Incidence and antibiotic treatment of erythema migrans in Norway 2005-2009

Clinical Manifestations of European Borreliosis on the Skin in Acute, Subacute and Chronic Disease

Background

Lyme borreliosis is a multisystemic infection caused by the spirochete Borrelia burgdorferi. Erythema migras is the main clinical marker of the disease.

Objective

This study aimed was to investigate the frequency and clinical manifestations of European borreliosis on the skin, and to determine the significance of these findings for diagnosis and therapy.

Methods

A retrospective-prospective clinical study of outpatients treated and monitored in a private clinic of an infectologist was conducted over nine years from to 2013-2021. The study was clinical, descriptive and analytical in nature.

Results

In the investigated period, 509 (30.8%) patients with borreliosis symptoms were treated. EM in our patients occurred under the following conditions: a) ringed redness, b) redness of target cels and d) continuous round or oval redness of different sizes of individual redness, or multiple occurrences with primary dissemination. Skin changes with multiorgan chronic symptoms of borreliosis occurred in 67.7% of cases the including: walking redness of different shapes and sizes, pink borreliosis stretch marks, white borreliosis stretch marks, borreliosis palms and soles, psoriatic changes, Acrodermatitis chronica atrophicans, Scleroderma circumscripta-morphae, Erythema nodosum, Granuloma anulare and Lichen striatus et atrophicans. Of the 509 patients treated for borreliosis, 32.3% with multi-organ symptomatology had no skin changes.

Conclusion

The skin manifestations of European borreliosis are multi-layered and Erythema migrans are basic, but not the only markers of the disease. 'Pink borreliose stretch marks, "white borreliosis striae", "borreliosis palms or soles", and intermittent redness accompanied by itching are unique markers for the diagnosis of chronic borreliosis, if they are manifested.

Demographic patterns in Lyme borreliosis seasonality over 25 years

Lyme borreliosis, the most common vector-borne disease in Europe and North America, is attracting growing concern due to its expanding geographic range. The growth in incidence and geographic spread is largely attributed to climate and land-use changes that support the tick vector and thereby increase disease risk. Despite a wide range of symptoms displayed by Lyme borreliosis patients, the demographic patterns in clinical manifestations and seasonal case timing have not been thoroughly investigated and may result from differences in exposure, immunity and pathogenesis. We analysed 25 years of surveillance data from Norway, supplemented by population demography data, using a Bayesian modelling framework. The analyses aimed to detect differences in case seasonality and clinical manifestations of Lyme borreliosis across age and sex differentiated patient groups. The results showed a bimodal pattern of incidence over age, where children (0-9 years) had the highest incidence, young adults (20-29 years) had low incidence and older adults had a second incidence peak in the ages 70-79 years. Youth (0-19 years) presented with a higher proportion of neuroborreliosis cases and a lower proportion of arthritic manifestations compared to adults (20+ years). Adult males had a higher overall incidence than adult females and a higher proportion of arthritis cases. The seasonal timing of Lyme borreliosis consistently occurred around 4.4 weeks earlier in youth compared to adults, regardless of clinical manifestation. All demographic groups exhibited a shift towards an earlier seasonal timing over the 25-year study period, which appeared unrelated to changes in population demographics. However, the disproportionate incidence of Lyme borreliosis in seniors requires increased public awareness and knowledge about this high-risk group as the population continues to age concurrently with disease emergence. Our findings highlight the importance of considering patient demographics when analysing the emergence and seasonal patterns of vector-borne diseases using long-term surveillance data.

Prevalence and factors associated with a prescription of a Lyme borreliosis serology for erythema migrans diagnosis in general practice: a study from the French sentinel network, 2009-2020

BACKGROUND

Serological testing of patients consulting for typical erythema migrans (EM) is not recommended in European recommendations for diagnosis of Lyme borreliosis (LB). Little is known on the level of adherence of French general practitioners to these recommendations. The objectives were to estimate the proportion of Lyme borreliosis serological test prescription in patients with erythema migrans seen in general practice consultations in France, and to study the factors associated with this prescription.

METHODS

LB cases with an EM reported by the French general practitioners (GPs) of the Sentinelles network between January 2009 and December 2020 were included. To assess the associations with a prescription of a serological test, multilevel logistic regression models were used.

RESULTS

Among the 1,831 EM cases included, a prescription for a LB serological test was requested in 24.0% of cases. This proportion decreased significantly over the study period, from 46.8% in 2009 to 15.8% in 2020. A LB serological prescription was associated with patients with no reported tick bite (Odds Ratio (OR): 1.95; 95% confidence interval [1.23-3.09]), multiple EM (OR: 3.82 [1.63-8.92]), EM of five centimeters or more (OR: 4.34 [2.33-8.08]), and GPs having diagnosed less than one EM case per year during the study period (OR: 5.28 [1.73-16.11]).

CONCLUSIONS

Serological testing of patients consulting for EM is not recommended in European recommendations for diagnosis of Lyme borreliosis. Therefore, the significant decrease in the rate of LB serological test for EM over the study period is encouraging. The factors identified in this study can be used to improve messaging to GPs and patients. Further efforts are needed to continue to disseminate diagnostic recommendations for LB to GPs, especially those who rarely see patients with EM.

The history of Lyme disease in Italy and its spread in the Italian territory

Lyme borreliosis (LB) is the most common vector-borne zoonotic inflammatory disease in the Northern Hemisphere. In Italy, the first case was diagnosed in 1985 in a woman in Liguria, while the second, in 1986 in Friuli-Venezia Giulia, documenting the infection in northern Italy. Both diagnoses were confirmed by serological assessment by an indirect immunofluorescence (IFI) technique. Borrelia cultivation from both Ixodes ricinus ticks and human lesions in Trieste (Friuli-Venezia Giulia) identified Borrelia afzelii as the prevalent genospecies; nevertheless, Borrelia garinii, Borrelia burgdorferi (sensu stricto), and Borrelia valaisiana (VS116 Group) were also detected, although less frequently. LB was also documented in other Italian regions: in Tuscany (1991), Trentino-Alto Adige (1995-1996), Emilia-Romagna (1998), Abruzzo (1998), and more recently, Lombardy. Nevertheless, data on LB in other Italian regions, especially in southern Italy and islands, are poor. The aim of this study is to document the spread of LB in Italy through the collection of data from LB patients in eight Italian hospitals located in different Italian regions. Diagnostic criteria for LB diagnosis are as follows: i) the presence of erythema migrans (EM) or ii) a clinical picture suggestive of LB, confirmed by serological tests and/or PCR positivity for Borrelia detection. In addition, data also included the place of residence (town and region) and the place where patients became infected. During the observation period, 1,260 cases were gathered from the participating centers. Although different in extent from northern Italy to central/southern Italy, this study shows that LB is widespread throughout Italy.

Lyme radiculopathy in a septuagenarian

A man in his 70s presented to hospital in early summer with a 5-week history of progressive lower back and right thigh pain, sensory deficit and right leg weakness. There had been limited response to analgesics in the community. Primary investigations on admission revealed no cause for his symptoms. Five days into admission, history emerged of a possible tick bite with subsequent rash sustained 3 months earlier, raising the possibility of neuroborreliosis leading to radiculopathy. Cerebrospinal fluid demonstrated a lymphocytic pleocytosis. An elevated Borrelia burgdorferi antibody index confirmed a diagnosis of Lyme neuroborreliosis. The patient was treated successfully with 28 days of intravenous ceftriaxone, analgesia and physiotherapy. Within the literature, Lyme radiculopathy is a common presentation of neuroborreliosis and should be considered and investigated in patients without radiological evidence of a mechanical cause of worsening lower back pain in settings with endemic Lyme disease.

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.

Seroprevalence of Borrelia IgG antibodies among individuals from Eastern Slovakia

OBJECTIVES

Lyme borreliosis is a tick-borne disease of increasing incidence and public concern. Our cross-sectional study was aimed at evaluating seroprevalence of Borrelia burgdorferi in a group of respondents from Eastern Slovakia.

METHODS

In total, 515 blood samples collected in 2013-2016 were analysed with NovaLisaTM, NovaTec - Borrelia IgG/IgM kit (Immunodiagnostica, Dietzenbach, Germany). Positive and equivocal IgG-antibody results were further examined with immunoblotting (LYMECHECK® OPTIMA IgG and IgM kits, BIOSYNEX, France). Data detected by serological methods were matched with those obtained from a questionnaire. Differences between groups by residence/seropositivity were tested by χ² test. The effect of socio-demographic and risk factors on seropositivity of IgG antibodies was assessed using binary logistic regression.

RESULTS

IgG antibodies against Borrelia burgdorferi were detected in 67 cases (13.01%) and IgM antibodies in 40 cases (7.8%). Previous tick bite had been noted in 67.2% of these seropositive individuals. Higher seropositivity was observed in men and persons aged over 61 years. Rural residents had higher seropositivity (39%) than those living in urban (29%) areas. Very few of these seropositive persons reported prior symptoms.

CONCLUSION

The study reveals that IgG-seropositivity for Borrelia burgdorferi in Eastern Slovakia is predominant in men and occurs mainly in rural areas. The findings also suggest that exposure to Borrelia burgdorferi (with subsequent antibody response in serum) does occur, mostly without giving rise to clinical Lyme borreliosis.

An intervention in general practice to improve the management of Lyme borreliosis in Denmark

Background

Our objectives were to improve the following outcomes in patients with Lyme borreliosis (LB) through an educational intervention in general practice: (i) increase the number of hospital referrals on suspicion of LB, (ii) increase the number of cerebrospinal fluid (CSF) tests examined for Borrelia burgdorferi antibody index, (iii) decrease the number of serum-B. burgdorferi antibody tests ordered, (iv) shorten delay from symptom onset to hospital in Lyme neuroborreliosis (LNB) patients, (v) increase LB knowledge among general practitioners.

Methods

A prospective non-blinded non-randomized intervention trial on the island of Funen, Denmark. The intervention included oral and written education about LB and was carried out in areas with an LNB incidence ≥4.7/100.000 between 22 January 2019 and 7 May 2019. Results were compared between the intervention group (49 general practices) and the remaining general practices in Funen (71 practices) 2 years before and after the intervention.

Results

In the study period, 196 patients were referred on suspicion of LB, a 28.9% increase in the intervention group post-intervention, 59.5% increase in the control group (P = 0.47). The number of CSF-Borrelia-antibody index tests increased 20.8% in the intervention group, 18.0% in the control group (P = 0.68), while ordered serum-B. burgdorferi antibody tests declined 43.1% in the intervention group, 34.5% in the control group (P = 0.30). 25.1% had the presence of serum-B. burgdorferi antibodies. We found no difference in LNB pre-hospital delay before and after intervention or between groups (P = 0.21). The intervention group performed significantly better on a follow-up questionnaire (P = 0.02).

Conclusion

We found an overall improvement in LB awareness and referrals among general practitioners but could not show any effect of the intervention on clinical outcomes of LNB.

Risk factors for Lyme disease stage and manifestation using electronic health records

BACKGROUND

Little is known about risk factors for early (e.g., erythema migrans) and disseminated Lyme disease manifestations, such as arthritis, neurological complications, and carditis. No study has used both diagnoses and free text to classify Lyme disease by disease stage and manifestation.

METHODS

We identified Lyme disease cases in 2012-2016 in the electronic health record (EHR) of a large, integrated health system in Pennsylvania. We developed a rule-based text-matching algorithm using regular expressions to extract clinical data from free text. Lyme disease cases were then classified by stage and manifestation using data from both diagnoses and free text. Among cases classified by stage, we evaluated individual, community, and health care variables as predictors of disseminated stage (vs. early) disease using Poisson regression models with robust errors. Final models adjusted for sociodemographic factors, receipt of Medical Assistance (i.e., Medicaid, a proxy for low socioeconomic status), primary care contact, setting of diagnosis, season of diagnosis, and urban/rural status.

RESULTS

Among 7310 cases of Lyme disease, we classified 62% by stage. Overall, 23% were classified using both diagnoses and text, 26% were classified using diagnoses only, and 13% were classified using text only. Among the staged diagnoses (n = 4530), 30% were disseminated stage (762 arthritis, 426 neurological manifestations, 76 carditis, 95 secondary erythema migrans, and 76 other manifestations). In adjusted models, we found that persons on Medical Assistance at least 50% of time under observation, compared to never users, had a higher risk (risk ratio [95% confidence interval]) of disseminated Lyme disease (1.20 [1.05, 1.37]). Primary care contact (0.59 [0.54, 0.64]) and diagnosis in the urgent care (0.22 [0.17, 0.29]), compared to the outpatient setting, were associated with lower risk of disseminated Lyme disease.

CONCLUSIONS

The associations between insurance payor, primary care status, and diagnostic setting with disseminated Lyme disease suggest that lower socioeconomic status and less health care access could be linked with disseminated stage Lyme disease. Intervening on these factors could reduce the individual and health care burden of disseminated Lyme disease. Our findings demonstrate the value of both diagnostic and narrative text data to identify Lyme disease manifestations in the EHR.

Seroprevalence of antibodies against Borrelia burgdorferi sensu lato in healthy blood donors in Romania: an update

BACKGROUND

The Borrelia burgdorferi sensu lato (s.l.) genogroup is the causative agent responsible for Lyme borreliosis, a common tick-borne infectious disease in some temperate regions of the Northern Hemisphere. In humans, the clinical manifestations of Lyme borreliosis vary from dermatological infection to severe systemic manifestations. In Romania, data on the seroprevalence of Lyme borreliosis and associated risk factors are scarce and outdated, as the only seroprevalence study with a large dataset was published more than 20 years ago. Therefore, the aim of the present study was to evaluate the seroprevalence for Borrelia burgdorferi s.l. in healthy blood donors from six Romanian counties and identify the associated risk factors.

METHODS

The study was conducted among 1200 healthy blood donors aged between 18 and 65 years during November 2019 and September 2020 from six counties in the northwestern and central parts of Romania. A two-tiered testing strategy was applied. Positive and equivocal immunoenzymatic test results for IgG and IgM antibodies were further confirmed by Western blot.

RESULTS

Serum samples from 20% of the blood donors had positive or equivocal IgG and IgM ELISA index values. In total, 2.3% of the serum samples for IgG and 1.8% for IgM were positive by Western blot. The seroprevalence for both antibodies varied between 1.5% (Satu-Mare) and 6.5% (Bistrița-Năsăud) in the six counties investigated. The highest seroprevalence was observed in men (4.7%), in blood donors performing their professional activities outdoors (4.2%), and in those aged  ≥ 56 years (8%).

CONCLUSIONS

These findings confirm the presence of specific IgG and IgM antibodies to B. burgdorferi s.l. among healthy blood donors from Romania. Furthermore, potential risk factors, such as gender, age, and behavior, associated with the presence of positive B. burgdorferi s.l. antibodies among healthy blood donors were identified.

Lyme disease in Western Europe: an emerging problem? A systematic review

Objectives: Lyme borreliosis is the most common zoonotic disease in Europe and causes an estimated total burden of 10.55 disability-adjusted life years (DALY) per 100 000 population. Its incidence in Western Europe is assumed to be increasing, yet this remains to be confirmed. The aim of this study was to assess the emergence of Lyme disease in Western Europe by performing a systematic review of the scientific literature.Methods: Pubmed, Embase and grey literature were searched from database inception until August 2018 for articles reporting the incidence of Lyme borreliosis in Western European countries. We included observational studies in English that reported data on a random sample of the population and fulfilled our definition of Lyme disease diagnosis. Annual population-weighted averages and the evolution of Lyme borreliosis incidence were extracted or calculated for every Western European country.Results: Our review identified 1514 and included 18 studies next to seven surveillance reports reporting data from 16 Western European countries. Incidence of Lyme borreliosis ranged from 0.001 (Italy) to 632 (Sweden, Blekinge county) cases/100 000/year. Iceland reported the strongest emergence with an average yearly increase of 21.15% over a 12-year period, whereas Italy reported the strongest average yearly decrease of 52.71% over a 5-year period. Very limited high-quality data were available on Lyme borreliosis incidence in the southern Western European countries.Conclusion: Diagnosis of Lyme borreliosis is on the rise in some Western European countries, mostly in the northern and central part. Better surveillance in the southern countries is necessary.

Neurosyphilis and Lyme neuroborreliosis

PURPOSE OF REVIEW

Neurosyphilis (NS) and Lyme neuroborreliosis (LNB) are spirochetal diseases with distinct clinical manifestations. The diagnosis of NS remains challenging due to imperfect diagnostic criteria and testing modalities. With LNB, misconceptions about diagnosis and treatment lead to considerable morbidity and drug related adverse effects.

RECENT FINDINGS

Although studies continue investigating alternate approaches and new diagnostic tests for NS, few data exist to change current approaches to diagnosis, management or follow up. In the diagnosis of LNB, the chemokine CXCL13 shows promising diagnostic accuracy. A systematic review discourages the use of cell-based assays when investigating Lyme disease. Clinical studies show no benefit from extended antibiotic treatment for patients with unspecific symptoms labelled as having Lyme disease.

SUMMARY

The diagnosis of NS may be delayed due to a lack of specificity of findings, low suspicion for syphilis, and/or similarities in presentation to other diseases. A high index of suspicion for syphilis is required provide timely diagnosis and management of NS. Fortunately, penicillin remains the treatment of choice. Overdiagnosis and overtreatment in patients labelled as having Lyme disease can be avoided by an evidence-based approach towards diagnosis and treatment.

Lyme borreliosis in Finland: a register-based linkage study

Background

In Finland, the routine surveillance of Lyme borreliosis (LB) is laboratory-based. In addition, we have well established national health care registers where countrywide data from patient visits in public health care units are collected. In our previous study based on these registers, we reported an increasing incidence of both microbiologically confirmed and clinically diagnosed LB cases in Finland during the past years. Here, we evaluated our register data, refined LB incidence estimates provided in our previous study, and evaluated treatment practices considering LB in the primary health care.

Methods

Three national health care registers were used. The Register for Primary Health Care Visits (Avohilmo) and the National Hospital Discharge Register (Hilmo) collect physician-recorded data from the outpatient and inpatient health care visits, respectively, whereas the National Infectious Diseases Register (NIDR) represents positive findings in LB diagnostics notified electronically by microbiological laboratories. We used a personal identification number in register-linkage to identify LB cases on an individual level in the study year 2014. In addition, antibiotic purchase data was retrieved from the Finnish Social Insurance Institution in order to evaluate the LB treatment practices in the primary health care in Finland.

Results

Avohilmo was found to be useful in monitoring clinically diagnosed LB (i.e. erythema migrans (EM) infections), whereas Hilmo did not add much value next to existing laboratory-based surveillance of disseminated LB. However, Hilmo gave valuable information about uncertainties related to physician-based surveillance of disseminated LB and the total annual number of EM infections in our country. Antibiotic purchases associated with the LB-related outpatient visits in the primary health care indicated a good compliance with the recommended treatment guidelines.

Conclusions

Avohilmo and laboratory-based NIDR together are useful in monitoring LB incidence in Finland. A good compliance was observed with the recommended treatment guidelines of clinically diagnosed LB in the primary health care. In 2018, Avohilmo was introduced in the routine surveillance of LB in Finland next to laboratory-based surveillance of disseminated LB.

Classification of patients referred under suspicion of tick-borne diseases, Copenhagen, Denmark

To provide better care for patients suspected of having a tick-transmitted infection, the Clinic for Tick-borne Diseases at Rigshospitalet, Copenhagen, Denmark was established. The aim of this prospective cohort study was to evaluate diagnostic outcome and to characterize demographics and clinical presentations of patients referred between the 1st of September 2017 to 31st of August 2019. A diagnosis of Lyme borreliosis was based on medical history, symptoms, serology and cerebrospinal fluid analysis. The patients were classified as definite Lyme borreliosis, possible Lyme borreliosis or post-treatment Lyme disease syndrome. Antibiotic treatment of Lyme borreliosis manifestations was initiated in accordance with the national guidelines. Patients not fulfilling the criteria of Lyme borreliosis were further investigated and discussed with an interdisciplinary team consisting of specialists from relevant specialties, according to individual clinical presentation and symptoms. Clinical information and demographics were registered and managed in a database. A total of 215 patients were included in the study period. Median age was 51 years (range 17-83 years), and 56 % were female. Definite Lyme borreliosis was diagnosed in 45 patients, of which 20 patients had erythema migrans, 14 patients had definite Lyme neuroborreliosis, six had acrodermatitis chronica atrophicans, four had multiple erythema migrans and one had Lyme carditis. Furthermore, 12 patients were classified as possible Lyme borreliosis and 12 patients as post-treatment Lyme disease syndrome. A total of 146 patients (68 %) did not fulfil the diagnostic criteria of Lyme borreliosis. Half of these patients (73 patients, 34 %) were diagnosed with an alternative diagnosis including inflammatory diseases, cancer diseases and two patients with a tick-associated disease other than Lyme borreliosis. A total of 73 patients (34 %) were discharged without sign of somatic disease. Lyme borreliosis patients had a shorter duration of symptoms prior to the first hospital encounter compared to patients discharged without a specific diagnosis (p<0.001). When comparing symptoms at presentation, patients discharged without a specific diagnosis suffered more often from general fatigue and cognitive dysfunction. In conclusion, 66 % of all referred patients were given a specific diagnosis after ended outpatient course. A total of 32 % was diagnosed with either definite Lyme borreliosis, possible Lyme borreliosis or post-treatment Lyme disease syndrome; 34 % was diagnosed with a non-tick-associated diagnosis. Our findings underscore the complexity in diagnosing Lyme borreliosis and the importance of ruling out other diseases through careful examination.

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.

A descriptive epidemiological study of the incidence of newly diagnosed Lyme disease cases in a UK primary care cohort, 1998-2016

BACKGROUND

Primary care is likely to see the highest number of Lyme disease patients. Despite this, there is limited published data regarding Lyme disease patients accessing primary care in the UK. We aim to describe trends in the incidence of a new diagnosis, and demographics of patients identified in a primary care electronic health database.

METHODS

A descriptive epidemiological study of Lyme disease coded patients in UK primary care. 3725 patients coded for Lyme disease during 1998-2016 were identified within The Health Improvement Network (THIN). Incidence rates and the demographics of cases identified were described. Poisson regression was used to analyse socio-demographic characteristics of the cases.

RESULTS

There was an increase in annual crude incidence rates, peaking in 2015 at 5.47 (95% CI 4.85-6.14) cases per 100,000 population per year. Multivariable analysis showed there were significant differences in the ages of those affected, incidence of a new diagnosis rose as deprivation levels improved, and that there was a higher incidence of cases living in rural areas compared to urban areas. There was no significant difference between sexes for the UK. Cases were significantly more likely to identify with being white compared to the national population.

CONCLUSIONS

An increasing incidence of patients newly coded with Lyme disease related Read codes was identified using data from a UK national primary care database. By comparing these incidence figures with national laboratory-confirmed surveillance data, a multiplication factor of 2.35 (95%CI 1.81-2.88) can be calculated in order to estimate the annual number of cases seen in primary care. The significant socio-demographic variables associated with a Lyme disease diagnosis likely reflect a complex interplay of socio-economic issues, which needs to be further explored. Future work is needed to examine the treatment and management of patients within this database.

Human seroprevalence of antibodies to tick-borne microbes in southern Norway

The tick Ixodes ricinus is widespread along the coastline of southern Norway, but data on human exposure to tick-borne microbes are scarce. We aimed to assess the seroprevalence of IgG antibodies to various tick-borne microbes in the general adult population living in a Norwegian municipality where ticks are abundant. Søgne is a coastline municipality in the southernmost part of Norway, and has a high density of ticks. All individuals aged 18-69 years with residential address in Søgne municipality (n = 7424) were invited to give a blood sample and answer a questionnaire. Blood samples from 3568 individuals were available for analysis. All samples were analyzed for IgG antibodies to Borrelia burgdorferi sensu lato (Bbsl), and around 1500 samples for IgG antibodies to other tick-borne microbes. Serum IgG antibodies to Bbsl were present in 22.0% (785/3568) of the tested samples, tick-borne encephalitis virus (TBEV) in 3.1% (45/1453), Anaplasma phagocytophilum in 11.0% (159/1452), Babesia microti in 2.1% (33/1537), Bartonella henselae/B. quintana in 0.1% (2/1451) and Rickettsia helvetica/R. conorii in 4.2% (60/1445). Serum IgG antibodies to A. phagocytophilum and R. helvetica/R. conorii were significantly more prevalent (p = 0.010 and p = 0.016, respectively) among individuals with serum IgG antibodies to Bbsl than among individuals without. In conclusion, our study showed a high exposure to Bbsl in the general adult population living in a coastline municipality in the southernmost part of Norway. The population is also exposed to A. phagocytophilum, R. helvetica/R. conorii, B. microti and TBEV, but very rarely B. henselae/B. quintana.

Epidemiology of Lyme Disease in a Highly Endemic European Zone

Background and objective: Lyme disease, also known as Lyme borreliosis (LB), is a tick-borne infectious disease caused by the spirochete bacteria Borrelia. The risk of infection depends on the geographical area, ecological factors, and human behavior. Clinical manifestations of Lyme borreliosis have a wide range, but the most frequent clinical symptom, which is also a diagnostic symptom, is a skin rash called erythema migrans (EM). The disease is very common worldwide. In Lithuania, the disease frequency is 99.9 cases per 100,000 population (Centre for Communicable Diseases and AIDS, Lithuania, 2017). The main aim of this study was to obtain the baseline characteristics of the disease regarding the infected Lithuanian population. Materials and Methods: We analyzed data from the Centre for Communicable Diseases and AIDS about all Lyme disease (A69.2) diagnosed patients over a three-year period (from 2014 to 2016) in Lithuania. Results: In 2014–2016, 7424 (crude incidence rate 85.4) cases with LB were diagnosed in Lithuania. Most of them (4633 (62.4%)) were identified in women. Older people were more likely to suffer from LB. Urban residents were 2.6 times more often affected that those living in villages. Tick bites were primarily observed in high season months, from May to September (90%), with the highest peak in July. There was a higher number of observed tick bites (p = 0.003) in the urban residents. Erythema migrans occurred in 75.6% LB cases, while other symptoms did not exceed a quarter of all LB cases. There were 7353 (99.6%) cases where LB was confirmed via clinical symptoms and/or laboratory tests. Also, 1720 (23.2%) patients were tested for LB immunoglobulins. Conclusions: This study found a high incidence of Lyme disease in Lithuania. We elucidated the baseline characteristics regarding the infected Lithuanian population which may ease medical clinicians’ work on new Lyme diagnoses.

The demographics and geographic distribution of laboratory-confirmed Lyme disease cases in England and Wales (2013-2016): an ecological study

OBJECTIVE

Lyme disease is a tick-borne disease of increasing incidence and public concern across the Northern Hemisphere. However, the socio-demographics and geographic distribution of the population affected in England and Wales are poorly understood. Therefore, the proposed study was designed to describe the demographics and distribution of laboratory-confirmed cases of Lyme disease from a national testing laboratory.

DESIGN

An ecological study of routinely collected laboratory surveillance data.

SETTING

Public Health England's national Lyme disease testing laboratory.

PARTICIPANTS

3986 laboratory-confirmed cases of Lyme disease between 2013 and 2016.

RESULTS

In England and Wales, the incidence of laboratory-confirmed Lyme disease rose significantly over the study period from 1.62 cases per 100 000 in 2013 to 1.95 cases per 100 000 in 2016. There was a bimodal age distribution (with peaks at 6-10 and 61-65 years age bands) with a predominance of male patients. A significant clustering of areas with high Lyme disease incidence was located in southern England. An association was found between disease incidence and socioeconomic status, based on the patient's resident postcode, with more cases found in less deprived areas. Cases were disproportionately found in rural areas compared with the national population distribution.

CONCLUSIONS

These results suggest that Lyme disease patients originate from areas with higher socioeconomic status and disproportionately in rural areas. Identification of the Lyme disease hotspots in southern England, alongside the socio-demographics described, will enable a targeted approach to public health interventions and messages.

Lyme neuroborreliosis and bird populations in northern Europe

Many vector-borne diseases are transmitted through complex pathogen-vector-host networks, which makes it challenging to identify the role of specific host groups in disease emergence. Lyme borreliosis in humans is now the most common vector-borne zoonosis in the Northern Hemisphere. The disease is caused by multiple genospecies of Borrelia burgdorferi sensu lato bacteria transmitted by ixodid (hard) ticks, and the major host groups transmit Borrelia genospecies with different pathogenicity, causing variable clinical symptoms in humans. The health impact of a given host group is a function of the number of ticks it infects as well as the pathogenicity of the genospecies it carries. Borrelia afzelii, with mainly small mammals as reservoirs, is the most common pathogen causing Lyme borreliosis, and it is often responsible for the largest proportion of infected host-seeking tick nymphs in Europe. The bird-borne Borrelia garinii, though less prevalent in nymphal ticks, is more likely to cause Lyme neuroborreliosis, but whether B. garinii causes disseminated disease more frequently has not been documented. Based on extensive data of annual disease incidence across Norway from 1995 to 2017, we show here that 69% of disseminated Lyme borreliosis cases were neuroborreliosis, which is three times higher than predicted from the infection prevalence of B. garinii in host-seeking ticks (21%). The population estimate of migratory birds, mainly of thrushes, explained part of the annual variation in cases of neuroborreliosis, with a one-year time lag. We highlight the important role of the genospecies' pathogenicity and the host associations for understanding the epidemiology of disseminated Lyme borreliosis.

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

BACKGROUND

It is heavily debated whether tick-borne infections cause chronic subjective health complaints. If the hypothesis of a major causal connection is true, one would expect to find more subjective health complaints in a population with high exposure to ticks than in a population with less exposure. In the current study we aimed to assess somatic symptoms and fatigue in a Norwegian population with high exposure to ticks, compare our findings to normative data, and assess predictors of somatic symptom load.

MATERIAL AND METHODS

All individuals aged 18-69 years with residential address in Søgne municipality in southern Norway were in the period June 2015 to June 2016 invited to participate in the study. Somatic symptoms were assessed by the Patient Health Questionnaire-15 (PHQ-15) and fatigue by the Fatigue Severity Scale (FSS). A multivariable regression analysis was performed to assess predictors of somatic symptom load.

RESULTS

Out of 7424 invited individuals, 2971 (40.0%) returned the questionnaire. 85.1% of 2950 responders reported exposure to tick-bite. PHQ-15 mean sum score was 5.3, and 16.5% reported moderate to severe somatic symptom load (i.e. ≥ 10). FSS mean score was 3.2, and 29.8% scored above the cut-off value for fatigue (i.e. ≥ 4.0). All gender and age groups in our study population had equal or lower mean sum score on PHQ-15 than reported in Swedish normative data, and lower mean score on FSS than reported in Norwegian normative data. In multivariable regression the following factors were associated with higher somatic symptom load (listed in order of descending beta coefficient): Anxiety and depression, number of other diseases, female gender, younger age, recruitment when visiting general practitioner's office, ≤ 6 years education after primary school, tick-bite earlier in life, erythema migrans earlier in life, less physical activity, and modern health worries.

CONCLUSION

The study population reported high exposure to tick-bites, but less or equal level of somatic symptoms and less fatigue than found in normative data. There was a weak association between somatic symptom load and exposure to tick-bite and erythema migrans, possibly related to selection bias. Our findings do not support the hypothesis of a major causal connection between tick-borne infections and subjective health complaints.

Comparison of phenoxymethylpenicillin, amoxicillin, and doxycycline for erythema migrans in general practice. A randomized controlled trial with a 1-year follow-up

OBJECTIVES

To compare the three most commonly used antibiotics for erythema migrans (EM) in Norwegian primary care.

METHODS

A randomized, parallel, controlled trial was carried out. Treatments were open to the patients, but blinded for the GPs and investigators. Patients eligible for inclusion were aged ≥18 years and clinically diagnosed with EM. Block randomization was processed in blocks of six. Patients were assigned to receive one of three antibiotic treatments for 14 days: phenoxymethylpenicillin (PCV), amoxicillin, or doxycycline. The primary outcome was the duration of EM in days in the three treatment groups. Patients kept a diary for the 14 days of treatment, in which they registered concomitant symptoms and side effects. The patients consulted their GP after 14 days of treatment and had a 1-year follow-up to monitor any development of disseminated Lyme borreliosis (LB). EMs with a duration of more than 14 days were followed until resolution. ClinicalTrials.govNCT01368341 and EU Clinical Trials Register 2010-023747-15.

RESULTS

One hundred and eighty eight patients (PCV: n = 56, amoxicillin: n = 64, doxycycline: n = 68) were included by 44 Norwegian general practitioners (GPs) from June 2011 to November 2013. Follow-up was completed by December 2014. The median duration of EM was altogether 14 days (range 3-293). For the PCV group median duration was 14 days (range 5-91), for amoxicillin 13 days (range 4-179) and for doxycycline 14 days (range 3-293). The duration of EM did not differ significantly between the three antibiotic groups (p 0.277). None of the patients developed disseminated LB within the 1-year follow-up.

CONCLUSIONS

We did not find 14 days of PCV, doxycycline, and amoxicillin treatments to differ in effectiveness or safety in the treatment of clinically diagnosed EM in primary care.

Symptom load and general function among patients with erythema migrans: a prospective study with a 1-year follow-up after antibiotic treatment in Norwegian general practice

OBJECTIVE

Promptly treated erythema migrans (EM) has good prognosis. However, some patients report persistent symptoms. Do patients with EM have more symptoms than the general population? We describe individual symptoms and general function in EM-patients at time of diagnosis and one year after treatment.

DESIGN

Prospective study with 1-year follow up after treatment. Questionnaires included a modified version of the Subjective Health Complaints Inventory, comprising three additional Lyme borreliosis (LB) related symptoms. General function was assessed using a five-point scale modified from the COOP/WONCA charts.

SETTING

Norwegian general practice.

SUBJECTS

A total of 188 patients were included in a randomized controlled trial comparing three antibiotic regimens for EM, of whom 139 had complete data for this study.

MAIN OUTCOME MEASURES

Individual symptoms, symptom load and general function.

RESULTS

Mild symptoms were common, reported by 84.9% at baseline and by 85.6% at follow-up. At baseline, patients reported a mean of 5.4 symptoms, compared with 6.2 after one year. Severely bothersome symptoms and severely impaired general function were rare. Tiredness was the most reported symptom both at baseline and at follow-up. Palsy (other than facial) was the least reported symptom, but the only one with a significant increase. However, this was not associated to the EM.

CONCLUSION

The symptom load was comparable to that reported in the general population. We found an increase in symptom load at follow-up that did not significantly affect general function.

IMPLICATION

Monitoring patients' symptom loads prior to treatment reduce the probability of attributing follow-up symptoms to LB. Key points Erythema migrans has a good prognosis.Patients treated for erythema migrans have a slight increase in symptom load one year after treatment. This increase does not affect general function. The levels of subjective health complaints in patients treated for erythema migrans are comparable to the background population.