Computational analysis of human metapneumovirus particle behaviour in the pulmonary system

Human metapneumovirus (hMPV) is a re-emerging pathogen implicated in severe respiratory illnesses worldwide. Effective management of hMPV outbreaks relies on understanding how viral particles behave within human pulmonary airways. This study utilizes computed tomography-derived airway models and advanced computational fluid dynamics to investigate the transport and deposition of hMPV-like particles across fifteen airway generations under physiologically representative breathing conditions. The effects of viral particle size and morphology, together with dynamic inhalation–exhalation cycles, are systematically analysed. Results highlight distinct deposition hotspots for cylindrical versus spherical particles, with pronounced differences between inhalation and exhalation phases and notable sensitivity to breathing flow rate. The observed deposition trends provide new insight into shape- and phase-dependent risk regions likely to influence infection patterns and guide aerosolized therapy design. By addressing previously neglected aspects of non-spherical particle transport and transient airflow, this work advances the quantitative modelling of airborne viral pathogen exposure in the human respiratory system. • HMPV particles' deposition varies by size and shape in realistic airflow conditions. • Cylindrical particles deposit more in upper airways; spherical ones deposit deeper. • 10 nm particles reach distal airways; 250 nm accumulate in central/upper airways. • Higher particle deposition during inhalation compared to exhalation for both shapes. • The deposition distribution on right branch is more spread out than on left branch.