Anson Au

Opinion | What the world learned from Sars stands us in good stead to curb Covid-19

Far from a gloomy observation, the fact Covid-19 behaves like Sars should give us hope. After all, we now know about how coronavirus infections cluster, where the hotspots are, and what public health measures are likely to prove effective

Reading Time:4 minutes

Why you can trust SCMP

People wear masks at the Kai Tak cruise terminal on February 5. In Hong Kong and elsewhere, the lessons of Sars are helping to combat the spread of the Covid-19 coronavirus. Photo: AFP

Anson Au

Published: 6:30am, 27 Feb 2020Updated: 6:37am, 27 Feb 2020

The Covid-19 epidemic sweeping through the Asia-Pacific appears to be heading inland towards Western Asia and Europe. This past week has witnessed the first major outbreaks outside the Asia-Pacific, in Iran and Italy, prompting temporary lockdowns on schools, museums, universities and cinemas, as well as bans on public gatherings.

With a climbing death toll and infections diffusing through the continent, Covid-19 takes on new meaning as it reopens the scars left by the severe acute respiratory syndrome, parallels that pundits have been eager to point out.

Yet, this comparison is our compass for navigating the way ahead. We have learned from Sars in ways that allow Hong Kong and other global cities to better prepare to curb the spread of Covid-19.

Cutting-edge network science research including the latest simulations over the past few weeks on the Covid-19 epidemic, as well as evidence on how Sars diffused in cities worldwide, help us to infer what to expect from Covid-19.

First, we can observe how and where respiratory viral epidemics are most likely to be transmitted. Sars revolutionised how we thought coronaviruses spread. Where before, our models assumed that everyone had an equal chance of getting infected, Sars showed that people have vastly unequal chances of infection because comparable coronaviruses tended to cluster.

The clustering patterns debunked the widespread myth that person-to-person contact on the streets was actually the most likely form of transmission. Disease transmission and contact rates are disproportionately higher in specific types of sites than anywhere else.