() — Disease detectives with the U.S. Centers for Disease Control and Prevention (CDC) are investigating a cluster of rare and severe brain abscesses in children in and around Las Vegas, Nevada. . Doctors in other parts of the country say they may also be seeing a rise in cases.
In 2022, the number of brain abscesses in children tripled in Nevada, from an average of four to five a year to 18.
“In my 20 years of experience, I’ve never seen anything like it,” said Dr. Taryn Bragg, an associate professor at the University of Utah who treated the cases.
Pediatric neurosurgeons like Bragg are rare. She is the only one in the entire state of Nevada, and because she treated all the cases, she was the first to notice the pattern and alert local health authorities.
“Starting in March 2022, there was a huge increase” in brain abscesses, Bragg explains. “I was seeing a large number of cases and that’s unusual.”
“And the similarities in terms of the presentation of the cases was striking,” Bragg said.
In almost all cases, the children suffered from a common childhood ailment, such as earaches or sinus infections, with a headache and fever, but within a week, according to Bragg, it was clear that it was something more serious.
After a presentation on the cases from the Nevada Epidemic Intelligence Service Conference on Thursday, doctors in other parts of the country said they are seeing similar increases in brain abscesses in children.
“We’re shocked by the number of cases we’re seeing,” said Dr. Sunil Sood, a pediatric infectious disease specialist at Northwell Health, a New York health system. He estimates they’re seeing at least twice as much as usual, though they haven’t made a formal tally. Sood has urged the CDC to continue investigating and to work to spread the word.
Brain abscesses are not, in and of themselves, notifiable diseases, which means that doctors are not required to alert public health departments when they have these cases.
They usually only become known to public health officials when doctors see an increase and contact them.
Sanitary detectives in the case
Brain abscesses are pus-filled pockets of infection that spread to the brain. They can cause seizures, visual disturbances, or changes in vision, speech, coordination, or balance. The first symptoms are headaches and intermittent fever.
Abscesses often require multiple surgeries to treat, and children can spend weeks or even months in the hospital recovering from one.
In it Clark County urban conglomerateapproximately three quarters of the cases were male, and most were around 12 years of age.
Dr. Jessica Penney is the CDC’s Epidemic Intelligence Service officer, or “disease detective,” assigned to the Southern Nevada Health District, the health department that investigated the cases. She presented her research from the Clark County group at the CDC’s Epidemic Intelligence Service annual conference on Thursday.
Penney says that in trying to figure out what was driving the increase, they looked at a number of factors — travel, a history of Covid-19 infection, underlying health, common activities or exposures — and found nothing that link the cases.
So, he says, they decided to look back in time, looking for cases of brain abscesses in children under the age of 18 to 2015.
“I felt like that helped us get a better idea of what might be causing this,” Penney said in an interview with .
From 2015 to 2020, Penney says the number of brain abscess cases in Clark County was fairly stable at around four per year. In 2020, the number of brain abscesses in children dropped, likely due to measures like social distancing, school closures, and mask-wearing, things that shut down the spread of all kinds of respiratory infections, not just covid-19.
In 2021, when the restrictions began to be lifted, the number of these episodes returned to normal levels, and then in 2022, there was a big spike.
Is there a relationship with the pandemic?
“So the ideas are, you know, maybe in that period where kids didn’t have these exposures, you’re not building the immunity that you would typically have previously, you know with these viral infections,” Penney said. “So maybe at the other extreme, when we had these exposures without that immunity from the years before, we saw a higher number of infections.”
This is a theory called immunity debt. Doctors have recently observed unusual increases in a number of serious childhood infections, such as invasive group A strep. Some believe that during the pandemic years, by not exposing children to the amount of viruses and bacteria they would normally deal with, their immune systems became less able to fight infection.
Sood says that he is not convinced by the theory that there is some kind of immunity debt. Instead, he believes that covid-19 temporarily displaced other infections for a while, displacing others. Now, as Covid-19 cases have been declining, she believes other childhood infections are making a comeback; She points to the unprecedented rise in RSV cases this past fall and winter as an example.
According to Sood, brain abscesses usually follow a very small percentage of sinus and inner ear infections in children. As there are now more infections of this type, the number of brain abscesses has also increased proportionally.
If the cause were immunodeficiency or a higher infection burden, it stands to reason that brain abscesses might have increased elsewhere as well.
Last year, the CDC worked with the Children’s Hospital Association to find and count brain abscesses in children, to see if there was some kind of national spike. The data collected up to May 2022 did not detect any type of generalized increase, according to a published study in the Morbidity and Mortality Weekly Report last fall.
But Bragg thinks the data cutoff for the study may have been too early. She says the spring of 2022 was when she saw cases in her area really take off. She says the CDC continues to collect information on brain abscesses and assess local and national trends.
About a third of the brain abscesses in the Clark County group were caused by a type of bacteria called Streptococcus intermedius it normally hangs out harmlessly in the nose and mouth, where our immune systems keep it in check. But when it gets into places where it shouldn’t, like the blood or the brain, it can cause problems.
This can happen, for example, after dental work or when someone has an underlying disease that weakens their immune system, such as diabetes.
However, this was not the case for the children in the Clark County group.
“These are healthy children. No significant medical history that would make them more prone… there was no known immunosuppression or anything like that,” says Bragg.
Similar to the cases in Clark County, Sood says most of the children they are seeing are older, in elementary and middle school. He says that until children reach this age, their sinus cavities are underdeveloped, not fully grown yet. This can make them especially vulnerable to infection. He believes that these small spaces can fill with pus and burst. When this occurs above the eyebrow or behind the ear, where the barrier between the brain and sinuses is thinner, the infection can reach the brain.
According to Sood, the signs of a sinus infection in children can be subtle, and parents don’t always know what to expect. If a child comes down with a cold or stuffy nose and wakes up the next day with a red, swollen eye, or a closed, swollen eye, it’s a good idea to seek medical attention. He may also complain of a headache and point to the point above the eyebrow as the place of pain.
Looking for new cases
Bragg says that so far, in 2023, he has treated two other children with brain abscesses, but the rate of new cases seems to be slowing, at least he hopes so.
Some of the children he treated required multiple head and neck and brain operations to clear their infections.
Sood says that at his hospital, the doctors have a patient who has been there for two or three months and had five surgeries, although he says it was an extreme case.
Penney says the CDC continues to closely monitor the situation.
“We’re going to continue to monitor throughout the year working very closely with our community partners to see you know what, what happens in southern Nevada,” he said.