By Marina Canalejo, Public Policy Assistant, Canadian Cancer Survivor Network
Edited by Jacqueline Thurston, Communications and Social Media Assistant
A new series of worldwide outbreaks has seen the return of a serious and deadly infectious disease: measles. Measles is a highly contagious disease that is transmitted through the air or through direct contact with someone who is infected. Complications such as pneumonia, dehydration, and acute encephalitis are the main causes of deaths in measles patients.
Before the development of the measles vaccine in 1963, 300 000 to 400 000 cases of measles were reported annually in Canada. Since then, the incidence of measles has decreased by 99%. In 1998, Canada was successful in achieving measles eradication thanks to the implementation of a second vaccine dose in the immunization program [1].
However, measles is easy to catch and is still fairly common in other parts of the world, meaning imported cases of measles continue to be reported. According to the World Health Organization (WHO), travel increases the risk of exposure to measles in susceptible populations if they are not vaccinated. The WHO recommends that all children be administered two doses of the measles vaccine, and anyone unsure of their immunization status should receive at least one dose prior to international travel [2].
Global data indicates that reported measles cases rose by 300% in the first three months of 2019. However, it’s important to realize that only 1 in 10 cases will be reported, and thus the actual numbers are much higher. In 2019, there have been 112 163 measles cases reported from 170 countries, in contrast to the 28 124 cases reported in 2018 [3]. So far, Canada has seen 51 cases of measles reported this year, compared to 29 cases in 2018 [4].
Measles is a very dangerous disease, in the sense that it is extremely contagious while also having the potential to be severe and even deadly. In 2017, the most recent year for which estimates are available, it caused close to 110 000 deaths. If not deadly, the possible complications can lead to lifelong disability, from brain damage and blindness to hearing loss [3]. The incidence and mortality of measles have been higher in lower income countries, particularly parts of Africa and Asia, due to weak health infrastructures, overcrowding, and lack of vaccination practices [5].
This rash typically begins three to five days after the first symptoms.
Measles is contagious up to 4 days before symptoms appear and 4 days after they disappear. You can therefore infect someone else before you even know you have it yourself. There are severe complications that can occur in adults, including ear infections, blindness, pneumonia, and swelling of the brain, or encephalitis, which can cause seizures, brain damage, and even death [6].
Studies have shown that vaccination is the best and safest to deal with measles — with both doses, vaccination is almost 100% effective. The first dose is usually administered between 12 and 15 months of age, and the second dose before entering school [7]. Evidence indicates that the vaccine induces long-term, and potentially life-long, immunity.
In Canada, all adults born before 1970 are generally assumed to have acquired natural immunity, as there were high levels of measles circulating before that time [7]. Any adults born in or after 1970, or who may have inadequate immunization records, are recommended to get the measles vaccine to ensure immunity [8].
The measles vaccine is not recommended for severely immunocompromised persons, as it is a live vaccine and may not be as safe or effective for these individuals. It is recommended to obtain approval from a physician before getting the vaccine [8]. Immunocompromised individuals may include people with cancer, recipients of organ transplants, those with hereditary diseases affecting the immune system, as well as many other groups.
According to the CDC, measles can be more severe and have a more prolong effect among immunocompromised persons, particularly those who have leukemia, lymphoma, or a human immunodeficiency virus (HIV) infection. In these cases, measles can appear without the typical symptom of a rash and may remain contagious for several weeks after the onset of the acute illness [9].
The vaccine typically causes no problems for those who have gotten it. However, there may be sometimes be mild and transient symptoms following vaccination, such as pain and redness at the injection site or low-grade fever. As with any other vaccine, there is also the possibility of an allergic reaction [10].
There is no cure for measles. The existing treatments act only to alleviate symptoms and prevent severe complications [6].
If it has been under 72 hours since contact with an individual infected by measles, it is still possible to administer the MMR vaccine to a susceptible person. However, this does not completely eliminate the possibility of measles infection following exposure [8].
Immune globulin (Ig) has been shown to be an effective preventative measure for susceptible individuals exposed to measles, particularly those for whom there is an increased risk of complications – this may include infants under a year old, pregnant women, or immunocompromised persons. Igs elevate the level of immune response and can help to reduce the risk of complications. Within 6 days of exposure, or as soon as possible (if indicated), administration of Ig to a non-immune person will modify or prevent the disease [8].
Here are several important facts about measles, courtesy of the National Foundation for Infectious Diseases [11]:
FACT: Measles can be prevented with a safe and effective vaccine.
FACT: The risk of death from measles is higher for adults and infants than for children.
FACT: Just under half of all measles cases in the USA occur in unvaccinated adults aged 20 years or older.
FACT: Pregnant women who contract measles have an increased risk of early labour, miscarriage, or low birth weight infants.
FACT: Measles is contagious from four days before until four days after the rash appears.
FACT: Measles can cause life-threatening pneumonia and brain inflammation, middle-ear infection, severe diarrhea, and even death.
FACT: Outbreaks of measles primarily affect those who are not vaccinated with the MMR (measles-mumps-rubella) vaccine.
FACT: Most cases of measles result from infections acquired in other countries, or are linked to imported cases.
FACT: Globally, measles continues to be endemic, resulting in 164,000 deaths each year.
[1] “Measles in Canada”, Public Health Canada, 2019.
https://www.canada.ca/en/public-health/services/diseases/measles/measles-in-canada.html
[2] “International Travel and Health”, World Health Organization, n.d.
https://www.who.int/ith/vaccines/measles/en/
[3] New measles surveillance data for 2019″, World Health Organization, n.d. https://www.who.int/immunization/newsroom/measles-data-2019/en/
[4] “Weekly measles and rubella reports”, Public Health Canada, 2019.
https://www.canada.ca/en/public-health/services/diseases/measles/surveillance-measles/measles-rubella-weekly-monitoring-reports.html
[5] “Measles”, World Health Organization, May 2019.
https://www.who.int/news-room/fact-sheets/detail/measles
[6] “Measles: Symptoms and treatment”, Public Health Canada, 2019.
https://www.canada.ca/en/public-health/services/diseases/measles.html
[7] “Measles: Prevention and risks”, Public Health Canada, 2019.
https://www.canada.ca/en/public-health/services/diseases/measles/prevention-risks.html
[8] “Measles vaccine: Canadian Immunization Guide”, Public Health Canada, 2018.
https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-4-active-vaccines/page-12-measles-vaccine.html
[9] “Measles, Mumps, and Rubella — Vaccine Use and Strategies for Elimination of Measles, Rubella, and Congenital Rubella Syndrome and Control of Mumps: Recommendations of the Advisory Committee on Immunization Practices (ACIP)”, Centers for Disease Control and Prevention, 1998.
https://www.cdc.gov/mmwr/preview/mmwrhtml/00053391.htm
[10] “Measles, Mumps, and Rubella Vaccine”, HealthLink BC, 2019.
https://www.healthlinkbc.ca/medications/zb1219
[11] “Facts about Measles for Adults”, National Foundation for Infectious Diseases, January 2012.
http://www.adultvaccination.org/vpd/measles/adultvaccination-facts-about-measles-for-adults.html