Modeling hamsters for evaluating West Nile virus therapies

Area of Science:

• Virology
• Infectious Diseases
• Animal Models

Background:

• West Nile virus (WNV) poses a significant public health threat.
• Existing animal models for WNV research have limitations in evaluating antiviral efficacy.
• Characterizing new models is crucial for advancing therapeutic development.

Purpose of the Study:

• To characterize a hamster model infected with a WNV New York crow brain isolate.
• To evaluate the suitability of this model, particularly using older hamsters, for antiviral therapy assessment.
• To compare disease progression and WNV viral loads in hamsters of different ages.

Main Methods:

• Infection of hamsters (young and old) and mice with WNV.
• Clinical observation and assessment of disease signs (weight loss, neurological deficits, climbing ability).
• Quantification of WNV viral titers in various tissues (plasma, kidney, brain, spleen) over time.
• Administration of Infergen (human interferon-alpha) to assess antiviral effects.

Main Results:

• Older hamsters exhibited approximately 50% mortality with more apparent disease signs compared to younger hamsters (>90% mortality).
• WNV viral loads peaked first in plasma, then highest in kidney tissue, with brain titers peaking before neurological signs and death.
• Older hamsters demonstrated more apparent responses to Infergen treatment regarding weight change, survival, and climbing ability.

Conclusions:

• The hamster model, especially using older animals, is a viable alternative to mice for evaluating WNV antiviral therapies.
• Older hamsters are more sensitive for detecting antiviral effects due to more pronounced disease progression.
• This model aids in the development of effective treatments against West Nile virus.