Non-specific symptoms in adult patients referred to a Lyme centre

There is controversy whether non-specific symptoms can be related to previous Lyme borreliosis (LB). Positive serology can be considered a proxy for previous or persistent LB. We assessed non-specific symptoms and serology in patients suspected of LB referred to a Lyme centre.

Included were adult patients who visited a Lyme centre between 2008 and 2014. Before medical consultation, serum samples were taken and questionnaires on non-specific symptoms completed. The prevalence of non-specific symptoms was calculated for patients with positive and negative IgG serology. Logistic regression was used to obtain odds ratios (ORs) with 95% confidence interval (CI) for an association between positive serology and non-specific symptoms.

Of 1439 included patients, 31.6% (455/1439) had positive serology. The most common non-specific symptoms were severe fatigue (61.4%, 883/1439), sleep disturbances (54.8%, 789/1439) and stiffness of neck/back (52.6%, 757/1439). The prevalence of severe fatigue was 53.0% (241/455) in patients with positive serology vs. 65.2% (642/984) in patients with negative serology (OR = 0.74; 95% CI, 0.58-0.94). The prevalence of sleep disturbances was respectively 46.2% (210/455) vs. 58.8% (579/984) (OR = 0.73; 95% CI, 0.58-0.93). The prevalence of stiffness of neck/back was respectively 47.7% (217/455) vs. 54.9% (540/984) (OR = 0.85; 95% CI, 0.67-1.06).

In patients referred to a Lyme centre, non-specific symptoms did not occur more frequently in patients with positive serology compared to patients with negative serology. Hence, a questionnaire on non-specific symptoms cannot be used for identifying patients with possible post-LB symptoms in clinical practice.