Measles Outbreak Continues Across U.S.

Unvaccinated students in schools across the country may lead to a worsening measles outbreak this year—a little more than two decades after the disease was declared eliminated from the United States.

The CDC reports that measles cases have been increasing around the country, with the last weekly analysis showing a total of 45 measles cases reported by 17 jurisdictions: Arizona, California, Florida, Georgia, Illinois, Indiana, Louisiana, Maryland, Michigan, Minnesota, Missouri, New Jersey, New York City, Ohio, Pennsylvania, Virginia, and Washington, as of March 7,2014.

A strong childhood vaccination program all but eliminated measles from the United States in 2000, say officials, and although overall childhood vaccination rates remain high in the U.S., measles still occurs frequently in other parts of the world.

But childhood vaccinations have been in decline nationwide since the COVID pandemic, according to the CDC. Officials say this alarming trend could increase the "risk of outbreaks of vaccine-preventable diseases," including measles. The measles-mumps-rubella vaccine (MMR) is part of the national immunization schedule for all children and adults and provides 97 percent effectiveness at preventing measles.

The World Health Organization has noted a significant increase in measles cases worldwide, with a 30-fold increase in Europe.  This includes popular international tourist destinations for Americans, like England. Unvaccinated travelers can bring the disease back to the U.S., where it can spread pretty quickly.

One or two new cases can spread rapidly, says the CDC, due to the contagiousness of measles—one person can infect up to 90 percent of the people close to them if they are not protected by vaccination (or, less commonly, prior infection). The measles virus can stay in the air for up to two hours after an infected person leaves an indoor space, and someone can get infected by simply being in a room where a person with measles walked through. In addition, people with measles can transmit to others when their symptoms are fever, cough, and runny nose, which look like common respiratory viruses.

Measles can easily come to the United States by way of unvaccinated travelers, most commonly occurring when people who live in the United States visit countries where there are measles outbreaks. Once someone gets measles and returns to America, measles can spread if people in their community aren’t up-to-date on their vaccinations.

And while measles have not been much of a consideration over the past 20 years in the U.S., it nonetheless can be very serious—particularly in children younger than 5 years and adults older than 20 years, groups that are more likely to experience complications. On average, nearly 1 in 5 unvaccinated people in the United States who get measles need to be hospitalized.

Ten of the recent measles cases were recorded in Florida in February. Nine cases were children who live in Broward County—seven of those are students at one elementary school there.

About 94 percent of seventh graders in Florida completed the mandatory vaccinations needed for school, including the MMR vaccine, for the 2021-2022 school year, according to the most recent school immunization report available online through the Florida Department of Health. This is just below the 95 percent threshold recommended by the WHO.

Florida for several years had a vaccination rate of 95 percent or higher among seventh graders until COVID-19 struck in March 2020. The vaccination rate is lower among kindergarten students in Florida schools, mirroring a national trend, according to reports.

“Measles was declared eliminated in the United States in 2000, but is still the most easily transmitted human virus presently in circulation,” says Marcus Plescia, MD, MPH, Chief Medical Officer with the Association of State and Territorial Health Officials (ASTHO). “Thankfully, by following established public health principles, Americans can make informed decisions, prevent outbreaks, and protect our communities. Vaccination is the best and safest way to protect children…When community vaccination rates drop below 95 percent, however, outbreaks become more common because the disease can spread from one vulnerable person to another.”

In Michigan, three confirmed cases of measles are unrelated, according to the state’s Department of Health and Human Services.

“If you are not vaccinated for measles, get vaccinated as quickly as you can,” Dr. Natasha Bagdasarian, chief medical executive said in a statement last week. “We are seeing increased cases of measles abroad and outbreaks of measles across the United States in the setting of declining childhood vaccination rates. Now measles is in Michigan, and it’s important to make sure you protect yourself from this vaccine-preventable disease.”

With international travel continuing to increase and spring break and summer travel fast approaching, the CDC recommends an updated vaccination schedule, including MMR, to help curb the measles outbreak.