Doctors watch for more cases after mysterious cluster of brain infections strikes children in southern Nevada

CNN
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Disease detectives from the United States Centers for Disease Control and Prevention are investigating a cluster of rare and severe brain abscesses in children in and around Las Vegas, and doctors in other parts of the country say they could also see an increase in cases. .

By 2022, the number of childhood brain abscesses has tripled in Nevada, from an average of four to five per 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 handled the cases.

Pediatric neurosurgeons like Bragg are rare. She’s the only one for the entire state of Nevada, and because she handled all of the cases, she was the first to notice the pattern and alert local public health officials.

“After March 2022, there was only a huge increase,” Bragg said. “I was seeing a large number of cases and that’s unusual.”

“And the similarities in terms of case presentation were striking,” Bragg said.

In almost all cases, the children would have a common childhood problem, such as an earache or sinus infection, along with a headache and fever, but within a week or so, Bragg says, it would become clear. that something more serious was happening.

After a presentation on the Nevada cases at the Epidemic Intelligence Service conference on Thursday, doctors in other parts of the country said they were seeing a similar increase in brain abscesses in children.

“We’re just in awe of the number of those we’re seeing right now,” said Dr. Sunil Sood, a pediatric infectious disease specialist at Northwell Health, a health system in New York. He estimates that they are seeing at least twice as many as usual, although they have not made an official count. He urged the CDC to continue its investigation and work to get the word out.

Brain abscesses are not, in and of themselves, reportable conditions, meaning doctors are not required to alert public health departments when they have these cases.

They usually only come to the attention of public health officials when doctors notice increases and contact them.

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 a fever that comes and goes. Abscesses often require multiple surgeries to treat, and children can spend weeks or even months in the hospital recovering from one.

In the Clark County Groupabout three-quarters of the cases were in boys, and most were around 12 years old.

Dr. Jessica Penney is the CDC’s Epidemic Intelligence Officer, or “disease detective,” assigned to the Southern Nevada Health District, the health department that investigated the cases. She presented his investigation from the Clark County cluster at the CDC’s Epidemic Intelligence Service annual conference on Thursday.

Penney says that as they tried to figure out what was causing the increase, they looked at a host of factors – travel, history of Covid-19 infection, underlying health, activities or exposures common – and they didn’t find anything related to the cases.

Then, she says, they decided to go back in time, looking for cases of brain abscesses in children under 18 to 2015.

“I felt like it helped us get a better idea of ​​what might be contributing to it,” Penney said in an interview with CNN.

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 has plummeted, likely due to measures such as social distancing, school closures and masking – things that have stopped the spread of all kinds of respiratory infections, not just Covid-19. In 2021, as restrictions began to be lifted, the number of such events returned to normal levels, and then in 2022, a big spike.

“So the thoughts are, you know, maybe in this period when kids didn’t have these exposures, you’re not building the immunity that you would usually get before, you know with these viral infections,” said said Penney. “And so maybe at the other end, when we had those exposures without that immunity from previous years, we saw a higher number of infections.”

It’s a theory called the immunity debt. Doctors have recently seen unusual increases in a number of serious childhood infections, such as invasive group A strep. Some believe that during the pandemic years, because children were not exposed to the number of viruses and bacteria they might normally encounter, it made their immune system less able to fight infections.

Sood said he was unconvinced by the theory that there is some sort of immunity debt at work. Instead, he thinks Covid-19 temporarily displaced other infections for a while, essentially crowding out the others. Now, as Covid-19 cases have plummeted, he believes other childhood infections are making a comeback – he cites the unprecedented spike in RSV cases last fall and winter as an example.

Sood says brain abscesses normally follow a very small percentage of sinus infections and inner ear infections in children. Because they are seeing more of these infections now, the number of brain abscesses has also risen proportionately.

If immune debt or a higher burden of infections were to blame, it stands to reason that brain abscesses might have increased in other places 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 sort of national spike. Data collected through May 2022 has not detected any kind of widespread increase, according to a study published in the Morbidity and Mortality Weekly Report last fall.

But Bragg thinks the data deadline for the study may have been too soon. 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 that normally hangs around harmlessly in the nose and mouth, where our immune system controls it. But when it gets into places it shouldn’t be, like the blood or the brain, it can cause problems.

This can happen after dental work, for example, or when a person has an underlying health condition that weakens their immunity, such as diabetes.

That wasn’t the case with the children in the Clark County group, however.

“These are healthy children. With no significant medical history that would make them more vulnerable…there was no known immunosuppression or anything like that,” Bragg says.

Like the cases in Clark County, Sood says most of the kids they see are older, in grade school and middle school. He says that until children reach this age, their sinus cavities are underdeveloped and have not yet reached full size. This can make them particularly vulnerable to infections. He thinks these small spaces may fill with pus and burst. When this happens above the eyebrow or behind the ear, where the barrier between the brain and the sinuses is thinner, the infection can spread to the brain.

Sood says the signs of a sinus infection in children can be subtle, and parents don’t always know what to look out for. If a child has a cold or stuffy nose and the next day wakes up with a red, swollen eye, or a swollen closed eye, it’s a good idea to see a doctor. They may also complain of a headache and point to the area above their eyebrow as the location of the pain.

Bragg says so far in 2023 she’s treated two more children with brain abscesses, but the pace of new cases seems to be slowing down — at least, she hopes that’s the case.

Some of the children she cared for required multiple brain, head and neck surgeries to clear their infections.

Sood says doctors at his hospital have a patient who has been there for two to three months and has had five surgeries, although he says she was an extreme case.

Penney says the CDC continues to monitor the situation closely.

“We will continue to monitor throughout the year working very closely with our community partners to see what is happening in southern Nevada,” she said.