Relating in vivo RSV infection kinetics to host infectiousness in different age groups

Area of Science:

• Virology
• Epidemiology
• Mathematical Biology

Background:

• Respiratory syncytial virus (RSV) poses a significant public health threat, particularly to young children and the elderly.
• Understanding individual-level viral kinetics is crucial for elucidating RSV transmission dynamics across different age demographics.
• Current knowledge on RSV transmission in various age groups, considering viral kinetics, remains incomplete.

Purpose of the Study:

• To investigate the relationship between individual-level viral kinetics and RSV transmission probabilities in pediatric, adult, and elderly populations.
• To estimate key viral kinetic parameters and their influence on transmission across different age groups.
• To inform the development of targeted public health strategies for RSV control.

Main Methods:

• A mathematical model was fitted to longitudinal viral kinetic data from 53 individuals across three age groups (pediatric, adult, elderly) using a hierarchical Bayesian framework.
• Viral kinetic parameters, including peak viral load and shedding duration, were estimated.
• A probabilistic model was employed to link within-host viral load to transmission probability for each age group.

Main Results:

• Children exhibited higher peak viral loads and significantly longer viral shedding periods compared to adults and the elderly.
• These findings suggest a higher probability of RSV transmission originating from pediatric cases.
• Estimated secondary attack rates across age groups aligned with empirical data from household transmission studies, validating the model's predictions.

Conclusions:

• Individual viral kinetics, particularly peak viral load and shedding duration, are critical determinants of RSV transmission potential.
• Children play a significant role in RSV transmission due to their distinct viral kinetic profiles.
• Age-specific interventions targeting pediatric populations may be the most effective strategy for controlling overall RSV transmission and reducing public health burden.