Measles, a highly contagious but preventable disease, is making a resurgence in parts of the United States, raising a warning about the dangers of strengthening the anti-vaccination movement.
The U.S. Centers for Disease Control and Prevention (CDC) has recorded more cases this year than in all of 2023, which was 58, although the agency is not expected to release exact numbers until Friday. On Monday, the agency recommended that health care providers ensure that unvaccinated patients, especially those traveling abroad, are up to date on their immunizations.
Dr. Manisha Patel, chief medical officer for the division of respiratory diseases at the Centers for Disease Control and Prevention, said the number of cases is likely to continue to rise due to a sharp increase in measles cases worldwide and spring travel to some outbreak areas, including the United Kingdom. .
Nearly all cases in the U.S. so far have been linked to unvaccinated travelers. “We’re not going to see widespread spread of measles cases across the country,” Dr. Patel said. “But we do expect more cases and outbreaks to occur.”
Measles is one of the most contagious diseases; each infected person can spread the virus to up to 18 people. The virus is airborne and can remain airborne for up to two hours after an infected person leaves a room, spreading rapidly through homes, schools and child care facilities.
In Chicago, a case of measles emerges in immigrant shelter grew to 13, prompting the CDC to send a team to help control the outbreak. (Two other cases in the city appear to be unrelated.)
In Florida, seven students at an elementary school contracted measles, even though Dr. Joseph Ladapo, the state’s health director, let parents decide whether unvaccinated children should attend school.
In Southwest Washington, officials discovered measles in six unvaccinated adult members of a family living in two counties.In Arizona, an international traveler infected with measles dined at a restaurant and spread the virus to at least two others.
Measles was eliminated in the United States in 2000, and American children generally must be vaccinated before going to school. However, every few years, sporadic cases lead to larger outbreaks. But now, the coronavirus pandemic has exacerbated the decline in vaccination rates, and experts fear a resurgence.
When vaccinations lag, “the disease that shows up first is measles because it’s highly contagious,” said Dr. Thad Omar, dean of the O’Donnell School of Public Health at UT Southwestern in Dallas.
According to the Centers for Disease Control and Prevention (CDC), 9 out of 10 unvaccinated people who come into close contact with someone with measles will become infected
Measles is much less deadly in countries with high immunization rates and good health care. For every 1,000 American children who get measles, fewer than 3 will die from serious complications such as pneumonia or encephalitis (brain swelling).
Nonetheless, regarding one fifth People with measles may end up in the hospital.
Because widespread measles outbreaks are rare, most Americans, including doctors, may not recognize the bright red rash that accompanies a measles infection with respiratory symptoms. They may forget the impact this disease has on individuals and communities.
“Most of our local health department personnel have never seen a measles outbreak,” said Dr. Christina Hahn, an epidemiologist in Idaho, which saw a small cluster of cases last year.
“If the next outbreak occurs, our response will be a huge challenge,” she said.
Before the first measles vaccine was introduced in the 1960s, the disease was estimated to cause 2.6 million people worldwide Per year. But its full impact could be much greater.
Measles weakens the immune system, making it easier for other pathogens to enter the body. 2015 research estimates Measles may account for half of all childhood infectious disease deaths.
About a month after acute illness occurs, measles disrupts the body’s first response to other bacteria and viruses, said Dr. Michael Mina, chief scientific officer of digital health company eMed and a former epidemiologist at the Harvard T.H. Chan School of Public Health. reaction.
This leaves patients “highly vulnerable to bacterial pneumonia and other illnesses,” said Dr. Mina, lead author of the 2015 study.
“For people in the first few weeks after measles, it’s very dangerous,” he added.
The virus also induces a form of immune system amnesia. Normally, the body “remembers” bacteria and viruses it has fought previously.Dr. Miner and colleagues Showcase 2019 Measles patients lose 11% to 73% of their hard-won immune systems, a loss that can last for years.
This doesn’t mean the body no longer recognizes these pathogens, but it does narrow the arsenal of weapons available to fight them.
“People should be aware that if they choose not to get vaccinated, this is the situation they are putting themselves and their families in,” Dr. Miner said.
The CDC recommends getting the first dose of measles vaccine after 12 months of age, and the second dose between 4 and 6 years of age. Even a single dose of the vaccine is 93% effective.Measles vaccination 56 million deaths averted Between 2000 and 2021, according to the World Health Organization.
U.S. vaccination rates show significant (albeit small) dip Increase from 95% in the 2019-20 school year to 93% in the 2022-23 school year – the level needed to protect everyone in the community.Vaccination exemption rate Increase 40 states and the District of Columbia.
in a last year’s surveyMore than half of Republicans say measles vaccinations should be required in public schools, compared with about 80% before the pandemic. (Support for vaccines remains steady among Democrats.)
Dr. Omar said that while vaccination rates may be high at the national or state level, there may be places where vaccination rates are lower, providing a trigger for the measles virus.
If there are enough unvaccinated cases to sustain an outbreak, even those who have been vaccinated but may have reduced immunity could be vulnerable, he said.
In Idaho, 12 percent of kindergarten-age children have no vaccination records. Dr. Hahn said part of the gap is due to parents being unable or unwilling to share records with schools, not because their children are not vaccinated.
Still, online schools, which have surged during the pandemic and remain popular in the state, have some of the highest vaccine exemption rates, she said.
In September, a young Idaho man became ill after bringing home measles from international travel. Enough to be hospitalized. Along the way, he exposed other passengers on two flights, dozens of health care workers and patients, and nine unvaccinated family members. All nine developed measles.
Dr. Hahn said Idaho has been “very lucky” during this outbreak because the family lives in a remote area. But there are many other areas of the state where the outbreak is likely to be difficult to control.
“We have a lot of Tinder, if you will,” she added.
In recent years, some large outbreaks have occurred among large unvaccinated populations, including Amish in Ohio and the Orthodox Jewish community in New York City.
In September 2018, an unvaccinated child returned to New York City from Israel with measles virus contracted during an outbreak in that country.
Although the city has maintained high vaccination rates, the single case sparked an outbreak that lasted nearly 10 months and was the country’s largest in decades. The city declared a public health emergency for the first time in more than a century.
“We had over 100 chains of transmission,” said Dr. Oxiris Barbot, the city’s health commissioner at the time and now president and CEO of the United Hospital Foundation.
“It was a challenge to keep all that going,” she recalls. “And with over 20,000 of these incidents to investigate, that’s a huge number.”
City officials worked with community leaders to administer about 200,000 doses of vaccine on an emergency basis. More than 550 city staff were involved in the response, resulting in losses to the city’s health department of $8 million.
Dr. Patel said the CDC is working with state and local health departments to identify areas with lower vaccination rates and prepare for outbreaks. The agency is also training health care providers to recognize measles symptoms, especially in patients with a history of international travel.
Measles is a cunning adversary, but public health departments are well versed in the tools needed to control it: screening, contact tracing and vaccinating those who are susceptible.
“We are not helpless bystanders,” Dr. Omar said. “The focus needs to be on the public health of meat and potatoes.”
