree from St. Jerome's University in Waterloo, ON, and studied journalism at Sheridan College in Oakville. She lives in Toronto with her husband and two children.

Monica Matysclose [x]

Monica Matys has been the health and wellness reporter for CTV News Toronto since 2001. Her feature health report, Lifetime, can be seen on CTV Toronto's News at Noon and at 6 p.m.

Her interest in the medical field began while working for a medical publishing company as the editor of a monthly magazine. One of Monica's favourite days on the job was the time she got to spend a day in Credit Valley Hospital's Emergency unit. "It really opened my eyes to the strains on our system," Monica explains.

Matys grew up in Scarborough, and has an honours degree in Journalism from Carleton University in Ottawa. She lives in Toronto with her husband and two children.

Avis Favaroclose [x]

Avis Favaro has been with CTV News since 1992, producing stories for CTV National and CTV News Channel - Newsnet- as well as for CTV affiliate stations across the country.

Avis and producer Elizabeth St. Philip won the 2008 Media Awards for Excellence in Health Reporting handed out by the Canadian Nurses Association and the Canadian Medical association for a story on BPA found in food cans.

She has been nominated for an impressive 12 Geminis, winning once for a unique story on an experimental cancer treatment developed in Winnipeg in the 1940's.

Avis has a masters in journalism from UWO and a Bachelor's degree in History, and launched her journalism career as a writer/reporter at Global in 1982.

Dr. Yoni Freedhoffclose [x]

Dr. Yoni Freedhoff, MD CCFP Dip ABBM, is the founder and Medical Director of the Bariatric Medical Institute in Ottawa, a multi-disciplinary behavioural weight management program. Formally trained in family medicine, since 2004 his practice has been exclusively dedicated to the treatment of overweight and obesity.

Dr. Freedhoff has been referred to as a "nutritional watchdog" by the Canadian Medical Association Journal and a national "obesity expert" by the Canadian Obesity Network. His advocacy efforts for improved public policies regarding nutrition and obesity have found him testifying in front of the Canadian House of Commons, giving press conferences with the Ontario Medical Association, commenting regularly in the national media, and as a sought after lecturer.

Dr. Freedhoff explores issues pertinent to nutrition, obesity, public policy and advocacy in his daily blog Weighty Matters which is ranked among the world's top health blogs and was voted the top Canadian health blog of 2008 by the Canadian Blog Awards.

Dr. Grant Lumclose [x]

Dr. Lum is a sports medicine physician. He is the medical director and founder of Athletic Edge Sports Medicine, a multidisciplinary sports medicine organization offering services to the athletic and active public.

He is involved in the care of recreational, elite amateur and professional athletes, including players in the NHL, NFL and NBA. He is also involved in the performing arts medical community, taking care of musicians, vocalists, dancers and other performing artists.

Dr. Lum studied medicine at the University of Toronto, where he graduated in 1992. He completed a two-year residency in Family Medicine, and then specialty training in Sports Medicine.

He is a lecturer at the University of Toronto's Faculty of Medicine, an adjunct professor at York University's Faculty of Fine Arts, and medical director of George Brown College's Fitness and Lifestyle Management Program.

Dr. Lorne Brandesclose [x]

A senior oncologist at CancerCare Manitoba, Dr. Brandes received his MD from the University of Western Ontario in 1968.

Following post-graduate training at the Royal Marsden Hospital (London) and the University of Manitoba, he joined the faculty at U. Of M. in 1975, where he is a professor in the Departments of Medicine and Pharmacology.

He is also affiliated with the Manitoba Institute of Cell Biology.

Dr. Katy Kamkar, Ph.D., C. Psych.close [x]

Dr. Katy Kamkar, Ph.D., C. Psych., is a Clinical Psychologist at the Work, Stress and Health Program/Psychological Trauma Program, at the Centre for Addiction and Mental Health (CAMH). She also provides private practice at the CBT Associates of Toronto and is a lecturer in the Department of Psychiatry, University of Toronto.

She completed her Honours Degree in Psychology and Mathematics at York University and her Masters and Ph.D. in Clinical Psychology at Concordia University. She also completed a Clinical/Research Postdoctoral Fellowship at CAMH. She has received numerous academic awards and distinctions.

Kamkar provides consultation, comprehensive assessments, and evidence-based Cognitive-Behavioural treatment for Mood and Anxiety Disorders, including psychological distress related to stress and anxiety in the workplace. She also provides training, education, and supervision as well as various educational seminars and workshops. She adheres to a scientist-practitioner model of practice and integrates research and science with practice.

One of Dr. Kamkar's greatest interests has been to provide education to enhance public awareness of mental health/illness in general and of psychological distress in the workplace. She has written articles for comprehensive public resources and provided numerous public relations - media work.

Dr. Neil Rauclose [x]

Dr. Neil Rau grew up in Ottawa. He initially studied mathematics at the University of Waterloo before completing his MD at the University of Toronto in 1991. He completed training in Internal Medicine and Infectious Diseases at McGill University in 1996, before establishing a busy private practice in Oakville. He is currently the medical director of Infection Prevention and Control at Halton Healthcare Services.

In 2008, he completed his training in medical microbiology at the University of Toronto and he now serves as the medical microbiologist and chair of the patient safety steering committee at his hospital.

He is a lecturer at the University of Toronto. Since 2008, he has also been Infectious Diseases section head at the Association for Medical Microbiology and Infectious Disease Canada. He is also a frequent contributor to CTV News.

He lives in Toronto with his wife and two children, and is an avid amateur concert pianist.

Cara Rosenbloom, RD close [x]

Registered dietitian Cara Rosenbloom believes that nutrition can make a difference in overall health and wellness and enjoys translating complex nutrition information into usable and helpful advice.

Rosenbloom holds a literature degree from the University of Western Ontario and a Bachelor of Applied Science in Food & Nutrition from Ryerson University. She completed a dietetic internship at North York General Hospital to become a registered dietitian.

Prior to becoming a nutrition columnist, Rosenbloom worked as a dietitian at The Hospital for Sick Children for three years. She is a member of Dietitians of Canada and the College of Dietitians of Ontario and the president of Words to Eat By, a nutrition communications company.