ArticleParasites & vectors2013
Genetic characterization of Theileria equi infecting horses in North America: evidence for a limited source of U.S. introductions.
Article in Parasites & vectors, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 20 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
20 citing papers in PubMed, 70 citations in OpenAlex.
- Equine piroplasmosis: an emerging tick-borne threat to equine health.Tropical animal health and production · 2026Review
- Molecular Prevalence and Genotypic Diversity ofVeterinary sciences · 2025Article
- First detection of Babesia spp. in Amblyomma mixtum from Veracruz, Mexico.Tropical animal health and production · 2025Article
- Molecular Diagnosis and Identification of Equine Piroplasms: Challenges and Insights from a Study in Northern Italy.Animals : an open access journal from MDPI · 2025Article
- The first study of the prevalence and genetic diversity of Theileria equi and Babesia caballi in horses in Russia.Parasitology research · 2024Article
- Revisiting the genotypes ofFrontiers in veterinary science · 2024Article
- New insights in the diagnosis and treatment of equine piroplasmosis: pitfalls, idiosyncrasies, and myths.Frontiers in veterinary science · 2024Review
- Survey of tick-borne pathogens in grazing horses in Kyrgyzstan: phylogenetic analysis, genetic diversity, and prevalence ofFrontiers in veterinary science · 2024Article
- Complete Genome Sequence of Theileria equi NVSL354.Microbiology resource announcements · 2023Article
- The Piroplasmida Babesia, Cytauxzoon, and Theileria in farm and companion animals: species compilation, molecular phylogeny, and evolutionary insights.Parasitology research · 2022Review
- Theileria equi claudin like apicomplexan microneme protein contains neutralization-sensitive epitopes and interacts with components of the equine erythrocyte membrane skeleton.Scientific reports · 2021Article
- Twenty Years of Equine Piroplasmosis Research: Global Distribution, Molecular Diagnosis, and Phylogeny.Pathogens (Basel, Switzerland) · 2020Review
- Molecular detection of Theileria species and Babesia caballi from horses in Nigeria.Parasitology research · 2020Article
- Ticks and Tick-Borne Diseases in Cuba, Half a Century of Scientific Research.Pathogens (Basel, Switzerland) · 2020Review
- Parasite load and genotype are associated with clinical outcome of piroplasm-infected equines in Israel.Parasites & vectors · 2020Article
- A Review on Equine Piroplasmosis: Epidemiology, Vector Ecology, Risk Factors, Host Immunity, Diagnosis and Control.International journal of environmental research and public health · 2019Review
- Phylogenetic analysis of Theileria equi and Babesia caballi sequences from thoroughbred mares and foals in Trinidad.Parasitology research · 2019Article
- First molecular evidence of Babesia caballi and Theileria equi infections in horses in Cuba.Parasitology research · 2018Article
- Piroplasmosis in an endemic area: analysis of the risk factors and their implications in the control of Theileriosis and Babesiosis in horses.Parasitology research · 2015Article
- Amblyomma cajennense is an intrastadial biological vector of Theileria equi.Parasites & vectors · 2013Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundTheileria equi is a tick-borne apicomplexan hemoparasite that causes equine piroplasmosis. This parasite has a worldwide distribution but the United States was considered to be free of this disease until recently.
methodsWe used samples from 37 horses to determine genetic relationships among North American T. equi using the 18S rRNA gene and microsatellites. We developed a DNA fingerprinting panel of 18 microsatellite markers using the first complete genome sequence of T. equi.
resultsA maximum parsimony analysis of 18S rRNA sequences grouped the samples into two major clades. The first clade (n = 36) revealed a high degree of nucleotide similarity in U.S. T. equi, with just 0-2 single nucleotide polymorphisms (SNPs) among samples. The remaining sample fell into a second clade that was genetically divergent (48 SNPs) from the other U.S. samples. This sample was collected at the Texas border, but may have originated in Mexico. We genotyped T. equi from the U.S. using microsatellite markers and found a moderate amount of genetic diversity (2-8 alleles per locus). The field samples were mostly from a 2009 Texas outbreak (n = 22) although samples from five other states were also included in this study. Using Weir and Cockerham's FST estimator (θ) we found strong population differentiation of the Texas and Georgia subpopulations (θ = 0.414), which was supported by a neighbor-joining tree created with predominant single haplotypes. Single-clone infections were found in 27 of the 37 samples (73%), allowing us to identify 15 unique genotypes.
conclusionsThe placement of most T. equi into one monophyletic clade by 18S is suggestive of a limited source of introduction into the U.S. When applied to a broader cross section of worldwide samples, these molecular tools should improve source tracking of T. equi outbreaks and may help prevent the spread of this tick-borne parasite.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.