Transmission Dynamics

Analysis of the Transmission Dynamics of COVID-19: An Open Evidence Review.

Jefferson T, Spencer EA, Plüddemann A, Roberts N, Heneghan C.
https://www.cebm.net/evidence-synthesis/transmission-dynamics-of-covid-19/

In the midst of the COVID-19 pandemic, uncertainty on the characteristics of a novel disease reigns. One of the most important aspects of these uncertainties regards the mode and circumstances of transmission of this newly identified agent.

The explosive nature of COVID-19 transmission, initially shown by the number of new cases and later by admissions and deaths, remains unexplained. The age distribution and the speed of transmission does not fit with what is known of “seasonal” coronaviridae.

Such uncertainties prevent a rational response to the threat and promote extreme actions such as total lockdown of whole countries.  One of the principal uncertainties regards the means by which COVID-19 is transmitted, with special regard to the factors which may accelerate or delay its spread, the mode of transmission, the role of asymptomatic infected people, its speed, the possible interactions with wildlife or livestock, urban or rural environments and population density.

The first part of the Open Evidence Synthesis will consist of a search of the evidence and description with tabulation of the findings.  In the second phase, as we make more information available, it may be possible to either define a mode of transmission or to set out a series of hypotheses to be tested by further work. We will set out the policy implications and recommendations in line with our evidence extractions.

Because of the public health importance of this work and its evolving nature, we will post extractions and summaries of all included studies on this site with brief comments. Our searches will be updated every two weeks and the results posted.