Decoding the mechanophysiology for inhaled onset of smallpox with model-based implications for mpox spread

Area of Science:

• Biophysics
• Infectious Disease Dynamics
• Computational Fluid Dynamics

Background:

• Orthopoxviruses transmit via inhalation of airborne particles, initiating respiratory infections.
• Understanding respiratory tract aerosol flow physics is vital for disease mitigation and pathology.
• Smallpox (variola virus) and mpox are significant Orthopoxvirus pathogens.

Purpose of the Study:

• To develop and validate a physiological fluid dynamics model for simulating inhaled Orthopoxvirus transmission.
• To estimate critical exposure durations for smallpox and mpox virus infection onset.
• To assess the impact of viral concentration and immune factors on transmission risk.

Main Methods:

• High-fidelity Large Eddy Simulations (LES) of airflow and particulate motion in anatomical airway models.
• Integration of fluid dynamics simulations with viral load and individual immune response data.
• Extension of the model to compare transmission dynamics between variola virus and mpox virus.

Main Results:

• Estimated critical exposure duration for smallpox infection onset: 1-19 hours.
• Estimated critical exposure window for mpox virus infection: 24-40 hours, with potential variation from 8 to 127 hours.
• Model findings align with existing smallpox literature and suggest airborne transmission possibility for mpox during prolonged proximity.

Conclusions:

• Physiological fluid dynamics modeling provides valuable insights into Orthopoxvirus airborne transmission.
• Critical exposure durations differ significantly between smallpox and mpox, influenced by viral factors.
• The framework highlights the importance of prolonged proximity for potential airborne transmission of these viruses.