Vector-borne Diseases In Europe Research Articles

Diversity of Viruses in Ixodes ricinus in Europe including Novel and Potential Arboviruses

Tick-borne pathogens are responsible for many vector-borne diseases in Europe, causing important problems for human and animal health. The composition of viral communities in ticks and their interactions with pathogens is little understood, especially in Eastern Europe, an area that represents a major hub for animal-arthropod vectors exchanges. In this study, we used metatranscriptomics to characterize the virome of 2,753 Ixodes ricinus ticks collected from France and Romania, focusing on viruses that could potentially have implications for human or animal health. Among the great viral diversity of viruses identified, we reported a novel strain of Tribec virus, an important human pathogen that was found in Romanian ticks. We detected viruses belonging to the Phenuiviridae and Nairoviridae families close to human and animal pathogens, suggesting that these viruses could constitute novel arboviruses. We used luciferase immunoprecipitation system targeting external viral proteins of viruses identified among the Sedoreoviridae, Phenuiviridae, and Nairoviridae families to screen serum samples from small ruminants’ exposed to tick bites. The results suggest that part (approximately 12%, 95% CI 9.1–16.2) of the small ruminant population from Danube Delta, was exposed to viruses related to bi- or tri-segmented nairoviruses, but cross-reactive viruses could not be confirmed with certainly. The strategy developed in this study serves as a key step in predicting potential new disease outbreaks and can be readily adapted to study other reservoirs, vectors, and interfaces involving susceptible hosts.

Long-lasting infection with Anaplasma ovis in sheep

Ovine anaplasmosis is an emerging vector-borne disease in Europe caused by Anaplasma ovis. The infection has spread quickly in recent years, causing moderate to severe outbreaks in sheep flocks, leading to relevant economic losses in sheep farming. This wider spread has been associated with global warming and climate change, favouring the maintenance and life cycle of their main vector, the ticks. However, another epidemiological aspect could favour this quick spread. Long persistence infection of Anaplasma ovis has been proposed as a hypothesis in several articles but never scientifically proven. The results of the present study demonstrate that eight adult sheep, both naturally or experimentally infected, maintain Anaplasma ovis load in blood during their whole productive life (4 to 6 years), being permanently infected. In addition, the results suggest that A. ovis bacterial load can be constant or suffer fluctuations, as has been demonstrated in other Anaplasma species. Both aspects can be determinants in the epidemiology and the transmission of the infection.

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.

Which trial do we need? Treatment of multiple erythema migrans with doxycycline for 7 days versus 14 days

Lyme borreliosis is the most prevalent vector-borne disease in Europe and North America [ 1 Mead P.S. Epidemiology of Lyme disease. Infect Dis Clin North Am. 2015; 29: 187-210https://doi.org/10.1016/j.idc.2015.02.010 Abstract Full Text Full Text PDF PubMed Scopus (268) Google Scholar ]; an estimated ≈232,000 cases in Western Europe [ 2 Sykes R.A. Makiello P. An estimate of Lyme borreliosis incidence in Western Europe. J Public Health. 2016; 39 (DOI: 0.1093/pubmed/fdw017): 74-81 Google Scholar ] and ≈476,000 cases in the US [ 3 Kugeler K.J. Schwartz A.M. Delorey M.J. Mead P.S. Hinckley A.F. Estimating the Frequency of Lyme Disease Diagnoses, United States, 2010–2018. Emerg Inf Dis. 2021; 27: 616-619https://doi.org/10.3201/eid2702.202731 Crossref PubMed Scopus (169) Google Scholar ] are diagnosed per year and erythema migrans is its most frequent clinical presentation, occurring in ≥80% of cases [ 1 Mead P.S. Epidemiology of Lyme disease. Infect Dis Clin North Am. 2015; 29: 187-210https://doi.org/10.1016/j.idc.2015.02.010 Abstract Full Text Full Text PDF PubMed Scopus (268) Google Scholar , 4 Stanek G. Strle F. Lyme borreliosis‒from tick bite to diagnosis and treatment. FEMS Microbiol Rev. 2018; 42: 233-258https://doi.org/10.1093/femsre/fux047 Crossref PubMed Scopus (96) Google Scholar ]. In solitary erythema migrans (SEM), the skin manifestation remains localised to the site of inoculation of borreliae, whereas multiple erythema migrans (MEM) represent hematogenous dissemination of borreliae, which may occur in 13.4% to 27% of US cases [ 5 Wormser G.P. McKenna D. Carlin J. et al. Brief communication: hematogenous dissemination in early Lyme disease. Ann Intern Med. 2005; 142: 751-755https://doi.org/10.7326/0003-4819-142-9k,-200505030-00011 Crossref PubMed Google Scholar , 6 Strle F. Nadelman R.B. Cimperman J. et al. Comparison of Culture-Confirmed Erythema Migrans Caused by Borrelia burgdorferi sensu stricto in New York State and by Borrelia afzelii in Slovenia. Ann Intern Med. 1999; 130: 32-36https://doi.org/10.7326/0003-4819-130-1-199901050-00006 Crossref PubMed Scopus (179) Google Scholar , 7 Nowakowski J. Nadelman R.B. Sell R. et al. Long-term follow-up of patients with culture-confirmed Lyme disease. Am J Med. 2003; 115: 91-96https://doi.org/10.1016/S0002-9343(03)00308-5 Abstract Full Text Full Text PDF PubMed Scopus (112) Google Scholar ] and less frequently (up to 7%) in Europe [ 4 Stanek G. Strle F. Lyme borreliosis‒from tick bite to diagnosis and treatment. FEMS Microbiol Rev. 2018; 42: 233-258https://doi.org/10.1093/femsre/fux047 Crossref PubMed Scopus (96) Google Scholar , 6 Strle F. Nadelman R.B. Cimperman J. et al. Comparison of Culture-Confirmed Erythema Migrans Caused by Borrelia burgdorferi sensu stricto in New York State and by Borrelia afzelii in Slovenia. Ann Intern Med. 1999; 130: 32-36https://doi.org/10.7326/0003-4819-130-1-199901050-00006 Crossref PubMed Scopus (179) Google Scholar ]. The current Infectious Diseases Society of America treatment guidelines recommend doxycycline for 10 days or cefuroxime axetil or amoxicillin for 14 days as first line therapy for both SEM and MEM [ 8 Lantos P.M. Rumbaugh J. Bockenstedt L.K. et al. Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA), American Academy of Neurology (AAN), and American College of Rheumatology (ACR): 2020 guidelines for the prevention, diagnosis and treatment of Lyme disease. Clin Infect Dis. 2021; 72: e1-e48https://doi.org/10.1093/cid/ciaa1215 Crossref PubMed Scopus (0) Google Scholar ]. However, the clinical course and outcome of SEM and MEM may differ [ 7 Nowakowski J. Nadelman R.B. Sell R. et al. Long-term follow-up of patients with culture-confirmed Lyme disease. Am J Med. 2003; 115: 91-96https://doi.org/10.1016/S0002-9343(03)00308-5 Abstract Full Text Full Text PDF PubMed Scopus (112) Google Scholar , 9 Dattwyler R.J. Volkman D.J. Conaty S.M. Platkin S.P. Luft B.J. Amoxycillin plus probenecid versus doxycycline for treatment of erythema migrans borreliosis. Lancet. 1990; 336: 1404-1406https://doi.org/10.1016/0140-6736(90)93103-V Abstract PubMed Scopus (154) Google Scholar , 10 Steere A.C. Hutchinson G.J. Rahn D.W. et al. Treatment of the early manifestations of Lyme disease. Ann Intern Med. 1983; 99: 22-26https://doi.org/10.7326/0003-4819-99-1-22 Crossref PubMed Scopus (321) Google Scholar , 11 Stupica D. Maraspin V. Bogovič P. et al. Comparison of Clinical Course and Treatment Outcome for Patients With Early Disseminated or Early Localized Lyme Borreliosis. JAMA Dermatol. 2018; 154: 1050-1056https://doi.org/10.1001/jamadermatol.2018.2306 Crossref PubMed Scopus (24) Google Scholar ] leading to concern that MEM requires a longer course of therapy than SEM. In Europe, 14-21 days of antibiotic therapy are recommended for treating early disseminated Lyme borreliosis, including MEM [ 4 Stanek G. Strle F. Lyme borreliosis‒from tick bite to diagnosis and treatment. FEMS Microbiol Rev. 2018; 42: 233-258https://doi.org/10.1093/femsre/fux047 Crossref PubMed Scopus (96) Google Scholar , 12 Hofmann H. Fingerle V. Hunfeld K.P. et al. Cutaneus Lyme borreliosis: guideline of the German Dermatology Society. Ger Med Sci. 2017; 15: 1-31https://doi.org/10.3205/000255.eCollection.2017 Crossref Google Scholar ], although a pathogenetic or pharmacodynamic rational for longer treatment is lacking. Results from our previous study showed that a 7-day course of doxycycline was non-inferior to a 14-day regimen for treating adult patients with SEM in Slovenia, where Lyme borreliosis is highly endemic [ 13 Stupica D. Collinet-Adler S. Blagus R. et al. Treatment of erythema migrans with doxycycline for 7 days versus 14 days in Slovenia: a randomised open-label non-inferiority trial. Lancet Infect Dis. 2023; 23: 371-379https://doi.org/10.1016/S1473-3099(22)00528-X Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar ]. The generalizability of these results to other regions or to patients with MEM is unclear. Multi-centre studies are preferable for optimal generalizability of conclusions, which may otherwise be limited due to the differential prevalence of various borrelial species throughout Europe and North America. Furthermore, the shortest effective treatment for MEM remains unknown. Shorter antibiotic treatment durations can reduce costs, side effects, and antimicrobial resistance [ 14 Sanchez G.V. Fleming-Dutra K.E. Roberts R.M. Hicks L.A. Core Elements of Outpatient Antibiotic Stewardship. MMWR Recomm Rep. 2016; 65: 1-12https://doi.org/10.15585/mmwr.rr6506a1 Crossref PubMed Scopus (337) Google Scholar ].

Treatment of erythema migrans with doxycycline for 7 days versus 14 days in Slovenia: a randomised open-label non-inferiority trial

Lyme borreliosis is the most prevalent vector-borne disease in Europe and the USA. Doxycycline for 10 days is the primary treatment recommendation for erythema migrans. To reduce potentially harmful antibiotic overuse by identifying shorter effective treatments, we aimed to assess whether oral doxycycline for 7 days is non-inferior to 14 days in adults with solitary erythema migrans. In this randomised open-label non-inferiority trial, we enrolled patients with a solitary erythema at the University Medical Centre in Ljubljana, Slovenia. Patients were excluded if they were pregnant or lactating, immunosuppressed, allergic to doxycycline, or had received antibiotics with anti-borrelial activity within 10 days preceding enrolment or had additional manifestations of Lyme borreliosis Adults were randomly allocated 1:1 to receive oral doxycycline 100 mg twice a day for 7 days or 14 days. The primary efficacy endpoint was the difference in proportion of patients with treatment failure, defined as persistent erythema, new objective signs of Lyme borreliosis, or borrelial isolation on skin re-biopsy at 2 months, in a per-protocol analysis (the population that completed the assigned doxycycline regimen according to the study protocol and did not receive any other antibiotics with anti-borrelial activity until the 2-month visit). The non-inferiority margin was 6 percentage points. Safety was assessed in all randomly assigned patients who followed the study protocol and were evaluable at the 14-day visit. This study is registered with ClinicalTrials.gov, NCT03153267. Between July 3, 2017, and Oct 2, 2018, we enrolled 300 patients (150 per group: median age 56 years [IQR 47-65]; 126 [45%] of 300 male; skin culture positive 72 [30%] of 239 assessed). 295 patients completed antibiotic therapy as per protocol and 294 (98%) patients were evaluable 2 months post-enrolment. Five (3%) of 147 patients from the 7-day group versus 3 (2%) of 147 patients from the 14-day group (one patient did not attend the 2-month visit and was unreachable by telephone) had treatment failure manifesting as persistence of erythema (difference 1·4 percentage points; upper limit of one-sided 95% CI 5·2 percentage points; p=0·64). No patients developed new objective manifestations of Lyme borreliosis during follow-up or had positive repeat skin biopsies. Two (1%) of 150 patients in the 7-day and one (1%) of 150 patients in the 14-day group discontinued therapy due to adverse events. Our data support 7 days of oral doxycycline for adult European patients with solitary erythema migrans, permitting less antibiotic exposure than current guideline-driven therapy. Slovenian Research Agency and the University Medical Centre Ljubljana.

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

BackgroundLyme 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.MethodsWe 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.ResultsIgG 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.ConclusionsWe 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

The false promise of cellular tests for Lyme borreliosis

Lyme borreliosis, caused by members of the Borrelia burgdorferi sensu lato (Bbsl) complex, is the most common vector-borne disease in Europe and the USA, with over 600 000 cases estimated to occur annually in these regions since 2010.1,2 Given this impressive global burden, it is remarkable that there are still substantial diagnostic gaps for Lyme borreliosis, including the absence of reliable assays for acute infection, difficulty in differentiating past disease from current disease, and an inability to monitor treatment response.

MODIRISK: Mosquito vectors of disease, collection, monitoring and longitudinal data from Belgium.

The MODIRISK project studied mosquito biodiversity and monitored and predicted biodiversity changes, to actively prepare to address issues of biodiversity change, especially invasive species and new pathogen risks. This work is essential given continuing global changes that may create suitable conditions for invasive species spread and the (re-)emergence of vector-borne diseases in Europe. Key strengths of MODIRISK, in the context of sustainable development, were the links between biodiversity and health and the environment, and its contribution to the development of tools for describing the spatial distribution of mosquito biodiversity. MODIRISK addressed key topics of the global Diversitas initiative, which was a main driver of the Belspo 'Science for a Sustainable Development' research program. Three different MODIRISK datasets were published in the Global Biodiversity Information Facility (GBIF): the Collection dataset (the Culicidae collection of the Museum of Natural History in Brussels); the Inventory dataset (data from the MODIRISK inventory effort); and the Longitudinal dataset (experiment data used for risk assessments).

Climate Changes Exacerbate the Spread of Ixodes ricinus and the Occurrence of Lyme Borreliosis and Tick-Borne Encephalitis in Europe-How Climate Models Are Used as a Risk Assessment Approach for Tick-Borne Diseases.

Climate change has influenced the transmission of a wide range of vector-borne diseases in Europe, which is a pressing public health challenge for the coming decades. Numerous theories have been developed in order to explain how tick-borne diseases are associated with climate change. These theories include higher proliferation rates, extended transmission season, changes in ecological balances, and climate-related migration of vectors, reservoir hosts, or human populations. Changes of the epidemiological pattern have potentially catastrophic consequences, resulting in increasing prevalence of tick-borne diseases. Thus, investigation of the relationship between climate change and tick-borne diseases is critical. In this regard, climate models that predict the ticks’ geographical distribution changes can be used as a predicting tool. The aim of this review is to provide the current evidence regarding the contribution of the climatic changes to Lyme borreliosis (LB) disease and tick-borne encephalitis (TBE) and to present how computational models will advance our understanding of the relationship between climate change and tick-borne diseases in Europe.

Temperate climate malaria in nineteenth century Denmark

BackgroundPlasmodium vivax was endemic in northern Europe until the early twentieth century. Considering climate change and the recent emergence of other vector borne diseases in Europe, historical insight into the relationship between malaria and environmental factors in northern Europe is needed. This article describes malaria epidemiology in late-nineteenth century Denmark.MethodsWe described the seasonality and spatial patterns of malaria, and the relationship of the disease with environmental factors such as soil types, clay content and elevation for the period 1862–1914. We studied demographic and seasonal patterns and malaria mortality in the high-morbidity period of 1862–1880. Finally, we studied the relationship between malaria seasonality and temperature and precipitation using a Spearman correlation test.ResultsWe found that the highest incidence occurred in eastern Denmark. Lolland-Falster medical region experienced the highest incidence (14.5 cases per 1000 pop.) and Bornholm medical region experienced the lowest incidence (0.57 cases per 1000 pop.). Areas with high malaria incidence also had high soil clay content, high agricultural production, and Lolland-Falster furthermore has a low elevation. Malaria incidence typically peaked in May and was associated with high temperatures in July and August of the previous year but not with precipitation. The case fatality rate was 0.17%, and the disease affected both sexes and all age groups except for infants. In 1873, a large epidemic occurred following flooding from a storm surge in November 1872.ConclusionsMalaria gradually declined in Denmark during our study period and had essentially disappeared by 1900. The high adult and low child morbidity in 1862–1880 indicates that malaria was not highly endemic in this period, as malaria is most frequent among children in highly endemic areas today. The association of high malaria incidence in spring with warmer temperatures in the previous summer suggests that transmission took place in the previous summers. The close geographical connection between malaria and soil types, agricultural production and elevation suggests that these factors are detrimental to sustain endemic malaria. Our findings of a close connection between malaria and environmental factors such as climate and geography provides insights to address potential reintroduction of malaria in temperate climates.

Anti-TBE Intrathecal Synthesis as a Prediction Marker in TBE Patients.

Tick-borne encephalitis (TBE) is an emerging vector-borne disease in Europe caused by tick-borne encephalitis virus (TBEV), which belongs to Flaviviridae. Although most of the patients quickly recover from TBE, some require further neurological and psychiatric treatment due to persistent symptoms. The aim of the study was to evaluate the usefulness of an antibodies index for predicting the course of the disease and potential persistent sequalae. Sixty-six patients (49 males and 17 females, mean age 45.97 ± 13.69 years) with TBE hospitalized in the Department of Infectious Diseases and Neuroinfections, Medical University of Bialystok, Poland, in years 2016–2019 were included to the study. TBE antibodies titer in serum and CSF samples were measured with an Anti-TBEV ELISA (IgM, IgG) EUROIMMUN test. Patients who developed persistent sequelae after TBE had significantly lower IgG intrathecal index at admission. Additionally, IgG2/IgG1was significantly higher in patients who developed sequelae. IgG intrathecal index might be a useful tool for the prediction of TBE sequelae development.

Tick ecology and Lyme borreliosis prevention: a regional survey of pharmacists’ knowledge in Auvergne-Rhône-Alpes, France

The most prevalent vector-borne diseases in Europe are caused by tick-borne pathogens, such as bacteria of the genus Borrelia that cause Lyme borreliosis.In this context, retail pharmacists are frequently the first medical source of information in the event of a tick bite. The objective of this study was to assess pharmacy professionals’ knowledge about both tick ecology and the appropriate measures for tick bites and Lyme borreliosis prevention. It was based on an online survey of 364 pharmacists and pharmacy assistants located in the Auvergne-Rhône-Alpes region of France. The results showed solid knowledge about preventive measures for tick bite and Lyme borreliosis, but weaker knowledge about tick biology (hosts, suitable habitats, favorable conditions for tick activity, etc.). In particular, several stereotypes were observed in the responses of the pharmacy professionals. These appear to result from a social construction of the knowledge on ticks and tick-borne diseases previously shown to the general population in the region. The results highlight the need for continuous training about ticks and tick-borne diseases for healthcare professionals serving local populations that live in endemic areas.

Long-term study of Borrelia and Babesia prevalence and co-infection in Ixodes ricinus and Dermacentor recticulatus ticks removed from humans in Poland, 2016\u20132019

BackgroundLyme borreliosis (LB) is the most common vector-borne disease in Europe. Monitoring changes in the prevalence of different Borrelia species in ticks may be an important indicator of risk assessment and of differences in pathogenicity in humans. The objective of our study was to assess the prevalence, co-infection and distribution of Borrelia and Babesia species in ticks removed from humans in a large sample collected during a study period of 4 years.MethodsThe ticks were collected throughout Poland from March to November over 4-year period from 2016 to 2019. All ticks (n = 1953) were morphologically identified in terms of species and developmental stage. Molecular screening for Borrelia and Babesia by amplification of the flagellin gene (flaB) or 18S rRNA marker was performed. Pathogen identity was confirmed by Sanger sequencing or PCR–restriction fragment length polymorphism analysis.ResultsThe ticks removed from humans in Poland during this study belonged to two species: Ixodes ricinus (97%) and Dermacentor reticulatus (3%). High Borrelia prevalence (25.3%), including B. miyamotoi (8.4%), was confirmed in Ixodes ricinus ticks removed from humans, as was the change in frequency of occurrence of Borrelia species during the 4-year study. Despite Babesia prevalence being relatively low (1.3%), the majority of tested isolates are considered to be pathogenic to humans. Babesia infection was observed more frequently among Borrelia-positive ticks (2.7%) than among ticks uninfected with Borrelia (0.8%). The most frequent dual co-infections were between Borrelia afzelii and Babesia microti. The presence of Borrelia was also confirmed in D. reticulatus (12.7%); however the role of these ticks in spirochete transmission to susceptible hosts is still unclear.ConclusionsAlthough the overall risk of developing LB after a tick bite is low in Europe, knowledge of the prevalence and distribution of Borrelia and Babesia species in ticks might be an important indicator of the risk of both these tick-borne diseases.Graphical abstract

Climate change impacts on vector-borne diseases in Europe: Risks, predictions and actions.

Climate change impacts on vector-borne diseases in Europe: Risks, predictions and actions.

Development and calibration of a model for the potential establishment and impact of Aedes albopictus in Europe

The Asian tiger mosquito (Aedes albopictus) is one of the most invasive disease vectors worldwide. The species is a competent vector of dengue, chikungunya, Zika viruses and other severe parasites and pathogens threatening human health. The capacity of this mosquito to colonize and establish in new areas (including temperate regions) is enhanced by its ability of producing diapausing eggs that survive relatively cold winters. The main drivers of population dynamics for this mosquito are water and air temperature and photoperiod. In this paper, we present a mechanistic model that predicts the potential distribution, abundance and activity of Asian tiger mosquito in Europe. The model includes a comprehensive description of: i) the individual life-history strategies, including diapause, ii) the influence of weather-driven individual physiological responses on population dynamics and iii) the density-dependent regulation of larval mortality rate. The model is calibrated using field data from several locations along an altitudinal gradient in the Italian Alps, which enabled accurate prediction of cold temperature effects on population abundance, including identification of conditions that prevent overwintering of the species. Model predictions are consistent with the most updated information on species’ presence and absence. Predicted population abundance shows a clear south-north decreasing gradient. A similar yet less evident pattern in the activity of the species is also predicted. The model represents a valuable tool for the development of strategies aimed at the management of Ae. albopictus and for the implementation of effective control measures against vector-borne diseases in Europe.

Emergent Sand Fly–Borne Phleboviruses in the Balkan Region

Sand fly–borne phleboviruses are associated with febrile diseases and nervous system infections in the Mediterranean basin. Sandfly fever was first reported in the Balkan Peninsula at the end of the 19th century. Since then, accumulating data show that the Balkan Peninsula, as a transboundary region between Asia and Europe, plays a major role in the emergence of vectorborne diseases in Europe. To provide an inclusive approach, we collected published data on phleboviruses in the Balkan countries and used them to evaluate the impact of these pathogens from virologic, epidemiologic, and public health perspectives. Recent findings show a high diversity of phleboviruses belonging to 3 species or serocomplexes circulating heavily in the Balkans. Focusing on undisputable human pathogens, we found direct and indirect laboratory documentation for Toscana virus, Sandfly fever Sicilian virus, and Adria virus. These data demonstrate that the Balkans are a hotspot for phleboviruses transmitted by sand flies.

Driving factors for the changing epidemiology of vector-borne diseases – a review

Vector-borne diseases regularly occurred in moderate climate areas of Europe in past decades. The changing epidemiology of vector-borne diseases in Europe is caused by changes of environmental factors – amongst these climate change -and human activity (transport mobility, urbanisation, renaturation etc.). The occurrence of invasive vector species (for example the Asian tiger mosquito [ Aedes albopictus] and the Asian bush mosquito [ Aedes japonicus japonicus]) in new habitats pose a risk of pathogen transmission in naive host populations. On the other hand, the presence of native competent vectors and adequate habitats are sufficient for the effective spread of a pathogen as seen in the Bluetongue Virus epidemic in Europe in 2006 onwards or the spread of West Nile Virus (WNV) lineage 1 in USA in 1999. The vector-borne diseases posing threat of spread are very often of viral origin (WNV fever, Chikungunya fever, Dengue fever, Tick-borne encephalitis, Yellow fever, Japanese encephalitis), but there is also the potential for parasitic (Malaria, Dirofilariosis, Piroplasmosis and Leishmaniosis) or bacterial diseases (Tularaemia, Rickettsiosis). Recently, the fast spreading epidemic of mosquito-borne Zika virus infection implicated the need of preparedness and constant monitoring of vector-borne diseases and their vectors in order to provide fast answers to emerging disease control and prevention. In this paper, we review major driving factors for the changing epidemiology of selected vector-borne diseases, provide a risk assessment for the introduction of new emerging diseases to Europe and present a new concept to face future challenges.

Assessment of the Public Health Threats Posed by Vector-Borne Disease in the United Kingdom (UK).

In recent years, the known distribution of vector-borne diseases in Europe has changed, with much new information also available now on the status of vectors in the United Kingdom (UK). For example, in 2016, the UK reported their first detection of the non-native mosquito Aedes albopictus, which is a known vector for dengue and chikungunya virus. In 2010, Culex modestus, a principal mosquito vector for West Nile virus was detected in large numbers in the Thames estuary. For tick-borne diseases, data on the changing distribution of the Lyme borreliosis tick vector, Ixodes ricinus, has recently been published, at a time when there has been an increase in the numbers of reported human cases of Lyme disease. This paper brings together the latest surveillance data and pertinent research on vector-borne disease in the UK, and its relevance to public health. It highlights the need for continued vector surveillance systems to monitor our native mosquito and tick fauna, as well as the need to expand surveillance for invasive species. It illustrates the importance of maintaining surveillance capacity that is sufficient to ensure accurate and timely disease risk assessment to help mitigate the UK’s changing emerging infectious disease risks, especially in a time of climatic and environmental change and increasing global connectivity.

Sequelae of tick-borne encephalitis in retrospective analysis of 1072 patients.

Tick-borne encephalitis (TBE) is an emerging vector-borne disease in Europe. The aim of the study was to evaluate sequelae and to analyse the potential risk factors predisposing to sequelae development. We performed a retrospective analysis of medical records of 1072 patients who received a 1-month follow-up appointment after hospital discharge. Medical data, such as patients' age, gender, place of living, subjective complaints, neurological and psychiatric sequelae were evaluated twice: at the moment of discharge and at follow-up visits 1 month after discharge. We observed that sequelae may affect 20.6% of TBE patients. Subjective sequelae were more frequent than subjective complaints during the hospitalisation (P < 0.001), while objective neurological symptoms during the hospitalisation were more pronounced than neurological sequelae (P < 0.001). Patients with meningoencephalomyelitis were predisposed to neurological complications, while subjective symptoms were more common in meningoencephalitis. Independent risk factors for sequelae development were: age and cerebrospinal fluid (CSF) protein concentration. The risk of late neurological complications persisting was increased in patients with higher CSF protein concentration. Based on the results of our study we concluded that, there is a need for a better vaccination program, which would prevent the development of sequelae.

THE KNOWLEDGE ON LYME BORRELIOSIS AND OTHER TICK-BORNE DISEASES AMONG NURSING STUDENTS FROM POLAND AND SLOVAKIA

Tick-borne diseases are infectious diseases transmitted by the bites of infected ticks. The most common vector-borne disease in Europe is Lyme borreliosis (LB). The number of the reported cases of LB has been steadily increasing. For this reason, it is important to undertake educational activities in the field of tick-borne diseases. The aim of the study was to investigate the level and scope of knowledge on tick-borne diseases among nursing students from Poland and Slovakia. The study sample consisted of 428 nursing students (192 students of the State School of Higher Education in Biała Podlaska, Poland and 236 students of the University in Presov, Slovakia). The knowledge of the surveyed students on tick-borne diseases is limited. Polish students demonstrated greater knowledge about LB, while students from Slovakia showed greater awareness of the threat posed by tick-borne encephalitis. Particularly worrying is the lack of knowledge on proper way of removal of a tick attached to the skin. Students recognize the need to broaden their knowledge on tick-borne diseases, which should be taken into consideration in realized studies curricula.