Asher Berglin had a bright, easy introduction ready whenever he met someone for the first time.
“Hi, I’m Asher. Asher means happy,” he would say, smiling.
His mother, Jill, says the name perfectly captured his personality.
Full of energy, curious and never afraid to speak his mind, Asher thrived at school. He threw himself into extracurricular activities and was constantly looking for something new to discover.
That changed dramatically in the summer of 2024, when Asher was 13.
The sudden transformation began soon after he had suffered a sore throat.
Jill recalls that her son’s personality “just kind of flipped.” He rapidly developed debilitating obsessive-compulsive disorder symptoms and vocal tics so severe that speaking a complete sentence became difficult.
Asher Berglin, now 15, had been in excellent health before the illness began affecting him in 2024
Jill described Asher as confident and self-reliant before his illness, but said severe OCD symptoms later left him dependent on her
His anxiety quickly became all-consuming. A boy who had once pleaded to cycle to school by himself could no longer step outside his bedroom unless he was holding on to his mother.
He also began having explosive episodes, screaming and kicking the wall—actions Jill said bore no resemblance to the child she had known.
“He would scream for hours, then stop as suddenly as he had started,” she said. “Afterward, he was able to discuss it and apologize.”
Searching for an explanation, Jill investigated Asher’s symptoms and learned about two rare conditions: pediatric acute-onset neuropsychiatric syndrome, known as PANS, and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections, or PANDAS.
PANS refers to the abrupt appearance of serious neuropsychiatric symptoms in children, such as OCD, anxiety, tics and striking shifts in mood or behavior.
PANDAS is a related condition specifically connected to Group A streptococcal infections, including strep throat and scarlet fever.
Some researchers believe an infection can prompt an unusual immune reaction that affects the brain. However, the precise causes of PANS—and the extent of infections’ involvement—remain disputed within the scientific community.
Jill says the family was referred between multiple doctors before she finally asked Asher’s pediatrician about PANS and PANDAS. The pediatrician then sent him to a specialist.
Jill says that specialist was certain Asher had PANDAS and described his condition as among the most severe cases they had seen. The doctor also considered Asher’s earlier sore throat a likely connection to the sudden emergence of his symptoms, according to Jill.
Asher’s severe PANDAS symptoms emerged soon after he experienced a sore throat. He is pictured receiving an infusion treatment with his mother in February 2026. Source: Jill Berglin/Instagram
WHAT IS PANDAS?
PANDAS—short for pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections—is considered an autoimmune and neuropsychiatric condition that may result from an abnormal immune response to an infection.
Symptoms include:
- Anxiety
- Tics
- Emotional lability and/or depression
- Irritability, aggression, and/or severely oppositional behaviors
- Behavioral (developmental) regression (increase in temper tantrums, loss of age-appropriate language, clingy behavior not related to anxiety)
- Sudden deterioration in school performance (due to difficulties with memory, concentration, hyperactivity, impulsivity, new deficits of visuospatial skills)
- Motor or sensory abnormalities (dysgraphia, clumsiness, tics, new sensory sensitivities to light, noise, smell, taste or texture)
- Insomnia and/or sleep disturbances
- Enuresis and/or urinary frequency
Source: PAN PANDAS UK
Worryingly, Asher’s story is far from unique.
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.
In PANDAS, strep may trigger the initial illness, while subsequent infections can trigger a flare-up of symptoms.
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 was taken to the hospital, but when Alissa arrived in the emergency room, the first person who came in was a psychiatrist.
‘The psychiatrist said they felt Lulu should be sent to a psychiatric institution, despite her medical diagnoses,’ Alissa said.
A neurologist at the hospital who had previously treated Lulu stepped in, and medically admitted her for testing and treatment.
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 due to a flare.
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. I fully believe that all she really wanted was to live a happy, healthy life.’
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. She eventually lost the ability to immerse herself in her imagination – the one thing that had helped keep her positive.
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.
