Equine infectious anemia (EIA) is a highly infectious disease in members of the Equidae family, caused by equine infectious anemia virus (EIAV). The disease severity ranges from subclinical to acute or chronic, and causes significant economic losses in the equine industry worldwide. Serologic tests for detection of EIAV infection have some concerns given the prolonged seroconversion time. Therefore, molecular methods are needed to improve surveillance programs for this disease. We attempted detection of EIAV in 6 clinical and 42 non-clinical horses in Nuevo Leon State, Mexico, using the agar gel immunodiffusion (AGID) test for antibody detection, and nested and hemi-nested PCR for detection of proviral DNA. We found that 6 of 6, 5 of 6, and 6 of 6 clinical horses were positive by AGID, nested PCR, and hemi-nested PCR, respectively, whereas 0 of 42, 1 of 42, and 9 of 42 non-clinical horses were positive by these tests, respectively. BLAST analysis of the 203-bp 5′-LTR/tat segment of PCR product revealed 83–93% identity with EIAV isolates in GenBank and reference strains from other countries. By phylogenetic analysis, our Mexican samples were grouped in a different clade than other sequences reported worldwide, indicating that the LRT/tat region represents an important target for the detection of non-clinical horses.
Bibliographical noteFunding Information:
This study was supported by a grant from Programa de Apoyo a la Investigación Científica y Tecnológica-UANL 2019 (grant CN-933) to Ricardo Gomez-Flores and by internal research support of Universidad de Sonora grant USO513006999 to Guadalupe González-Ochoa.
We thank Laboratorio de Inmunología y Virología of Facultad de Ciencias Biológicas at Universidad Autónoma de Nuevo León (FCB-UANL) for supporting the development of this study. This study was supported by a grant from Programa de Apoyo a la Investigación Científica y Tecnológica-UANL 2019 (grant CN-933) to Ricardo Gomez-Flores and by internal research support of Universidad de Sonora grant USO513006999 to Guadalupe González-Ochoa.
© 2021 The Author(s).
- asymptomatic infection
- equine infectious anemia virus
- viral disease