Prevalence of fibromyalgia 10 years after infection with Giardia lamblia: a controlled prospective cohort study, 2021, Hunskar et al

Abstract

Objectives
To investigate whether acute infection with Giardia lamblia is associated with fibromyalgia 10 years after infection and whether fibromyalgia is associated with irritable bowel syndrome (IBS) and chronic fatigue (CF) in this setting.

Methods
A cohort study was established after an outbreak of G. lamblia in Bergen, Norway, 2004. Laboratory-confirmed cases and a matched control group were followed for 10 years. The main outcome was fibromyalgia 10 years after giardiasis, defined by the 2016 revisions of the fibromyalgia diagnostic criteria using the Fibromyalgia Survey Questionnaire (FSQ).

Results
The prevalence of fibromyalgia was 8.6% (49/572) among Giardia exposed compared to 3.1% (21/673) in controls (p<0.001). Unadjusted odds for having fibromyalgia was higher for Giardia exposed compared to controls (odds ratio (OR): 2.91, 95% confidence interval (CI): 1.72, 4.91), but adjusted for IBS and CF it was not (OR: 1.05, 95% CI: 0.57, 1.95). Among participants without CF the odds for fibromyalgia was 6.27 times higher for participants with IBS than those without (95% CI: 3.31, 11.91) regardless of exposure. Among participants without IBS the odds for fibromyalgia was 4.80 times higher for those with CF than those without (95% CI: 2.75, 8.37).

Conclusions
We found a higher prevalence of fibromyalgia among Giardia exposed compared to controls 10 years after the acute infection. Fibromyalgia was strongly associated with IBS and CF, and the difference between the exposed and controls can be attributed to the high prevalence of IBS and CF among the Giardia exposed. Notably, this study was not designed to establish causality between Giardia exposure and the outcomes.

Open access, https://www.degruyter.com/document/doi/10.1515/sjpain-2021-0122/html

 

Further quote from the paper:

Introduction

The term medically unexplained physical symptoms (MUPS) describes a range of symptoms that are not explained by measurable pathology, but are seen to occur together and lead to different symptom patterns, commonly described as syndromes [1, 2]. There is a certain overlap in criteria for the different syndromes and considerable overlap in the prevalence as patients frequently meet the criteria for several conditions [3], [4], [5], [6]. Whether MUPS should be considered different presentations of one common condition or as distinct and different syndromes is an ongoing discussion. Many now support a view that this is a wide collection of symptoms that might have shared etiology, but can also be divided into subgroups [6, 7]. Irritable bowel syndrome (IBS), chronic fatigue (CF) (including chronic fatigue syndrome (CFS)), and fibromyalgia are among the most studied in this group of disorders. They are associated with each other and overlap [7], [8], [9], [10].

CFS/CF and IBS are well-known complications following infections. Previous studies have shown that long-term fatigue can complicate different infections like mononucleosis and viral meningitis, and fatigue has also been a major concern following the recent COVID-19 pandemic [11], [12], [13]. Post-infectious IBS may follow gastroenteritis caused by parasites, bacteria and viruses [14], [15], [16], [17]. Smaller studies on fibromyalgia following infections such as mycoplasma, Lyme disease and different viruses have not provided clear support for such an association [18], [19], [20], [21], [22].

 

Until the pandemic, this outbreak of Giardia in Bergen, Norway, was said to be the first time researchers knew for sure what had initiated ME, which made this particular patient group very interesting to study. Now it seems the researchers have moved away from "ME" to FM and "chronic fatigue". Lots of red flags among the references they use in the paper, as Moss-Morris, Chalder, Wessely, Fink, Sharpe.


Searching for threads on this research group on the forum, I see I complained about the same thing already in 2019...

 

Here's an article from 2004 where it states that 100 people still felt fatigued after having contracted the Giardia parasite in the outbreak in Bergen in 2004. Over 20 of them got diagnosed with ME according to same article and the researchers wanted to study ME as part of this.

google translation: Exhausted by the drinking water