Equine herpesvirus 2 in pulmonary macrophages of horses.

The research paper investigates the prevalence of equine herpesvirus 2 in the pulmonary macrophages in horses suffering from chronic pulmonary disease. It is discovered that the virus is uniquely present in the majority of sick horses, but absent in the healthy ones.

Research Objective and Methodology

• The objective of this research was to identify possible viral agents present in horses suffering from chronic pulmonary disease.
• To do so, the researchers analyzed pulmonary macrophages, a type of white blood cell, of horses for traces of the equine herpesvirus 2.
• Pulmonary macrophages were harvested using a technique known as bronchoalveolar lavage and then sorted based on density using metrizamide gradients.
• These macrophages were then examined for the presence of viral antigens using a method called indirect immunofluorescence staining.
• This process was performed on 9 horses with chronic pulmonary disease and their results were compared with those of one healthy horse.

Research Findings

• Results showed that 8 out of 9 horses with chronic pulmonary disease hosted the equine herpesvirus 2 antigens, while the healthy horse did not.
• Further examination of a second group of horses revealed that viral antigens were present in 90% of bronchoalveolar lavage cells after a week of cultivation.
• Unexpectedly, these antigens were also found in 2 out of 3 healthy horses.
• No antigens for five other investigated viruses, including equine herpesvirus 1 and 4, parainfluenza virus 3, or adenovirus, were detected in lung tissues from a third group of 14 horses with varying health statuses.
• The presence of equine herpesvirus 2 in the pulmonary macrophages of horses was confirmed qualitatively by the isolation of the infective virus through a procedure called cocultivation.
• The infective virus could also be isolated from the pulmonary macrophages and mixed-blood leukocytes of another group of horses with chronic pulmonary disease.

Conclusion

• The research indicates a unique presence of equine herpesvirus 2 in horses suffering from chronic pulmonary disease.
• This could suggest a potential link between chronic pulmonary disease and equine herpesvirus 2, although more research is required to provide a definitive conclusion.