Study finds no evidence of persistent tick-borne infection in people who link chronic illness to ticks

Accurate diagnoses are critical to the correct treatment of tick-related diseases

Norwegian University of Science and Technology

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When researchers studied Norwegians who thought tick bites caused their chronic health problems, they found no objective evidence linking the symptoms to ticks.

The same study finds that health problems reported by participants were associated with little physical activity and low labour force participation.

Many Norwegians pull ticks from their bodies every single summer. Roughly 2 per cent of those who are bitten are infected by a bacterium that leads to Lyme disease.

The disease can start with a rash that eventually spreads in the skin with a ring-shaped pattern. In some people, the disease can develop into facial paralysis, meningitis or other complications.

Can develop facial paralysis

"It is possible to get really sick from tick bites, but no matter how badly you are affected, antibiotics are the curative treatment. Most people need two weeks of treatment, while a few need up to four weeks," says Audun Olav Dahlberg.

Dahlberg is a senior consultant in clinical neurophysiology at Helse Møre og Romsdal HF, and is a specialist in clinical neurophysiology and neurology as well as a PhD research fellow at NTNU, the Norwegian University of Science and Technology.

As part of his doctoral dissertation, he examined 470 Norwegians who themselves link chronic and long-term health problems to tick bites.

His research found no evidence that the chronic health problems reported by this group are linked to ongoing tick-borne infections.

The study also shows that around 0.12 per cent of adults in Norway link chronic health problems to previous tick bites.

Depression, sick leave and exhaustion

"This is the first time that we have quantified how many people in Norway themselves link chronic health problems to tick bites. This group suffers greatly, including from a limited ability to work, severe fatigue and other health issues. Their symptoms have persisted for more than six months and they believe tick bites are the cause. However, blood tests indicate that active tick-borne infection cannot explain these persistent symptoms," says Dahlberg.

To recruit participants, the researchers sent SMS messages to  270,000 people randomly drawn throughout Norway, while GP offices, the Norwegian National Advisory Unit on Tick-borne Disease and the Norwegian Lyme Borreliosis Disease Association also helped with the recruitment.

A total of 470 participants were examined and compared with control groups. All were over 18 years old, and had had symptoms for more than six months.

More than one in three have Lyme disease antibodies

Persistent symptoms were most prevalent in areas with a lot of ticks. In South-Western Norway, around 0.15 per cent had problems attributed to tick bites, while the percentage in Northern Norway was just 0.03 per cent.

Among the participants, 37.5 per cent had antibodies against the bacterium that most often causes Lyme disease. This shows that many people have been in contact with the bacterium and developed an immune response.

The participants also had antibodies against Borrelia and other tick-borne microbes more often than the control group. However, the study found no proven association between these antibodies and the persistent symptoms.

The study shows that 23 per cent of the participants had been diagnosed abroad. Dahlberg says this raises questions regarding the diagnostic methods used in some countries, as some laboratories use test methods that are not in line with established professional practice.

Important to get correct diagnosis

"We have thoroughly investigated whether ticks can explain the suffering in this group of participants. Since the study found no link between persistent symptoms and ongoing infection, it can contribute to more targeted follow-up and treatment. Objective findings are important for making diagnoses, and long-term antibiotic treatment beyond established practice is not recommended. An incorrect diagnosis can lead to other medical conditions being overlooked. That makes it crucial to have a thorough investigation based on objective findings," says Dahlberg.

Lyme disease can make you very ill. Dahlberg says this means people should see their doctor if they develop symptoms after a tick bite so that correct treatment can be assessed and possibly started.

Dahlberg emphasizes that the study's findings apply at the group level.

"Of course, some individuals may experience long-term ailments after tick-borne infections, such as persistent nerve damage, immune responses, or a combination of biopsychosocial factors, such as psychological stress or social circumstances. However, the study shows no indications at the group level that a large number of Norwegians experience long-term symptoms that can be attributed to persistent tick infections," Dahlberg said.

Reference: Dahlberg, A.O., Aase, A., Reiso, H. et al. Prevalence and clinical characteristics of Norwegians who report persistent health complaints attributed to tick bites or tick-borne diseases. BMC Infect Dis 25, 1663 (2025). https://doi.org/10.1186/s12879-025-12182-w

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Journal

BMC Infectious Diseases

DOI

10.1186/s12879-025-12182-w 

Method of Research

Observational study

Subject of Research

People

Article Title

Prevalence and clinical characteristics of Norwegians who report persistent health complaints attributed to tick bites or tick-borne diseases.

 

Researchers develop a high-efficiency photocatalyst using iron instead of rare metals

Nagoya University researchers used iron and blue LEDs to synthesize natural molecules, cutting the need for expensive chiral components by two-thirds.

Nagoya University

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image: 

The newly designed iron photocatalyst (front) and the previous catalyst (back)

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Credit: Yuzuru Endo

Photocatalysts facilitate chemical reactions by absorbing light. Metal-based photocatalysts are widely used in organic synthesis due to their durability and the ability to tune their function by modifying the ligands attached to the central metal atom.

Most metals used in photocatalysts, such as ruthenium and iridium, are rare and expensive. Researchers at Nagoya University, Japan, previously developed an iron-based alternative, but it required large amounts of costly chiral ligands, which act as spatial templates to determine the three-dimensional structure of chemical products.

In a recent study published in the Journal of the American Chemical Society, the researchers developed an iron catalyst that reduces the use of chiral ligands by two-thirds and enables photocatalytic reactions under energy-efficient blue LED light.

Using this new catalyst, they completed the asymmetric total synthesis of (+)-heitziamide A, a natural compound from medicinal plants that suppresses respiratory bursts.

Professor Kazuaki Ishihara, Assistant Professor Shuhei Ohmura, and graduate student Hayato Akao at Nagoya University's Graduate School of Engineering developed this technology.

 

Redefining the design of iron catalysts

In their 2023 study, the researchers developed an iron photocatalyst that used three chiral ligands per iron atom, but only one-third of these ligands contributed to enantioselectivity, making the process inefficient.

Meanwhile, the newly developed iron photocatalyst combines cost-effective achiral bidentate ligands with chiral ligands to target a specific iron(III) salt structure. The chiral ligand controls the three-dimensional configuration, while the achiral bidentate ligand tunes the catalytic activity.

Using this catalyst, researchers achieved a precise radical cation (4 + 2) cyclization, joining two molecules to form a hexagonal ring. This method enables the synthesis of 1,2,3,5-substituted adducts, structures common in natural products such as heitziamide A.

"The new catalyst design represents the definitive form of chiral iron(III) photoredox catalysts," stated Ohmura, one of the study's corresponding authors. "We believe this achievement marks a significant milestone in advancing iron-based photocatalysis."

 

Advancing artificial synthesis of (+)-heitziamide A

While artificial synthesis of heitziamide A has been previously reported, the total asymmetric synthesis of its natural enantiomer has not yet been achieved.

Using selective six-membered-ring formation with an iron photocatalyst activated by blue light, the researchers achieved the first total asymmetric synthesis of (+)-heitziamide A. This indicates that using the mirror-image catalyst would also allow the synthesis of (-)-heitziamide A, thereby enabling the selective production of both enantiomers.

 

Significance and future perspectives

The newly developed iron photocatalyst enables the precise synthesis of complex molecules, including pharmaceutical precursors, using abundant iron and blue LEDs instead of rare metals.

"Achieving the first-ever asymmetric total synthesis of (+)-heitziamide A using this catalytic reaction is a remarkable accomplishment," stated Ishihara, the study's other corresponding author. "Several additional bioactive substances can be accessed through total synthesis, with enantioselective radical cation (4 + 2) cycloaddition serving as a key step. We intend to publish follow-up papers on the asymmetric total synthesis of these compounds in the near future."

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Journal

Journal of the American Chemical Society

DOI

10.1021/jacs.5c20243 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

A Rational Design of Chiral Iron(III) Complexes for Photocatalytic Asymmetric Radical Cation (4 + 2) Cycloadditions and the Total Synthesis of (+)-Heitziamide A

 

Researchers warn: opioids aren’t effective for many acute pain conditions

University of Sydney

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The world’s largest review of opioid pain relievers prescribed for acute pain found these medicines provide only small, short-term relief for some acute conditions and are ineffective for some others.  

Led by researchers from the University of Sydney, the study set out to review the efficacy and harms of opioid pain relievers (eg codeine, morphine, oxycodone, tramadol) compared with placebo for acute pain. The review includes 59 systematic reviews covering more than 50 acute pain conditions in children and adults, and comprehensively maps where opioids are effective and where evidence is lacking. The review provides the strongest and most comprehensive evidence to date on when opioids do and do not work for acute pain. 

The findings were published today in Drugs, one of the most prestigious journals on medicines. 

“Opioids are among the most commonly prescribed treatments for acute pain, however, our review found that they did not provide large or lasting pain relief compared with placebo for the vast majority of acute pain conditions, with pain relief typically lasting only a few hours,” said lead author Associate Professor Christina Abdel Shaheed, from the School of Public Health at the University of Sydney. 

“Overall, oral opioids were only slightly better than placebo for acute musculoskeletal pain, which they are often prescribed for, in the six to 48 hours after starting treatment. Opioids also increased the risk of side effects when used for acute musculoskeletal pain, some types of post-surgical pain or traumatic limb pain. 

“By showing that the benefits are generally small, short-lived, absent for many common conditions, and sometimes harmful, our research challenges the widely held belief that opioids are the most effective ‘go-to’ option for acute pain”.  

Key findings of the systematic overview and meta-analysis: 

• Opioids provide only small, time-limited pain relief for some pain conditions like stomach pain, dental surgery, ear procedures, traumatic limb pain, pain following childbirth, caesarean pain and bunionectomy (bunion removal). 

• Opioids were no better than placebo for some limb surgeries, kidney stone pain, pain after removal of tonsils and pain in newborns on assisted breathing devices. 

• Opioids were not consistently beneficial over time for heart-related pain, pain following hysterectomy (removal of a woman’s uterus) and topical use (patches) for dermatological (skin) pain.  

• Opioids increased the risk of side effects compared with placebo when used for acute musculoskeletal pain, traumatic limb pain and pain after some types of surgery. Side effects included nausea and vomiting. 

• Very short-term use of opioids can reduce pain for some acute conditions, however, regular use comes with a risk of harm including dependence and tolerance. Serious opioid-related harms can include misuse, overdose, hospitalisation and deaths. 

• Inadequate reporting of side effects means the true risks of these medicines are likely underestimated, urging better reporting of harms in clinical trials, and highlighting the need for safer, and more effective alternatives. 

• Overall, the evidence does not support regular opioid use for acute pain and some studies evaluated single doses, which does not reflect real world use. 

Concerns over opioid use and misuse 

“Persistent use of opioid medicines can develop quickly following first time use (sometimes within days), and may arise from regular use for acute pain,” said co-first author Dr Stephanie Mathieson from the University of Sydney’s Institute for Musculoskeletal Health and School of Pharmacy.  

“It is important that patients are informed about the potential harms from opioids when prescribed them, and that doctors prescribe these medicines judiciously (lowest effective dose for the smallest amount of time) for acute pain,” she said. 

Co-first author Associate Professor Joshua Zadro from the University's Institute for Musculoskeletal Health and School of Health Sciences added: “These findings are important for patients across all age groups who experience acute pain, doctors treating these conditions and policy makers who regulate the safe use of these medicines in the community.” 

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Journal

Drugs

DOI

10.1007/s40265-026-02284-3 

Method of Research

Systematic review

Subject of Research

People

Article Publication Date

26-Feb-2026

 

Thinking in a second language may reduce creative performance, study finds

Koç University

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image: 

Prof. Dr. Tilbe Göksun, faculty member in the Department of Psychology at Koç University and director of The Language and Cognition Lab, co-author of the research examining how language context influences creative thinking in bilingual individuals.

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Credit: Koç University

Most of us have experienced a moment when we couldn’t quite recall a word in another language: the idea is there in our minds, but we simply can’t find the expression for it. The research, published in Bilingualism: Language and Cognition, is part of Dr. Gyulten Hyusein’s PhD dissertation research at the Language and Cognition Laboratory in the Department of Psychology at Koç University, conducted in collaboration with Prof. Dr. Tilbe Göksun.  It explores a question with clear everyday relevance: When bilingual individuals switch to their second language, does their creativity decline?

To find out, researchers asked Turkish-English bilingual university students to complete two classic creativity tests, one in Turkish (their native language) and one in English (their second language). The first test, the Alternative Uses Task, asked participants to come up with as many unusual uses for everyday objects as possible. This measured divergent thinking, the ability to generate many original ideas. The second test, the Remote Associates Test, presented three seemingly unrelated words and asked participants to find a single word connecting them all, measuring convergent thinking, the ability to zero in on a correct solution.

The results were clear-cut: Participants were more creative in Turkish across the board. They generated more ideas, came up with more original responses, and were better at finding the connecting word. But the researchers wanted to understand why. And this is where the study gets particularly interesting.

One key factor turned out to be mental imagery. After each task, participants rated how vividly they had been picturing things in their minds while working through the problems. Those mental images were richer and clearer in Turkish than in English. And the vividness of the mental images was strongly linked to better divergent thinking performance, regardless of which language was being used. In other words, the more vividly you can picture something, the more creative you tend to be. And, your native language seems to help you picture things more vividly.

The study also looked at hand gestures, the spontaneous movements we tend to make while we speak. Gesturing while talking in Turkish was gently linked to better creative idea generation, while gesturing in English was associated with worse performance. One explanation is that in a second language, people may use their hands to compensate for what they cannot easily say, but the gestures end up substituting for ideas rather than generating them. For convergent thinking, more gesturing combined with vivid imagery actually predicted lower scores in both languages, suggesting that rich visual thinking might sometimes get in the way of homing in on a single correct answer.

Perhaps the most surprising finding was that English proficiency, how well participants rated their own command of English, did not translate into richer mental imagery in English, nor did it explain the creativity gap on its own. This suggests that creativity in a second language is not simply a matter of how fluent you are. Something deeper, connected to the emotional and sensory richness that our native language carries, seems to matter as well.

For the millions of people who work, study, and collaborate in a language that is not their first, these findings raise important practical questions. They suggest that the language we think in is not just a passive vehicle for expressing ideas: It actively shapes the very texture of those ideas.

 

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Journal

Bilingualism Language and Cognition

Method of Research

Experimental study

Subject of Research

People

Article Title

Thinking creatively in two languages: Effects of mental imagery vividness, foreign language proficiency and hand gestures on bilingual creativity