After the acute infection, the measles virus can remain hidden in the body from time to time and cause dangerous illness years later. (Photo credit: CDC/Allison M. Maiuri, MPH, CHES)
Measles kills between 1 and 3 out of every 1,000 children infected with the viral disease. But even for those who survive the disease, the long-term consequences can be serious. Long after recovery from the acute infection, the immune system is compromised – and in rare cases, the measles virus can hide in the nervous system, only to reactivate and cause dangerous disease many years later.
In the short term, measles, caused by a highly contagious virus, typically causes fever, respiratory symptoms such as cough, and a distinctive rash that spreads from the hairline down the body. It feels like “a bucket of rash” being dumped on your head, says Patsy Stinchfield, an infectious disease nurse and recent president of the nonprofit National Foundation for Infectious Diseases (NFID).
Because the two-dose measles, mumps, and rubella (MMR) vaccine is 97% effective at preventing measles, many health care professionals in the U.S. have never encountered the disease that is now causing major outbreaks in Texas and neighboring states, experts told Live Science. Incidence rates were so low in the U.S. that measles was declared eradicated in 2000.
However, in 2017, Stinchfield responded to a measles outbreak in Minnesota that affected many children.
“The kids who come into the emergency room and go home look like rag dolls in their parents' arms,” Stinchfield told Live Science. “They're miserable.”
According to the Centers for Disease Control and Prevention (CDC), 1 in 5 children who get measles will be hospitalized, and 1 in 20 will develop pneumonia, which is fatal in most children who die from the disease. Stinchfield added that some of those hospitalized children will need to be placed on a ventilator to recover.
About 1 in 1,000 cases of measles results in swelling of the brain, or encephalitis, which can cause seizures. If it is not fatal, the swelling may go away, but it can leave permanent brain damage and other long-term effects, such as blindness or deafness.
“Immune amnesia”
Even patients with mild cases of measles may experience long-term side effects.
Measles binds to receptors that are coincidentally present on several important immune cells: T cells, B cells, and long-lived plasma cells. These cells “remember” past infections for decades, allowing the immune system to quickly mount a defense when it encounters a pathogen again.
In the process, protective proteins known as antibodies are produced and other immune system defenders are recruited. However, a 2019 study found that after contracting measles, people lose between 11% and 73% of the antibodies they had from previous infections.
To recover from this so-called immune amnesia, a person would need to be reinfected with all of these diseases, said Stephen Elledge, a geneticist at Harvard Medical School and senior author of the 2019 study. At the same time, that means they become vulnerable to a variety of infections after having measles.
What's more, a 2015 study led by Elledge's colleague, epidemiologist Dr. Michael Min, found that children who contracted measles had higher rates of death from other infectious diseases in subsequent years.
These infectious diseases, including measles, are the main reason why nearly one in five children died before reaching age 5 in the United States in 1900. A 2024 study published in The Lancet estimated that vaccinations have increased by 1.5 percent since 1974.
Sourse: www.livescience.com
