Pub Date : 2026-03-17DOI: 10.1016/j.ttbdis.2026.102624
Martin Slížek, Lukáš Chovanec, Vojtěch Pražák, Aleš Chrdle, Kateřina Pohludková, Lenka Petroušová, Jitka Bolchová, Kryštof Šram, Juraj Sečník, Olga Džupová, Dita Smíšková
Tick-borne encephalitis (TBE) is the most common non-purulent neuroinfection in Central Europe and a major public health concern in the Czech Republic, where vaccination coverage remains low. Even after recovery from the acute disease, many patients experience long-term sequelae known as postencephalitic syndrome (PES). This prospective multicentre study examined predictors of acute disease severity and long-term outcomes, including motor deficits and other forms of PES. A total of 209 patients with laboratory-confirmed TBE were enrolled at four Czech centres in 2023 and 2024; 187 completed six-month follow-up. Logistic regression models were used to evaluate the associations between patient characteristics, acute disease severity, and outcomes. Age over 50 years was significantly associated with a severe acute course (OR = 2.70, 95 % CI 1.44-5.07). After six months, 84 of 187 patients (44.9 %) reported at least one sequela. PES affected patients across all age groups, while age showed only a non-significant trend toward higher PES frequency and severity. Persistent motor deficits occurred in 23 patients (12.3 %) and were linked to older age (OR = 3.73, 95 % CI 1.34-10.4, p < 0.05); female sex was associated with lower risk (OR = 0.31, 95 % CI 0.11-0.92, p < 0.05). Comorbidities showed no independent association. These findings indicate that while acute-phase severity contributes to adverse outcomes, PES can develop regardless of age or disease severity and only motor deficits are strongly age-associated. The results underscore the need for vaccination across all age groups in endemic regions.
蜱传脑炎（TBE）是中欧最常见的非化脓性神经感染，也是疫苗接种覆盖率仍然较低的捷克共和国的一个主要公共卫生问题。即使在从急性疾病中恢复后，许多患者也会经历长期的后遗症，即脑后综合征（PES）。这项前瞻性多中心研究检查了急性疾病严重程度和长期预后的预测因素，包括运动缺陷和其他形式的PES。2023年和2024年，共有209名实验室确诊的TBE患者在四个捷克中心登记；187人完成了6个月的随访。使用Logistic回归模型评估患者特征、急性疾病严重程度和结局之间的关联。年龄超过50岁与严重急性病程显著相关（OR = 2.70, 95% CI 1.44-5.07）。6个月后，187例患者中有84例（44.9%）报告了至少一个后遗症。PES影响所有年龄组的患者，而年龄仅显示出较高的PES频率和严重程度的无显著趋势。23例患者（12.3%）出现持续性运动障碍，并与年龄相关（OR = 3.73, 95% CI 1.34-10.4, p < 0.05）；女性患病风险较低（OR = 0.31, 95% CI 0.11 ~ 0.92, p < 0.05）。合并症无独立关联。这些发现表明，尽管急性期严重程度会导致不良结果，但PES的发展与年龄或疾病严重程度无关，只有运动缺陷与年龄密切相关。结果强调需要在流行地区的所有年龄组接种疫苗。
{"title":"Complications and long-term sequelae of tick-borne encephalitis: association with age and other predictors - a multicenter observational study.","authors":"Martin Slížek, Lukáš Chovanec, Vojtěch Pražák, Aleš Chrdle, Kateřina Pohludková, Lenka Petroušová, Jitka Bolchová, Kryštof Šram, Juraj Sečník, Olga Džupová, Dita Smíšková","doi":"10.1016/j.ttbdis.2026.102624","DOIUrl":"https://doi.org/10.1016/j.ttbdis.2026.102624","url":null,"abstract":"<p><p>Tick-borne encephalitis (TBE) is the most common non-purulent neuroinfection in Central Europe and a major public health concern in the Czech Republic, where vaccination coverage remains low. Even after recovery from the acute disease, many patients experience long-term sequelae known as postencephalitic syndrome (PES). This prospective multicentre study examined predictors of acute disease severity and long-term outcomes, including motor deficits and other forms of PES. A total of 209 patients with laboratory-confirmed TBE were enrolled at four Czech centres in 2023 and 2024; 187 completed six-month follow-up. Logistic regression models were used to evaluate the associations between patient characteristics, acute disease severity, and outcomes. Age over 50 years was significantly associated with a severe acute course (OR = 2.70, 95 % CI 1.44-5.07). After six months, 84 of 187 patients (44.9 %) reported at least one sequela. PES affected patients across all age groups, while age showed only a non-significant trend toward higher PES frequency and severity. Persistent motor deficits occurred in 23 patients (12.3 %) and were linked to older age (OR = 3.73, 95 % CI 1.34-10.4, p < 0.05); female sex was associated with lower risk (OR = 0.31, 95 % CI 0.11-0.92, p < 0.05). Comorbidities showed no independent association. These findings indicate that while acute-phase severity contributes to adverse outcomes, PES can develop regardless of age or disease severity and only motor deficits are strongly age-associated. The results underscore the need for vaccination across all age groups in endemic regions.</p>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 3","pages":"102624"},"PeriodicalIF":3.4,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147482338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-17DOI: 10.1016/j.ttbdis.2026.102626
Dejan Jakimovski, Pavle Banović, Sofija Mateska, Marija Stavrova, Angela Stamenkovska, Mile Bosilkovski, Dragana Mijatović, Ivana Bogdan, Verica Simin, Kinga Lis, Adrian A Diaz-Sanchez, Dasiel Obregon, Sara Moutailler, Angélique Foucault-Simonin, Zbigniew Zając, Natasha Griffith, Alejandro Cabezas-Cruz
Ticks and tick-borne pathogens (TBPs) pose an expanding health threat across Europe, yet few studies link tick infection data directly to human clinical outcomes. We conducted a prospective, cross-border "One Health" study in Serbia and North Macedonia to assess the prevalence, diversity, and potential transmission of TBPs from ticks to humans. A total of 133 tick-infested patients were enrolled at two healthcare centers (112 in Skopje, 26 in Novi Sad), and 135 ticks were collected from these individuals, alongside paired blood and serum samples. Overall, TBP DNA was detected in 66.6 % of ticks, with Rickettsia helvetica (25.9 %) and Rickettsia monacensis (12.5 %) were most common. Mixed infections occurred in 15 % of ticks, with up to three pathogens co-occurring. Other detected TBPs included Borrelia afzelii, Borrelia garinii, Borrelia lusitaniae, Anaplasma phagocytophilum, Babesia microti, and Babesia divergens. Four patients (3 %) had detectable pathogen DNA in blood, primarily Rickettsia spp. and Anaplasma spp., yet remained asymptomatic. Most common clinical outcome during the observation period was local hypersensitivity reaction (21.1 %), while α-Gal sensitization was detected in two cases. Phylogenetic analysis revealed Balkan Rickettsia and Borrelia strains were mostly identical to Western and Central European lineages, with a notable exception: a Bo. garinii strain from North Macedonia clustered with strains from Russia and China, indicating possible long-distance introduction. The present study demonstrates that human exposure to multiple TBPs is common and while asymptomatic bloodstream infections do occur, local hypersensitivity reactions are much more common.
{"title":"Tick-borne pathogen diversity and clinical impact of tick-infestation in Serbia and North Macedonia.","authors":"Dejan Jakimovski, Pavle Banović, Sofija Mateska, Marija Stavrova, Angela Stamenkovska, Mile Bosilkovski, Dragana Mijatović, Ivana Bogdan, Verica Simin, Kinga Lis, Adrian A Diaz-Sanchez, Dasiel Obregon, Sara Moutailler, Angélique Foucault-Simonin, Zbigniew Zając, Natasha Griffith, Alejandro Cabezas-Cruz","doi":"10.1016/j.ttbdis.2026.102626","DOIUrl":"https://doi.org/10.1016/j.ttbdis.2026.102626","url":null,"abstract":"<p><p>Ticks and tick-borne pathogens (TBPs) pose an expanding health threat across Europe, yet few studies link tick infection data directly to human clinical outcomes. We conducted a prospective, cross-border \"One Health\" study in Serbia and North Macedonia to assess the prevalence, diversity, and potential transmission of TBPs from ticks to humans. A total of 133 tick-infested patients were enrolled at two healthcare centers (112 in Skopje, 26 in Novi Sad), and 135 ticks were collected from these individuals, alongside paired blood and serum samples. Overall, TBP DNA was detected in 66.6 % of ticks, with Rickettsia helvetica (25.9 %) and Rickettsia monacensis (12.5 %) were most common. Mixed infections occurred in 15 % of ticks, with up to three pathogens co-occurring. Other detected TBPs included Borrelia afzelii, Borrelia garinii, Borrelia lusitaniae, Anaplasma phagocytophilum, Babesia microti, and Babesia divergens. Four patients (3 %) had detectable pathogen DNA in blood, primarily Rickettsia spp. and Anaplasma spp., yet remained asymptomatic. Most common clinical outcome during the observation period was local hypersensitivity reaction (21.1 %), while α-Gal sensitization was detected in two cases. Phylogenetic analysis revealed Balkan Rickettsia and Borrelia strains were mostly identical to Western and Central European lineages, with a notable exception: a Bo. garinii strain from North Macedonia clustered with strains from Russia and China, indicating possible long-distance introduction. The present study demonstrates that human exposure to multiple TBPs is common and while asymptomatic bloodstream infections do occur, local hypersensitivity reactions are much more common.</p>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 3","pages":"102626"},"PeriodicalIF":3.4,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147482279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Most tick-borne pathogens (TBPs) are acquired secondarily, when ticks feed on infected hosts, meaning the pathogen must establish itself within an already assembled microbiota. These scenarios are subject to “priority effects,” where the order of microbial arrival influences the success of later colonizers. Microbial interactions within arthropod vectors can therefore shape infection outcomes, producing either infection-refractory states, where resident microbes and their interactions reduce the likelihood of pathogen establishment, or infection-permissive states, where such barriers are absent or weakened and the pathogen establishes infection successfully. Hamilton et al. (2021) assessed larval microbiota before pathogen exposure and sequenced the microbiota of fed nymphs, both exposed or not to Borrelia afzelii, enabling priority-effect hypotheses to be tested. Despite uniform exposure to the highly infectious B. afzelii strain NE4049, only a subset of ticks became Borrelia-positive, suggesting refractory and permissive microbiota states. We reanalyzed the original dataset to test whether differences in microbiome community assembly and co-occurrence network features, beyond diversity metrics, were associated with these states. Refractory nymph networks exhibited higher connectivity and structural resilience, with Staphylococcus emerging as a central taxon already present in unfed larvae. In contrast, permissive networks showed reduced robustness and a marginal role for Staphylococcus. Notably, dysbiosis altered microbial assembly but did not prevent network reconfiguration in refractory ticks. Our findings suggest that colonization resistance is better explained by microbial network integrity than by diversity alone. Methodologically, they show that integrating community assembly theory and network analyses can reveal key features of the tick microbiota associated with vector competence.
{"title":"Microbial network stability, not diversity, drives colonization resistance against Borrelia afzelii in Ixodes ricinus ticks","authors":"Lianet Abuin-Denis , Lourdes Mateos-Hernández , Apolline Maitre , Alejandra Wu-Chuang , Myriam Kratou , Salma Kaoutar Abdelali , Ana Laura Cano-Argüelles , Štefánia Skičková , Dasiel Obregon , Alina Rodríguez-Mallon , Alejandro Cabezas-Cruz","doi":"10.1016/j.ttbdis.2026.102613","DOIUrl":"10.1016/j.ttbdis.2026.102613","url":null,"abstract":"<div><div>Most tick-borne pathogens (TBPs) are acquired secondarily, when ticks feed on infected hosts, meaning the pathogen must establish itself within an already assembled microbiota. These scenarios are subject to “priority effects,” where the order of microbial arrival influences the success of later colonizers. Microbial interactions within arthropod vectors can therefore shape infection outcomes, producing either infection-refractory states, where resident microbes and their interactions reduce the likelihood of pathogen establishment, or infection-permissive states, where such barriers are absent or weakened and the pathogen establishes infection successfully. Hamilton et al. (2021) assessed larval microbiota before pathogen exposure and sequenced the microbiota of fed nymphs, both exposed or not to <em>Borrelia afzelii</em>, enabling priority-effect hypotheses to be tested. Despite uniform exposure to the highly infectious <em>B. afzelii</em> strain NE4049, only a subset of ticks became <em>Borrelia</em>-positive, suggesting refractory and permissive microbiota states. We reanalyzed the original dataset to test whether differences in microbiome community assembly and co-occurrence network features, beyond diversity metrics, were associated with these states. Refractory nymph networks exhibited higher connectivity and structural resilience, with <em>Staphylococcus</em> emerging as a central taxon already present in unfed larvae. In contrast, permissive networks showed reduced robustness and a marginal role for <em>Staphylococcus</em>. Notably, dysbiosis altered microbial assembly but did not prevent network reconfiguration in refractory ticks. Our findings suggest that colonization resistance is better explained by microbial network integrity than by diversity alone. Methodologically, they show that integrating community assembly theory and network analyses can reveal key features of the tick microbiota associated with vector competence.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 2","pages":"Article 102613"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146203510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-05DOI: 10.1016/j.ttbdis.2026.102611
Zhongqiu Teng , Xinting Li , Li Yang , Xianxian Zhang , Na Zhao , Junrong Liang , Jia He , Xue Zhang , Lupeng Dai , Xiaobo Lu , Tian Qin
Rickettsia conorii Indian tick typhus strain (R. conorii subsp. indica, ITTR) was detected in both a human patient and an attached Rhipicephalus turanicus tick that was removed from the patient in Yanqi County, Xinjiang Uygur Autonomous Region (XUAR), China. The molecular identification of the pathogen, along with previous reports, suggests it may be distributed across the area. A 55-year-old female farmer presented with fever, headache, eschar, and a maculopapular rash following a tick bite. Laboratory findings indicated thrombocytopenia, liver enzyme elevation, and proteinuria, which, combined with clinical symptoms, strongly suggested a rickettsial infection. PCR and sequencing of multiple rickettsial genes confirmed the presence of ITTR in both the patient and the tick. Furthermore, the genetic identity between these sequences provided evidence that R. turanicus can act as a vector of ITTR. This case provides valuable insights into the clinical manifestation, diagnosis, and treatment of ITTR infections. These findings highlight the need for improved surveillance and awareness of tick-borne rickettsial diseases in regions with high tick exposure.
{"title":"Identification of Rickettsia conorii Indian tick typhus strain in a Patient and an Attached Rhipicephalus turanicus Tick in Xinjiang, China","authors":"Zhongqiu Teng , Xinting Li , Li Yang , Xianxian Zhang , Na Zhao , Junrong Liang , Jia He , Xue Zhang , Lupeng Dai , Xiaobo Lu , Tian Qin","doi":"10.1016/j.ttbdis.2026.102611","DOIUrl":"10.1016/j.ttbdis.2026.102611","url":null,"abstract":"<div><div><em>Rickettsia conorii</em> Indian tick typhus strain (<em>R. conorii</em> subsp. <em>indica,</em> ITTR) was detected in both a human patient and an attached <em>Rhipicephalus turanicus</em> tick that was removed from the patient in Yanqi County, Xinjiang Uygur Autonomous Region (XUAR), China. The molecular identification of the pathogen, along with previous reports, suggests it may be distributed across the area. A 55-year-old female farmer presented with fever, headache, eschar, and a maculopapular rash following a tick bite. Laboratory findings indicated thrombocytopenia, liver enzyme elevation, and proteinuria, which, combined with clinical symptoms, strongly suggested a rickettsial infection. PCR and sequencing of multiple rickettsial genes confirmed the presence of ITTR in both the patient and the tick. Furthermore, the genetic identity between these sequences provided evidence that <em>R. turanicus</em> can act as a vector of ITTR. This case provides valuable insights into the clinical manifestation, diagnosis, and treatment of ITTR infections. These findings highlight the need for improved surveillance and awareness of tick-borne rickettsial diseases in regions with high tick exposure.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 2","pages":"Article 102611"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146132679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-06DOI: 10.1016/j.ttbdis.2026.102609
Katrine M Paulsen , Maria J Diekmann , Malene S Dieseth , Arnulf Soleng , Petra Strakova , Jiří Salát , Daniel Růžek , Karen A Krogfelt , Erik G Granquist , Rose Vikse , Snorre Stuen , Åshild K Andreassen
Tick-borne encephalitis virus (TBEV) is a medically important orthoflavivirus endemic across Europe and Asia, transmitted primarily by Ixodes ticks but also through ingestion of unpasteurized milk from infected ruminants. While milk-borne human infections are well documented, experimental evidence for natural mother-to-offspring transmission in livestock remains scarce. Here, we experimentally assessed the potential for lactogenic transmission of TBEV in sheep. Eight ewes were infected subcutaneously with the European subtype TBEV strain Hochosterwitz and co-housed with 16 three-week-old lambs (two per ewe) for an 18-day observation period. Clinical parameters, hematology, and virological and serological profiles were monitored. All animals remained asymptomatic, with no hematological abnormalities. TBEV RNA was detected in ewes’ serum and milk from day one post-infection, and in lamb serum from day five. Virus-specific antibodies emerged in ewes from day four and in lambs from day 13. These findings provide direct experimental evidence that TBEV can be transmitted via milk from ewes to their suckling lambs throughout the lactation period, underscoring a potential but underappreciated route for virus transmission in endemic areas.
{"title":"Experimental evidence for milk-borne transmission of tick-borne encephalitis virus to suckling lambs","authors":"Katrine M Paulsen , Maria J Diekmann , Malene S Dieseth , Arnulf Soleng , Petra Strakova , Jiří Salát , Daniel Růžek , Karen A Krogfelt , Erik G Granquist , Rose Vikse , Snorre Stuen , Åshild K Andreassen","doi":"10.1016/j.ttbdis.2026.102609","DOIUrl":"10.1016/j.ttbdis.2026.102609","url":null,"abstract":"<div><div>Tick-borne encephalitis virus (TBEV) is a medically important orthoflavivirus endemic across Europe and Asia, transmitted primarily by <em>Ixodes</em> ticks but also through ingestion of unpasteurized milk from infected ruminants. While milk-borne human infections are well documented, experimental evidence for natural mother-to-offspring transmission in livestock remains scarce. Here, we experimentally assessed the potential for lactogenic transmission of TBEV in sheep. Eight ewes were infected subcutaneously with the European subtype TBEV strain Hochosterwitz and co-housed with 16 three-week-old lambs (two per ewe) for an 18-day observation period. Clinical parameters, hematology, and virological and serological profiles were monitored. All animals remained asymptomatic, with no hematological abnormalities. TBEV RNA was detected in ewes’ serum and milk from day one post-infection, and in lamb serum from day five. Virus-specific antibodies emerged in ewes from day four and in lambs from day 13. These findings provide direct experimental evidence that TBEV can be transmitted via milk from ewes to their suckling lambs throughout the lactation period, underscoring a potential but underappreciated route for virus transmission in endemic areas.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 2","pages":"Article 102609"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-13DOI: 10.1016/j.ttbdis.2026.102618
Rodanthi Zindrili , Malin Lager , Megan Simpson , Ayham Alnabulsi , Christopher J. Secombes , Anna Jonsson Henningsson , Robin Brittain-Long , Abdo Alnabulsi , Tiehui Wang , Per-Eric Lindgren
Lyme borreliosis (LB), caused by different species belonging to the Borrelia burgdorferi sensu lato group, is the most common tick-borne disease in Europe. However, its true burden remains difficult to assess, partly due to the diagnostic variability of commercial assays. This study evaluated seroprevalence and seroconversion following tick bite, using four serological assays with distinct antigenic compositions. Participants provided blood samples within three days of the tick bite and three months after to assess seroconversion. We evaluated the seroprevalence, seroconversion, inter-assay variation, consensus scoring, and factors affecting the detection rate for both seroprevalence and seroconversion.
Seroprevalence evaluation varied across the four serology assays: 33% using Anti-Borrelia plus VlsE (ABV), 26% using Epitogen™ Lyme (Epitogen), 22% using C6 Lyme ELISA (C6) and 10% using IDEIA™ B. burgdorferi (IDEIA). Estimation of overall seroconversion rates also differed: C6 had the highest rate (93%), followed by Epitogen (78%), ABV (58%) and IDEIA (38%). Using a consensus scoring approach that required positivity of at least two assays (including immunoblot) yielded a seropositivity rate of 23% at inclusion and an overall seroconversion rate of 86%. The Epitogen assay showed the highest level of concordance with the consensus score, followed by C6, ABV, and IDEIA assays.
Seroprevalence and seroconversion estimates in LB are highly assay-dependent. Assay choice significantly influenced outcome, mainly reflecting differences in antigen composition. This study underscores the importance of evaluating the antigen composition used in assays to ensure accurate result interpretation, particularly in the context of potential species variability across differing geographical regions. The use of consensus scoring across complementary multi-assays, or the implementation of well-designed assays with appropriate antigen coverage, offers a pathway to improved diagnostic accuracy and enhanced comparability.
{"title":"Seroprevalence and seroconversion of Lyme borreliosis among tick-bitten individuals: A multi-assay serosurveillance study","authors":"Rodanthi Zindrili , Malin Lager , Megan Simpson , Ayham Alnabulsi , Christopher J. Secombes , Anna Jonsson Henningsson , Robin Brittain-Long , Abdo Alnabulsi , Tiehui Wang , Per-Eric Lindgren","doi":"10.1016/j.ttbdis.2026.102618","DOIUrl":"10.1016/j.ttbdis.2026.102618","url":null,"abstract":"<div><div>Lyme borreliosis (LB), caused by different species belonging to the <em>Borrelia burgdorferi</em> sensu lato group, is the most common tick-borne disease in Europe. However, its true burden remains difficult to assess, partly due to the diagnostic variability of commercial assays. This study evaluated seroprevalence and seroconversion following tick bite, using four serological assays with distinct antigenic compositions. Participants provided blood samples within three days of the tick bite and three months after to assess seroconversion. We evaluated the seroprevalence, seroconversion, inter-assay variation, consensus scoring, and factors affecting the detection rate for both seroprevalence and seroconversion.</div><div>Seroprevalence evaluation varied across the four serology assays: 33% using Anti-<em>Borrelia</em> plus VlsE (ABV), 26% using Epitogen™ Lyme (Epitogen), 22% using C6 Lyme ELISA (C6) and 10% using IDEIA™ <em>B. burgdorferi</em> (IDEIA). Estimation of overall seroconversion rates also differed: C6 had the highest rate (93%), followed by Epitogen (78%), ABV (58%) and IDEIA (38%). Using a consensus scoring approach that required positivity of at least two assays (including immunoblot) yielded a seropositivity rate of 23% at inclusion and an overall seroconversion rate of 86%. The Epitogen assay showed the highest level of concordance with the consensus score, followed by C6, ABV, and IDEIA assays.</div><div>Seroprevalence and seroconversion estimates in LB are highly assay-dependent. Assay choice significantly influenced outcome, mainly reflecting differences in antigen composition. This study underscores the importance of evaluating the antigen composition used in assays to ensure accurate result interpretation, particularly in the context of potential species variability across differing geographical regions. The use of consensus scoring across complementary multi-assays, or the implementation of well-designed assays with appropriate antigen coverage, offers a pathway to improved diagnostic accuracy and enhanced comparability.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 2","pages":"Article 102618"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-03-13DOI: 10.1016/j.ttbdis.2026.102625
Freja Gustafsson , Lasse Fjordside , Lene Holm Harritshøj , Bitten Aagaard Jensen , Christian Erikstrup , Dorte Kinggaard Holm , Susanne Gjørup Sækmose , Karen Angeliki Krogfelt , Charlotte Sværke Jørgensen , Helene Mens , Anne-Mette Lebech
Background
Francisella tularensis is the causative agent of tularaemia. The incidence of tularaemia has increased in Europe in recent years. Due to the non-specific symptoms and diverse clinical manifestations, potential underreporting may exist. Additionally, the recent expansion in tick-borne pathogens could have increased the risk of F. tularensis transmission. We therefore aimed to estimate the seroprevalence of F. tularensis in Danish blood donors and tick-exposed individuals.
Methods
Plasma samples from healthy blood donors collected in 2022 (n=999) from all five administrative regions in Denmark, samples from blood donors from the Capital region collected in 2024 (n=200), and samples from tick-exposed individuals diagnosed with Lyme borreliosis (n=200), were screened for F. tularensis IgG using a commercial ELISA test. Positive samples for IgG were further tested using an in-house agglutination diagnostic assay measuring total F. tularensis antibodies and tested for Brucella antibodies to control for cross-reactivity.
Results
A total of 31/1399 samples were confirmed for F. tularensis antibodies resulting in an overall seroprevalence of 2.2% (CI [1.5;3.3]). All F. tularensis positive samples were negative for Brucella antibodies. The seroprevalence ranged from 1.0%-4.0% within the Danish regions with no significant regional differences. In the Capital region the seroprevalence was 1.0% in 2022 compared to 2.5% in 2024 (P-value 0.45). No significant difference in seroprevalence between blood donors and tick-exposed individuals was observed.
Conclusion
The seroprevalence of F. tularensis in Denmark was modest and comparable to other European countries. The study indicates that tularaemia may be underdiagnosed in Denmark.
{"title":"A nationwide seroprevalence study of Francisella tularensis in Denmark","authors":"Freja Gustafsson , Lasse Fjordside , Lene Holm Harritshøj , Bitten Aagaard Jensen , Christian Erikstrup , Dorte Kinggaard Holm , Susanne Gjørup Sækmose , Karen Angeliki Krogfelt , Charlotte Sværke Jørgensen , Helene Mens , Anne-Mette Lebech","doi":"10.1016/j.ttbdis.2026.102625","DOIUrl":"10.1016/j.ttbdis.2026.102625","url":null,"abstract":"<div><h3>Background</h3><div><em>Francisella tularensis</em> is the causative agent of tularaemia. The incidence of tularaemia has increased in Europe in recent years. Due to the non-specific symptoms and diverse clinical manifestations, potential underreporting may exist. Additionally, the recent expansion in tick-borne pathogens could have increased the risk of <em>F. tularensis</em> transmission. We therefore aimed to estimate the seroprevalence of <em>F. tularensis</em> in Danish blood donors and tick-exposed individuals.</div></div><div><h3>Methods</h3><div>Plasma samples from healthy blood donors collected in 2022 (n=999) from all five administrative regions in Denmark, samples from blood donors from the Capital region collected in 2024 (n=200), and samples from tick-exposed individuals diagnosed with Lyme borreliosis (n=200), were screened for <em>F. tularensis</em> IgG using a commercial ELISA test. Positive samples for IgG were further tested using an in-house agglutination diagnostic assay measuring total <em>F. tularensis</em> antibodies and tested for <em>Brucella</em> antibodies to control for cross-reactivity.</div></div><div><h3>Results</h3><div>A total of 31/1399 samples were confirmed for <em>F. tularensis</em> antibodies resulting in an overall seroprevalence of 2.2% (CI [1.5;3.3]). All <em>F. tularensis</em> positive samples were negative for <em>Brucella</em> antibodies. The seroprevalence ranged from 1.0%-4.0% within the Danish regions with no significant regional differences. In the Capital region the seroprevalence was 1.0% in 2022 compared to 2.5% in 2024 (P-value 0.45). No significant difference in seroprevalence between blood donors and tick-exposed individuals was observed.</div></div><div><h3>Conclusion</h3><div>The seroprevalence of <em>F. tularensis</em> in Denmark was modest and comparable to other European countries. The study indicates that tularaemia may be underdiagnosed in Denmark.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 2","pages":"Article 102625"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147449155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Candidatus Borrelia kalaharica was proposed as bacterial species in 2016 using DNA extracted from a traveller returning from Southern Africa. We investigated DNA of three soft ticks collected in the Kalahari Game Reserve near Maun, Botswana via PCR. One of the DNA extracts yielded positive results for four Borrelia multilocus sequence typing (MLST) genes with allele sequences closely or exactly matching alleles of Ca. B. kalaharica. Sequencing of PCR products targeting the Ornithodoros 16S rRNA gene revealed closest matches (99 - 100% coverages, >99.7 % identity) to Ornithodoros kalahariensis. Thus, we suggest that Ornithodoros kalahariensis is a potential vector for this Borrelia species.
{"title":"Ornithodoros kalahariensis, a potential vector for Candidatus Borrelia kalaharica","authors":"Volker Fingerle , Heidelore Hofmann , Christine Hartberger , Gabriele Margos","doi":"10.1016/j.ttbdis.2026.102620","DOIUrl":"10.1016/j.ttbdis.2026.102620","url":null,"abstract":"<div><div><em>Candidatus</em> Borrelia kalaharica was proposed as bacterial species in 2016 using DNA extracted from a traveller returning from Southern Africa. We investigated DNA of three soft ticks collected in the Kalahari Game Reserve near Maun, Botswana via PCR. One of the DNA extracts yielded positive results for four <em>Borrelia</em> multilocus sequence typing (MLST) genes with allele sequences closely or exactly matching alleles of <em>Ca</em>. B. kalaharica. Sequencing of PCR products targeting the <em>Ornithodoros</em> 16S rRNA gene revealed closest matches (99 - 100% coverages, >99.7 % identity) to <em>Ornithodoros kalahariensis</em>. Thus, we suggest that <em>Ornithodoros kalahariensis</em> is a potential vector for this <em>Borrelia</em> species.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 2","pages":"Article 102620"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147322403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-03-07DOI: 10.1016/j.ttbdis.2026.102623
Hanna Hägring , Ella Hällnäs , Per-Eric Lindgren , Malin Lager , Peter Wilhelmsson
From a One Health perspective, ticks play a key role as vectors of infectious agents, whereas bats can act both as hosts for ticks and as reservoirs of the agents, thereby contributing to transmission of infection. In Sweden, the argasid (soft) tick Carios vespertilionis, which is associated with the soprano pipistrelle (Pipistrellus pygmaeus), is the only known bat-associated tick species. Our study investigated Trypanosoma species and Spiroplasma ixodetis in C. vespertilionis, assessing the potential role of this tick species as a vector. A total of 78 ticks, collected in 2015 and 2018, representing all active developmental stages, were analysed using real-time PCR, and positive samples were subsequently subjected to further molecular examination. Trypanosoma DNA was detected in 22 ticks, with sequence analyses confirming the species as Trypanosoma vespertilionis. No samples tested positive for S. ixodetis. These findings provide molecular evidence of T. vespertilionis in C. vespertilionis in Sweden, showing that soft ticks can naturally harbour Trypanosoma species. The observed increase in prevalence across tick developmental stages suggests an accumulative effect of repeated blood-feeding, which could indicate some level of parasite persistence. Nevertheless, Trypanosoma DNA may originate from ingested host blood rather than established infection, and any potential vector role of this tick species should therefore be interpreted with caution.
{"title":"Trypanosoma vespertilionis detected but not Spiroplasma ixodetis in Carios vespertilionis (short-legged bat ticks) collected in Sweden","authors":"Hanna Hägring , Ella Hällnäs , Per-Eric Lindgren , Malin Lager , Peter Wilhelmsson","doi":"10.1016/j.ttbdis.2026.102623","DOIUrl":"10.1016/j.ttbdis.2026.102623","url":null,"abstract":"<div><div>From a One Health perspective, ticks play a key role as vectors of infectious agents, whereas bats can act both as hosts for ticks and as reservoirs of the agents, thereby contributing to transmission of infection. In Sweden, the argasid (soft) tick <em>Carios vespertilionis</em>, which is associated with the soprano pipistrelle (<em>Pipistrellus pygmaeus</em>), is the only known bat-associated tick species. Our study investigated <em>Trypanosoma</em> species and <em>Spiroplasma ixodetis</em> in <em>C. vespertilionis</em>, assessing the potential role of this tick species as a vector. A total of 78 ticks, collected in 2015 and 2018, representing all active developmental stages, were analysed using real-time PCR, and positive samples were subsequently subjected to further molecular examination. <em>Trypanosoma</em> DNA was detected in 22 ticks, with sequence analyses confirming the species as <em>Trypanosoma vespertilionis</em>. No samples tested positive for <em>S. ixodetis</em>. These findings provide molecular evidence of <em>T. vespertilionis</em> in <em>C. vespertilionis</em> in Sweden, showing that soft ticks can naturally harbour <em>Trypanosoma</em> species. The observed increase in prevalence across tick developmental stages suggests an accumulative effect of repeated blood-feeding, which could indicate some level of parasite persistence. Nevertheless, <em>Trypanosoma</em> DNA may originate from ingested host blood rather than established infection, and any potential vector role of this tick species should therefore be interpreted with caution.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 2","pages":"Article 102623"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147379355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ticks occupy diverse habitats, increasing the risk of human exposure. Assessing the public health threat posed by ticks requires rigorous monitoring of their distribution and of the prevalence of tick-borne pathogens. In France since 2017, the citizen science program CiTIQUE monitors human tick bites through multiple complementary approaches. Citizens can report bites and submit biting ticks to a national tick bank for research and surveillance. This study aimed to investigate human exposure to tick-borne microorganisms including pathogens across France, using ticks submitted through the CiTIQUE program. In total, 2009 ticks were selected from the CiTIQUE tick bank, identified, and screened for microorganisms using a real-time microfluidic PCR method. Most bites involved Ixodes ricinus nymphs except in Mediterranean regions where Dermacentor and Rhipicephalus ticks were more common. Twenty-six microorganisms were detected, eighteen of which are potentially pathogenic to humans. These pathogens were widely distributed across the country. Borrelia spp. were the most frequently detected pathogens with spatial variation among regions. Anaplasma phagocytophilum infection rates varied from region to region. Neoehrlichia mikurensis was found in seven out of twelve French regions. Rickettsia species diversity was highest in the southeast, associated with a greater diversity of vectors. Five percent of ticks were infected with more than one pathogen. Although spatial heterogeneity was observed, no region was free of infected ticks. This study demonstrates the power of citizen science for nationwide surveillance of tick-borne pathogens, providing a large-scale overview of pathogen diversity and distribution across France from crowdsourced tick data.
{"title":"Distribution of tick-borne microorganisms in human-biting ticks in France collected through a Citizen-science program","authors":"Jonas Durand , Thierno-Madiou Bah , Isabelle Lebert , Clémence Galon , Irene Carravieri , Sébastien Masseglia , Jean-Marc Armand , Julien Marchand , Cyril Galley , Karine Chalvet-Monfray , Muriel Vayssier-Taussat , Gwenaël Vourc’h , Annick Brun-Jacob , Sara Moutailler , Xavier Bailly , Pascale Frey-Klett","doi":"10.1016/j.ttbdis.2026.102612","DOIUrl":"10.1016/j.ttbdis.2026.102612","url":null,"abstract":"<div><div>Ticks occupy diverse habitats, increasing the risk of human exposure. Assessing the public health threat posed by ticks requires rigorous monitoring of their distribution and of the prevalence of tick-borne pathogens. In France since 2017, the citizen science program CiTIQUE monitors human tick bites through multiple complementary approaches. Citizens can report bites and submit biting ticks to a national tick bank for research and surveillance. This study aimed to investigate human exposure to tick-borne microorganisms including pathogens across France, using ticks submitted through the CiTIQUE program. In total, 2009 ticks were selected from the CiTIQUE tick bank, identified, and screened for microorganisms using a real-time microfluidic PCR method. Most bites involved <em>Ixodes ricinus</em> nymphs except in Mediterranean regions where <em>Dermacentor</em> and <em>Rhipicephalus</em> ticks were more common. Twenty-six microorganisms were detected, eighteen of which are potentially pathogenic to humans. These pathogens were widely distributed across the country. <em>Borrelia</em> spp. were the most frequently detected pathogens with spatial variation among regions. <em>Anaplasma phagocytophilum</em> infection rates varied from region to region. <em>Neoehrlichia mikurensis</em> was found in seven out of twelve French regions. <em>Rickettsia</em> species diversity was highest in the southeast, associated with a greater diversity of vectors. Five percent of ticks were infected with more than one pathogen. Although spatial heterogeneity was observed, no region was free of infected ticks. This study demonstrates the power of citizen science for nationwide surveillance of tick-borne pathogens, providing a large-scale overview of pathogen diversity and distribution across France from crowdsourced tick data.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 2","pages":"Article 102612"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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