Whenever Asher Berglin met someone for the first time, he had a bright introduction ready.
“Hi, I’m Asher. Asher means happy,” he would say, smiling.
His mother, Jill, says the name was an especially appropriate one for her son.
Asher was lively, outspoken and endlessly inquisitive. He enjoyed school, filled his schedule with extracurricular activities and was constantly looking for something new to discover.
That changed with startling speed in the summer of 2024, when Asher was 13.
The transformation came not long after he had been ill with a sore throat.
Jill said her son’s personality “just kind of flipped.” He abruptly began experiencing debilitating obsessive-compulsive disorder (OCD) symptoms and vocal tics so severe that completing a sentence became difficult.
Asher Berglin, now 15, had been in excellent health before the illness began taking its toll in 2024
Jill described Asher as outgoing and independent before his illness, but said severe OCD symptoms later left him dependent on her
His anxiety soon became all-consuming. A boy who had once pleaded to ride his bicycle to school alone could no longer leave his bedroom without holding tightly to his mother.
He also began having powerful outbursts, screaming and kicking the wall—actions Jill said were entirely unlike the child she knew.
“He would scream for hours, then suddenly stop,” she said. “Afterward, he could discuss what had happened and apologize.”
Looking for an explanation, Jill researched the symptoms and discovered two relatively little-known conditions: pediatric acute-onset neuropsychiatric syndrome (PANS) and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS).
PANS refers to the sudden emergence of serious neuropsychiatric symptoms in children, including OCD, anxiety, tics and striking changes in mood or behavior.
PANDAS is a related condition specifically associated with Group A streptococcal infections, including strep throat and scarlet fever.
Some experts believe an infection can prompt an unusual immune response that affects the brain. However, the precise causes of PANS—and the extent of infections’ role—remain matters of scientific debate.
Jill said she was referred from one doctor to another before she eventually brought up PANS and PANDAS with Asher’s pediatrician. The pediatrician then sent him to a specialist.
According to Jill, the specialist said there was no doubt Asher had PANDAS and described the case as among the most severe they had seen. The doctor also believed Asher’s earlier sore throat was connected to the sudden appearance of his symptoms, she said.
Asher developed severe PANDAS symptoms after falling ill with a sore throat. He is pictured with his mother during an infusion treatment in February 2026. Source: Jill Berglin/Instagram
And, worryingly, Asher’s experience is not an isolated one.
Parents of children with PANS and PANDAS, speaking to the Daily Mail, say they spent months or even years searching for an explanation for dramatic changes in their children’s behavior – often while they were treated primarily for psychiatric symptoms.
And now, emerging research is raising a troubling possibility: that difficult-to-detect infections could be the cause, at least in some cases.
Among those under scrutiny are bartonella and babesia – pathogens spread primarily by fleas and ticks – after researchers found evidence of the infections in a small group of chronically ill young people who had experienced severe suicidal thoughts or died by suicide.
Babesia is a parasite that infects red blood cells, while bartonella is a group of bacteria that can infect red blood cells and the cells lining blood vessels.
Babesia, in particular, is spreading rapidly across parts of the US. The number of reported cases of babesiosis more than doubled from 1,742 in 2014 to a record 3,586 in 2023, according to the latest CDC figures.
Once concentrated largely in a handful of states in the Northeast and Midwest, the infection has also been spreading into new areas. Maine, New Hampshire and Vermont, for example, were not previously considered states where babesiosis was endemic but have since seen significant increases in cases.
The true scale of bartonella infection is harder to establish because, unlike babesiosis, it is not nationally reportable. An earlier CDC study estimated that around 12,000 Americans a year are diagnosed with cat-scratch disease – the most common form of bartonella infection in the US – with around 500 hospitalized.
But experts say some bartonella infections can be difficult to detect, meaning the number of diagnosed cases may not reflect the true prevalence.
Both infections have been linked in research to neurological and psychiatric symptoms, although there is currently insufficient evidence to establish that either directly causes severe psychiatric illness.
So how could a bug bite trigger symptoms that appear psychiatric – and why might doctors miss it?
One theory is that the immune response to an infection can go haywire and attack healthy tissue, potentially affecting the brain and triggering severe OCD, intrusive thoughts, rage, mood swings, tics and even suicidal thoughts.
Crucially, these symptoms may emerge after the initial infection has passed – meaning routine tests may no longer reveal an obvious cause.
Dr Shannon Delaney, a New York neuropsychiatrist who has studied the possible role of infections in psychiatric illness and treats patients with complex symptoms linked to PANS and tick-borne disease, says these infections can be particularly difficult to spot.
‘When people think about an infection, they often think about an acute illness – fever, flu-like symptoms or other obvious signs that someone is sick,’ she said.
‘But most patients I see with chronic neuropsychiatric symptoms related to these infections never experienced an obvious acute phase. Instead, they developed neuropsychiatric symptoms later, presumably after an initial infection that went unnoticed.’
Delaney is also the lead author of a 2024 study that found evidence of bartonella in 43 percent of patients with psychosis, compared with 14 percent of healthy controls.
But perhaps the most striking findings emerged from a recent case series involving six chronically ill young people.
Four had died by suicide. Another died after receiving medical aid in dying following prolonged severe illness, while the sixth, who had experienced suicidal thoughts, died from another medical condition.
Researchers tested postmortem blood, tissue and urine using methods including blood cultures and DNA sequencing.
Five of the six had confirmed evidence of infection with babesia, bartonella or both.
The findings cannot establish that the infections caused their psychiatric symptoms or contributed to their deaths – and a six-person case series is far too small to determine how common such an association might be.
But the researchers argue the possibility warrants further investigation.
Two of the parents whose children were included in the study have spoken to the Daily Mail about their children’s illnesses – and why they believe doctors should be looking more closely at the possible role of infection.
Louisa Johnson, nicknamed Lulu, was 11 when she was diagnosed with PANDAS
Lulu’s notebook, where she tried to illustrate how her disease felt in her brain
After the doctors discovered she had bartonella infection, she received treatment for 10 days before she died by suicide
Among the six young people included in the study was Louisa Johnson, known to her family as Lulu.
Her mother, Alissa, remembers an intelligent, sociable 11-year-old who earned straight As, loved dancing, theater and singing and showed no signs of anxiety or depression.
Then, on January 2, 2019, ‘her mind and body changed overnight.’
Lulu had recently recovered from a five-day illness involving fever, fatigue and nausea. Within days, she stopped eating normally, barely slept and became profoundly fatigued.
After repeated hospital visits, she complained of a persistent sore throat and eventually tested positive for strep.
Antibiotics initially appeared to help. But two months later, after a stomach bug, Alissa says Lulu suddenly developed extreme agitation, rage and compulsive behavior.
‘By the time we left the doctor’s office and were driving home, she was kicking the back of the seat while I was trying to drive and yelling,’ Alissa said.
Blood tests subsequently showed elevated antibodies associated with a previous strep infection, and Lulu was diagnosed with PANDAS.
At one point, Alissa says, Lulu’s OCD was so extreme that she could not persuade her to leave the bathroom for a blood test and eventually called 911.
Lulu gradually improved during treatment in 2020, but later deteriorated again.
In May 2021, she tested positive for bartonella.
Ten days before her death, she began treatment for the infection. Alissa says her neuropsychiatric symptoms then suddenly intensified.
On the day she died, Lulu was exhausted, irritable and suffering chronic pain. Alissa left her resting in her bedroom.
Top row from top left: Alec Dulude, Emma Soorikian, Valerie Lindner and bottom row from left: Jake Picker, Louisa Johnson, Alex Manfull. All were found in postmortem tests to have bartonella or babesia infection
Henry Lindner and his daughter Valerie, who died in 2023 at age 30 due to a complication from her disease
A scan of Valerie’s brain before she underwent treatment for her infection. The scan shows areas that are more active than normal, particularly in regions involved in movement and emotions. This may indicate inflammation. Other areas are less active than normal, suggesting the brain cells in those regions are not working properly. On the scan, lighter areas show more activity, while darker areas show less
A follow-up scan of Valerie’s brain 18 months after she was treated for infection. The scan shows that activity in the outer layers of the brain has improved on both sides. However, some areas deep inside the brain are still more active than normal
Later that day, Lulu left the family home and died after jumping in front of a train.
Alissa does not believe her daughter wanted to die.
‘The illness can cause intrusive thoughts, including suicidal intrusive thoughts,’ she said. ‘But she wanted to feel better. She wanted to have her life back.’
Postmortem testing subsequently found evidence of bartonella and babesia – making Lulu one of five young people in the study in whom researchers detected one or both pathogens.
Since Lulu’s death, Alissa has become a co-founding member of the National Alliance for PANS/PANDAS Action and is campaigning for more research into infection-associated neuropsychiatric conditions, better diagnostic testing and greater access to treatment.
Another young person included in the study was Valerie Lindner, 30, whose father, neurologist Dr Henry Lindner, 68, describes her as his ‘best friend, best colleague, best patient and beloved daughter.’
Henry says Valerie had struggled since childhood with an attachment disorder that affected her ability to experience love, joy and happiness. To cope, she would lose herself in her imagination and write fantasy stories.
But he says her health deteriorated dramatically after she was bitten by two deer ticks at age ten in 2003.
She developed no obvious fever or rash, but over the following years became increasingly depressed and suicidal.
Despite her illness, Valerie excelled academically. She began taking college courses at 14 and, in 2016, graduated as the top STEM student at Penn State University.
By then, however, her physical health was deteriorating. She became disabled and her psychiatric symptoms worsened.
As a neurologist, Henry became convinced there was a physical component to his daughter’s illness.
‘That’s when it clicked in my head that she has to have some form of encephalitis,’ he said, referring to inflammation of the brain.
Lyme disease is a tick-borne illness typically caused by the bacterium Borrelia burgdorferi transmitted by a deer tick. Co-infections can occur from Lyme disease, such as bartonella and babesia
Initial infection tests were negative. But after Henry sought testing from a specialist laboratory, he says Valerie tested positive for bartonella and babesia.
She began treatment in 2018 and improved enough to return to graduate school in physics in 2022.
The following year, however, after contracting a cold, Valerie developed a severe immune reaction known as hemophagocytic syndrome and died.
‘The terrible infections that ruined her life ended up taking her life,’ Henry said.
Henry says the postmortem findings did not surprise him. He has since campaigned for greater awareness of bartonella and babesia on a state and federal level, along with advocating for more research into the infections’ potential long-term effects.
‘You see your child suffering mentally, emotionally, and you don’t know why, and there’s nothing you can do,’ he said. ‘It is truly horrifying for a parent.’
It is a frustration familiar to Asher’s mother, Jill.
Now 15, Asher is bedridden and his illness has, she said, ‘completely taken over’ the family’s life.
He is being treated with intravenous immunoglobulin (IVIG), a treatment derived from donated blood plasma, and rituximab, an immune-modulating drug. Jill says the combination has produced the biggest improvement in his symptoms so far.
But the family is paying for treatment themselves while fighting their insurer for coverage.
Jill has also begun documenting Asher’s illness on social media, where she has amassed nearly 70,000 followers.
‘The larger support system we can build, the quicker we can hopefully get help for children and get them to a place where they can heal,’ she said.
