| Popis: |
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is pandemic. Developments in vaccination, antiviral treatment, prevention, and control strategies requires an improved understanding of SARS-CoV-2 dynamics. We rapidly reviewed the literature on SARS-CoV-2 viral dynamics and their correlation with outcome. We sought comparisons of SARS-CoV-2 with other respiratory viruses such as SARS-CoV-1 and MERS. The literature on infective dose, routes of exposure, and route of administration was limited, especially in humans, and different endpoints were used for measurement of infection The evidence, albeit limited, indicated that the minimum infective dose of COVID-19 in humans, may be lower than 1000 particles, slightly higher than hundreds of particles estimated for SARS-CoV-1. Although variability was observed in animal studies, there was some evidence that increased dose at exposure correlated with higher viral load clinically. The higher viral load measures could not necessarily reflect the COVID-19 severity. Aerosol transmissions seem to raise the risk of more severe pulmonary symptoms and lower respiratory tract complications. An accurate quantitative estimate of the infective dose of SARS-CoV-2 in humans is not currently feasible and our estimates need further refinement. Further work is also required on the relationship between routes of transmission and outcomes. |
