Measles is not just a rash and fever.
The outbreak of the disease in West Texas has sent 29 people, most of them, to hospitals, as they continue to grow. Two people have died, including a six-year-old child.
It remains to be seen how many people have become ill in the outbreak. There have been at least 223 confirmed cases, but experts believe hundreds more people may have been infected since late January. As public health officials try to slow the spread of the highly contagious virus, some experts are worried about long-term complications.
Measles is different from other childhood viruses that come and go. In severe cases, it can cause pneumonia. According to the Centers for Disease Control and Prevention, approximately one in 1,000 patients develop encephalitis or encephalitis or encephalitis, with one or two deaths in 1,000 people.
This virus can wipe out the immune system, a complication known as “immune amnesia.”
When you get sick with a virus or bacteria, the immune system has the ability to form memories that can quickly recognize and respond to pathogens if they are encountered again.
Measles targets cells in the body, such as plasma cells and memory cells, and contains their immunological memory, and destroys some of them in the process.
“No one can escape this,” said Dr. Michael Mina, a vaccine expert and a former professor of epidemiology at the Harvard Chan School of Public Health.
In a 2019 survey, Mina and his team discovered that measles infections can be wrecked from anywhere 11% to 73% of human antibody stockpiledepends on how serious the infection is. This means that if people had 100 antibodies to Chicken Pox before they developed measles, they would be left at just 50 after measles infection, potentially catching them and getting sick.
Iwasakimon, professor of immunology at Yale University School of Medicine, said: You forget who the enemy is. ”
Virtually everyone who contracts measles weakens the immune system, but some are hit harder than others.
“There's no world where you get measles and it won't destroy some [immunity]He said. “The problem is that it will destroy enough to have clinical impact.”
In a previous study in 2015, Mina presumed that the virus was a virus before vaccination, when measles was common It may be related to half of childhood deaths due to infectionmainly from other diseases such as pneumonia, sepsis, diarrheal diseases, meningitis.
Researchers found that after measles infection, the immune system was suppressed almost immediately and remained intact for two to three years.
“Immune amnesia begins as soon as the virus replicates in them [memory] Cells,” Mina said.
The best protection against serious complications is the measles vaccine. Two doses of the vaccine are 97% effective in preventing infection.
What is “immune amnesia”?
Our bodies are constantly exposed to a variety of bacteria and viruses in our environment. Over time, our immune system learns to remember a particular intruder and can take action immediately if we find something that doesn't belong to our body.
“Children are in contact with all sorts of microorganisms, and most of those encounters have not led to illness,” said Dr. Adam Ratner, pediatrician and director of the Department of Pediatric Infectious Diseases at NYU Langone Health. “Children often recover and have memories, so if they see the same strain of the virus that causes diarrhea, they will be the second disease they are exposed to.”
With immune amnesia, he said that if people are exposed to strains of the same virus again, their bodies will act as if it was the first time they had it and they don't have that robust protection.
This means that the measles virus can destroy the immunity that people have accumulated over time, such as pneumonia, colds, flu, bacteria, and more that can cause other pathogens.
Mina elicited a comparison with HIV, saying that the level of immunosuppression in severe measles infection can be compared to HIV that has not been treated for years. However, he warned that HIV affects various parts of the immune system, and that people's immune systems can ultimately recover from measles.
How does measles destroy the immune system?
Highly contagious viruses can destroy long-lived plasma cells that are present in the bone marrow and are essential to the immune system. Cells are like factories that expel antibodies to protect us from intruders entering our bodies.
“It's almost like bombing a sacred city,” Mina said.
Measles also targets cells in our body, called memory cells. This is a cell that remembers what intruders look like, allowing the immune system to quickly identify and fight them in the future.
When you breathe a virus, it is enveloped in cells called macrophages. Macrophages function as “trojan horses” to collect viruses in lymph nodes, Iwasaki said.
Once there, the virus can bind and destroy these memory cells, wiping away some of our built-in immunity in the process.
“one time [memory cells] As it is excluded, we basically no longer have any memory of those specific pathogens, so we are more susceptible to most infectious diseases that are unrelated to measles,” Iwasaki said.
Will the immune system recover?
The way your body begins to regain immune memory after being surrounded by measles is to be exposed to other viruses and bacteria, get sick again, and boost your immune system.
Such immunity can be relearned, but University of Pennsylvania immunologist John Welley says that while such immunity can be relearned, he is particularly susceptible to other infectious diseases.
“As every parent of a daycare child knows, if you'’re building a lot of immunity at the time, you’re suffering through it,” Welley said.
Mina relearned our immunity and compared it to why babies seem to get sick frequently.
“The illness a baby gets is not because the baby is more vulnerable, because they don't have the same immunological memory set yet,” he said. “They have to spend several years accumulating it through exposure, which is kind of what people experience after measles.”
How Measles Causes Brain Inflammation
What's even more frightening is an untreated measles complication called subacute sclerosing pan encephalitis (SSPE), a brain disease that can occur for more than a decade, which is fatal after someone recovers from an infection.
For poorly understood reasons, the measles virus can cause persistent infections and lead to brain damage, leading to cognitive decline, coma, and death.
Researchers believe that SSPE was once considered rare, but is more common than realization. a Review of measles cases in California From 1998 to 2015, SSPE cases were found to occur at a higher rate than expected among children who were not vaccinated.
Dr. Bessie Gibberge, a pediatric infectious disease expert at Northwest Medicine, said the disease is progressive and symptoms occur at normal stages.
“It can start with just a change in personality and a change in behavior,” she said. In children, it can be as subtle as worse performance in school.
The disease then progresses and can eventually lead to seizures and abnormal movements, Siebarghese said. Finally, parts of the brain that regulate vital signs such as breathing, heart rate, and blood pressure can be damaged and can lead to death.
There is no cure for this disease and is almost always fatal. Patients usually survive 1-3 years after diagnosis. In the US, there are usually four to five cases each year, which can be underestimated, says Ratner of Nyu Langone Health.
“It’s probably more common than we think because it’s not always diagnosed,” he said. “But as these outbreaks become more common, I think we will clearly see more cases of SSPE.”
