Molecular detection of Theileria equi in horses from Veracruz, Mexico

Ticks Tick Borne Dis. 2021 May;12(3):101671. doi: 10.1016/j.ttbdis.2021.101671. Epub 2021 Jan 27.


Equine piroplasmosis is a tropical parasitic disease caused by several intraerythrocytic members of the genera Babesia and Theileria. These pathogens are transmitted by multiple tick species and are considered as important exotic microorganisms in several countries. Equine piroplasmosis causes significant economic losses due to abortions, decreased activity and even death of equines, making surveillance of these infectious disease essential. In the northern and eastern parts of Mexico, few molecular and serological reports have been made on the presence and exposure of horse to these agents. For this reason, the aim of the current work was to perform a molecular detection study of Babesia and Theileria in equines from the state of Veracruz, Mexico. A total of 100 whole blood samples were tested. Chelex-100 resin was used for DNA extraction and a fragment of 459 bp of the 18S rRNA gene of members of the genera Babesia/Theileria were identified. Of the 100 samples analysed, 18 tested positive for Babesia/Theileria, resulting in a prevalence of 18 %. Identity analyses and phylogenetic reconstruction revealed that all samples were infected with Theileria equi. This work represents the first molecular record of Babesia/Theileria in equines from the state of Veracruz, Mexico, and demonstrates the endemicity of T. equi in this region of the country.

Keywords: 18S-rRNA; Equine piroplasmosis; Piroplasmid; Tick-borne pathogen; Vector-borne disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Babesia / isolation & purification*
  • Babesiosis / epidemiology*
  • Babesiosis / parasitology
  • Female
  • Horse Diseases / epidemiology*
  • Horse Diseases / parasitology
  • Horses
  • Male
  • Mexico / epidemiology
  • Phylogeny
  • Prevalence
  • RNA, Protozoan / analysis
  • RNA, Ribosomal, 18S / analysis
  • Theileria / isolation & purification*
  • Theileriasis / epidemiology*
  • Theileriasis / parasitology


  • RNA, Protozoan
  • RNA, Ribosomal, 18S