Canada has made great progress in its goal of measles elimination. Before the introduction of the vaccine in 1963 to 1964, measles occurred in cycles with an increasing incidence every two to three years. At that time, an estimated 300,000 to 400,000 cases occurred annually. Since the introduction of vaccine, the transmission of measles has been interrupted by high vaccine coverage as a part of routine infant and childhood immunization programs. As a consequence, between 2002 and 2010, a total of 327 confirmed cases of measles were reported in Canada. It was estimated that the 10% to 15% of children who remained unprotected by the vaccine was a proportion large enough to allow circulation of the virus.
After more than 200 recently identified cases of measles in the eastern Fraser Valley, it is timely to review what medical professionals know about the disease.
Measles is a highly contagious disease caused by a virus. The virus is transmitted by airborne droplets or direct contact with nasal or throat secretions of infected persons. Less commonly, the virus spreads through contact with articles freshly soiled with nasal and throat secretions. It is so contagious that if one person has it, 90% of the people around him or her will also become infected if they are not protected.
Measles is also a serious disease. For every 3,000 children who get measles, one may die from complications. Symptoms of measles begin seven to 18 days after infection and include fever, runny nose, drowsiness, irritability and red eyes. Small white spots (known as "Koplik's spots") can appear on the inside of the mouth and throat. Then, three to seven days after the start of the symptoms, a red, blotchy rash appears on the face and then progresses down the body. In young children, complications from measles include ear infections, diarrhea, pneumonia, hospital stay, encephalitis (swelling of the brain), and, even, death.
Measles can be prevented by immunization. It is free and recommended for children at 12 months and between four to six years of age as part of their other childhood immunizations. The measles vaccine is combined with the mumps and rubella vaccine (MMR vaccine), so a person can receive protection from several diseases with one shot.
It is recommended that people born in 1970 or later get two doses of the MMR vaccine. This vaccine is also free and recommended for adults who have never had measles, mumps or rubella or received the vaccine.
The effectiveness of protection given at 12 months of age is estimated to be 85% to 95%. With a second dose, effectiveness is almost 100%. Despite this fact, some people choose not to vaccinate because they believe that vaccines contain dangerous substances and have several damaging and long-tem side effects that are yet unknown – even fatal. This is simply not correct. MMR is an attenuated (weakened) live virus vaccine. This means that after injection, the viruses grow and cause a harmless challenge to the immune system of the vaccinated person with very few, if any, symptoms. The person's immune system fights the infection caused by these weakened viruses and immunity develops which lasts throughout that person’s life.
Others believe that it is better to be immunized through disease than through vaccines. This is also incorrect. Vaccines interact with the immune system to produce an immune response similar to that produced by the natural infection, but they do not cause the disease or put the immunized person at risk of its potential complications. In contrast, the ultimate price paid for getting immunity through natural infection might be death from measles.
The health professionals at the Agassiz Community Health Centre are urging you to take a significant step in preventing your family from being infected by measles. Contact Public Health at 604.793.7160 for child immunization. Adults can contact their local pharmacy for vaccination. If symptoms require medical assistance, contact your doctor, hospital or emergency room before you arrive and self isolate to prevent spread of the infection.
– submitted by the Agassiz Community Health Centre