Somatic symptoms and fatigue in a Norwegian population with high exposure to ticks

Incidence of Lyme disease in the United Kingdom and association with fatigue: A population-based, historical cohort study

Background

Estimations of Lyme disease incidence rates in the United Kingdom vary. There is evidence that this disease is associated with fatigue in its early stage but reports are contradictory as far as long-term fatigue is concerned.

Methods and findings

A population-based historical cohort study was conducted on patients treated in general practices contributing to IQVIA Medical Research Data: 2,130 patients with a first diagnosis of Lyme disease between 2000 and 2018 and 8,510 randomly-sampled patients matched by age, sex, and general practice, followed-up for a median time of 3 years and 8 months. Main outcome measure was time to consultation for (1) any fatigue-related symptoms or diagnosis; or (2) myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Adjusted hazard ratios (HRs) were estimated from Cox models. Average incidence rate for Lyme disease across the UK was 5.18 per 100,000 person-years, increasing from 2.55 in 2000 to 9.33 in 2018. In total, 929 events of any types of fatigue were observed, leading to an incidence rate of 307.90 per 10,000 person-years in the Lyme cohort (282 events) and 165.60 in the comparator cohort (647 events). Effect of Lyme disease on any subsequent fatigue varied by index season: adjusted HRs were the highest in autumn and winter with 3.14 (95%CI: 1.92–5.13) and 2.23 (1.21–4.11), respectively. For ME/CFS, 17 events were observed in total. Incidence rates were 11.76 per 10,000 person-years in Lyme patients (12 events) and 1.20 in comparators (5 events), corresponding to an adjusted HR of 16.95 (5.17–55.60). Effects were attenuated 6 months after diagnosis but still clearly visible.

Conclusions

UK primary care records provided strong evidence that Lyme disease was associated with subsequent fatigue and ME/CFS. Albeit weaker on the long-term, these effects persisted beyond 6 months, suggesting patients and healthcare providers should remain alert to fatigue symptoms months to years following Lyme disease diagnosis.

Nonspecific symptoms following infection with Borrelia burgdorferi sensu lato: A retrospective cohort study

Whether infection with Borrelia burgdorferi sensu lato (sl) can cause nonspecific symptoms is a matter of controversy. We investigated whether individuals infected with B. burgdorferi sl develop unspecific symptoms more frequently than non-infected controls. Eighty-nine persons having presented with B. burgdorferi sl infection between 2015 and 2019 were asked to participate. The infection was defined as erythema migrans diagnosed either in the course of a previous study, during medical visits in the outpatient department, or as seroconversion in asymptomatic subjects. The control group consisted of 85 seronegative individuals without erythema migrans in the past. About two and a half years later, participants were asked to fill out a questionnaire with a list of nonspecific symptoms. The data of 37 persons with previous Borrelia infection and 49 uninfected controls were available for analysis. Muscle pain was significantly (P = 0.040) more frequent in the control group. Fatigue occurred more often in the infected group, but this was not statistically significant (P = 0.109). Likewise, the distribution of other symptoms did not differ considerably. The analysis revealed no difference in the frequency of symptoms of persons who had EM or asymptomatic Borrelia infection 2 years prior assessment in comparison to persons without Borrelia infection.

Psychosomatic symptoms questionnaire (PSQ-39): a psychometric study among general population of Iranian adults

BACKGROUND

Psychosomatic symptoms, characterized by physical-bodily complaints not fully explained by organic reasons, are highly prevalent. The present study aimed to culturally adapt and evaluate the psychometric properties of Psychosomatic Symptoms Questionnaire 39-item version (PSQ-39) among Iranian general adult population.

METHODS

This study included 996 Persian-speaking people, living in Isfahan, Iran. The translation of the PSQ-39 was performed using the forward-backward method. Test-retest reliability was evaluated through Intraclass correlation (ICC) coefficient and internal consistency by using Cronbach's α. Construct validity was investigated by using both exploratory (EFA) and confirmatory (CFA) factor analysis. Short Form Health Survey (SF-36) was used to assess divergent validity. Known-group validity was also assessed.

RESULTS

The Persian version of the PSQ-39 showed excellent test-retest reliability in all domains (ICCs: 0.95-0.99). The computed Cronbach's alpha coefficients for domains of PSQ-39 were in the range good to excellent. The PSQ-39 showed good known-group validity and differentiated patients from the general population (Area under the curve [AUC] of 0.78 (95% CI: 0.73, 0.84). Construct validity evaluated by EFA led to extraction of seven factors (Cardiorespiratory, musculoskeletal, psychological, gastrointestinal, general, body balance and Globus), and the CFA confirmed the adequacy of extracted factors by EFA (CFI = 0.91, TLI = 0.90, PCFI = 0.77, PNFI = 0.71, CMIN = 1413.18 (df = 654), CMIN/DF = 2.16, and RMSEA = 0.06). Significant negative correlations between all domains of PSQ and SF-36 revealed an acceptable divergent Validity.

CONCLUSIONS

The Persian version of the PSQ-39 is a reliable and valid questionnaire with applicability in a broad range of Persian language populations for assessing common psychosomatic symptoms in research as well as in clinical practice.

Subjective health complaints and exposure to tick-borne infections in southern Norway

OBJECTIVES

Whether tick-borne infections can cause chronic subjective health complaints is heavily debated. If such a causal connection exists, one would expect to find more health complaints among individuals exposed to tick-borne infections than among non-exposed. In this study, we aimed to assess if exposure to tick-borne infections earlier in life, evaluated by examination of serum for IgG antibodies to tick-borne microbes, was associated with self-reported somatic symptom load.

MATERIALS & METHODS

All individuals with residential address in Søgne municipality in southern Norway, aged 18-69 years, were invited to participate in the study. Blood samples were analyzed for IgG antibodies to different tick-borne microbes, and somatic symptom load was charted by the Patient Health Questionnaire-15 (PHQ-15).

RESULTS

Out of 7424 invited individuals, 2968 (40.0%) were included in the study. We detected IgG antibodies to Borrelia burgdorferi sensu lato (Bb) in 22.9% (95% CI 21.4-24.4). Bb seropositive individuals reported less frequently moderate to severe somatic symptom load (ie, PHQ-15 sum score ≥ 10) than seronegative individuals (12.5% versus 17.7%, difference 5.2% [95% 2.1-8.0]). However, when adjusting for several other variables in a multivariable linear regression model, presence of serum IgG antibodies to Bb was not associated with somatic symptom load. Presence of IgG antibodies to other tick-borne microbes than Bb, or seropositivity to at least two microbes, was also not associated with somatic symptom load.

CONCLUSION

Presence of serum IgG antibodies to tick-borne microbes was not associated with self-reported somatic symptom load.

Patient-reported outcome after treatment for definite Lyme neuroborreliosis

OBJECTIVE

To chart patient-reported outcome measures (PROMs) in Norwegian patients treated for definite neuroborreliosis (NB).

MATERIAL AND METHODS

Adult patients treated for definite NB 1-10 years earlier supplied demographics, symptoms and treatment during NB, and answered validated questionnaires; Fatigue Severity Scale (FSS), Hospital Anxiety and Depression Scale (HADS), health-related quality of life questionnaire (RAND-36), and Patient Health Questionnaire (PHQ-15).

RESULTS

A higher proportion of NB-treated persons reported severe fatigue, defined as FSS score ≥ 5, than in Norwegian normative data, but when removing persons with confounding fatigue associated comorbidities (n = 69) from the analyses, there was no difference between groups. Physical health-related quality of life (RAND-36 PCS), mean FSS score, proportions of persons reporting moderate or severe somatic symptom burden (PHQ-15 score ≥ 10), anxiety (HADS-A ≥ 8), or depression (HADS-D ≥ 8) did not differ between NB-treated persons and reference scores. Mental health-related quality of life (RAND-36 MCS) was poorer than in normative data (47.1 vs. 53.3), but associated with anxiety, depression and current moderate or severe somatic symptom burden, and not with NB characteristics.

CONCLUSIONS

Results on validated PROM questionnaires measuring fatigue, anxiety, depression, self-reported somatic symptom burden, and physical health-related quality did not differ between persons treated for definite NB 1-10 years earlier and reference scores. NB-treated persons tended to report a slightly poorer mental health-related quality of life than found in normative data, but when adjusting for confounders the causative connection is questionable. Overall, the long-term prognosis of definite NB seems to be good.