You might not be worried about measles and wonder what the fuss is about. It was a normal part of growing up when I was a kid. By our mid-teens, most of us had had measles and are now immune. However, measles wasn't easy for everyone. Before the first measles vaccine was licensed in 1963, there were about 3 million cases in the U.S. every year with 48,000 hospitalizations and 500 deaths. Diarrhea, ear infections and pneumonia were common complications, with pneumonia the major cause of death; brain infections were rare but frequently fatal or caused permanent damage.
Measles is very contagious. Measles is mainly transmitted person-to-person by large droplets, but transmission has occurred from small aerosolized droplets that remain suspended in air in closed spaces, like an exam room, for up to two hours after the contagious person had left. About 90 percent of susceptible close contacts will become infected if exposed to measles. This is why we ask people who may have measles to stay away from others and call ahead to their doctor or emergency department, to avoid passing measles to others in waiting rooms. People are infectious in the early stage of measles -- several days before the rash, and may have a fever and runny nose or cough, similar to a cold. They can transmit the virus to their household or close friends, or to people they are near to in public during the early disease until four days after the start of the rash.
Most outbreaks of measles in the U.S. start with someone who is not vaccinated traveling to countries where measles are still common, becoming infected and becoming ill and contagious one to three weeks later. This is often while in transit or after returning home, infecting other susceptible contacts. There were 11 outbreaks of measles in the U.S. last year, with 189 reported cases. The nearby outbreak in British Columbia started one month ago and has had over 300 cases and two hospitalizations so far. It started with a case imported from the Netherlands where there have been over 2,600 cases since May 2013. Almost all of these cases have occurred in a religious community that does not approve of vaccination. Whatcom County had no measles for over a decade until two weeks ago, when one case was reported in a household affiliated with the community in B.C., and four household members also became ill. The sixth case was exposed in the home of the first case, and was in several public places while contagious, before being diagnosed. Other unrelated potential measles exposures to the public have occurred at SeaTac airport and on San Juan Island in the past two weeks.
The good news is that we have a safe and effective vaccine that has virtually eliminated measles from the Americas since 2000, with fewer than 60 cases reported in the U.S. most years, all either imported or related to an imported case. The vaccine, given combined with mumps, rubella in what's called MMR, and sometimes varicella or chickenpox, called MMRV, is 95 percent effective in preventing measles after one dose, and 99 percent effective after two. In many outbreaks, less than 1 percent of immunized contacts get measles, while 90 percent of unvaccinated close contacts become infected.
However, fear and avoidance of vaccine has led to groups of people who are unimmunized and remain susceptible to measles. Although the suspected link between vaccines and autism has been clearly disproved, many still hold on to the belief that the vaccine causes autism. The vaccines are associated with some side effects, most are temporary, and some rarely serious.
Some choose not to vaccinate for religious or personal reasons. Some very few people shouldn't be vaccinated for medical reasons. Infants are not routinely vaccinated until after their first birthday. Most of these people do not choose to be susceptible, and they depend on the rest of us getting vaccinated to avoid being exposed to measles and the risk of its complications.
We can build community immunity and eliminate measles, protect ourselves and our families and neighbors with a safe and effective vaccine. Check your medical provider or the health department for information on vaccinations and the diseases they prevent.
ABOUT THE AUTHOR
Dr. Greg Stern is the Whatcom County health officer. For more about measles, go online to http://www.whatcomcounty.us/health/flu/measles_information.jsp.