india

Updated: Mar 27, 2020 01:55 IST

A near-complete lockdown of cities can potentially beat back the Covid-19 outbreak to such an extent that people can be allowed within weeks to return to work without causing the virus to take hold again, and in the absence of any countermeasure by countries, the virus would have infected 7 billion of the world’s population.

That’s the finding of a statistical analysis of several cities in China, led by a team from London’s Imperial College.

The findings lend weight to the strategy adopted in India, where virtually all of the country’s 1.3 billion people are now confined to their homes for a three-week period in what is the strongest counter measure adopted by any country in the world in terms of scale and duration. While announcing the lockdown, Prime Minister Narendra Modi underlined that there was one — and only one — way to defeat Covid-19. This was through social distancing, which the lockdown would ensure.

The analysis published on Tuesday compares disease spread data in Chinese cities with indicators of how people moved (derived from GPS tracking devices) between January 1 and March 17.

“Initially, within-city movement and transmission were very strongly correlated in the five provinces most affected by the epidemic and Beijing. However, that correlation is no longer apparent even though within-city movement has started to increase,” said the report.

The Imperial College team warned that the disease would have infected almost everyone on the planet — 7 billion people — if countries had not taken any countermeasures.

The lockdown in China began on January 23 with the Hubei province, the epicentre of the Sars-Cov-2 coronavirus outbreak that has since raced across the world, infecting close to 500,000 and killing 23,000 people in less than three months. The administration in Hubei began allowing some factories to reopen on March 11 — roughly seven weeks after everything had ground to a halt.

For the first time since the outbreak began, China reported no new local spread of the infection for the five consecutive days till March 23. After one brief local infection on March 24, it again reported no new such cases till Wednesday — all of its new cases are now being imported from other countries.

“A similar analysis for Hong Kong shows that intermediate levels of local activity can be maintained while avoiding a large outbreak,” added the report by the Imperial College Covid-19 Response Team.

A previous analysis by the team — which is credited to have jolted the administrations of United States and United Kingdom into action — said countries across the world will need to put in place aggressive social distancing measures for at least two-thirds of the next 18 months, the period at the end of which scientists expect a viable vaccine to halt Covid-19.

The remaining period will need a tiered action plan that countries can use to pare back some of these restrictions when the outbreak relents, but immediately reimpose if infection rates pick up. But, the scientists added in that report, countries will need to set in place a strong mechanism to monitor the outbreak.