Herd-level occurrence and spread of Theileria equi and its associated ticks on an Austrian horse farm.

Equine piroplasmosis (EP) is a protozoan disease in horses, mainly caused by Theileria equi, and is associated with non-specific signs such as fever, anemia, and edema. The lack of specific clinical signs, coupled with the high prevalence of carrier horses, highlights the critical need for a rapid and highly accurate diagnostic test for the detection of Theileria equi. Existing methods, including molecular, serological, and microscopic techniques, require specialized equipment, skilled personnel, and considerable time. The current study aims to develop a rapid and accurate assay for the detection of Theileria equi in horses by using pre-labeled DNA in combination with recombinase polymerase amplification (RPA) and a lateral flow device (LFD). The proposed assay was evaluated in terms of time efficiency, sensitivity and specificity. Of the 30 samples tested, 23 were positive for Theileria equi, with no false positives observed. Moreover, the assay demonstrated a detection limit as low as 5 ng per microliter of input DNA, and the entire process from sample preparation to result interpretation was completed within 25 minutes without the need for specialized equipment. The findings demonstrate that the proposed assay exhibits 100% specificity, high sensitivity, and strong potential for clinical application. However, further studies are required to optimize the assay for direct pathogen detection from samples, eliminating the need for DNA extraction.

Circulating microRNA profiles as diagnostic and prognostic biomarkers for acute and carrier Theileria equi infection.

The tropical horse tick, Dermacentor nitens Neumann, 1897, has a wide distribution throughout the Neotropics, and is a vector of protozoan haemoparasites that cause equine piroplasmosis. Despite this, little is known about the genetic diversity of this tick species, particularly in Cuba, where horses are important domestic animals used in agriculture and for transportation. The objective of this study was to assess the magnitude of genetic variation in 115 D. nitens adults (57 females and 58 males) collected from horses in the Cuban province of Mayabeque using sequence data of two mitochondrial genes, cytochrome c oxidase subunit 1 gene (cox1) and NADH dehydrogenase subunit 4 gene (nad4). The results revealed the presence of 7 cox1 haplotypes, 14 nad4 haplotypes, and 23 haplotypes with concatenation of the two genetic markers. However, the results of the rarefaction curve analyses predict the existence of other rare haplotypes in Mayabeque Province. The most common haplotype for each genetic marker was identical to a D. nitens from Brazil, Colombia, Panama, and French Guiana. The star-like haplotype networks, each with a central (ie "ancestral") and most abundant haplotype, combined with the significant negative values for the Tajima's D and Fu's F tests, is consistent with a hypothesis of the introduction of D. nitens on horses from mainland South America (ie a founder effect) followed by demographic expansion. Additional population genetic studies on D.nitens are needed in other countries where this species occurs to examine the phylogeography of this tick species of socioeconomic importance.

Stage-specific expression of immune-related redox metabolism genes in Rhipicephalus (Boophilus) microplus following Theileria equi infection.

Theileria equi sensu lato genetic diversity and phylogeny: new insights from mitochondrion, apicoplast and nucleus multilocus gene analysis.

Comprehensive molecular characterization of Theileria equi: Detection, genetic diversity, and risk factors assessment.

Anti-Theileria equi activity of methanolic extract of Artemisia scoparia: In vitro efficacy, in vivo safety, and identification of lead molecules.

In vitro cultivation of Babesia caballi genotype B2 and its genetic, growth, and morphological characterization.

Equine piroplasmosis, caused by Theileria equi, T. haneyi and Babesia caballi, significantly impacts on the veterinary and economic aspects of the global horse industry. However, many countries, including Vietnam, have not yet conducted epidemiological surveys to determine the prevalence of these haemoparasites. This study aimed to detect T. equi and/or B. caballi infections in horses and to identify their genotypes. Blood samples were collected from 154 apparently healthy horses in eight districts of Hanoi, Thai Nguyen, and Son La provinces located in the northern part of the country. Twenty-four horses (15.58%, 95%CI: 10.70–22.14%) were found to be infected with T. equi across six districts. Babesia caballi was not detected. No significant association was found between gender, host age, and the number of infected horses. Phylogenetic analysis of the 18S rRNA sequences from the positive DNA samples revealed genotypes A, C, and E. These results confirm the presence of equine theileriosis in northern Vietnam, highlighting the need for nationwide studies of equine piroplasmosis involving larger sample sizes.

BackgroundEquine piroplasmosis (EP) is a tick-borne disease of equids caused by the intraerythrocytic apicomplexan parasites Theileria equi, Babesia caballi and the recently identified Theileria haneyi. Acute cases can be severe, with anemia, jaundice, abortion or sudden death. Survivors remain lifelong carriers, serving as reservoirs for tick-borne and iatrogenic transmission. No vaccines are currently available, and control strategies rely heavily on accurate diagnostics and chemotherapeutic intervention. Imidocarb dipropionate (ID) is the current standard of care for both acute treatment and radical cure. However, growing concerns regarding ID-resistant parasite strains and its associated toxicity have highlighted the urgent need for novel, safer and more effective antiparasitic agents. Here, we assessed the in vitro efficacy of tafenoquine succinate (TFQ), a synthetic 8-aminoquinoline with broad antiparasitic activity, against T. equi and B. caballi as a potential treatment for equine piroplasmosis.MethodsThe effect of TFQ on T. equi and B. caballi was evaluated in vitro in parasite cultures. The percentage of parasitized erythrocytes was measured by flow cytometry, and the effect of TFQ on parasite growth was compared to that of ID. TFQ toxicity on horse peripheral blood mononuclear cells (PBMCs) was assessed via a colorimetric metabolic assay.ResultsTFQ reduced T. equi parasitemia in a dose-dependent manner, matching ID efficacy at 72 h. For B. caballi, TFQ had no effect at 5–10 µM but inhibited growth at 15 µM, similar to the results obtained with ID. TFQ exhibited approximately threefold greater potency against T. equi [half-maximal inhibitory concentration [IC50] 5.90 μM, 95% confidence interval (CI) 4.99–5.96; 99% inhibitory concentration (IC99) 60.74 μM, 95% CI 37.41–113.3] compared to B. caballi [IC50 14.5 μM, 95% CI 13.81–15.23; IC99 20.44 μM, 95% CI 17.77–28.84]. The narrower confidence intervals for T. equi suggest a more consistent antiparasitic response across replicates. Cytotoxicity assays showed no toxic effects on equine PBMCs at 2.5–5 μM (P > 0.05), while concentrations ≥ 10 μM indicated potential toxicity. These findings suggest that TFQ selectively targets parasites over host cells, supporting its therapeutic potential.ConclusionsTFQ significantly inhibited T. equi and B. caballi growth at doses tolerated by equine PBMCs, supporting its potential as an alternative treatment for EP and warranting further in vivo study.

The forest fly (Hippobosca equina) is an obligate haematophagous dipteran insect (order Diptera) that primarily infests horses and may contribute to the circulation of vector-borne pathogens. This study aimed to investigate the presence of Anaplasma phagocytophilum, Borrelia burgdorferi s.l., Babesia caballi, and Theileria equi, important vector-borne pathogens of equids, in forest flies collected from horses in endemic areas of Spain. A total of 170 forest flies were collected from 39 equids across four geographical regions in Spain (Segovia, Madrid, Toledo, and Menorca) and blood samples were collected from 27 of these horses. All flies were morphologically and molecularly identified as H. equina, and DNA extracted from flies and equine blood was screened using multiplex real-time and nested PCR, followed by sequencing and phylogenetic analysis. Neither flies nor horses tested positive for A. phagocytophilum, whereas one fly was positive for B. burgdorferi s.l. (0.6%). In contrast, T. equi and B. caballi DNA were detected in 11.2% and 1.2% of flies, respectively, and all positive flies were collected from horses positive for equine piroplasmosis (T. equi/B. caballi infection), with identical 18S rRNA sequences between hosts and flies. Nested PCR showed a higher detection rate than real-time PCR for the detection of these piroplasms in flies and blood samples. These findings provide the first molecular evidence of EP pathogens in H. equina and support further investigation into the epidemiological importance of forest flies in equine pathogen surveillance.

Equine piroplasmosis: an emerging tick-borne threat to equine health.

Background: Equine piroplasmosis (EP), caused by Babesia caballi and Theileria equi, is a prevalent tick-borne hemoprotozoan disease worldwide. In Iran, the disease is endemic and often manifests in subclinical form. To control the disease by detecting carrier horses, real-time polymerase chain reaction (PCR) is a suitable method. Objectives: We aimed to detect B. caballi and T. equi in horses in Ardabil Province, Iran, using SYBR Green I real-time PCR. Methods: This study was conducted from April to August 2015 in 5 cities (Ardabil, Nir, Namin, Sareyn, and Meshginshahr) in Ardabil Province, Iran. Blood samples were randomly collected from 92 healthy horses, noting their age, gender, and sampling location. Genomic DNA was extracted from each sample and assessed, followed by SYBR green I real-time PCR. Data analysis was conducted using Rotor-Gene Q Series software to calculate the target DNA concentration based on the unknown sample’s cycle threshold (Ct) value. Positive values were defined as exceeding 1 ng/reaction. The relationship between horse infection rate and different age groups (1-5, 6-10, and >10 years), gender, and sampling locations was investigated using a chi-square test through SPSS statistical software. P<0.05 were considered significant. Results: In this study, the frequency of B. caballi-infected horses was 9(9.8%), and that of T. equi-infected horses was 4(4.4%). A significant relationship was observed between the B. caballi infection and the age group of 5-10 years. However, there was no significant relationship between the B. caballi infection and gender or sampling locations. Furthermore, no significant relationship was observed between the T. equi infection and the age groups, gender, and sampling locations of the horses. Conclusion: The infection found in apparently healthy horses suggests endemic EP in this region. Therefore, greater focus is needed on controlling and treating carrier horses.

Babesia caballi and Theileria equi in ticks from horses in four Indigenous communities of Costa Rica.

Equine piroplasmosis (EP) is a globally distributed tick-borne haemoprotozoan disease of equids caused primarily by Theileria equi and Babesia caballi. The infection spectrum ranges from subclinical carrier states to severe, life-threatening hemolytic anemia. EP poses veterinary, economic and trade challenges due to chronic carrier status, diagnostic complexities, and limitations of current therapeutics and control strategies. This review synthesizes current knowledge on taxonomy and etiology, life cycle and vectors, epidemiology and risk factors, pathogenesis and clinical manifestations, laboratory diagnosis (microscopy, serology, molecular methods), treatment and chemotherapeutic limitations, prevention and control strategies, and gaps and priorities for research and policy.

An insight into the ovary and midgut transcriptome of Dermacentor nitens tick.

Genetic diversity of equine piroplasmosis agents in Guadeloupe (Caribbeans): first report of Theileria haneyi, evaluation of diagnostic tools and impact of horse movement.

Equine piroplasmosis (EP), caused by the intracellular protozoa Theileria equi, Babesia caballi, and Theileria haneyi, represents a major health and economic threat to the equine industry worldwide. Existing diagnostic methods, including PCR, serology, and microscopy, are constrained by their dependence on specialized equipment, lengthy protocols, and the requirement for skilled personnel. This study aimed to develop a rapid, accurate, and field-deployable molecular diagnostic assay for T. equi. A nucleic acid-based diagnostic platform combining recombinase polymerase amplification (RPA) with CRISPR/Cas13-mediated detection and lateral flow device (LFD) readout was developed. The assay targets a conserved region of the erythrocyte merozoite antigen 1 (EMA-1) gene of T. equi. Validation was performed using 22 blood samples collected from horses, as well as specificity controls including B. caballi- and Anaplasma phagocytophilum-infected samples, synthetic EMA-1 DNA, and non-template controls. All assay steps were conducted at room temperature. The integrated RPA-CRISPR/Cas13-LFD assay generated clear visual results within 50 minutes. It demonstrated complete specificity with no false positives across all tested samples. The method effectively differentiated horses infected with T. equi, including both clinically affected and asymptomatic individuals, from healthy, uninfected animals, confirming its high accuracy and reliability. The developed assay provides a rapid, precise, and equipment-free diagnostic platform suitable for both field and clinical environments. Although the current protocol relies on DNA extraction, future optimization will aim to enable direct detection from unprocessed blood samples, thereby further simplifying point-of-care diagnostics for equine piroplasmosis.

Background: About ninety percent of the world's horse population, according to the UN Food and Agricultural Organization, live in regions where Equine piroplasmosis is endemic.Horses, mules, and donkeys across the world are susceptible to the economically significant tickborne illness, which can produce moderate subclinical to severe acute clinical symptoms.Horses are kept for transportation, sports, and meat production in the multibillion dollar horse business.Chronic carriers include horses that are asymptomatic and those who have recovered from clinical disease.Because chronically infected carriers may act as a cause of infection that might result in the spread of disease to uninfected animals, surveillance of these carriers is crucial. Aims:In the middle Euphrates area of Iraq, the study aimed to assess the effectiveness of real-time PCR as a quick detection test for Theileria equi infections and to determine the frequency and risk variables (ages, sexes, and study seasons) for the infection in equids (horses, mules, and donkeys). Materials and Methods: A total of 85 blood samples are collected from each equids family, comprising of 50 horses, 15 mules and 20 donkeys in different sexes(84 females and 37 males), ages ( 1-5 years to 10 years) and different regions of middle Euphrates, Iraq during period from beginning of December