By Adam Vaughan
MORE than half a million people are now confirmed to have died from the coronavirus, as local outbreaks around the world trigger fears of a second wave of covid-19. Globally, a record 189,077 cases were reported on 27 June, and cases are rising in Africa, Asia and North and South America.
Some of the surge is due to greater testing, and the rate of deaths is yet to see an equivalent increase. However, the World Health Organization (WHO) believes the growth in daily cases is down to a genuine acceleration in the spread of the virus. “Intense transmission is going on in many communities in many parts of the world,” a spokesperson says. There are also flare-ups in countries that successfully lowered infection rates but have since relaxed restrictions.
Azra Ghani at Imperial College London notes that in many countries that rapidly introduced lockdowns, such as South Korea, only around 5 per cent of people have had the virus. “Which means as soon as you start to open up and connections start to come back between countries, it’s very likely to take off again,” she says.
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The South Korean government declared the start of a “second wave” of infections last week, due to small clusters of cases after an easing of restrictions in May. A jump in cases in the Australian state of Victoria has led to the reintroduction of lockdown in some areas of Melbourne. China has reimposed a lockdown on 400,000 people in Anxin county near Beijing after 18 new cases.
“We are likely to see, in every place, a relaxation and then maybe a ramping up of interventions again to control it. I expect we will see continual waves,” says Ghani.
The US, which has the world’s highest number of confirmed cases and deaths, has had an uptick in both in places that previously seemed to have the virus under control. Two months ago, almost all 50 states had an estimated reproduction number (R) of under 1, indicating that the epidemic was in decline. But according to one analysis, 33 now have an estimated R of 1 or above, meaning the virus will spread exponentially.
“Nearly 300 people who went to a Swiss nightclub were quarantined after one later tested positive”
Ghani, whose colleagues have modelled epidemics at a state-level in the US, says many states began to relax restrictions while R was still above 1. She says: “I think it’s inevitable we’ll see increasing cases and deaths in the US.”
In Europe, cases rose in the week commencing 15 June, the first increase in months. Sweden, Albania and Bosnia and Herzegovina were among the nations that the WHO identified as having a rise. Sweden said its increase was due to greater testing rather than fresh outbreaks.
Local outbreaks across Europe have seen authorities taking new action, such as nearly 300 people who went to a Swiss nightclub being quarantined after one person later tested positive. Meat‑processing facilities, where people work close together, have emerged as the source of case clusters in several countries, including Germany.
However, the WHO has made it clear that not all local outbreaks are equal. The agency is less concerned about some clusters in Europe that were controlled with a “rapid and targeted response”, including restrictions and ramped-up testing, than in places where there is no such quick and proportionate reaction.
David Heymann at the London School of Hygiene & Tropical Medicine says second waves are “not the right way to think about it” because, unlike flu, covid-19 seems to spread in summer. “It may be [better] to think about suppressing and unsuppressing. That’s what the countries are going to have to do: unlock their suppressing activities and if they see suppression isn’t working as they wanted it to do, they’ll have to lockdown again,” he says.
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