Prevalence & clinical characteristics of Norwegians who report persistent health complaints attributed to tick bites/tick-borne diseases,2025,Dahlberg

[Dolphin]

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

Background Persistent symptoms attributed to tick bites or tick-borne diseases are poorly understood. We estimate regionally adjusted prevalence of persistent symptoms, investigate seroprevalence (IgG) and ongoing infections, and examine associated demographic and clinical factors. Methods...

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

• Research
• Open access
• Published: 27 November 2025
• Volume 25, article number 1663, (2025)
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• Audun Olav Dahlberg,
• Audun Aase,
• Harald Reiso,
• Hanne Quarsten,
• Øivind Øines &
• Rune Midgard

Abstract​

Background​

Persistent symptoms attributed to tick bites or tick-borne diseases are poorly understood. We estimate regionally adjusted prevalence of persistent symptoms, investigate seroprevalence (IgG) and ongoing infections, and examine associated demographic and clinical factors.

Methods​

Persons aged 18 years or older with persistent symptoms lasting six months or more attributed to tick bites or tick-borne diseases, were recruited into a nationwide cross-sectional study. Demographic data were recorded. Medical records were collected (February 2020 - April 2022) and reviewed for tick bites, tick-borne infections, antibiotic treatment, and clinical findings. Outcome measures included somatic symptoms (PHQ-15), fatigue (Fatigue Severity Scale), physical health (RAND-36), and affective symptoms (HAD Scale). Laboratory assessments included polymerase chain reaction (PCR) analysis of blood samples for Borrelia burgdorferi (Bb) and other known tick-borne pathogens, along with IgG antibody detection.

Results​

The highest prevalence of persistent symptoms attributed to tick bites or tick-borne diseases was found in southwestern Norway (0.152–0.155%); the lowest was in the north (0.033%), which also had significantly lower Bb-IgG seroprevalence (15.4% compared to the national average 37.5%). Symptom persistence was not associated with confirmed tick exposure or tick-borne infection. Somatic symptoms were associated with low physical activity and comorbidity. Fatigue and poor physical health were strongly associated with underemployment. Fatigue was also associated with depressive symptoms, low activity, sick leave, and comorbidities.

Conclusions​

Persistent symptoms were most prevalent in tick-endemic regions but were not associated with prior tick exposure or tick-borne infections. Symptom burden was primarily associated with comorbidities, especially physical inactivity and underemployment.

Clinical trial number​

Not applicable.

 

[Utsikt]

I’m not sure we can learn much from this study due to the substantial risk of recruitment bias.

The authors have some less informed opinions about their observations:

Misinformation from media and the internet [46] can lead to cognitive bias [47]. Cognitive mechanisms for functional disorders may involve the nocebo effect, body awareness, and negative expectations increasing anxiety and attention to one’s own symptoms [48].

FND gets a mention.

An ‘infectious’ disease, like CLD, can also more readily reduce stigma [49, 50], thereby reinforcing the desire to obtain a treatable diagnosis.

This can probably explain some of the cases, but it has nothing to do with FND, and everything to do with medicine’s failure to acknowledge and address its ignorance, leaving patients to try and figure it out on their own - and some of them fall prey to the quacks.

Comparatively, another study during the COVID-19 pandemic, found that persistent physical symptoms were more associated with the belief of being infected than with confirmed infection [51].

This is a study with so many flaws and limitations that no serious researcher would go anywhere near it.

https://www.s4me.info/threads/association-of-self-reported-covid-19-infection-and-sars-cov-2-serology-test-results-with-persistent-physical-symptoms-2021-matta-et-al.23227/

Furthermore, persistent physical symptoms are very common in the general population, with both symptom expression and underlying explanations being heterogeneous [52, 53].

«And underlying explanations being unknown».

Our study population may share many phenotypic similarities with other related conditions, such as CFS/ME [56, 57]. One of the cardinal symptoms of CFS/ME is ‘post-exertional exhaustion,’ and in our study population, low physical activity was the variable most strongly associated with fatigue. The direction of this association remains unclear.

It’s been a while since I’ve seen PEE. It’s clear they don’t understand PEM or ME/CFS at all.

Nevertheless, physical activity and cognitive behavioural therapy has been found to have an effect in CFS/ME [58] and long-COVID-19 [59], and it may be worthwhile to further investigate this in a population with persistent physical symptoms attributed to ticks.

58 is PACE. Enough said, really..

59 is Garner, Busse, Flottorp etc.

https://www.s4me.info/threads/interventions-for-the-management-of-long-covid-post-covid-condition-living-systematic-review-2024-zeraatkar-flottorp-garner-busse.41391/

The lead author Dahlberg is from NTNU, where Live Landmark is doing her PhD on LP. Maybe they’ve crossed paths?

 

[Yann04]

Misinformation from media and the internet [46] can lead to cognitive bias […] body awareness.

Ah yes, being aware of your body is now a cognitive bias.