Endemic and emerging tick-borne diseases in humans and animals in the US are becoming more frequent and are likely driven by several socioecological factors. Although numerous hard and soft ticks are of medical and veterinary significance, this review focuses on species that are most relevant for the One Health practitioner. This article presents key aspects on significant tick species and tick-borne diseases in the US. Tick biology and ecology of several ticks are discussed, including black-legged ticks (Ixodes scapularis), western black-legged ticks (Ixodes pacificus), American dog ticks (Dermacentor variabilis), Rocky Mountain wood ticks (Dermacentor andersoni), lone star ticks (Amblyomma americanum), Gulf Coast ticks (Amblyomma maculatum), brown dog ticks (Rhipicephalus sanguineus), and the recent invader, Longhorned ticks (Haemaphysalis longicornis). In addition, the epidemiology of several diseases is also discussed, such as Lyme disease, spotted fever rickettsioses, babesiosis, and anaplasmosis/ehrlichiosis. Finally, management recommendations for diagnosis, treatment, and prevention are provided. By integrating knowledge of key tick species, associated pathogens, and evidence-based management recommendations, this review adopts a One Health perspective to inform coordinated veterinary and human health responses to tick-borne diseases in the US. The companion Currents in One Health article by Eleftheriou et al, AJVR, June 2026, addresses research gaps and developments in tick and tick-borne disease research across biological scales.

Microbial networks and pathogen detection: Insights from ticks and patients with acute febrile illness.

Survey of tick species and tick-borne pathogens in pet dogs and cats in mainland China.

Crimean-Congo haemorrhagic fever (CCHF) is an emerging zoonotic disease of significant public health concern caused by Crimean-Congo haemorrhagic fever virus (CCHFV), primarily transmitted by tick vectors. Its spread is further compounded by global warming, tick range expansion, and traditional farming practices. This study aimed to assess the prevalence of CCHFV in ticks parasitizing livestock in Kermanshah Province, Iran, which borders Iraq, a country that has experienced major CCHF outbreaks in recent years. Serum and tick samples were collected from 302 small ruminants (SRs) in six districts, considering previous CCHF cases and regional differences. Following RNA extraction from both ticks and sera, a homemade real-time RT-PCR was used to detect CCHFV infection. All sera tested negative, while 0.67% (4/604) of ticks were infected with CCHFV (Hyalomma asiaticum and Rhipicephalus sanguineus were positive). This study confirms the circulation of CCHFV in the western region of Iran and, more importantly, reports the detection of an Aigai virus (formerly CCHFV genotype VI or AP-92-like strain) in tick populations for the first time in Iran. These findings emphasize the need for continued molecular surveillance, vector control, and cross-border cooperation to mitigate the risk of CCHF transmission in humans.

Ticks are major ectoparasites and vectors of pathogens affecting humans, livestock, and wildlife. They harbor diverse microbial communities that may influence tick biology and interactions with microorganisms; however, functional information on tick-associated microbiomes remains limited, particularly in North Africa. In this pilot study, we applied a metaproteomic approach based on high-resolution tandem mass spectrometry to characterize bacterial communities associated with three tick species collected in Algeria: Rhipicephalus sanguineus sensu lato, Hyalomma aegyptium, and Hyalomma dromedarii. Peptide spectra were assigned to taxa using a two-step database search strategy based on NCBInr, and bacterial composition and relative abundance were compared across tick species and sampling locations. A total of 40 bacterial genera belonging to 32 families and four phyla were identified. Microbiome composition differed significantly between tick genera and collection locations, suggesting an influence of species-specific and geographical factors on microbial community structure. Dominant genera included Streptomyces, Bacillus, Clostridium, Escherichia, Flavobacterium, Paenibacillus, and Providencia. Peptides related to Coxiella spp. were frequently detected, consistent with previous reports of Coxiella-like endosymbionts in ticks. This pilot study provides a first metaproteomic characterization of tick-associated communities in Algeria. The results reveal species- and location-associated differences in microbial composition and highlight the potential of metaproteomics for exploring tick-associated microbiomes in North Africa.

Ticks are among the most significant ectoparasites of livestock and humans, posing serious health and economic risks. The growing resistance to conventional acaricides highlights the need for safer and more effective alternatives. This study aimed to evaluate the acaricidal efficacy of different ivermectin (IVM) nanoformulations against different developmental stages of Rhipicephalus sanguineus tick. Different ivermectin nanoformulations were fabricated and evaluated for their physicochemical properties. An in vitro study was performed using larval, nymphal, and adult immersion tests, followed by an in vivo trial against unfed adults using the most effective formulation. All nanoformulations showed particle sizes from 450 to 650 nm and a polydispersity index range from 0.34 to 0.65. IVM spanlastics exhibited the smallest particle size, highest encapsulation efficiency (92%), and a sustained release profile. Based on LC50 values, IVM spanlastics showed superior acaricidal activity against larvae (LC50: 0.05%), nymphs (LC50: 0.09%), and unfed adults (LC50:0.16%); followed by IVM-SeNPs, where the LC50 values were 0.10, 0.23, and 0.38% for larvae, nymphs, and unfed adults, respectively. The in vivo study of IVM spanlastics demonstrated 100% mortality of adult ticks within four days after application. IVM spanlastics could be topically applied as an alternative to conventional injectable IVM to control R. sanguineus ticks. Further toxicological studies are necessary to ensure the safety of these formulations for environmental and veterinary use.

This study reports the first molecular detection of Hepatozoon spp. in domestic cats from central Argentina, expanding current knowledge of its distribution and genetic diversity in South America. Blood samples (n = 257) from domestic cats in Santa Fe, Esperanza, and San José del Rincón were analyzed by PCR targeting the 18S rDNA gene of Hepatozoon spp. Four samples (1.6%) tested positive for Hepatozoon spp. Phylogenetic analyses revealed two distinct lineages: two sequences clustered with Hepatozoon canis, typically found in dogs and transmitted by Rhipicephalus sanguineus, and two were closely related to a rodent-associated Hepatozoon lineage. Spatial analysis identified a significant cluster in the northern area of Esperanza (p = 0.003), suggesting that local environmental conditions may facilitate parasite transmission at the urban-natural interface. All positive cats had outdoor access, supporting the role of environmental exposure and potential trophic transmission. No gamonts were observed in blood smears, consistent with the subclinical nature and low parasitemia characteristic of feline hepatozoonosis. Although the small number of positive cases limited statistical analysis, this study provides baseline molecular and spatial epidemiological data on feline Hepatozoon in Argentina. The coexistence of H. canis and a rodent-related Hepatozoon lineage indicates complex, multi-host transmission dynamics at the domestic-wildlife interface.

BackgroundTicks are important vectors for bacterial, viral, rickettsial, and protozoal diseases in different animals and humans, especially in tropical countries. Tick-borne pathogens (TBPs) are host and vector-species-specific and depict geographical variations. This study was conducted to determine the diversity of ticks and their geographical distribution among domestic animals.Methodology/Principal FindingsTicks were collected from a total of 210 domestic animals: cattle (n = 30), buffaloes (n = 40), sheep (n = 50), goats (n = 30), and dogs (n = 60), representing Chitwan (Terai), Kathmandu (mid-hill), and Rasuwa (high-hill) of Nepal. The genus and species of ticks were identified using morphological keys under a stereomicroscope. Analysis was performed using MS Excel, and Shannon-Wiener’s and Simpson’s diversity indexes were calculated. A total of 4 genera of hard ticks were observed, representing Rhipicephalus, Haemaphysalis, Dermacentor, and Hyalomma. Among them, Rhipicephalus (Boophilus) microplus (30.42%) was most abundant, followed by Haemaphysalis longicornis (26.74%), Rhipicephalus sanguineus (18.8%), Haemaphysalis sulcata (13.23%), and Rhipicephalus decoloratus (2.86%). Similarly, Haemaphysalis spp. (2.18%), Haemaphysalis leachi (2.05%), Dermacentor sp. (1.36%), Rhipicephalus spp. (1.36%), Hyalomma sp. (0.41%), and Rhipicephalus parva (0.14%). Geographical distribution and tick species diversity were higher in Chitwan. Similarly, species diversity in the case of the host was found to be greater in small ruminants. The result suggested higher tick distribution and diversity among warm tropical regions of Nepal.ConclusionsThis study investigates the distribution of ticks (Haemaphysalis, Rhipicephalus, Dermacentor, and Hyalomma) in domestic animals across various climatic conditions, identifying the high-risk areas and animal species for tick-borne diseases, including zoonoses. The findings highlight the need for advanced research on tick ecology, epidemiology of TBPs, and the implementation of effective control strategies.

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne pathogen responsible for severe and often fatal disease in East Asia; however, information from Southeast Asia remains limited. We report two fatal human SFTS cases in Thailand confirmed by quantitative reverse transcription polymerase chain reaction, in which viral RNA was detected in multiple specimen types from both patients, including plasma, cerebrospinal fluid, respiratory secretions, urine, and stool, indicating systemic infection. Rhipicephalus sanguineus ticks collected from pet dogs and from the patients' households also tested positive for SFTSV RNA, with cycle threshold values ranging from 15.6 to 30.6. Phylogenetic analyses based on the S, M, and L segments showed that sequences obtained from human and tick samples clustered within genotype B-1 and were closely related to previously reported Thai and related Chinese strains. These findings provide molecular evidence of SFTSV in dog-associated R. sanguineus ticks and suggest a possible epidemiological association with human cases; however, their role in transmission and the direction of transmission remain uncertain. These findings expand the known geographic and ecological context of SFTSV and underscore the importance of heightened clinical awareness and integrated human-animal-vector surveillance in Southeast Asia, particularly in dengue-endemic regions where SFTS may be clinically overlooked.

Metagenomic and serological evidence of emerging tick-borne viruses in livestock, humans, and rats in Pakistan.

Ticks are hematophagous ectoparasites of significant veterinary and public health importance, transmitting a wide array of zoonotic pathogens to both animals and humans. Understanding tick infestation patterns in different regions is crucial for effective control and prevention strategies. This study aimed to assess and compare tick infestations in household dogs across two regions in Nigeria, Minna (Niger State) and Ibadan (Oyo State), to evaluate regional variations in tick intensity and their zoonotic implications. A total of 392 dogs were sampled, yielding 1,385 ticks, with Rhipicephalus sanguineus being the most prevalent species (91.4%), followed by Boophilus sp. (5.4%) and Haemaphysalis sp. (3.2%). Younger dogs (< 1year) harbored most ticks, with infestation patterns significantly associated with the dog's age (χ2 = 32.512, p < 0.001), sex and household roles, and management practices. Dogs in Ibadan exhibited a higher mean tick intensity (7.98) compared to Minna (1.55), as confirmed by the Mann-Whitney U test (U = 0.0, p < 0.001). Infestation rates also varied by household roles and management practices; caged dogs in Ibadan were predominantly infested with Rhipicephalus sanguineus and Haemaphysalis sp., while free-range dogs in Minna were more commonly infested with Boophilus sp. The zoonotic risks associated with tick-borne pathogens, including Rickettsia sp. and Babesia sp., highlight the urgent need for integrated tick control strategies. These should include regular acaricide application, improved dog management practices, and public health campaigns to raise awareness of zoonotic risks. This study provides critical insights into the regional dynamics of tick infestation and offers recommendations for mitigating the public health burden of tick-borne diseases in Nigeria.

Characterization of the mitochondrial genome of Rhipicephalus linnaei Audouin, 1826 (Arachnida: Ixodida: Ixodidae) and phylogenetic considerations of the Rhipicephalus sanguineus complex.

Species composition, distribution, and host associations of ixodid ticks in domestic animals on lowland pastures in North Macedonia.

Background and Objectives:Anaplasmosis, an ailment affecting both captive and free-ranging small ruminants, is instigated by Anaplasma spp., a tick-vectored, obligate intracellular rickettsial bacterium. Iran’s ovine and caprine populations, numbering roughly 71 million, are vital to its financial structure.Materials and Methods:This study investigated the prevalence of Anaplasma species in sheep and goats within West Azerbaijan province. Additionally, nucleic acid specimens were isolated from gathered ticks and examined for Anaplasma spp. Through polymerase chain reaction (PCR) utilizing the major surface protein gene (groEL).Results:Anaplasma was detected in 161 (69.0%) of 919 ovine and 82 (71.3%) of 243 caprine blood DNA extracts. Subsequently, genetic material from 426 ticks comprised of Rhipicephalus sanguineus (n=146), Rhipicephalus turanicus (n=63), Hyalomma asiaticum (n=56), Hyalomma anatolicum (n=74), and Hyalomma egebtiom (n=87) was screened for A. ovis utilizing the same methodology.Conclusion:This research not only confirmed the presence of A. ovis within Iranian sheep and goats but also implicated ticks as a possible vector for its transmission. The findings emphasize the importance of monitoring the health status of Iran’s small ruminants to detect clinical manifestations of anaplasmosis and of implementing effective tick control strategies worldwide.

This study examined the distribution and seasonal population dynamics of tick species infesting cattle, sheep, and goats in Ağrı Province, Türkiye. From January to December 2024, 913 hosts were examined, and 545 intact tick samples were collected from 386 infested animals and morphologically identified. The overall sex ratio was 52.7% female and 47.3% male. The identified species included Dermacentor niveus, D. marginatus, Rhipicephalus sanguineus, R. turanicus, R. bursa, Haemaphysalis punctata, Hae. sulcata, Hyalomma marginatum, H. anatolicum anatolicum, H. anatolicum excavatum, and H. detritum detritum. Seasonal tick activity peaked in summer (51.7%) and spring (42.9%), with a significant decline in autumn (χ2 = 48.72, df = 3, p < 0.001). No active ticks were observed in winter due to the harsh continental climate. Adult Hyalomma ticks, which are known potential vectors of Crimean–Congo hemorrhagic fever (CCHF), remained active except during winter. The high prevalence of these vector species suggests a need for further investigation into pathogen circulation in the region. This research provides a scientific foundation for integrated vector control and surveillance programs within the One Health framework.

Epidemiological and clinicopathological factors associated with infection by multiple pathogens transmitted by Rhipicephalus sanguineus sensu lato in naturally infected dogs in the Semiarid area of Northeastern Brazil.

HighlightsPublic health relevance—How does this work relate to a public health issue?Our study focuses on how tick-borne diseases circulate in popular tourist spots like Brijuni National Park, where the interaction between nature and people is very high.We wanted to fill the gap in data regarding where and why these pathogens appear, helping to better understand the real risk for anyone visiting or working in Mediterranean island environments.Public health significance—Why is this work of significance to public health?We confirmed that three serious pathogens (Borrelia, Anaplasma, and Ehrlichia) are actively present in the park’s tick population.Particularly important is our finding that nearly 30% of ticks carry more than one pathogen, which is a big deal for doctors because a single tick bite can cause a much more complex illness than expected.Public health implications—What are the key implications or messages for practitioners, policy makers and/or researchers in public health?We discovered that even well-maintained areas like park gardens can hide ticks because of irrigation, meaning tourists might be at risk even where they feel “safe.”These findings give park managers clear directions: they can now focus on specific “hotspots” for maintenance and better warn visitors exactly where to be careful.Tick-borne diseases are a growing public health concern in the Mediterranean. Brijuni National Park (BNP), a unique, highly visited island ecosystem characterized by increased large game host density and diverse Mediterranean habitats, presents an elevated risk for pathogen co-circulation. This study addresses the lack of spatial and epidemiological data to accurately assess human exposure risk in this environment. We performed a detailed geospatial and epidemiological risk mapping of pathogen co-circulation in BNP. A total of 587 hard ticks were collected across 26 georeferenced micro-locations (2020–2022). Ticks were morphologically identified and subsequently screened for six key zoonotic bacterial pathogens using qPCR. The Minimal Infection Rate (MIR) and a Co-infection Rate (CR) were calculated. Geographic Information System (GIS) mapping was utilized to map ecological determinants of risk. Ixodes ricinus was the overwhelmingly dominant vector (94.0%), peaking in spring, with activity absent in summer. Recorded diverse tick fauna also included Hyalomma marginatum (3%), Haemaphysalis punctata (2%), Ixodes frontalis (0.8%) and Rhipicephalus sanguineus (0.2%). Active circulation of Borrelia burgdorferi s.l. (Bbsl), Anaplasma phagocytophilum, and Ehrlichia canis were confirmed. Bbsl presented the highest MIR (3.05). The Co-infection Rate (CR) was notably high at 29.41%, with triple co-infections (Bbsl, A. phagocytophilum, E. canis) concentrated in cultivated mosaics and holm oak forests (Quercus ilex L.). The highest number of ticks was recovered from ecotone zones, accounting for 50.0% of the total catch, confirming them as high-risk interfaces. The absence of Rickettsia conorii may be attributed to the strict control/absence of its primary host (domestic dogs). The presence of the exotic vector H. marginatum was also confirmed. The high rate of co-infection and the spatial concentration of risk in specific habitats underscore an elevated and complex public health risk in BNP, closely linked to habitat structure and increased game host density. This research provides an essential geospatial framework for targeted ‘One Health’ management, prioritizing vector control in ecotone zones and dense forest refugia. Urgent surveillance for the exotic H. marginatum is warranted to monitor the potential risk of Crimean-Congo Hemorrhagic Fever.

Canine ehrlichiosis in Northern Australia: A sensitivity and elasticity analysis of R0.

Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has recently emerged as a promising method for arthropods identification. A total of 125 ticks collected from 2013 until 2023 in Italy either stored frozen at -20 °C (n = 75) or preserved in 70% ethanol (n = 50) were identified using morphological keys before being analyzed by MALDI-TOF MS and, when necessary, by molecular biology in Marseille, France. Of the 125 samples analyzed by MALDI-TOF MS, 106 (84.8%) yielded good quality MS spectra (i.e., intensity>3000 arbitrary units with low background noise). The spectra of 21 specimens from eight tick species, including Dermacentor marginatus, Haemaphysalis parva, Haemaphysalis punctata, Ixodes hexagonus, Ixodes ricinus, Rhipicephalus pusillus, Rhipicephalus sanguineus s.s., and Rhipicephalus turanicus whose morphological identities were confirmed by molecular methods, were used to update an in-house MALDI-TOF MS arthropod spectra database. Blind testing of the remaining 85 good quality spectra against the updated database produced the log score values (LSVs) ranging from 1.56 to 2.57. Overall, identification by MALDI-TOF MS matched morphological identification for 59/85 (69.4%) spectra, whereas 26/85 (30.6%) spectra were discordant with morphological identification. Molecular identification using 16S rRNA gene sequencing was available for 17/26 discordant samples, and 16/17 (94.1%) supported the MALDI-TOF MS result. Considering only samples confirmed by both MALDI-TOF MS and molecular methods, 71/72 (98.6%) were correctly identified by MALDI-TOF MS, with 68/72 (94.4%) showing LSVs > 1.8, a value previously reported as relevant for arthropod identification. This study confirms the effectiveness of MALDI-TOF MS for tick identification and highlights its potential as a new tool for tick identification in Italy.

BackgroundFleas and ticks can be found globally and are of both veterinary and human health concern due to their ability to transmit various vector-borne diseases. Heavy flea and tick infestations can result in significant blood loss, while flea infestations can result in intense pruritus. The use of safe and effective ectoparasiticides in veterinary medicine is a crucial part of protecting both pets and humans from infestations and transmission of vector-borne diseases.MethodsThe efficacy of a novel endectocide, Credelio Quattro, containing lotilaner, moxidectin, praziquantel, and pyrantel, was evaluated in four masked studies: one against Ctenocephalides felis and three against the dose-limiting tick Rhipicephalus sanguineus. Dogs were orally administered placebo, Credelio Quattro™, lotilaner only (Credelio™, Study 2), or pyrantel only (Study 2) in a fed state on Day 0. Experimental infestations with C. felis were conducted on Days −1, 6, 13, 20, 29, and 35 with 100 adult fleas. Fleas were removed and categorized as either live or dead 24 h post-treatment and 24 h post-infestation thereafter. Experimental infestations with R. sanguineus were conducted on Days −2, 5, 12, 19, and 30 with 50 adult ticks. Ticks were removed and categorized as attached or unattached and then live or dead 48 h post-treatment and 48 h post-infestation thereafter.ResultsCredelio Quattro demonstrated 100% (P < 0.0001) efficacy against C. felis, with no live fleas recovered at time points evaluated through 36 days post-treatment. Additionally, Credelio Quattro demonstrated 97.1–100% (P < 0.0001) efficacy through Day 30 against the established dose-limiting tick species, R. sanguineus. In Study 2, pyrantel demonstrated ≤ 46.6% (P ≥ 0.0601) efficacy while lotilaner provided ≥ 99.6% (P ≤ 0.0007) efficacy, confirming lotilaner as the acaricidal active ingredient in Credelio Quattro. Adverse events were reported in both treatment groups, including dermatitis, alopecia, lameness, and a chest wound. One dog in a Credelio Quattro treatment group experienced vomiting and bloody diarrhea that was considered possibly treatment-related.ConclusionsThese studies confirm the safety and effectiveness of a single dose of Credelio Quattro for the treatment and control of C. felis and R. sanguineus infestations on dogs for 1 month.Graphical Supplementary InformationThe online version contains supplementary material available at 10.1186/s13071-026-07405-1.