March 15, 2020

scientist comment on possible impact of behaviour change on reducing spread

Comment on possible impact of behaviour change on reducing the spread of COVID-19.

Dr Adam Kucharski, Associate Professor in Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, said:

“Early in a new outbreak, each COVID-19 case infects 2–3 others on average*, and there’s potentially around 5 days between one infection and next. If each case infects 2.5 others, we’d expect one case to potentially lead to 2.5^6 = 244 new cases appearing a month or so later. If we could halve transmission, so each case infects 1.25 others instead, we’d expect 4 new cases to appear after this same period.

“Even if we can’t fully stop transmission, sustained changes in behaviour (e.g. self-isolation for a week when ill, hand washing and other disciplined infection control habits, reducing close-knit interactions where possible) could dramatically reduce spread.

“(The above calculation assumes reproduction number of 2.5 and serial interval of 5–7 days for COVID-19 in early stages of an outbreak. These are obviously rough calculations based on average values, and transmission may vary between locations.)”

*https://cmmid.github.io/topics/covid19/current-patterns-transmission/global-time-varying-transmission.html  

All our previous output on this subject can be seen at this weblink:

http://www.sciencemediacentre.org/tag/covid-19

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