It is rare for people who have the coronavirus but have no symptoms to spread it, a World Health Organization official has said, instead urging countries to focus on tracing symptomatic cases.
One of the many unanswered questions about the coronavirus is the proportion of people who spread it without displaying any symptoms, with some studies suggesting it could be up to 50 per cent.
But Dr Maria Van Kerkhove, the WHO’s technical lead for Covid-19, told a press briefing yesterday that data from countries that had carried out detailed tracking and following up of contacts, there was little evidence of true asymptomatic spread.
“We have a number of reports from countries who are doing very detailed contact tracing, they’re following asymptomatic cases, they’re following contacts and they’re not finding secondary transmission onwards - it’s very rare,” she said.
The statement should go some way to reassuring head teachers who are reluctant to reopen schools over fears that children may be asymptomatic carriers of the coronavirus and could pass it on to teaching staff.
Dr Van Kerkhove said that evidence showed that most people who were asymptomatic in fact had a very mild case of the coronavirus or were pre-symptomatic, that is, not yet displaying signs of the disease.
“When we actually go back and see how many of them were truly asymptomatic we find out that many have really mild disease,” she said.
They may not have the classic Covid-19 symptoms of shortness of breath, fever or cough yet, she added.
“Having said that, we do know that there can be people that are truly asymptomatic and [test] positive,” Dr Van Kerkhove added.
There is very little hard data on the number of asymptomatic carriers. Yesterday, Reuters reported that authorities in Singapore, which has one of the most sophisticated contact tracing systems in the world, believe that half of new Covid-19 cases are asymptomatic.
“Based on our experience, for every symptomatic case you would have at least one asymptomatic case,” Lawrence Wong, the joint head of the country’s coronavirus taskforce, told the news agency.
Some scientists have expressed surprise at the WHO’s statement.
Liam Smeeth, professor of clinical epidemiology at the London School of Hygiene and Tropical Medicine, said that evidence so far suggests that asymptomatic and pre-symptomatic are an “important source of infection to others”.
“There remains scientific uncertainty, but asymptomatic infection could be around 30 per cent to 50 per cent of cases. The best scientific studies to date suggest that up to half of cases became infected from asymptomatic or pre-symptomatic people.”
New Zealand appears to have completely eradicated coronavirus, as the last known patient in the country recovered on Monday.
There have been no new coronavirus infections in New Zealand during the past 17 days. The country has seen only around 1,500 total cases out of a population of about 5 million, helped in part by its relatively isolated location in the southern Pacific Ocean. Prime Minister Jacinda Ardern placed the country on strict lockdown at the end of March, but on Monday announced the full cessation of internal restrictions.
“We can hold public events without limitations. Private events such as weddings, functions and funerals without limitations,” Ardern said at a press conference. “Retail is back without limitations. Hospitality is back without limitations. Public transport and travel across the country is fully opened.”
The prime minister told reporters, “We almost certainly will see cases here again, and I do want to say that again, we will almost certainly see cases here again, and that is not a sign that we have failed, it is a reality of this virus. But if and when that occurs we have to make sure — and we are — that we are prepared.”
New Zealand will focus its coronavirus prevention measures in border control. The country has banned entry of all non-residents, and requires returning citizens to be tested upon arrival and quarantined for two weeks.
The kids are not all right. The isolation and the loneliness of the COVID-19 lockdown hasn’t been good for any of us. We’re on edge and angry at each other. A Gallup poll in April found “the percentages of US adults experiencing significant stress and worry on a daily basis have increased in an unprecedented manner.”
But that’s nothing compared to what many kids have been going through and how they have been dismissed by those in charge.
Kids are resilient, true. But it’s been months of this lockdown. Parents I spoke to feel lied to about how long we would be kept indoors. “It was supposed to be two weeks to stop the spread,” one mom told me. “My kid is getting weird,” three separate parents commented to me.
Ten days can be a long time in constitutional law. On May 29 a closely divided U.S. Supreme Court, with Chief Justice John Roberts joining the four more liberal Justices, refused to order California to lift its restrictions, meant to curb transmission of the novel coronavirus, on church services that have more than 100 attendees or fill more than 25 percent of building capacity. I wrote about that ruling last Tuesday, noting that the question for both Roberts and dissenting Justice Brett Kavanaugh was whether California had discriminated against worship services with respect to comparable secular gatherings. Roberts declined to find such discrimination, observing that California’s rules had cracked down across the board on activities in which “large groups of people gather in close proximity for extended periods of time.”
Today, that case very possibly—probably?—would come out differently, because, over the past week, California, like other states, has allowed public assembly in crowds of far more than 100 persons to protest the death of George Floyd in police custody.
Whether or not making an exception for the protests was the right thing to do, it has crucial legal implications, as attorney Anthony Sanders points out in a new piece for the Institute for Justice. Under the Court’s free‐speech jurisprudence, to allow assembly for the purpose of expressing one kind of message but not another is a content‐based restriction on speech of the sort that nearly always fails constitutional review. It triggers strict scrutiny as to whether the restriction is the least intrusive possible and has been narrowly tailored to advance a compelling government interest.
Religious liberty jurisprudence points the same way. While the prevailing standard on whether the government is required to offer affirmative accommodation of religious exercise may have shifted over the years, it has been clear all along that strict scrutiny will apply if the government discriminates against such exercise.
One element of public health regulation that might withstand strict scrutiny is the distinction between indoor and outdoor meetings since the novel coronavirus appears to transmit much more readily indoors than outdoors. But the implication is that religious and other assemblies should at least be free to go forward if they take place in the out of doors. And current state rules have by no means conceded such a liberty. For example, it is not uncommon for states to ban a 20‐person family graveside memorial at which all participants wear masks and refrain from hugging, chanting, or singing.
We can now expect courts to begin striking down some of these rules if states do not revoke them first. The same goes for other time‐place‐and‐manner restrictions on assembly, speech, and movement: if a state declines to enforce an announced curfew on those who stay out to protest, it may face strict scrutiny trying to enforce that curfew on persons who have stayed out for a worship service.
