Search Results (302)

The objective of this study was to evaluate essential oils (EOs) as an alternative control method for Rhipicephalus microplus and Amblyomma mixtum larvae. The EOs used were obtained by steam distillation from the leaves of cinnamon (Cinnamomum verum), mexican mint (Plectranthus amboinicus), lemongrass (Cymbopogon citratus), peppercorns (Pimenta dioica), and peruvian pepper tree (Schinus molle). To evaluate the acaricidal effect of EOs against the larvae of two tick species, a larval immersion test (LIT) was performed using six concentrations (10 mg/mL, 5 mg/mL, 2.5 mg/mL, 1.87 mg/mL, 1.25 mg/mL, and 0.6 mg/mL), in addition to a negative control group (water + ethanol) and three positive controls (organophosphate, formamidine, and pyrethroid). LIT results were obtained 48 h after exposure. Data were processed using Probit procedure to determine the lethal concentrations at 50% (LC₅₀), 95% (LC₉₅), and 99% (LC₉₉). For R. microplus, 99% mortality was obtained at concentrations as low as 1.4 mg/mL for S. molle, while the highest LC₉₉ was recorded with P. dioica at 23 mg/mL. In the case of A. mixtum, higher concentrations were required to achieve a high mortality rate. EO of P. amboinicus had the lowest acaricidal effect, requiring 26.2 mg/mL to achieve an LC₉₉, while S. molle required a concentration of 6.9 mg/mL to achieve an LC₉₉. Full article

Ticks are vectors of pathogens affecting wildlife, livestock, and humans. Knowledge of their abundance, species composition, and ecological drivers is essential for an understanding of tick-borne disease ecology. In this study, four natural sites in Sicily (southern Italy) were selected, and 39 sampling events from April 2024 to August 2025 yielded 1200 ticks: 407 larvae, 474 nymphs, and 319 adults. Five genera were identified (Dermacentor, Haemaphysalis, Rhipicephalus, Ixodes, and Hyalomma); Rhipicephalus bursa was the most abundant species, followed by Haemaphysalis punctata. Most ticks were collected in spring–summer, except at one site where abundance peaked in autumn–winter. A significant association was found between site and season (p < 0.0001), but tick abundance per sampling event did not differ among sites (p = 0.431) or seasons (p = 0.769). No significant correlations emerged between tick abundance and environmental variants. However, significant associations were detected between site and sex (p < 0.0001), site and developmental stage (p < 0.0001), and species and developmental stage (p < 0.0001). Sites exclusively hosting wild boar showed higher species richness. These findings underscore the ecological complexity of tick populations in Mediterranean protected areas and provide baseline data useful for integrated tick surveillance and wildlife health management. Full article

Tick-borne protozoa (TBP), including Babesia spp. and Theileria spp., cause substantial health and productivity losses in cattle. In Thailand, most epidemiological studies have focused on dairy herds, while beef cattle remain underinvestigated. This study assessed TBP infections in beef cattle and their ticks at the Thai–Myanmar border. Blood samples were collected from 158 beef cattle, including local animals from Thong Pha Phum and Sangkhlaburi districts and cross-border cattle imported from Myanmar. Engorged ticks, predominantly Rhipicephalus microplus, were removed and identified morphologically. DNA was extracted from blood and tick samples, and PCR assays were performed to detect Babesia and Theileria species. Overall, 51.3% of cattle were positive for Babesia or Theileria DNA. Babesia bigemina (10.8%) and Babesia bovis (8.2%) were the most frequently detected species. Infection prevalence was higher in local cattle from Thong Pha Phum (56.0%) and Sangkhlaburi (54.6%) than in cross-border cattle (39.5%). In contrast, ticks collected from cross-border cattle showed a significantly higher prevalence of TBP DNA (40.0%) compared with ticks from Thong Pha Phum (12.8%) and Sangkhlaburi (8.7%). These findings provide important epidemiological evidence of TBP circulation at the Thai–Myanmar border and highlight the influence of cattle movement and tick exposure on pathogen distribution and spread in this region. Full article

Rhipicephalus microplus infestations are a major concern for cattle production in neotropical regions. Anti-tick vaccines represent a sustainable alternative to chemical acaricides; however, improving vaccine efficacy remains challenging. This study evaluated the protective efficacy of polypeptide-based formulations of pBm86 and pSubolesin administered as co-immunization or as a cocktail in naturally infested cattle. Twelve calves were assigned to three groups: G1: 100 μg pBm86 + 50 μg pSubolesin co-immunized; G2: same formulation in cocktail; and G3: control. The cocktail significantly reduced adult female tick numbers, oviposition, and larvae hatching (p < 0.05), achieving a vaccine efficacy of 75%. In contrast, co-immunization achieved 50% efficacy. Vaccinated cattle developed significantly increased antigen-specific IgG levels against Subolesin than Bm86. IgG antibodies recognized native tick proteins by Western blot, and their efficacy was confirmed in vitro using blood-feeding assays. These results indicate that the cocktail formulation showed improved efficacy compared with co-immunization in this study, possibly by affecting complementary biological processes in ticks. Finally, this study supports the development of multi-antigen, polypeptide-based vaccines as a promising and sustainable approach for the control of R. microplus under natural field conditions. Full article

Ehrlichioses and anaplasmosis are among the most commonly reported tick-borne diseases in humans and some animal species. Ehrlichia canis is the causative agent of canine monocytic ehrlichiosis; it primarily affects dogs and is usually transmitted by Rhipicephalus sanguineus ticks. Some reports suggest that this bacterium is a zoonotic pathogen capable of causing clinical symptoms consistent with human monocytotropic ehrlichiosis caused by Ehrlichia chaffeensis. Non-human primates seem to be susceptible to E. canis-infection, although it is not clear whether the bacterium can cause disease in these mammals. The number of cases of E. canis infections in human beings and other primates could be underestimated, mainly because inappropriate laboratory diagnoses are often carried out. Serological tests do not distinguish infection by E. canis from those due to other ehrlichial species; therefore, a correct diagnosis is possible only through molecular methods. Furthermore, E. canis is not usually recognized by veterinarians and clinicians as a possible pathogen of primates, and it is not included in the panel of tick-borne pathogens routinely investigated. Further studies are pivotal to verify the pathogenicity of E. canis in primates, and epidemiological investigations are needed to monitor its spread in animal and tick species not usually associated with this agent. Full article

This study was conducted to investigate tick species that may harbour severe fever with thrombocytopenia syndrome virus (SFTSV) and Babesia microti in the provinces of Henan, Anhui, and Zhejiang, as well as in Shanghai in the central and eastern parts of China. Between March and September 2023, 721 pools of ticks were collected belonging to three genera and five species: Haemaphysalis longicornis (n = 612; 84.9%), Haemaphysalis fusca (n = 94; 13.0%), Rhipicephalus microplus (n = 10; 1.4%), Amblyomma testudinarium (n = 3; 0.4%), and Haemaphysalis wellingtoni (n = 2; 0.3%). The SFTSV-positive pool rate was 20.0%, 13.0%, 5.8%, and 4.1% in Xinyang, Henan; Songjiang, Shanghai; Lu’an, Anhui; and Zhoushan, Zhejiang, respectively. SFTSV was detected in all five tick species collected. Among the SFTSV-positive pools, H. longicornis constituted the highest proportion (83.9%, 78/93), whereas pools containing R. microplus and H. wellingtoni each represented the lowest proportion (1.1%, 1/93). Babesia microti was assayed only in these SFTSV-positive tick pools, and co-infection was found in both H. longicornis and H. wellingtoni, though it was most frequent in H. longicornis. Full article

Ticks are one of the most important vectors of zoonotic pathogens in Europe, including Rickettsia spp. In Romania, several pathogenic species belonging to the Spotted Fever Group (SFG) transmitted primarily through tick bites have been identified. The aim of the present study was to determine the prevalence of Rickettsia spp. infection in ticks collected from public shelter dogs in Tulcea County, Romania, as an indicator of pathogen circulation within shelter environments and their potential epidemiological relevance. A total of 730 ticks collected between March 2023 and September 2024 from 216 public shelter dogs, belonging to four species (Rhipicephalus sanguineus s.l., Ixodes ricinus, Dermacentor marginatus, and Dermacentor reticulatus), were morphologically identified and pooled by species, sex, and developmental stage resulting in 132 pools. DNA extracted from pools was tested by Real-Time PCR, targeting the gltA gene, specific for Rickettsia spp. Overall, 123/132 (93.2%) pools tested positive for Rickettsia spp. DNA, while the Minimum Infection Rate (MIR) at tick level was 16.8%. High pool positivity rates were consistently observed across all four species: 93.6% positive pools for Rhipicephalus sanguineus s.l. (MIR 15%), 88.2% for Ixodes ricinus (MIR 20.5%), 87.5% for Dermacentor marginatus (MIR 58.3%), and 100% for Dermacentor reticulatus (MIR 21.7%). These findings demonstrate a substantial circulation of Rickettsia spp. in dog-shelter associated ticks, highlighting the role of dogs as sentinel hosts. Continuous molecular surveillance and identifying circulating species is needed for a better determination of the zoonotic risk. Full article

Babesia ovis is a significant tick-borne parasite of sheep, capable of causing both acute disease and long-lasting, low-grade infections. Imidocarb dipropionate (IMDP) is commonly used against babesiosis, yet whether it can completely eliminate B. ovis remains uncertain. In this study, we examined whether the parasite persists after treatment and whether such residual infections can still be transmitted. Three sheep were experimentally infected, treated with IMDP once clinical signs appeared, and then monitored for 180 days by microscopy, nested PCR, and iELISA. Fever and microscopic parasitemia resolved soon after treatment, but nPCR intermittently detected parasite DNA for several weeks. By day 180, all treated sheep were negative by nPCR and microscopy, while two still showed detectable antibodies. Blood collected at this time was transfused into naïve sheep. Two of the three recipients showed nPCR positivity at scattered time points and later seroconverted while showing no clinical signs. In contrast, Rhipicephalus bursa ticks that fed on the treated donors neither acquired the parasite nor transmitted it to recipients, likely because post-treatment parasitemia remained below the acquisition threshold. Overall, these results indicate that IMDP controls clinical disease but may not fully clear B. ovis, allowing silent transmission through blood despite negative routine tests. Full article

Jingmen tick virus (JMTV) is a novel flavi-like virus first identified in 2010 in Rhipicephalus microplus in the Jingmen region of Hubei Province, China and has been reported in different Asian countries, Central and South America, Africa, and Europe. Beyond ticks, JMTV has been detected in a range of other arthropods and in vertebrate hosts. In humans, JMTV has been found in patients with Crimean-Congo hemorrhagic fever in Kosovo and Turkey, and in febrile patients with a history of tick bites in China, suggesting it may be a novel human pathogen. To investigate the presence of JMTV in Italy, we developed a One-step real-time RT-PCR assay and applied it to individually screen 1150 ticks collected from northeastern, central, and southern Italy. JMTV RNA was detected in multiple tick species, including Ixodes ricinus, Rhipicephalus bursa, Rhipicephalus sanguineus s.l., Dermacentor marginatus, and Hyalomma marginatum with a prevalence ranging from 0.52% to 18.42% in questing ticks. The detection of JMTV in ticks from all surveyed areas, indicates that the virus is geographically widespread in Italy. These findings highlight the need for comprehensive surveillance strategies to identify new areas of active virus circulation and to investigate the potential impact of JMTV on public health. Full article

Tick-borne diseases (TBD) pose a significant threat to both animal and public health, particularly in tropical regions. In the Colombian Caribbean region, there is limited knowledge of the epidemiology of TBD in domestic animals and their vectors. In this study, conducted in northern Colombia from 2021 to 2022, we analyzed the molecular diversity of Anaplasmataceae in a total of 1156 ticks and blood samples collected from their infested hosts: 56 cattle and 17 equids (horses and mules). Polymerase chain reaction (PCR) assays were performed, using primers to amplify the mitochondrial 16S rRNA gene for tick identification and bacterial 16S and 23S rRNA to detect Anaplasmataceae. The amplified products were sequenced and analyzed for molecular characterization of species. Four tick species were identified: Dermacentor nitens (55.6%), Rhipicephalus microplus (43.0%), Rhipicephalus sanguineus sensu lato (0.7%), and Amblyomma patinoi (0.7%). Overall, 9.4% of the pooled tick samples were identified as R. microplus, and 64.4% of the blood samples tested positive for Anaplasmataceae. Molecular analyses identified Anaplasma marginale in cattle and several species in ticks, including an Anaplasma sp. closely related to A. platys-like, Ehrlichia ruminantium, and E. muris and Ehrlichia variants closely related to Candidatus E. rustica, E. canis, and E. minasensis. The results indicate high infection rates and the circulation of both well-known and potentially novel Anaplasmataceae species, suggesting complex transmission dynamics among ticks and hosts. Full article

Tick-borne pathogens (TBPs) pose a significant threat to canine health in Nigeria. Despite this, there is little data on the molecular identification of ticks and TBPs of dogs in Nigeria. This study assessed the prevalence of ticks and TBPs in Nigerian dogs, along with associated risk factors. A total of 259 dogs were enrolled in the study, from which 112 adult ticks were collected. Of these, 40 were characterized by molecular barcoding confirming Rhipicephalus sanguineus (R. sanguineus, 35/40) and Haemphysalis leachi (H. leachi, 5/40) infestations. Nucleotide sequences showed high percentage similarity to R. sanguineus tropical lineage and H. leachi sequences from Chad. Point-of-care (POC) testing of 259 dogs detected antibodies to TBPs in 40.9% of blood samples, with Ehrlichia (29.7%), Anaplasma (10.8%), and Dirofilaria (0.4%) species identified. PCR assays revealed a prevalence of 58.7% for TBPs, including Ehrlichia (40.5%) and Babesia (17.4%), with 7.3% co-infected. Risk factor analysis showed that adult dogs and those infested with ticks had a higher likelihood of TBP seropositivity. Exotic breeds and dogs examined during the rainy season were more likely to test positive for TBPs via PCR. Overall, this study demonstrates the high prevalence of diverse TBPs in Nigerian dogs and suggests that dog breed may play a role in susceptibility to diseases. Full article

Coxiella burnetii (C. burnetii) is a zoonotic pathogen with significant public and veterinary significance. Whilst livestock are considered as primary reservoirs of the pathogen, ticks play a crucial role in transmission and environmental contamination. Within Namibia, there is serological evidence of pathogen circulation in livestock and wildlife. However, no study has ever been conducted to determine the prevalence of C. burnetii in ticks in Namibia. Thus, this study investigated the prevalence and genetic diversity of C. burnetii in ticks collected from two different ecological settings. A total of 502 ticks (Rhipicephalus, Amblyomma, and Hyalomma) collected from 278 cattle (139 from each of the tropical Zambezi and arid Khomas regions) were screened for C. burnetii using PCR targeting the genus-specific 16S rRNA and the species-specific isocitrate dehydrogenase (icd) genes. Based on the isocitrate dehydrogenase (icd) genes, an overall prevalence of 8% (40/502) was observed for C. burnetii, with significantly higher infection rates observed in the more tropical Zambezi region (11.7%) when compared to the more arid Khomas region (2.8%) [p = 0.0005]. Variation was observed amongst tick species [p = 0.00121], with prevalence being slightly higher in Amblyomma ticks (12.9%) and Hyalomma (10.6%) as compared to Rhipicephalus ticks (3.6%). Phylogenetic analysis based on the icd gene sequences confirmed 99–100% identity with C. burnetii strains from around the world, thus confirming the circulation of this pathogen in ticks, ultimately supporting their potential role in the epidemiology of this pathogen in Namibia. The observed regional prevalence difference could be driven by variation in the ecological factors, with the subtropical climatic conditions of Zambezi likely favoring higher tick infection rates. Our findings highlight the need for One Health–based surveillance to mitigate the risks associated with pathogen risk. This study provides the first molecular evidence of C. burnetii in ticks in Namibia, highlighting their role in the pathogen’s epidemiology and providing relevant information for informed control strategies. Full article

We investigated tick infestations in stray dogs from Chișinău, the capital of the Republic of Moldova, focusing on tick species distribution, and pathogen infection rates. Ticks were collected from 232 stray dogs across six major urban parks in 2021–2022. A total of 443 ticks were collected, belonging to five species: Ixodes ricinus (43.8%), Dermacentor reticulatus (35.2%), Dermacentor marginatus (20.5%), Rhipicephalus sanguineus s.l. and Haemaphysalis punctata with only 1 specimen. Notably, 92.5% of ticks were adults, while only 7% were nymphs and <1% were larvae. On average, 44.4% of stray dogs were infested with ticks, with an overall mean intensity of ~4.3 ticks per infested dog. Tick burden varied by location: dogs in large, less-maintained parks carried the most ticks. Tick pathogen screening revealed 24.4% of ticks (108/443) carried at least one pathogen. The most frequently detected were Babesia spp. in 12.2% of ticks, Borrelia burgdorferi s.l. in 7.4%, Rickettsia spp. in 3.4%, Anaplasma spp. in 2.5%, and Ehrlichia spp. in 0.5%; 4 ticks harbored co-infections. We discuss implications for public health and animal welfare and recommend control measures such as integrated stray-dog management and vegetation maintenance in urban parks. Full article

Rhipicephalus microplus, also known as the Asiatic blue tick, is an invasive ectoparasite of significant economic and animal health importance in South Africa. This review synthesises evidence on its ongoing range expansion, which is displacing the native R. decoloratus, driven by factors including climate suitability, livestock movement, and communal grazing practices. The tick’s success is compounded by widespread, multi-class acaricide resistance, which has been documented across all major chemical classes. Molecular diagnostics are crucial for accurate surveillance, and population genetics reveal significant gene flow facilitated by livestock movement. Projections indicate that climate change will further expand the tick’s suitable habitat. Current reliance on chemical control is unsustainable. We conclude that an integrated parasite management (IPM) approach combining strategic acaricide rotation, targeted selective treatments, pasture management, and strict biosecurity is critical for sustainable control. Key recommendations include establishing standardised, national resistance monitoring, validating molecular markers for resistance prediction, and developing farmer-facing decision-support tools. This synthesis provides a framework for research and policy to mitigate the impact of R. microplus at the wildlife-livestock interface in South Africa. Full article

The tick Rhipicephalus sanguineus is the most prevalent ectoparasite in dogs, causing discomfort to the animals and acting as a vector for several pathogens, including the bacterium Ehrlichia canis and the protozoa Babesia canis, Babesia gibsoni, and Hepatozoon canis. Control of this parasite is traditionally carried out with synthetic chemical acaricides. However, due to the increasing number of cases of resistance, phytotherapy has been increasingly investigated as a promising alternative. In this study, the larvicidal activity of the crude ethanolic extract and essential oil obtained from the inflorescences of Achyrocline satureioides was evaluated, whose constituents were identified through phytochemical analyses and gas chromatography. The analyses revealed that the extract is rich in flavonoids, tannins, and saponins, while the essential oil is composed mainly of terpenes. In contact tests with impregnated paper, the extract at 100 mg/mL showed a mortality rate of 32.2% in R. sanguineus larvae with LC₅₀ calculated at 249.62 mg/mL, while the essential oil, at the same concentration, resulted in 56.55% mortality, and the LC₅₀ and LC₉₀ were 119.73 mg/mL and 185.53 mg/mL, respectively. These results indicate that the essential oil of A. satureioides has significant larvicidal activity and has potential for use as an alternative, alone or in combination with other extracts or synthetic acaricides. Full article