Molecular Detection and Genetic Characteristics of Equine Herpesvirus in Korea

• Published in: Pathogens (Basel) Vol. 9; no. 2; p. 110
• Main Authors: Seo, Min-Goo, Ouh, In-Ohk, Lee, Sang Kyu, Lee, Jong-Seok, Kwon, Oh-Deog, Kwak, Dongmi
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 11.02.2020; MDPI AG
• Subjects: ehv-1; ehv-2; ehv-5; herpesvirus; horse; phylogeny; horse; EHV-1; phylogeny; EHV-5; EHV-2; herpesvirus
• ISSN: 2076-0817; 2076-0817
• DOI: 10.3390/pathogens9020110

Respiratory diseases cause significant economic losses (especially in the horse racing industry). The present study describes the detection and genetic characteristics of equine herpesvirus (EHV) from a total of 1497 samples from clinically healthy horses in Korea, including 926 blood samples, 187 lung tissues, and 384 nasal swabs. EHV-2 and EHV-5 were detected in 386 (41.7%; 95% CI: 38.5-44.9) and 201 (21.7%; 95% CI: 19.1-24.4) blood samples, respectively, and in 25 (13.4%; 95% CI: 8.5-18.2) and 35 (18.7%; 95% CI: 13.1-24.3) lung tissues, respectively. EHV-1 and EHV-4 were not detected in either blood or lung tissues. EHV-1, EHV-2, and EHV-5 were detected in 46 (12.0%; 95% CI: 8.7-15.2), 21 (5.5%; 95% CI: 3.2-7.7), and 43 (11.2%; 95% CI: 8.0-14.4) nasal swabs, respectively. EHV-4 was not detected in nasal swabs. Co-infection with EHV-2 and EHV-5 was detected in 11.6% (107/926) of the blood samples and 6.4% (12/187) of lung tissues. In nasal swabs, co-infection with EHV-1, EHV-2, and EHV-5 was detected in 0.8% (3/384) of samples. Phylogenetic analysis of the gene showed that EHV-1, EHV-2, and EHV-5 strains demonstrated significant genetic diversity in Korea, with a nucleotide sequence identity among them that ranged from 95.7% to 100% for EHV-1, 96.2%-100% for EHV-2, and 93.8%-99.3% for EHV-5. These results are the first phylogenetic analyses of EHV-1 in Korea in nasal swabs from a nationwide population of clinically healthy horses. Both EHV-2 and EHV-5 from blood, lung tissues, and nasal swabs were also detected.