Is the K number the new R number? What you need to know

Medical staff are seen looking after a patient inside the provisional military hospital of the Campo Militar No. 1, which takes care of patients with symptoms of the coronavirus disease (COVID-19) in Mexico City, Mexico June 9, 2020. Picture taken June 9, 2020.REUTERS/Carlos Jasso

Doctors are discussing a new way to monitor the spread of COVID-19. Image: REUTERS/Carlos Jasso

Adam Kleczkowski
Professor of Mathematics and Statistics, University of Strathclyde
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Epidemic spread with R=3; four generations are shown from the first person marked in red, through yellow, green and blue. Numbers indicate how many new infections originate from each case.
What a spread of R=3 looks like. Image: Adam Kleczkowski
Mary Mallon in hospital (foreground).
Mary Mallon in hospital. Image: Wikimedia Commons
Epidemic spread with a distribution of secondary cases with low dispersion and value of K much larger than 1.
Spread of COVID-19 with a value of K much larger than 1. Image: Adam Kleczkowski
Epidemic spread with a distribution of secondary cases with high dispersion and value of K around or below 1.
Epidemic spread with a distribution of secondary cases with high dispersion and value of K around or below 1. Image: Adam Kleczkowski
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COVID-19Global RisksGlobal HealthHealthcare Delivery
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