The daily death toll from Covid-19 in the United States could have been more than halved if authorities had acted more swiftly in recommending self-isolation and the wearing of face masks, according to a new study.
Several US states began issuing stay-at-home orders in late March, while federal health authorities began recommending the use of face masks for all in early April. However, had such measures been implemented just four days earlier, the roughly 2,000 Covid-19 deaths currently being recorded each day would have been cut to less than 1,000, the study said.
Furthermore, lifting the measures in a bid to kick-start the economy would almost instantly increase the daily death toll to more than 3,000, it said.
"These findings may inform policymaking," said the researchers from Princeton Medical Centre and other research institutes in a yet-to-be-peer reviewed paper posted on Medrxiv.org on Wednesday.
US health authorities only began recommending the use of face masks for all in early April. Photo: Getty Images via AFP alt=US health authorities only began recommending the use of face masks for all in early April. Photo: Getty Images via AFP
The findings echoed comments made last month by Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases in the US.
"Obviously, if we had right from the very beginning shut everything down, it may have been a little bit different," he said in a television interview on April 12. "But there was a lot of pushback about shutting things down back then".
Both Fauci and other senior health officials were banned from speaking freely to the media or testifying at congressional hearings by the Trump administration, according to media reports.
Swifter action "could have saved lives", he said, without giving an exact number.
But the figures could be found in publicly available data, according to the research team led by Lanjing Zhang, director of gastrointestinal and liver pathology at Princeton Medical Centre.
By tracking the changes in the numbers of infections and deaths after the implementation of the containment measures in the US, Zhang's team was able to build a mathematical model to simulate the impact of the policies, and then used it to estimate what might have happened had they been introduced at different times.
California was the first state to issue a stay-at-home order to its 4 million residents on March 19, and by April 7 similar restrictions had been implemented across the country, affecting almost 90 per cent of the population.
On April 3, the US Centres for Disease Control and Prevention changed its long-standing policy on the wearing of face masks, and urged everyone to cover their nose and mouth when in public.
The effect of the policies was almost instant, the study said. The growth rate for both infections and deaths began slowing on March 23 and by April 4 had plateaued and begun a gentle decline.
But according to the model, had the same measures been introduced just four days earlier, the number of new daily infections in April would have fallen by about two-thirds to 10,000. And had the move been made a week sooner, that figure would have dropped to just 3,000, with about 300 daily deaths, it said.
China imposed a total lockdown in Wuhan, the city at the centre of the initial outbreak, and imposed nationwide quarantine measures in late January.
According to Zhang's study, had the US introduced rules on self-isolation and mask wearing just a month after Beijing made its move " and about the time Fauci and other health officials were pushing the government to take aggressive mitigation efforts " the US would now be facing just 30 new infections and fewer than 10 deaths per day from Covid-19.
Zhang said that the massive dip in cases suggested by the model was due to the fact that measures such as social distancing and wearing face masks reduced the rate at which the virus spread. And removing them too soon would have the opposite effect.
"Caution is therefore needed in decision-making regarding the lifting of the stay-at-home orders," the paper said.
President Donald Trump is keen to reboot the US economy, after it shrank by 4.8 per cent in the first quarter of the year. Photo: AP alt=President Donald Trump is keen to reboot the US economy, after it shrank by 4.8 per cent in the first quarter of the year. Photo: AP
President Donald Trump is keen to reboot the US economy, after it shrank by 4.8 per cent in the first quarter of the year and economic indicators suggest unemployment is set to spike in the months ahead.
Zhang's findings have been replicated by other research teams. A model built by the Federal Emergency Management Agency, under the US Department of Homeland Security, predicted that the daily death toll would jump to 3,000 and new infections to 200,000 by June if the containment measures were lifted too soon.
A team led by Professor Andrew Tatem from the University of Southampton in England, said that without a vaccine for the coronavirus or effective medication to fight Covid-19, the best way to contain its spread was through non-pharmaceutical intervention.
"China's aggressive, multifaceted response is likely to have prevented a far worse situation, which would have accelerated the spread globally," he said in a recent report.
Beijing's actions gave the rest of the world a "preparation window and fighting chance" against the deadly disease, he said.
This article originally appeared in the South China Morning Post (SCMP), the most authoritative voice reporting on China and Asia for more than a century. For more SCMP stories, please explore the SCMP app or visit the SCMP's Facebook and Twitter pages. Copyright © 2020 South China Morning Post Publishers Ltd. All rights reserved.
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