Measles, a highly contagious and preventable disease, is re-emerging across the United States, raising a warning about the dangers of the growing anti-vaccination movement.
The Centers for Disease Control and Prevention has recorded more cases this 12 months than the 58 reported in all of 2023, although the agency isn’t expected to release exact numbers until Friday. On Monday, the agency advised health care providers to ensure that unvaccinated patients, especially those traveling abroad, are kept up to date on their vaccinations.
The number of cases will likely proceed to rise due to a surge in measles cases around the world, in addition to spring travel to some regions where there are outbreaks of the disease, including the United Kingdom, said Dr. Manisha Patel, medical director in the division of respiratory diseases CDC.
Nearly all of the U.S. cases to this point involve unvaccinated travelers. “We will not see widespread cases of measles across the country,” Dr. Patel said. “But we expect there will be additional cases and outbreaks.”
Measles is one of the most contagious diseases; each infected person can transmit the virus to up to 18 other people. The virus is airborne and might remain in the air for up to two hours after an infected person leaves the room, spreading rapidly through homes, schools and child care facilities.
In Chicago, one case of measles was reported at an immigrant shelter increased to 13, prompting the CDC to send a team to help contain the epidemic. (Two additional cases in the city appear to be unrelated.)
In Florida, seven elementary school students contracted measles, despite the fact that the state’s surgeon general, Dr. Joseph Ladapo, left it up to parents to resolve whether unvaccinated children should attend school.
In Southwest Washington, officials identified measles in six unvaccinated adult members of a family living in two counties. And in Arizona, a world traveler infected with measles dined at a restaurant and transmitted the virus there at the least two others.
Measles was eliminated in the United States in 2000, and customarily speaking, American children should be vaccinated to attend school. However, sporadic cases lead to larger epidemics every few years. But now declining vaccination rates, exacerbated by the coronavirus pandemic, have experts frightened about a renewed surge in vaccinations.
When vaccinations are delayed, “the first disease to show up is measles because it’s highly contagious,” said Dr. Saad Omer, dean of the O’Donnell School of Public Health at UT Southwestern in Dallas.
According to the CDC, nine out of 10 unvaccinated individuals who come into close contact with a measles patient will change into infected
Measles is far less deadly in countries with high vaccination rates and good medical care. Fewer than three in 1,000 American children with measles will die from serious complications reminiscent of pneumonia or encephalitis, which is swelling of the brain.
Still around one in five individuals with measles could also be hospitalized.
Because widespread measles outbreaks have been rare, most Americans, including doctors, may not recognize the vivid red rash that accompanies respiratory symptoms when infected with measles. They can have forgotten the impact of the disease on individuals and communities.
“Most people in the local health department have never seen a measles outbreak,” said Dr. Christine Hahn, epidemiologist for the state of Idaho, which reported a small cluster of cases last 12 months.
“Responding to the next epidemic will be a major challenge for us,” she said.
It is estimated that before the first measles vaccine was introduced in the Sixties, the disease killed 2.6 million people worldwide annually. But its full impact might have been much greater.
Measles weakens the immune system, making it easier for other pathogens to enter the body. 2015 the study estimated that measles could have caused as many as half of all deaths from infectious diseases in children.
For about a month after an acute illness, measles can stun the body’s first response to other bacteria and viruses, said Dr. Michael Mina, chief science officer at the digital health company eMed and a former epidemiologist at the Harvard TH Chan School of Public Health.
This makes patients “very susceptible to bacterial pneumonia and other diseases,” said Dr. Mina, lead creator of the 2015 study.
“It is very risky for people in the first few weeks after measles,” he added.
The virus also causes a kind of amnesia of the immune system. Usually the body “remembers” the bacteria and viruses it fought previously. Doctor Mina and his colleagues showed in 2019 that individuals with measles lose between 11 and 73 percent of their hard-won immune repertoire, and this loss can last for years.
This doesn’t mean that the body doesn’t recognize these pathogens in any respect, nevertheless it reduces the arsenal of weapons available to fight them.
“People should be aware that by choosing not to vaccinate, they are putting themselves and their families in this situation,” said Dr. Mina.
The CDC recommends receiving the first dose of the measles vaccine at age 12 months and the second dose at age 4 to 6 years. Even a single dose of the vaccine is 93% effective. Measles vaccination prevented 56 million deaths According to the World Health Organization in 2000–2021.
Vaccination rates in the United States have shown a clear, although small, immerse to 93 percent in the 2022–23 school 12 months from 95 percent in the 2019–20 school 12 months – the level required to protect all community members. Vaccination exemption rates increased in 40 states and the District of Columbia.
IN study last 12 months, just over half of Republicans said public schools should require measles vaccinations, up from about 80 percent before the pandemic. (Vaccine support amongst Democrats stays regular.)
While vaccination rates could also be high at the national or state level, there could also be areas of low vaccination rates that provide kindling for the measles virus, Dr. Omer said.
If the number of unvaccinated cases becomes sufficient to sustain the epidemic, even those that have been vaccinated but whose immunity can have waned are vulnerable, he added.
In Idaho, 12 percent of preschool children don’t have any vaccination history. Some of the gaps are because parents are unable or unwilling to share data with schools, not because their children are not vaccinated, Dr. Hahn said.
Still, online schools, which have proliferated during the pandemic and remain popular in the state, have amongst the highest rates of vaccine exemptions, she added.
In September, a young man from Idaho brought measles back from a trip abroad and have become unwell enough to get you to hospital. Along the way, he exposed fellow passengers on two flights, dozens of health care staff and patients, and nine unvaccinated members of the family. All nine developed measles.
Dr. Hahn said Idaho was “very lucky” with the outbreak because the family lived in a distant area. However, there are likely many other areas in the state where it’ll be difficult to contain the epidemic.
“We have plenty of tinder, if you don’t mind,” she added.
In recent years, several large epidemics have occurred amongst large groups of unvaccinated people, including unvaccinated people Amish in Ohio and the Orthodox Jewish community in New York.
In September 2018, one unvaccinated child returned to New York from Israel carrying the measles virus detected during the outbreak in that country.
Although vaccination rates remain high in the city, this single case sparked an epidemic that raged for nearly 10 months and was the country’s largest in a long time. The city declared a public health emergency for the first time in over 100 years.
“We had over 100 chains of transmission,” said Dr. Oxiris Barbot, then the city’s health commissioner and now president and CEO of the United Hospital Fund.
“It was a challenge to keep it all organized,” he recalls. “And having to examine over 20,000 of these exposures was huge.”
Working with community leaders, city officials rushed to administer about 200,000 doses of the vaccine. More than 550 city employees participated in the effort, and the final cost to the city health department exceeded $8 million.
The CDC is working with state and native health departments to discover areas with low vaccination rates and prepare them for outbreaks, Dr. Patel said. The agency can be training health care staff to recognize the symptoms of measles, especially in patients who’ve traveled abroad in the past.
Measles is a slippery foe, but the public health sector knows full well the tools needed to stop it: screening, contact tracing and vaccinating susceptible people.
“We are not helpless observers,” said Dr. Omer. “The focus needs to be on public health regarding meat and potatoes.”
Audio produced by Tally Abecassis.
