Study on the epidemiology of equine arteritis virus infection with different diagnostic techniques by investigating 96 cases of equine abortion in Hungary.

The research focuses on the occurrence and detection of equine arteritis virus (EAV), a virus inducing abortions in horses, within Hungary. By employing various laboratory techniques, including polymerase chain reaction and immunohistochemistry, and gathering data from 96 cases, the study reveals substantial EAV infection prevalence and identifies the most effective detection tests.

Study Background and Methodology

• Equine arteritis virus (EAV) is a significant virus that leads to abortions in horses. This study aimed to understand the prevalence, pattern, and diagnosis of EAV induced abortion in Hungary over a three-year period.
• The researchers collected tissue samples from 96 aborted equine foetuses or newborn foals, which came from 57 farms scattered across Hungary.
• The methods used to detect EAV infection were virus isolation, polymerase chain reaction (PCR), immunohistochemistry, and serology, which involves detecting antibodies in the serum.

Research Findings

• The study detected EAV infection in 65% of the mares. This high seroprevalence indicates that the virus is considerably prevalent in the studied farms.
• EAV induced abortion was documented in eight cases (amounting to 8.3% of the total cases), spread across six herds (10.5% of the total herds). The occurrence of abortion was sporadic in all herds, except one where an abortion epidemic occurred.
• Six out of eight aborted foetuses/newborn foals (75%) had EAV antibodies in the serum, implying that the virus could be passed onto them. In one case (12.5%), EAV was isolated from tissues, a process which will typically occur when a sufficient amount of the virus is present. The polymerase chain reaction, a technique used to amplify small segments of DNA, confirmed EAV in all four cases where this technique was applied.
• Immunohistochemistry, a process that visualizes proteins in cells of a tissue, managed to detect the virus in seven of the eight cases (87.5%). The virus was largely present in the spleen, followed by other organs and the allantochorion, a part of the placenta.

Conclusion

• The research reveals a considerable prevalence of EAV among the tested equine population in Hungary. The sporadic nature of abortions suggests the infection can stay undetected until triggered by certain factors.
• In diagnosing EAV, polymerase chain reaction and immunohistochemistry appear as the most sensitive and useful tests. These tools help to enhance the understanding and management of the EAV induced abortion in horses.