As the United States faces its worst measles outbreak in decades, a panel of health experts from the World Health Organization (WHO) will meet this week to assess the latest data on the outbreak in the United States and determine if our country will maintain its measles elimination status. There are now 5,400 measles cases in the United States. Among the areas hardest hit are Lancaster, Mifflin and Chester counties in Pennsylvania, which account for more than 800 of these cases.
Responding to the current outbreak, the Pennsylvania Department of Health is now expanding its MMR recommendations, including adding an earlier dose for babies 6 to 11 months of age who will be in areas of continued community spread of measles. The recommendations also include a shot for 1-year olds or older if they have not already done so, with a subsequent shot 28 days after the first jab for added protection.
Measles symptoms generally appear starting about week to two weeks after infection and start with red, watery eyes and flu-like symptoms, such as cough, runny nose and high fever. A few days after that, small white spots known as Koplik spots may form in the mouth as well as a rash of small red bumps around the body that are the hallmark of the disease. In rare cases, the disease can be life-threatening, particularly for unvaccinated people, pregnant women or those with weakened immune systems.
The Drexel News Blog checked in with Jennifer Hamilton, MD, PhD, a professor of family, community and preventive medicine in Drexel University’s College of Medicine, about what metrics experts look at to determine measles elimination status, where she expects the outbreak to go in the near future, how measles is uniquely contagious compared to mumps and rubella and what she generally recommends for most of her patients to minimize their risk of measles. Hamilton also talked about the importance of the two-dose measles, mumps and rubella (MMR) vaccine, which is 97% effective at preventing measles, according to the Pennsylvania Department of Health.
Pennsylvania surpassed 1,500 measles cases earlier this week according to the Commonwealth’s Department of Health. What’s the main recommendation you give patients to protect themselves against this viral disease?
Measles is one of the most contagious diseases in the world. The single best thing to prevent measles is to get vaccinated. And if you are one of the people who cannot get vaccinated – because of being immunocompromised or pregnant – ask the people who are close to you to get themselves vaccinated and limit your encounters in areas where we know the virus is spreading. Near Philadelphia, Lancaster and Chester counties have had the highest number of cases, but it has been reported in Montgomery and Bucks counties, too.
Members of the United Nations’ Pan American Health Organization are meeting this week to determine whether the United States will hold onto its measles elimination status. If they deem that we’ve lost it, do you think that will cause health officials and the general public to spur into action or is it just a designation that doesn’t have much impact in practice?
I hope it will motivate action, but I doubt that it will. Everyone involved can see the case counts and the death reports; we don’t need another organization to look at those numbers and tell us that in the 21st century, no one needs to die from measles. Where it may make a difference is in developing countries that are deciding how much effort to put forward on measles elimination: if the U.S. can’t maintain its status, some may think, why should we try? Sadly, our loss of measles elimination status may lead to more sickness and deaths in other countries.
What determines if this country maintains measles elimination status?
One of the considerations is whether the different outbreaks are linked. If there were several outbreaks centered around airports, for example, and each local outbreak had different genetic characteristics, that would suggest that the disease was coming into the country with international travel and getting stopped in the various areas before it could spread nationwide. So genetic sequencing is one of the tools used to decide if the U.S. can maintain its measles elimination status. But what I’ve heard about the sequencing results so far suggests that outbreaks in Wisconsin and Pennsylvania are linked to a shared U.S. source.
Why is it crucial to get the vaccination rate to at least 95%? I’ve seen reporting of the current vaccination rate among kindergarteners to be around 92%.
The more contagious a disease is, the higher the percentage of people who need to be immune to block its spread. If one infected person spreads the disease to two other people, on average, you’d need just over half the population to be immune to halt a widespread outbreak. Measles is one of the most contagious diseases known: someone with measles can walk into an elevator, not touch any buttons, and ride to another floor. Two hours later, someone using that same elevator can get measles. If no one around them is immune, someone with measles can infect 12 to 18 other people.
Because it’s so contagious, measles will spread through a population unless about 95% of people are immune. That’s why we’re seeing outbreaks of measles before rubella or mumps, even though the same vaccine is used to prevent all three – those aren’t as contagious and vaccination rates would need to drop lower before we have sustained outbreaks of them.
Nationwide, our immunization rates are dipping below that key threshold. In Pennsylvania there are plenty of schools that fall well below the 95% mark. You can check the vaccination rate for each school at this PA government site. I suspect that if measles reaches Philadelphia, it will spread quickly in children at certain schools.
This summer, a federal executive order urged drugmakers to break up the MMR shot and consumers have faced mixed signals when it comes to the safety of vaccines. How can clinicians increase vaccination?
It’s easy for trust to be lost when figures in the public eye make claims and spread stories unsupported by evidence. Combination MMR vaccines have been used in the U.S. since the 1970s. The MMR has been studied again and again for possible links to other conditions, such as autism. It’s a safe, effective vaccine. Right now, there isn’t a stand-alone measles vaccine approved for use in the U.S. The ones we had in the 1960s were replaced by MMR because they didn’t provide long-lasting protection.
Some states have increased vaccination rates by requiring vaccination to attend schools and eliminating exemptions for religious or philosophical reasons. That has worked, but I don’t want to force people to get vaccinated. I’d rather that they become so aware of the benefits of vaccination that they’re eager to get themselves and their children protected.
Since the current outbreak began, Lancaster County public health has been doing outreach to the Plain communities (primarily Amish and Mennonite groups) there, such as offering free vaccination clinics at convenient places and times, including house calls. As I understand it, many in the Plain communities don’t have objections to immunization – they just didn’t see it as something important. Now that they’re seeing measles close up, interest in vaccination has increased.
Measles is a disease most people simply don’t know. People in their 50s or younger, who grew up in the MMR era, may never have seen a case of the disease. If all they know about measles comes from watching reruns of the Brady Bunch, they may think it’s no big deal. So, if they ask about the vaccine, I let them know that Roald Dahl, who wrote Charlie and the Chocolate Factory, Matilda, and other books they may have grown up with, lost his daughter to measles. It’s a big deal, it can kill and it’s preventable.
Reporters interested in talking with Hamilton should contact Greg Richter, assistant director, News & Media Relations, at gdr33@drexel.edu or 215.895.2614.
