Isolation of equine herpesvirus type 5 in New Zealand.

The research paper discusses the initial identification of a type of equine herpesvirus (EHV-5) in horses in New Zealand and how these findings might impact the understanding of respiratory diseases in horses.

Methodology

• The research began by collecting nasal swabs and peripheral blood leukocytes from 114 foals and adult horses.
• These samples were inoculated onto equine fetal kidney, rabbit kidney and Vero cell lines to observe any cytopathic effects, which are observable changes in cellular behaviour due to viral infection.
• Researchers identified EHV-5 isolates using a specific polymerase chain reaction (PCR), a common technique in molecular biology to amplify and detect DNA sequences.
• Samples positive for EHV-5 were subsequently checked for the presence of other herpesviruses, including EHV-2, EHV-1 and EHV-4, using published type-specific primers.
• The research team confirmed PCR results through dot blot and Southern hybridisation with specific DIG-labelled probes. These procedures are used to verify the presence and quantity of specific DNA sequences in the samples.

Results

• The study successfully isolated EHV-5 from nasal swabs or peripheral blood leukocytes of 38 out of the 114 horses sampled.
• Most of the horses analyzed were infected with both EHV-2 and EHV-5 viruses.
• EHV-5 often isolated more than once from horses that were sampled multiple times.
• The researchers could not associate the presence of EHV-5 with respiratory disease in this study, indicating that additional research is required to understand the role of EHV-5 in horse health.

Conclusion

• The study revealed the presence of Equine herpesvirus 5 in the New Zealand horse population.
• Despite isolating the virus, the researchers could not determine its specific role in causing or predisposing horses to respiratory diseases, prompting further investigation in future studies.