Posttreatment Symptoms in Lyme Borreliosis

Diagnostic probability classification in suspected borreliosis by a novel Borrelia C6-peptide IgG1- subclass antibody test

The tick-borne multisystemic infection caused by Borrelia burgdorferi sensu lato, Lyme borreliosis, or Lyme disease, occurring in temperate regions of the northern hemisphere, continues to spread geographically with the expanding tick population. Despite the rising perceived risk of infection in the population, the clinical diagnosis of Borrelia infection is not always obvious and the most important laboratory test, antibody detection, has limited accuracy in diagnosing active disease. According to international guidelines, the primary serology test, which has a high sensitivity-low specificity, should, be verified using a high specificity confirmation test to improve the specificity. However, this enhancement in specificity comes at the cost of lower sensitivity. This two-step procedure is often omitted in everyday clinical practice. An optimal primary test would be one where no secondary tests for confirmation would be necessary. In the present study, the performance of a novel assay for quantitating IgG1-subclass antibodies to Borrelia C6-peptide was compared to a commercial reference assay of total IgG and IgM antibodies to Borrelia C6-peptide in the setting of a high endemic area for borreliosis. A derivation study on a retrospective clinical material was performed to compare the performance parameters and assess the discriminatory properties of the assays, followed by a prospective validation study. The IgG1-antibody assay achieved comparable summary performance parameters to those of the reference assay. The sensitivity was almost 100% while the specificity was about 50%. In a high-endemic setting, characterized by high background seropositivity of about 50% and disease prevalence of approximately 10%, antibody tests are unable to rule-in active Borrelia infection. The rule-out assessment of the methods revealed that of 1000 patients, 7 - 54 with negative results based on the reference method could have an active Borrelia infection. Such uncertainty was not found for the index test and may help improve the risk classification of patients.

Consumption of healthcare services and antibiotics in patients with presumed disseminated Lyme borreliosis before and after evaluation of an infectious disease specialist

Our objective was to study the consumption of healthcare services and antibiotics in patients with suspicion of disseminated Lyme borreliosis (LB) before and after consultation of an infectious disease specialist. We evaluated retrospectively all presumed disseminated LB patients (n = 256) with a referral to the Department of Infectious Diseases (DID) in Helsinki University Hospital in 2013. Medical records from all healthcare providers in the area were reviewed and the number of physician contacts because of symptoms leading to LB suspicion and antimicrobial purchases were calculated 1 year before and after consultation or treatment at the DID. Patients were divided into three groups according to certainty of LB: unlikely, possible or probable/definite LB. The number of healthcare contacts 1 year before referral was higher among 121 patients with unlikely LB (6; interquartile range [IQR] 3-10), than 65 possible (4; IQR 2.5-7; p = 0.018) or 66 probable/definite LB patients (4; IQR 2.8-7; p = 0.010). The median number of contacts to healthcare during one year after consultation or treatment was 3 (IQR 0.5-7), 1 (IQR 0-3) and 0.5 (IQR 0-2.3), respectively, with a statistically significant difference between the groups (p<0.001). Antibiotics were purchased by 151 (60%) patients one year before referral and by 127 (50%) patients year after consultation or treatment at DID without statistically significant difference between groups with different LB certainty. These antibiotic purchases do not include the treatments prescribed by infectious disease specialists. In the case of 27 patients, an antimicrobial treatment was recommended in the consultation reply. In conclusion, patients with unlikely LB used more healthcare services than patients with possible or probable/definite LB. Antimicrobial consumption was similar between groups of different LB certainty.

Lyme Disease in Humans

Lyme disease (Lyme borreliosis) is a tick-borne, zoonosis of adults and children caused by genospecies of the Borrelia burgdorferi sensu lato complex. The ailment, widespread throughout the Northern Hemisphere, continues to increase globally due to multiple environmental factors, coupled with increased incursion of humans into habitats that harbor the spirochete. B. burgdorferi sensu lato is transmitted by ticks from the Ixodes ricinus complex. In North America, B. burgdorferi causes nearly all infections; in Europe, B. afzelii and B. garinii are most associated with human disease. The spirochete's unusual fragmented genome encodes a plethora of differentially expressed outer surface lipoproteins that play a seminal role in the bacterium's ability to sustain itself within its enzootic cycle and cause disease when transmitted to its incidental human host. Tissue damage and symptomatology (i.e., clinical manifestations) result from the inflammatory response elicited by the bacterium and its constituents. The deposition of spirochetes into human dermal tissue generates a local inflammatory response that manifests as erythema migrans (EM), the hallmark skin lesion. If treated appropriately and early, the prognosis is excellent. However, in untreated patients, the disease may present with a wide range of clinical manifestations, most commonly involving the central nervous system, joints, or heart. A small percentage (~10%) of patients may go on to develop a poorly defined fibromyalgia-like illness, post-treatment Lyme disease (PTLD) unresponsive to prolonged antimicrobial therapy. Below we integrate current knowledge regarding the ecologic, epidemiologic, microbiologic, and immunologic facets of Lyme disease into a conceptual framework that sheds light on the disorder that healthcare providers encounter.