Tick-transmitted co-infections among erythema migrans patients in a general practice setting in Norway: a clinical and laboratory follow-up study

Pathogenicity and virulence of Borrelia burgdorferi

Infection with Borrelia burgdorferi often triggers pathophysiologic perturbations that are further augmented by the inflammatory responses of the host, resulting in the severe clinical conditions of Lyme disease. While our apprehension of the spatial and temporal integration of the virulence determinants during the enzootic cycle of B. burgdorferi is constantly being improved, there is still much to be discovered. Many of the novel virulence strategies discussed in this review are undetermined. Lyme disease spirochaetes must surmount numerous molecular and mechanical obstacles in order to establish a disseminated infection in a vertebrate host. These barriers include borrelial relocation from the midgut of the feeding tick to its body cavity and further to the salivary glands, deposition to the skin, haematogenous dissemination, extravasation from blood circulation system, evasion of the host immune responses, localization to protective niches, and establishment of local as well as distal infection in multiple tissues and organs. Here, the various well-defined but also possible novel strategies and virulence mechanisms used by B. burgdorferi to evade obstacles laid out by the tick vector and usually the mammalian host during colonization and infection are reviewed.

Determinants of persistent symptoms after treatment for Lyme borreliosis: a prospective observational cohort study

BACKGROUND

Patients treated for Lyme borreliosis (LB) frequently report persistent symptoms. Little is known about risk factors and etiology.

METHODS

In a prospective observational cohort study with a follow-up of one year, we assessed a range of microbiological, immunological, genetic, clinical, functional, epidemiological, psychosocial and cognitive-behavioral variables as determinants of persistent symptoms after treatment for LB. Between 2015 and 2018 we included 1135 physician-confirmed LB patients at initiation of antibiotic therapy, through clinical LB centers and online self-registration. Two reference cohorts of individuals without LB (n = 4000 and n = 2405) served as a control. Prediction analyses and association studies were used to identify determinants, as collected from online questionnaires (three-monthly) and laboratory tests (twice).

FINDINGS

Main predictors of persistent symptoms were baseline poorer physical and social functioning, higher depression and anxiety scores, more negative illness perceptions, comorbidity, as well as fatigue, cognitive impairment, and pain in 295 patients with persistent symptoms. The primary prediction model correctly indicated persistent symptoms in 71.0% of predictions (AUC 0.79). In patients with symptoms at baseline, cognitive-behavioral responses to symptoms predicted symptom persistence. Of various microbiological, immunological and genetic factors, only lower IL-10 concentrations in ex vivo stimulation experiments were associated with persistent symptoms. Clinical LB characteristics did not contribute to the prediction of persistent symptoms.

INTERPRETATION

Determinants of persistent symptoms after LB were mainly generic, including baseline functioning, symptoms and cognitive-behavioral responses. A potential role of host immune responses remains to be investigated.

FUNDING

Netherlands Organisation for Health Research and Development (ZonMw); the Dutch Ministry of Health, Welfare and Sport (VWS).

The Impact of Telemedicine in the Diagnosis of Erythema Migrans during the COVID Pandemic: A Comparison with In-Person Diagnosis in the Pre-COVID Era

Background: Erythema migrans (EM) is the hallmark manifestation of the Lyme borreliosis (LB), and therefore its presence and recognition are sufficient to make a diagnosis and to start proper antibiotic treatment to attempt to eradicate the infection. Methods: In this study we compared the clinical data of 439 patients who presented an EM either according to the diagnostic modality through physical assessment or through telemedicine. Conclusions: Our data clearly show that telemedicine for EM diagnosis is useful as it enables prompt administration of appropriate antibiotic therapy, which is critical to avoid complications, especially for neurologic and articular entities. Therefore, telemedicine is a tool that could be adopted for the diagnosis of Lyme disease both by specialized centers but also by general practitioners.

Early Lyme Disease (Erythema Migrans) and Its Mimics (Southern Tick-Associated Rash Illness and Tick-Associated Rash Illness)

Erythema migrans, an expanding erythematous skin lesion that develops days to weeks following an Ixodes species tick bite, is the most common clinical manifestation of Lyme disease. Presentations in the United States differ somewhat from that in Europe, presumably because of the different etiologic agents. Diagnosis is based on the appearance of the skin lesion, rather than on laboratory testing. After treatment with an appropriate oral antibiotic for 10 to 14 days, the prognosis is excellent. Two conditions that cause a similar skin lesion following a tick bite, but are of unknown cause, are Southern tick-associated rash illness in the United States and tick-associated rash illness in Japan.

Babesiosis in Southeastern, Central and Northeastern Europe: An Emerging and Re-Emerging Tick-Borne Disease of Humans and Animals

There is now considerable evidence that in Europe, babesiosis is an emerging infectious disease, with some of the causative species spreading as a consequence of the increasing range of their tick vector hosts. In this review, we summarize both the historic records and recent findings on the occurrence and incidence of babesiosis in 20 European countries located in southeastern Europe (Bosnia and Herzegovina, Croatia, and Serbia), central Europe (Austria, the Czech Republic, Germany, Hungary, Luxembourg, Poland, Slovakia, Slovenia, and Switzerland), and northern and northeastern Europe (Lithuania, Latvia, Estonia, Iceland, Denmark, Finland, Sweden, and Norway), identified in humans and selected species of domesticated animals (cats, dogs, horses, and cattle). Recorded cases of human babesiosis are still rare, but their number is expected to rise in the coming years. This is because of the widespread and longer seasonal activity of Ixodes ricinus as a result of climate change and because of the more extensive use of better molecular diagnostic methods. Bovine babesiosis has a re-emerging potential because of the likely loss of herd immunity, while canine babesiosis is rapidly expanding in central and northeastern Europe, its occurrence correlating with the rapid, successful expansion of the ornate dog tick (Dermacentor reticulatus) populations in Europe. Taken together, our analysis of the available reports shows clear evidence of an increasing annual incidence of babesiosis across Europe in both humans and animals that is changing in line with similar increases in the incidence of other tick-borne diseases. This situation is of major concern, and we recommend more extensive and frequent, standardized monitoring using a “One Health” approach.