Tick fever incidence in mid-eastern Mexico (Vericruz)

With increased surveillance of traveling horses and better detection methods, the US experience with episodes of tick fever (Theileria equi), has become rarer. Not considered a disease of the US or Canada but endemic in Mexico APHIS now reports that the majority of cases arising in the US are due to contaminated medical apparatuses or products.
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Molecular detection of Theileria equi in horses from Veracruz, Mexico
Ticks Tick Borne Dis. 2021 Jan 27;12(3):101671.

Authors
Dora Romero-Salas 1 , Marlene Solis-Cortés 2 , Héctor M Zazueta-Islas 2 , Fernanda Flores-Vásquez 2 , Anabel Cruz-Romero 1 , Mariel Aguilar-Domínguez 1 , José Luis Salguero-Romero 1 , Adalberto Pérez de León 3 , Edith A Fernández-Figueroa 4 , Miguel Ángel Lammoglia-Villagómez 5 , Ingeborg Becker 2 , Sokani Sánchez-Montes 6
Affiliations

1 Laboratorio de Parasitología, Posta Zootécnica Torreón del Molino, Facultad de Medicina Veterinaria y Zootecnia, Universidad Veracruzana, Veracruz, Mexico.
2 Centro de Medicina Tropical, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.
3 USDA, San Joaquin Valley Agricultural Sciences Center, CA, United States.
4 Centro de Medicina Tropical, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico; Computational and Integrative Genomics, Instituto Nacional de Medicina Genómica, Ciudad de México, Mexico.
5 Facultad de Ciencias Biológicas y Agropecuarias, Universidad Veracruzana, Veracruz, Mexico.
6 Centro de Medicina Tropical, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico; Facultad de Ciencias Biológicas y Agropecuarias, Universidad Veracruzana, Veracruz, Mexico. Electronic address: sok10108@gmail.com.

PMID: 33545504
DOI: 10.1016/j.ttbdis.2021.101671

Abstract

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.