Ticks and Tick-borne Diseases最新文献

{"title":"An insight into the ovary and midgut transcriptome of Dermacentor nitens tick","authors":"Stephen Lu ,&nbsp;Christopher F. Bosio ,&nbsp;Vinicius Andrade-Silva ,&nbsp;Ially de Almeida Moura ,&nbsp;Giancarlo Bomfim Ribeiro ,&nbsp;Markus Berger ,&nbsp;Wendell Marcelo De Souza Perinotto ,&nbsp;Itabajara da Silva Vaz Junior ,&nbsp;Lucas Tirloni","doi":"10.1016/j.ttbdis.2025.102600","DOIUrl":"10.1016/j.ttbdis.2025.102600","url":null,"abstract":"<div><div>The tropical horse tick, <em>Dermacentor nitens</em>, is a one-host hard tick widely distributed across tropical and subtropical regions of the Americas, where it primarily parasitizes horses and occasionally cattle and other livestock. This species is of veterinary importance due to its role as a vector of <em>Babesia caballi</em>, the causative agent of equine piroplasmosis. Despite its significance, genomic resources for <em>D. nitens</em> remain scarce, limiting molecular and functional studies. Here, we present the most comprehensive transcriptome assembly of <em>D. nitens</em> to date, encompassing midgut and ovary transcriptomes during the rapid phase of blood feeding. Using deep sequencing approaches, we identified and annotated a large repertoire of transcripts expressed during blood feeding and reproduction, processes central to tick survival and pathogen transmission. To further facilitate gene discovery in <em>D. nitens</em>, we conducted orthology searches against annotated transcripts from the genomes of <em>Dermacentor albipictus, Dermacentor andersoni, Dermacentor silvarum, Dermacentor variabilis, Hyaloma asiaticum, Haemaphysalis longicornis, Ixodes scapularis, Ixodes persulcatus, Rhipicephalus microplus,</em> and <em>Rhipicephalus sanguineus</em>. Our dataset provides new insights into midgut and ovary physiology, including genes associated with blood meal digestion and oogenesis, which are critical for reproduction and life cycle progression. These findings expand the molecular toolkit available for <em>D. nitens</em>, enabling future studies on tick physiology, evolution, and vector competence. Moreover, this resource offers a framework for comparative analyses with other <em>Dermacentor</em> species of medical relevance, thereby advancing our understanding of conserved biological mechanisms underlying feeding, reproduction, and pathogen transmission.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 1","pages":"Article 102600"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145913751","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}

{"title":"Borrelia circulating in soft ticks infesting colonial breeding seabirds along the Portuguese coast","authors":"Ana Cláudia Norte ,&nbsp;Maria Sofia Núncio ,&nbsp;Maria Teresa Luz ,&nbsp;Paulo Parreira ,&nbsp;Jorge Pereira ,&nbsp;Adriana Sofia Domingues ,&nbsp;Maria Inês Laranjeiro ,&nbsp;Sara Veríssimo ,&nbsp;Ivo dos Santos ,&nbsp;Catarina Santos Lopes ,&nbsp;Filipe Rafael Ceia ,&nbsp;Vítor Hugo Paiva ,&nbsp;Jaime Albino Ramos ,&nbsp;Isabel Lopes de Carvalho","doi":"10.1016/j.ttbdis.2025.102591","DOIUrl":"10.1016/j.ttbdis.2025.102591","url":null,"abstract":"<div><div>Seabirds are hosts of several tick species, but there is little information on their infestation by soft ticks and pathogens they harbour is available. In this study, we evaluated soft tick infestation in gull chicks from two breeding colonies in Portugal and assessed the prevalence of anti-Borrelia antibody in adults gull and shearwaters from these colonies, as well as from two additional urban colonies. The prevalence of infestation by <em>Ornithodorus maritimus</em> ticks in gull chicks varied between (17.6 %) in three yellow legged gull (<em>Larus michahellis</em>) and 84.8 % in the Audouin’s gull (<em>Ichthyaetus audouinii</em>), with a mean infestation intensity of 4.50 ticks per infested yellow-legged gull chick and 5.59 ticks per infested Audouin’s gull chick. All ticks, except one, were at the larval stage. Infestation prevalence was significantly higher at Deserta Island (south Portugal) compared to Berlenga Island. Of the 133 ticks screened, only two tested positive for <em>Borrelia</em>: one for <em>Borrelia turdi</em> (from a yellow legged gull) and one <em>Borrelia mayonii</em> from a Audouin’s gull. However, only one gene could be sequenced for each. No relapsing fever Borrelia species were detected. Although differences among colonies were only marginally significant, Deserta Island exhibited higher anti-<em>Borrelia</em> antibody prevalence than Berlenga Island. No significant differences were observed between bird species. These findings highlights the need for further investigation into Borrelia- soft tick- seabird interactions, and the potential infection risks associated with gull breeding habitats, particularly in areas of human-wildlife contact.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 1","pages":"Article 102591"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145913761","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}

{"title":"Corrigendum to “A review on the role of birds as disseminators of ticks, with special emphasis on Hyalomma species and Crimean-Congo haemorrhagic fever virus” [Ticks and Tick-borne Diseases, 16 (2025), 102535]","authors":"Gergő Keve ,&nbsp;Attila D. Sándor ,&nbsp;Sándor Hornok","doi":"10.1016/j.ttbdis.2025.102587","DOIUrl":"10.1016/j.ttbdis.2025.102587","url":null,"abstract":"","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 1","pages":"Article 102587"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145994593","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}

{"title":"Spotted fever group Rickettsia in Haemaphysalis ticks: genetic diversity and first detection of “Candidatus Rickettsia jingxinensis” in India","authors":"Vinayak V ,&nbsp;R. Balasubramanian ,&nbsp;Siba S ,&nbsp;Jayashri Patil ,&nbsp;Pradnya Bhadale ,&nbsp;Harsuni H ,&nbsp;Sithalakshmi S ,&nbsp;Jerlyn Varghese ,&nbsp;Kalichamy Alagarasu","doi":"10.1016/j.ttbdis.2025.102580","DOIUrl":"10.1016/j.ttbdis.2025.102580","url":null,"abstract":"<div><div>Ticks are important vectors of rickettsial pathogens, particularly in regions where livestock, wildlife, and humans overlap. Despite increasing reports of rickettsioses in India, molecular evidence of <em>Rickettsia</em> species in questing ticks from the Western Ghats of Kerala remains scarce. Questing ticks were collected from forest-edge and fringe habitats in Wayanad, Idukki, and Thrissur districts using standardized dragging. Species were identified morphologically, pooled, and screened for <em>Rickettsia</em> DNA by PCR targeting <em>gltA</em> and <em>ompA</em> genes. Amplicons were sequenced, and phylogenetic analysis was performed using reference sequences. Among 237 ticks belonging to six species, 24 % (12/50 pools) were PCR-positive for <em>Rickettsia</em>. The highest prevalence was observed in <em>Haemaphysalis spinigera</em> (50 %), followed by <em>Haemaphysalis bispinosa</em> (30 %) and <em>Haemaphysalis turturis</em> (9.5 %). Sequence analysis revealed the presence of <em>Rickettsia massiliae</em> and <em>Rickettsia vini</em> like species. Importantly, sequences closely related to “<em>Candidatus</em> Rickettsia jingxinensis<em>”</em> were detected for the first time in India, in <em>H. turturis</em>. Several isolates showed genetic divergence from known strains, suggesting the circulation of uncharacterized <em>Rickettsia</em> species or strains in tick population. This study provides the first molecular evidence of “<em>Ca.</em> R. jingxinensis” in <em>H. turturis</em> from India and demonstrates a high prevalence of <em>Rickettsia</em> spp. in questing ticks of Kerala. Given the pathogenic potential of some of these species, enhanced surveillance and incorporation of rickettsioses into differential diagnoses of febrile illnesses are needed in South India.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 1","pages":"Article 102580"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145745326","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}

{"title":"Comparison and complete mitogenomes of two morphologically similar but ecologically different tick species, Ixodes arboricola and Ixodes lividus (subgenus Pholeoixodes)","authors":"Sándor Hornok ,&nbsp;Paulina Lesiczka ,&nbsp;Tim Warbroek ,&nbsp;Tijs J.M. van den Bosch ,&nbsp;Andor Pitó ,&nbsp;Gergő Keve ,&nbsp;Nóra Takács ,&nbsp;Jenő Kontschán ,&nbsp;Attila D. Sándor","doi":"10.1016/j.ttbdis.2025.102589","DOIUrl":"10.1016/j.ttbdis.2025.102589","url":null,"abstract":"<div><div><em>Ixodes arboricola</em> and <em>Ixodes lividus</em> are ornithophilic tick species. The former is typically associated with tree-hole dwelling birds, while the latter is a host-specific parasite of sand martins (<em>Riparia riparia</em>). These two tick species share important morphological characters that make them difficult to identify when they are collected from atypical hosts, such as birds of prey. Despite this, high resolution digital pictures have not been reported to compare <em>I. arboricola</em> and <em>I. lividus</em>, nor was their complete mitogenome reported. The aim of this study was to compensate for this lack of illustrations and sequence data. Nymphs and females of <em>I. arboricola</em> and <em>I. lividus</em> were used for morphological comparison, and one specimen of each species to generate mitogenome sequences.</div><div>The results showed that females of these two species are different in the shape of their scutum, porose areas, the length of basis capituli, palps, coxae, genital pore, anal groove and tarsus I. On the other hand, nymphs of <em>I. arboricola</em> and <em>I. lividus</em> can be distinguished according to their cervical grooves, cornuae, auricular ridges and spiracular plates. The mitochondrial genome size was 14,539 and 14,536 bp, for <em>I. arboricola</em> and <em>I. lividus</em>, respectively. The mitogenome sequences of <em>I. arboricola</em> and <em>I. lividus</em> were 91.1% identical to each other. Phylogenetic analysis of <em>Ixodes</em> species showed that <em>I. arboricola</em> and <em>I. lividus</em> are sister species, and cluster together with <em>Ixodes crenulatus</em>/<em>canisuga</em> under strong support.</div><div>In conclusion, results of this study confirmed that the front of the basis capituli is crucial in distinguishing <em>Ixodes</em> species, especially in the subgenus <em>Pholeoixodes</em> where these two species are phylogenetically closest related to <em>I. canisuga</em>. Another phylogenetically relevant morphological character is the scutal surface which is wrinkled (rugose) as a common feature of <em>Pholeoixodes</em> species in the clade of <em>I. arboricola</em> and <em>I. lividus</em> (including <em>I. canisuga, I. rugicollis</em> and <em>I. ariadnae</em>). Although the host ranges of <em>I. arboricola</em> and <em>I. lividus</em> do not substantially overlap, they may transmit some of the shared pathogens. Relevant data indicate that the eco-epidemiological significance of the two ornithophilic tick species studied here may in part be similar and they may play a role in the transmission of rickettsiae, borreliae and viruses of which birds act as reservoirs.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 1","pages":"Article 102589"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939355","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}

{"title":"Comparative transcriptomic insights into ticks infected by alongshan and tick-borne encephalitis viruses","authors":"Cara Leonie Ebert ,&nbsp;Paula Hornauer ,&nbsp;Klaus Jung ,&nbsp;Julia Metzger ,&nbsp;Stefanie C. Becker","doi":"10.1016/j.ttbdis.2025.102592","DOIUrl":"10.1016/j.ttbdis.2025.102592","url":null,"abstract":"<div><div>Ticks are hematophagous ectoparasites and key vectors of a wide range of pathogens, including viruses, bacteria, and protozoa. Climate change and environmental shifts have contributed to the expansion of tick populations and the pathogens they harbor. Ticks rely solely on their innate immune system to combat infections, utilizing mechanisms such as RNA interference, phagocytosis, and antimicrobial peptide expression. However, pathogens have evolved strategies to evade or manipulate these defenses to facilitate their replication and transmission. This study compares the infection dynamics of two tick-borne viruses: <em>Orthoflavivirus encephalitidis</em> (TBEV) and Alongshan virus (ALSV). TBEV, a well-adapted arbovirus, requires both tick and vertebrate hosts for its life cycle and is a major cause of human meningitis and encephalitis across Europe and Asia. In contrast, ALSV appears to be primarily restricted to ticks, with its dependence on vertebrate hosts still unclear. Transcriptomic analyses of <em>Ixodes ricinus</em> ticks revealed distinct gene expression patterns in response to these viruses. TBEV infection primarily regulated genes related to immunity, defense, and digestion—reflecting its adaptation to dual-host environments and acquisition via blood feeding. ALSV infection, however, influenced signaling and infection-related pathways, suggesting a more specialized adaptation to ticks. These findings underscore the differences in immune modulation and metabolic responses between TBEV and ALSV, highlighting the need for further genomic and proteomic studies to enhance our understanding of virus-vector interactions. Such insights could inform strategies for controlling tick-borne diseases and tracking pathogen evolution.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 1","pages":"Article 102592"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145913753","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}

{"title":"Response letter to Rebuttal to Zimmermann et al. (2025) critique of TerL-based PCR","authors":"Manja Zimmermann ,&nbsp;Gabriele Margos ,&nbsp;Christine Hartberger ,&nbsp;Reto Lienhard ,&nbsp;Anna J. Henningsson ,&nbsp;Malin Lager ,&nbsp;Mateusz Markowicz ,&nbsp;Anna-Margarita Schötta ,&nbsp;Andreas Sing ,&nbsp;Benoit Jaulhac ,&nbsp;Per-Eric Lindgren ,&nbsp;Alje P. van Dam ,&nbsp;Joppe W.R. Hovius ,&nbsp;Volker Fingerle","doi":"10.1016/j.ttbdis.2025.102594","DOIUrl":"10.1016/j.ttbdis.2025.102594","url":null,"abstract":"","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 1","pages":"Article 102594"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145913814","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}

{"title":"Nationwide seroprevalence of severe fever with thrombocytopenia syndrome virus in South Korea: Regional patterns and public health implications","authors":"Jongyoun Yi ,&nbsp;Chang-Ki Kim ,&nbsp;Ahreum Kim ,&nbsp;Changhoon Kim ,&nbsp;Maengseok Noh ,&nbsp;Mee Kyung Ko ,&nbsp;Hyun Jin Son ,&nbsp;Kye-Hyung Kim","doi":"10.1016/j.ttbdis.2025.102601","DOIUrl":"10.1016/j.ttbdis.2025.102601","url":null,"abstract":"<div><h3>Objectives</h3><div>Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne viral disease with a high fatality rate and is endemic to East Asia. This study aimed to estimate the seroprevalence of SFTS virus (SFTSV) antibodies in South Korea and analyze regional and demographic variations to guide public health strategies.</div></div><div><h3>Methods</h3><div>We conducted a cross-sectional study using 12,684 residual serum samples from clinics in 17 administrative regions (July 2019–June 2020) using a double-antigen sandwich enzyme-linked immunosorbent assay. Crude and standardized seroprevalence was calculated, and trends were assessed using generalized additive mixed models.</div></div><div><h3>Results</h3><div>The overall crude seroprevalence was 1.63 % and was higher among older adults, particularly those aged 80–99 years (3.03 %). Jeju (2.99 %) and Gangwon (2.28 %) Provinces had the highest standardized seroprevalence. SFTSV seroprevalence did not differ significantly by sex or urban-rural status but was higher in agricultural regions, suggesting occupational exposure as a risk factor.</div></div><div><h3>Conclusions</h3><div>This nationwide estimate of SFTSV seroprevalence highlights high-risk groups, particularly older adults. These findings provide a baseline for surveillance and targeted interventions to mitigate SFTS risk and inform public health strategies in East Asia.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"17 1","pages":"Article 102601"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146013091","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}

{"title":"Trends in incidence of tick bites and physician-reported early and late Lyme borreliosis in the Netherlands","authors":"Oda E. van den Berg,&nbsp;Margriet G. Harms,&nbsp;Anna D. Tulen,&nbsp;Vanessa D. Brown,&nbsp;Jan van de Kassteele,&nbsp;Agnetha Hofhuis,&nbsp;Cees C. van den Wijngaard","doi":"10.1016/j.ttbdis.2025.102561","DOIUrl":"10.1016/j.ttbdis.2025.102561","url":null,"abstract":"<div><div>Lyme borreliosis (LB) is a prevalent vector-borne disease in Europe. Untreated, it can cause severe complications, with some patients experiencing persistent symptoms post-treatment. In the Netherlands, tick bite consultations and erythema migrans (EM) diagnoses tripled from 1994 to 2009, but tick bite consultations declined and EM diagnoses stabilized in 2014. This study examines trends in tick bite consultations, EM diagnoses, and other LB manifestations in the Netherlands from 2014 onward.</div><div>In 2017 and 2021, questionnaires were sent to Dutch GPs to collect data on tick bite consultations and EM diagnoses. The 2021 survey additionally addressed disseminated LB and persistent symptoms attributed to LB. Data were analyzed using a negative binomial distribution, with bootstrapping applied to account for uncertainty.</div><div>The population coverage was 51 % in 2017 and 32 % in 2021. The incidence of tick bite consultations per 100,000 was 534 (518–551) in 2017 and 447 (426–470) in 2021. The incidence of EM diagnoses per 100,000 was 150 (145–155) in 2017 and 147 (140–154) in 2021. In 2021, the incidence was 5.0 (4.2–5.9) per 100,000 for disseminated LB and 5.0 (4.4–5.5) per 100,000 for persisting symptoms attributed to LB.</div><div>Compared to 2014, GP consultations for tick bites and EM diagnoses had increased in 2017. In 2021, tick bite consultations were lower than in 2017, likely due to COVID-19 restrictions. EM diagnoses were similar to 2017. Disseminated LB was lower in 2021 compared to 2010, whilst persisting symptoms attributed to LB remained stable.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"16 6","pages":"Article 102561"},"PeriodicalIF":3.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145423341","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}

{"title":"Genetic diversity of equine piroplasmosis agents in Guadeloupe (Caribbeans): first report of Theileria haneyi, evaluation of diagnostic tools and impact of horse movement","authors":"Mickaël Mège ,&nbsp;Claire Bonsergent ,&nbsp;Laetitia Viry ,&nbsp;Mélanie Dhune ,&nbsp;Sylvie Lecollinet ,&nbsp;Laurence Malandrin","doi":"10.1016/j.ttbdis.2025.102547","DOIUrl":"10.1016/j.ttbdis.2025.102547","url":null,"abstract":"<div><div>Equine piroplasmosis is a major tick-borne horse disease, caused by the intracellular development of piroplasms (<em>Theileria equi</em> sensu lato and <em>Babesia caballi</em>), with significant economic and sanitary consequences. In 2024, 203 blood samples were collected in Guadeloupe (Caribbean) from asymptomatic horses. Using an 18S rRNA nested PCR (nPCR) specific for each equine genus parasite, 79 samples tested positive for <em>Theileria equi</em> and 9 for <em>Babesia caballi</em>, resulting in respective prevalence of 38.9% and 4.4%. Three horses were co-infected. For <em>B. caballi</em>, 18S rRNA sequence analysis revealed the presence of the genotype A only. For <em>T. equi,</em> the genotypes A and C were evidenced as mono-infections A (16/79, 20.3% of the infected horses) or mono-infections C (15/79, 19.0% of the infected horses). Interestingly, mono-infections with <em>T. equi</em> genotype E (17/79, 21.5% of the infected horses) were also detected, but only on horses imported from Europe and especially from metropolitan France, where this genotype is dominant. Further characterization using published <em>T. equi ema-1</em> and <em>T. haneyi</em> specific nPCRs revealed two major points. First, most 18S rRNA genotype C isolates (13/15) were detected using the <em>T. haneyi</em> specific nPCR. Second, the genotype E of <em>T. equi</em> could not be detected by any of these two nPCRs. Co-infection occurrence and types were then evaluated using a combination of the three analyses: 18S rRNA sequencing, <em>T. haneyi</em> specific nPCR and <em>T. equi ema-1</em> nPCR. Horses co-infected with the genotypes A and C (<em>T. haneyi</em>) represented the main population (32/79, 40.5% of the infected horses), while the co-infections AE (5/79, 6.3% of the horses) and CE (2/79, 2.5% of the horses) were rare. One horse was detected with a triple infection ACE. Taking into account all detected genotypes (120), 45.0% of the isolates belonged to the genotype A (54/120), 38.3% to the genotype C <em>T. haneyi</em> (46/120) and 16.7% to the Eurasian genotype E (20/120). The rarity of co-infections with the genotype E and the absence of this genotype on locally born horses suggest the absence of transmission of the genotype E by locally present vector ticks.</div><div>This work represents the first molecular record of <em>Theileria haneyi</em> in South and Central America and in the Caribbeans. We also demonstrate the introduction of <em>T. equi</em> genotype E from Europe with infected horses but not its installation, as well as a diagnostic issue to detect this genotype using PCR targeting <em>ema-1</em> gene.</div></div>","PeriodicalId":49320,"journal":{"name":"Ticks and Tick-borne Diseases","volume":"16 6","pages":"Article 102547"},"PeriodicalIF":3.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160092","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}