This article appeared on CNN Health. Read more here.
At least 41 measles cases have been reported in 16 states since the start of the year, according to the newest tally by the US Centers for Disease Control and Prevention.
That number is up from last week, when the CDC reported 35 cases in 15 states. Michigan is the new addition to the list, with one travel-related case of measles in Oakland County confirmed by the Michigan Department of Health and Human Services.
Florida has also seen an increase in measles cases this week after an outbreak at an elementary school in Weston led to nine confirmed cases in Broward County, according to the state’s Department of Public Health.
The outbreak made headlines after Florida Surgeon General Dr. Joseph Ladapo issued a letter that deferred to parents on whether to send unvaccinated children to school, directly contradicting CDC guidance that recommends unvaccinated children be excluded from school for 21 days after exposure.
The increases are concerning as the number of measles cases recorded across the US in the first two months of 2024 nears the total number — 58 — recorded all of last year.
In a statement Monday, the Association of State and Territorial Health Officials (ASTHO) said it is “alarmed” at the measles outbreaks in the United States.
“Measles was declared eliminated in the United States in 2000 but is still the most easily transmitted human virus presently in circulation. 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,” Dr. Marcus Plescia, chief medical officer of ASTHO, said in the statement.
The increase in measles cases is due in part to falling vaccination rates and to increased travel, which can result in unvaccinated people acquiring measles abroad and bringing it back to the US, according to the CDC.
Experts recommend that children get the measles, mumps and rubella or MMR vaccine in two doses: the first between 12 months and 15 months of age, and a second between 4 and 6 years old. One dose is about 93% effective at preventing measles infection; two doses are about 97% effective.
Nationwide, about 92% of US children have gotten the MMR vaccine by age 2, according to a 2023 report from the CDC – below the federal target of 95%.
The percentage of kindergartners who got their state-required vaccines for measles also remained below the federal target for the 2022-23 school year, according to CDC data. And the rate of vaccine exemptions for children has reached the highest level ever reported in the US.
Measles is a highly contagious disease that can lead to complications and turn deadly, according to the CDC. Symptoms may include fever, cough, runny nose, watery eyes and a rash of red spots. In rare cases, it may lead to pneumonia, encephalitis or death. Measles also can weaken the immune system and may “delete” its immune memory.
“Measles can be particularly serious for children and potentially deadly. At least 1 in 5 unvaccinated people in the United States who contract measles is hospitalized,” Plescia said.
The last significant measles outbreak in the US was in 2018-19 in Rockland County, New York, focused among unvaccinated children in Orthodox Jewish communities. In 2019, the US had 1,274 cases of measles in 31 states, the highest number of cases reported since 1992, according to the CDC.