Equine herpesvirus type 1 induces both neurological and respiratory disease in Syrian hamsters.

This research investigates the pathogenic effects of the Equine herpesvirus type 1 (EHV-1) on the Central Nervous System (CNS) and respiratory system of Syrian hamsters. Specifically, the study assesses the impact of four different Brazilian EHV-1 strains and finds all tested strains result in both severe CNS and respiratory diseases.

Background

• The Equine herpesvirus type 1 (EHV-1) is a significant agent of myeloencephalopathy and respiratory disease in horses.
• Syrian hamsters have often been used as animal models to study the impact of EHV-1 infections.
• However, past research has seldom focused on exploring the pathogenesis of EHV-1 in the CNS and respiratory system of these hamsters.

Research Aim

• The study aims to provide an understanding of the pathogenic effects of four different Brazilian strains of EHV-1 on the CNS and lungs of Syrian hamsters.

Methodology and Results

• Hamsters were intranasally infected with one of the four EHV-1 strains: A4/72, A9/92, A3/97, and Iso/72.
• All infected hamsters developed severe neurological and respiratory signs and resulted in death within 3 to 5 days.
• The A4/72 and A9/92 strains caused more intense neurological signs, while the A3/97 and Iso/72 strains induced more severe respiratory symptoms.
• Hamsters infected with A3/97 and Iso/72 exhibited predominantly inflammatory lesions in the CNS, whereas those infected by A4/72 and A9/92 strains primarily developed neuronal and liquefactive necrosis.
• Interstitial pneumonia resulting from infiltration of macrophages, neutrophils, and lymphocytes was observed across the hamsters.
• Exceptionally, hamsters infected with the A9/92 strain experienced severe hemorrhaging within the airways.
• EHV-1 antigens were detected in the CNS and pulmonary lesions post-infection.
• The virus was successfully recovered from the CNS of all infected hamsters, and from the lungs of A4/72, A9/92, and Iso/72 infected hamsters.

Conclusion

• This research concluded that EHV-1 infection results in both serious CNS and respiratory diseases in Syrian hamsters, irrespective of the strain.
• As the study establishes the detrimental effects of EHV-1 strains on both the respiratory and CNS of Syrian hamsters, it likely paves the way for the animal becoming an important research model for future studies on EHV-1 infection.