Epidemiological Surveillance of Lyme Borreliosis in Bavaria, Germany, 2013-2020

Differentiating Lyme arthritis: a case-based review

The incidence or prevalence of Lyme arthritis (LA) in Denmark is unknown and assumed very low. No published cases of polymerase chain reaction (PCR)-confirmed LA from Denmark exist. Clinically, LA does not differ from other rheumatic oligoarthritic disorders posing a differential diagnostic challenge. To review the incidence and prevalence of LA to our knowledge and to present a case series of PCR-confirmed LA cases from Denmark. We conducted a systematic literature review via MEDLINE and EMBASE to explore incidence and prevalence rates of LA. Additionally, we present six cases of patients diagnosed with LA in Denmark. Our literature review identified 23 studies reporting prevalence or incidence, yet only ten studies provided estimates ranging from 1.1 to 280/100.000 in the general population. Our case series identified six patients with LA from a localized region in Southern Denmark; all confirmed by Borrelia-specific real-time PCR from synovial fluid. The diagnostic delay was up to 38 months. All patients except one had a history of previous tick bites; none had erythema migrans lesions. All presented with recurrent arthritis in the knee joint, and two had arthritis in the wrist. The literature review showed an incidence of LA ranging from 1.1 to 15.8 per 100.000 in Europe. Our case series suggests a potentially higher prevalence of LA in Denmark than previously believed. Lack of tick exposure history, antibody assessments and test of Borrelia burgdorferi sensu lato DNA in synovial fluid might lead to misdiagnosed cases potentially explaining the assumed low incidence of LA in Denmark.

Incidence of Lyme Borreliosis in Germany: A retrospective observational healthcare claims study

Lyme borreliosis (LB) is the most common tick-borne disease in Germany. Although the incidence of LB in Germany has been assessed in several studies, those studies either used data from statutory surveillance, which frequently underreport cases, or data from health claims databases, which may overestimate cases due to non-specific LB case definitions. Here, using a more specific case definition, we describe the incidence of medically-attended LB by disease manifestation, age group, and federal state for the period 2015-2019. Both inpatient and outpatient cases were analyzed from a claims database. To be eligible for inclusion, patients were required to have an LB specific ICD-10 GM diagnosis code plus an antibiotic prescription, and for disseminated manifestations, a laboratory test order additionally. LB cases were classified as erythema migrans (EM), or disseminated disease including Lyme arthritis (LA), Lyme neuroborreliosis (LNB), and all other disease manifestations (OTH). Between 2015 and 2019, the incidence of medically-attended LB cases ranged from 195.7/100,000 population per year (95% confidence interval [CI], 191.0 - 200.5) to 254.5/100,000 population per year (95% CI, 249.0 - 260.0) per year. The majority of cases (92.2%) were EM, while 2.8% presented as LA, 3.8% as LNB, and 1.2% as OTH. For both EM and disseminated disease, the incidence peaked in children aged 5-9 years and in older adults. By federal state, the incidence of medically-attended EM ranged from 74.4/100,000 population per year (95% CI, 71.9 - 77.0) per year in Hamburg, to 394.1/100,000 population per year (95% CI, 370.7 - 417.6) per year in Saxony, whereas for medically-attended disseminated disease, the highest incidence was in Thuringia, Saxony, and Bavaria (range: 22.0 [95% CI, 19.9 - 24.0] to 35.7 [95% CI, 34.7 - 36.7] per 100,000 population per year). This study comprehensively estimated the incidence of all manifestations of medically-attended LB and showed a high incidence of LB throughout Germany. Results from the study support performing epidemiological studies in all federal states to measure the burden of LB and to invest in public health interventions for prevention.

Combining Double-Dose and High-Dose Pulsed Dapsone Combination Therapy for Chronic Lyme Disease/Post-Treatment Lyme Disease Syndrome and Co-Infections, Including Bartonella: A Report of 3 Cases and a Literature Review

Three patients with relapsing and remitting borreliosis, babesiosis, and bartonellosis, despite extended anti-infective therapy, were prescribed double-dose dapsone combination therapy (DDDCT) for 8 weeks, followed by one or several two-week courses of pulsed high-dose dapsone combination therapy (HDDCT). We discuss these patients' cases to illustrate three important variables required for long-term remission. First, diagnosing and treating active co-infections, including Babesia and Bartonella were important. Babesia required rotations of multiple anti-malarial drug combinations and herbal therapies, and Bartonella required one or several 6-day HDDCT pulses to achieve clinical remission. Second, all prior oral, intramuscular (IM), and/or intravenous (IV) antibiotics used for chronic Lyme disease (CLD)/post-treatment Lyme disease syndrome (PTLDS), irrespective of the length of administration, were inferior in efficacy to short-term pulsed biofilm/persister drug combination therapy i.e., dapsone, rifampin, methylene blue, and pyrazinamide, which improved resistant fatigue, pain, headaches, insomnia, and neuropsychiatric symptoms. Lastly, addressing multiple factors on the 16-point multiple systemic infectious disease syndrome (MSIDS) model was important in achieving remission. In conclusion, DDDCT with one or several 6-7-day pulses of HDDCT, while addressing abnormalities on the 16-point MSIDS map, could represent a novel effective clinical and anti-infective strategy in CLD/PTLDS and associated co-infections including Bartonella.

Knowledge, Attitudes and Behaviors regarding Tick-Borne Encephalitis Vaccination and Prevention of Tick-Borne Diseases among Primary Care Physicians in Bavaria and Baden-Wuerttemberg, Germany, May-September 2022

In 2020, a record number of tick-borne encephalitis (TBE) cases was reported in major endemic areas in Germany, i.e., the southern federal states of Baden-Wuerttemberg and Bavaria. Most cases were unvaccinated. Other tick-borne diseases (TBDs), including Lyme borreliosis and tularemia, are rising, too. Thus, strategies are needed to increase TBE vaccination uptake in risk areas and promote education on TBD prevention. Primary care physicians are key providers of both vaccinations and TBD education. The TBD-Prevention (TBD-Prev) study aimed to investigate the knowledge, attitudes and behaviors of primary care physicians in Baden-Wuerttemberg and Bavaria with regard to TBE vaccination and prevention of TBDs and to derive strategies for increasing vaccination rates and improving knowledge about TBE and other TBDs in the population and among primary care physicians. We invited all primary care physicians (N = 14,046) in both states to participate by mail. Using standardized, self-administered questionnaires, available both on paper and online, we asked physicians anonymously about their knowledge, attitudes and behaviors with respect to TBE vaccination and TBD prevention and their need for further information/educational materials. A total of 2321 physicians participated between May and September 2022 (response rate 17%), of whom 1222 (53%) worked in Baden-Wuerttemberg and 1067 (46%) in Bavaria. Among the participating physicians, 56% were male, 71% were >50 years and 51% worked in an individual practice. Furthermore, 91% were aware of the German national vaccination guidelines, and 98% perceived their knowledge of the risks and benefits of vaccination as adequate. A total of 97% offer TBE vaccinations, 67% provide vaccination counselling during initial consultations with new patients and 64% actively remind patients about due vaccinations. In addition, 24% expressed a need for further information materials, mainly traditional, analogue media such as flyers (82%) and posters (50%), and named timeliness, quality assurance, easy comprehensibility and independence from the pharmaceutical industry as the most important characteristics of such materials. Almost all participating physicians reported offering TBE vaccinations and feeling well-informed about TBE vaccination and TBDs. However, active offering of vaccinations and education could be further improved, and additional, low-threshold information materials are needed. Based on these results, we will develop and provide various materials on TBE vaccination and TBDs, in particular flyers and posters, for use by physicians during consultations.

Seroepidemiology of Borrelia burgdorferi s.l. among German National Cohort (NAKO) Participants, Hanover

Lyme borreliosis is the leading tick-related illness in Europe, caused by Borrelia Burgdorferi s.l. Lower Saxony, Germany, including its capital, Hanover, has a higher proportion of infected ticks than central European countries, justifying a research focus on the potential human consequences. The current knowledge gap on human incident infections, particularly in Western Germany, demands serological insights, especially regarding a potentially changing climate-related tick abundance and activity. We determined the immunoglobulin G (IgG) and immunoglobulin M (IgM) serostatuses for 8009 German National Cohort (NAKO) participants from Hanover, examined in 2014-2018. We used an enzyme-linked immunosorbent assay (ELISA) as the screening and a line immunoblot as confirmation for the Borrelia Burgdorferi s.l. antibodies. We weighted the seropositivity proportions to estimate general population seropositivity and estimated the force of infection (FOI). Using logistic regression, we investigated risk factors for seropositivity. Seropositivity was 3.0% (IgG) and 2.1% (IgM). The FOI varied with age, sharply increasing in participants aged ≥40 years. We confirmed advancing age and male sex as risk factors. We reported reduced odds for seropositivity with increasing body mass index and depressive symptomatology, respectively, pointing to an impact of lifestyle-related behaviors. The local proportion of seropositive individuals is comparable to previous estimates for northern Germany, indicating a steady seroprevalence.

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.

Epidemiology of Lyme borreliosis based on outpatient claims data of all people with statutory health insurance, Germany, 2019

Introduction

Evidence of nationwide and regional morbidity of Lyme borreliosis (LB) in Germany is lacking.

Aims

We calculated the total number of incident LB cases in Germany in 2019, compared regional variations, investigated the extent of possible under-reporting in notification data and examined the association between high incidence areas and land cover composition.

Methods

We used outpatient claims data comprising information for people with statutory health insurance who visited a physician at least once between 2010 and 2019 in Germany (n = 71,411,504). The ICD-10 code A69.2 was used to identify incident LB patients. Spatial variations of LB were assessed by means of Global and Local Moran’s Index at district level. Notification data were obtained for nine federal states with mandatory notification from the Robert Koch Institute (RKI).

Results

Of all insured, 128,177 were diagnosed with LB in 2019, corresponding to an incidence of 179 per 100,000 insured. The incidence varied across districts by a factor of 16 (range: 40–646 per 100,000). We identified four spatial clusters with high incidences. These clusters were associated with a significantly larger proportion of forests and agricultural areas than low incidence clusters. In 2019, 12,264 LB cases were reported to the RKI from nine federal states, while 69,623 patients with LB were found in claims data for those states. This difference varied considerably across districts.

Conclusions

These findings serve as a solid basis for regionally tailored population-based intervention programmes and can support modelling studies assessing the development of LB epidemiology under various climate change scenarios.

Regional seropositivity for Borrelia burgdorferi and associated risk factors: findings from the Rhineland Study, Germany

Background

Lyme borreliosis is the most prevalent vector-borne disease in Europe, and numbers might increase due to climate change. However, borreliosis is not notifiable in North Rhine-Westphalia (NRW), Germany. Hence, little is known about the current human seroprevalence in NRW. However, the proportion of Borrelia burgdorferi sensu lato-infected ticks has increased in a NRW nature reserve. The literature suggests increasing age and male sex as risk factors for seropositivity, whereas the influence of socioeconomic status is controversial. Thus, we aimed to determine regional seropositivity for Borrelia burgdorferi sensu lato (B. burgdorferi s.l.) and its risk factors in the Rhineland Study population in Bonn, NRW, and to compare it with previous surveys to evaluate potential effects of climate change.

Methods

We assessed seropositivity in 2865 Rhineland Study participants by determining immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies for B. burgdorferi s.l. using a two-step algorithm combining enzyme-linked immunosorbent assay tests and line immunoblots. We calculated the odds of being classified as IgG or IgM positive as a function of age, sex, and educational level using binomial logistic regression models. We applied varying seropositivity classifications and weights considering age, sex and education to compensate for differences between the sample and regional population characteristics.

Results

IgG antibodies for B. burgdorferi s.l. were present in 2.4% and IgM antibodies in 0.6% of the participants (weighted: 2.2% [IgG], 0.6% [IgM]). The likelihood of IgG seropositivity increased by 3.0% (95% confidence interval [CI] 1.5–5.2%) per 1 year increase in age. Men had 1.65 times the odds for IgG seropositivity as women (95% CI 1.01–2.73), and highly educated participants had 1.83 times the odds (95% CI 1.10–3.14) as participants with an intermediate level of education. We found no statistically significant link between age, sex, or education and IgM seropositivity. Our weighted and age-standardized IgG seroprevalence was comparable to the preceding serosurvey German Health Interview and Examination Survey for Adults (DEGS) for NRW.

Conclusions

We confirmed that increasing age and male sex are associated with increased odds for IgG seropositivity and provide evidence for increased seropositivity in the highly educated group. B. burgdorferi s.l. seropositivity remained constant over the past decade in this regional German population.

Graphical abstract

Assessing Tick-Borne Disease Risk and Surveillance: Toward a Multi-Modal Approach to Diagnostic Positioning and Prediction

The true extent of tick-borne disease (TBD) incidence and risk among humans is largely unknown, posing significant public health challenges. This study offers an exploratory analysis of a multimodal dataset and is part of a larger ongoing project to determine if entomological data, canine serological reports, self-reported human tick bite encounters (TBEs), and/or associated TBD diagnoses can serve as proxies for human disease risk. Focusing on the United States (U.S.), it characterizes self-reported TBD diagnoses (specifically, anaplasmosis, ehrlichiosis, and Lyme disease), co-infections, and their frequency and distribution across U.S. counties in relation to the presence of other factors related to TBD risk. Survey data was used to construct a list of TBEs localizable to individual U.S. counties. National data regarding these counties—namely the presence of official Lyme Disease (LD) case reports from the Centers for Disease Control and Prevention, as well as the tick vectors I. scapularis and I. pacificus within a given county—were then linked with survey-reported TBEs, tabulated by diagnosis (including co-infections), to determine the distribution of county-level endpoints across diagnostic categories. In addition, data on the presence of positive serological diagnostic tests conducted in canines were considered due to their potential utility as a proxy for TBD and TBE risk. The final dataset contained 249 TBEs localized to a total of 144 counties across 30 states. Diagnostic categories included respondents with LD (n = 70) and those with anaplasmosis and ehrlichiosis diagnoses and co-infections (n < 20 per diagnostic category). TBEs also were indicated by respondents who did not report TBD diagnoses, with some indicating uncertainty. The distribution of respondent-reported TBEs varied between canine TBDs, with LD-positive respondents reporting noticeably larger proportions of TBEs in counties with canine LD and smaller proportions in counties with canine anaplasmosis, compared to respondents without an LD diagnosis; a notional logistic regression suggests these differences may be significant (canine LD: Odds Ratio [OR] = 6.04, p = 0.026) (canine anaplasmosis: OR = 0.50, p = 0.095). These results suggest that certain widely available diagnostic TBD data in animals (in this case, domesticated dogs) may be sensitive to differences in human TBD risk factors and thus may have utility as proxies in future research. In the absence of an available standardized, unified, and national TBD database, such proxies, along with relevant surveys and reports, may provide a much-needed working solution for scientists and clinicians studying TBDs.

Tick bites in different professions and regions: pooled cross-sectional study in the focus area Bavaria, Germany

BACKGROUND

As the vector-borne diseases tick-borne encephalitis (TBE) and Lyme borreliosis (LB) are common in Germany and transmitted by tick bites, the aim of this study was to assess differences in the number of tick bites in various professions and regions across southern Germany to evaluate the differences in tick-associated risk.

MATERIALS AND METHODS

The analysis is based on three cross-sectional studies that were conducted in 2016 and 2017 in two real-life settings and in one medical setting in Bavaria. All participants filled in a paper-based questionnaire about their history with tick bites. Only adult participants (≥ 18 years) were included in this study.

RESULTS

Overall, 3503 individuals (mean age 50.8 ± 15.2 years, median age 53.0 ± 12.2 years, 54.0% female) were included. Of these, 50% worked in an outdoor profession and 56% lived in environs. Around 70% of participants reported at least one previous tick bite. In comparison to indoor workers, forestry workers (OR = 2.50; 95% CI: 1.10-5.68) had the highest risk for a tick bite followed by farmers (OR = 1.22; 95% CI: 1.01-1.47). Furthermore, people living in rural areas (OR = 1.97, 95% CI:1.49-2.59) and environs (OR = 1.98, 95% CI: 1.54-2.55) were twice as likely to have a previous tick bite than people living in urban areas. In general, slightly more tick bites were reported by people living in eastern Bavaria.

CONCLUSION

Rising numbers of TBE and LB indicate the need for further prevention strategies, which should focus on outdoor professions with a higher risk and people living in environs and rural areas.