According to the CDC, from January 1 to February 13, 2015, 141 people from 17 states and Washington DC were reported to have measles. Although there are currently no cases in Massachusetts, there are 6 cases in 4 east coast states and the District of Columbia.
Dr. Ben Kruskal, a pediatrician and Chief of Infectious Disease at Harvard Vanguard Medical Associates, answers some common questions about measles.
What is Measles?
Measles is a viral infection that used to be very common but had been largely eliminated from our country over the past decades due to high vaccination rates. It is characterized by a fever and a distinctive rash, which may sound like chicken pox and therefore seem benign, but the rate of complications from measles is higher than other childhood rash illnesses such as chickenpox.
We fear the measles so because of its rate of severe complication, the contagiousness of the disease, and the period of time that it’s transmissible without being recognizable.
What are the symptoms?
During the first 2-4 days, the symptoms are very general and resemble other viruses: fever, cough, runny nose, and red, swollen eyes, easily mistaken for ordinary conjunctivitis.
After 2-4 days of these symptoms, the distinctive rash appears. Small red spots, which may be raised slightly, break out, first on the face and especially along the hairline and behind the ears. The spots cluster and give the skin a blotchy appearance.
Even if you don’t have complications, measles can make you feel very ill. The rash itself is not itchy or painful, but the disease just wipes people out. (Think about how you feel if you’ve had the flu and make it worse and last longer – 10 or more days.)
What complications are common with measles?
Pneumonia and ear infection are common by-products of the illness, but encephalitis (swelling of the brain) is also a complication of measles and is very serious indeed. The rate of moderate complications like ear infection and pneumonia is 1 in 3 to 1 in 10, and 1 in 1,000 can get encephalitis from the disease. One in 1,000 will die from measles.
How contagious is measles?
The measles is one of the most contagious diseases we know. If someone has the flu, he or she typically gives it to one or two other people; someone with the measles can infect on average 15 to 18 people.
How long does it take after exposure to begin to show symptoms?
One of the reasons that measles is so contagious is because it has a long “incubation period,” or the time it takes from infection to the onset of symptoms. For measles, the incubation period is 7 to 14 days. Moreover, the first symptoms are very hard to pinpoint as measles. Someone who has measles can infect others from 4 days before until 4 days after the rash appears, so a person can pass along the illness before any symptoms at all appear, and certainly before the illness is recognizable as definite measles.
How do you treat measles?
There is no specific anti-viral medication to treat measles; you can only use comfort measures to try and lessen the symptom impact. And if you do develop complications, there’s no treatment either, just supportive care. The best way to deal with it is to avoid getting it, through vaccination.
Why don’t we vaccinate children younger than 12 months for the measles?
Each year, the Advisory Committee on Immunization Practices (ACIP) publishes immunization schedules for routine vaccines for children age 18 years and younger. For the measles, mumps, and rubella (MMR) vaccine, the recommended minimum age is 12 months for routine vaccination. Children younger than 12 months carry antibodies in their blood that they received from their mothers while still in the womb. Most mothers have antibodies in their blood from their own vaccines, and these are passed to the baby via the placenta and are slowly broken down in the baby’s blood stream, disappearing completely by the age of 12 months. When there are maternal antibodies present for measles, and you try to give that child the measles vaccine, the antibodies bind up the vaccine and inhibit it from working properly. Therefore, while you can vaccinate earlier than 12 months, you cannot rely upon the vaccine to work effectively. We do vaccinate children under 12 months in special circumstances – for example, if they are going to areas with ongoing measles circulation, like Africa.
Can people get the measles even if they have been vaccinated?
The short answer is yes, but the odds are small. Measles is actually one of our better vaccines, but no vaccine is 100% effective. After a single dose of measles vaccine, 95% of people are protected, and after the second dose, 99% of people are protected. But there’s still that 1% of the population who are susceptible for which no reason has been identified.
A note about our adult populations: people born before 1957 are presumed to be immune because measles circulated so widely at that time that everyone got it and once you’ve had it, you’re immune. Anyone who’s had the two doses of vaccine has got the best protection we can offer. If you don’t have vaccine records, there is a blood test which is helpful to determine immunity. If that test has ever been positive in your life, you’re usually immune for life.
Why do people choose not to have their children vaccinated against measles?
Sadly, the internet contains a lot of incomplete or inaccurate information that scares parents about vaccine safety in general or tries to convince them that they don’t need to vaccinate their children. One of my colleagues summarized many of the myths about vaccines in this blog post.
For the measles vaccine in particular, much of the fear stems largely from a paper published by Andrew Wakefield in 1998 that suggested a link between the vaccine and autism. The paper, however, has since been completely discredited – it was revealed that he had falsified his records, was paid millions of dollars by lawyers representing families of kids purported to be injured by vaccines, used highly ethically-questionable means to recruit his research subjects, and the findings he reported in his summary did not match the data he collected.
Based on fear of vaccines and other personal beliefs, we do know that there are communities in our country where a higher-than-average percentage of people are refusing vaccination. Measles, because it’s so contagious, requires very high levels of immunity in the community to avoid spread. When you have a high enough percentage of the population immune, the disease cannot spread because it cannot find enough people to infect. Obviously, the opposite is also true.
What if I think someone in my family has measles?
There have been no cases currently reported in Massachusetts, although there have been a few cited on the east coast, so we are monitoring things carefully. If you or your child has a fever with a rash, we ask that you please call the office first – don’t walk in! If we do suspect it is measles, we need to bring you or your child into the office in a way that does not expose others. And even if there’s no rash, if you think you’ve been exposed to measles and are showing any of the early symptoms (fever, cough, runny nose, or red eyes), please also call and let the staff know you think you or your child may have measles. We can review your history over the phone in order to decide whether measles can be ruled out and how to best and most safely evaluate you or your child.