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Rapid Covid tests are being used more widely: can they be trusted?

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Britain and France agreed to use on-the-spot rapid Covid-19 tests to end a 48-hour block on movement between the two countries last week, the latest adoption of a technology that could become a crucial tool in controlling the spread of coronavirus in 2021.

The UK government has spent at least £1.5bn on so-called lateral flow tests and has already provided the simple devices to local authorities, care homes, hospitals and universities. The UK regulator went further on Tuesday, granting the tests an emergency authorisation for use by members of the public with no medical training.

Proponents of lateral flow tests say the devices, which can deliver a result in 20 minutes, will significantly boost the UK’s testing capacity and are a useful tool for finding people who are currently infectious. From next month, the tests will be deployed across Britain’s schools to identify cases of the virus before the start of the new term.

“Testing asymptomatic people is an enormous priority,” said John Bell, Regius professor of medicine at Oxford university, who has overseen studies into the accuracy of these tests for the government. “If there’s no testing, they don’t get caught. Every successful positive you get is a win.”

But several scientists have remained sceptical despite the regulator’s approval and increasingly widespread uptake, arguing that the public has been misled about the tests’ accuracy.

Unlike RT-PCR tests, which look for Covid-19’s genetic material, lateral flow tests identify a protein antigen on the virus’s surface. Lateral flow devices do not amplify the virus (unlike RT-PCR tests) and therefore struggle at detecting lower levels of infection.

Several analyses have found that the lateral flow test developed by Innova — the biggest supplier to the UK government and one of a handful of tests that has met the government’s criteria for accuracy — picked up less than half of active infections.

“Schools are going to be a nightmare,” said Tom Lewis, clinical lead for pathology at North Devon District Hospital. “If you’re relying on this to pick up cases, you’re going to miss more than half of them.”

Professor Tim Peto at the University of Oxford disagreed. “They’re not perfect, but that doesn’t stop them being a game changer for helping detect cases of infectious disease,” said Prof Peto, who has worked with Prof Bell on validating the tests’ accuracy.

Their analysis found that the Innova tests pick up between 84 and 96 per cent of infections in people with a high viral load, making it ideal for identifying people who are currently infectious. The study also concluded that using the devices to identify and then quarantine cases of Covid-19 can reduce transmission by between 67 and 90 per cent.

This means the test is most effective in catching people who are infectious, and less effective at identifying people who have a low viral load, who are normally at the start or the end of their Covid-19 infection. In contrast, the “gold standard” PCR tests detect all forms of the virus.

Using lateral flow tests to identify and quarantine cases is estimated to reduce transmission of Covid-19 by between 67 and 90% © Matthew Horwood/Getty

The best source of data for widespread use of rapid tests to plot infection and reduce transmission comes from Slovakia, where two-thirds of the population — 3.6m people — were tested between October 31 and November 1 and more than 57,000 cases were identified. 

An analysis of the campaign by researchers at the London School of Hygiene and Tropical Medicine estimated that the mass testing regime, coupled with quarantine measures, led to a 60 to 70 per cent reduction in the rate of infection across Slovakia.

“We see strong evidence that the combination of short lockdown and mass testing has led to a very rapid reduction in the burden of Covid-19,” said Stefan Flasche, professor of vaccine epidemiology at LSHTM and co-author on the paper.

The biggest pilot programme in the UK was conducted in Liverpool, where 25 per cent of the city’s 497,000 residents took a rapid test in November, leading to the identification of 897 positive cases, according to comprehensive data released on Wednesday. The Innova tests used were found to have picked up 40 per cent of PCR-positive cases, with two-thirds of those detected having a high viral load.

The academics who ran the study said that targeted rapid testing was both popular and valuable. Though they could not prove that the tests had led to a fall in infection rate, they noted that cases in Liverpool had fallen more quickly than in neighbouring Manchester.

The evidence suggesting that lateral flow tests are able to detect the virus when carriers are infectious suggests they may be particularly useful for making short-term behavioural decisions, such as whether to enter a care home to visit a relative. However, scientists largely agree that some pre-symptomatic cases will be missed, making it an imperfect tool.

“There is no perfect test, that’s the trouble, everything is a compromise” said Jo Martin, professor of pathology at Queen Mary University of London. “You have to know its limitations when you take it.”

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'It’s more than sport – every day we are fighting for our rights to be equal’

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French pro basketball player and podcaster Diandra Tchatchouang on her role beyond the court



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Emily Dean on how allyship amplifies the female experience on film

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When I was six years old, I decided to be an artist. When I was 12, I decided to be a filmmaker. And instead of saying no, you can’t do that, or it’s not possible, my mum bought me a video camera.

After several years of working in the industry, I’m working with a female director for the first time. And it’s been such a gratifying experience. Women express leadership in different ways. Maybe you don’t have to be the loudest person in the room. But you can have great ideas.

And the best thing about being mentored by women and being a mentor to women is that make friends with women.

There’s something so powerful the women coming alongside other women, especially in a group setting. Because it means that you can and back each other up. You can support each other’s decisions, and you can amplify each other’s voices.

It’s about seeing yourself in your work. Seeing some part of yourself reflected is really gratifying. It’s also important that we speak up for female characters. I want to see girls and women on screen who have the whole cacophony of experience of what it’s like to be female.

I want to see their flaws. I want to feel their struggles. I want to see their joy. That is so important to making a character feel real. And it took me a little while to settle into myself and realise, if the characters I like to come up with are not your everyday run of the mill characters you see in animation, that’s fine. Because this is who I am.

When you walk into a story room, when you’re working on a film, you have to leave your ego at the door. I think that can be interpreted like keep your ego out of the work. But I’d also say for women who are maybe more shy that leaving your ego at the door means you walk in. And your job is to focus on what’s best for the story and for the film.

The story needs you. The film needs you, and it needs your best ideas. It won’t thrive unless you speak up.



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Crimea ‘water war’ opens new front in Russia-Ukraine conflict

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When a cyclone drenched Crimea in rainfall last month, rivers burst their banks and thousands of people in the Russia-annexed peninsula had to be evacuated from the floods.

The silver lining to the deluge was that the rains also filled Crimea’s depleted reservoirs, temporarily alleviating a crisis brought on by an extended drought and a Ukrainian blockade of the Soviet-built canal that previously provided up to 85 per cent of the peninsula’s water supplies.

Moscow’s struggle to supply Crimea’s 2.4m residents with fresh water has become a flashpoint in an undeclared war, seven years after Russian troops seized Crimea from Ukraine. An even longer conflict between Kyiv and Russian-backed separatists in eastern Ukraine has claimed more than 14,000 lives.

Russia has accused Ukraine of “genocide” over the building of a concrete dam across the North Crimean Canal, in addition to the existing sandbag and earth dam that was built in 2014. Kyiv fears that Moscow is plotting a military incursion to secure water flows from the nearby Dnipro river.

Coupled with surging food prices and international isolation because of western sanctions, the water shortages threaten to undermine President Vladimir Putin’s promise of a better life for Crimeans under Russian rule.

Though state-run pollsters claim Putin remains more popular in Crimea than on average across Russia, the patriotic fervour that sent his approval ratings to record levels after the 2014 annexation has long since subsided.

Map showing Ukraine and the North Crimean Canal, Crimea

“The water reserves and fields have dried up,” said Viktor, 47, a Crimean who regularly travels to Ukraine for work. “Each year it’s getting worse and worse. We didn’t have this problem before annexation,” he said, adding that most Crimeans blamed Ukraine for the crisis.

A $3.7bn bridge across the Kerch Strait linking Crimea with mainland Russia has become a conduit for trucks ferrying water for locals to take away in plastic containers. Popular Black Sea tourist resorts can turn on their taps for just a few hours a day during peak droughts, while the canal has filled with grass and weeds.

Crimea’s agricultural output has fallen owing to a lack of irrigation, making it all but impossible to grow water-intensive crops such as rice.

Construction of the canal began in 1957 after the Soviet Union transferred the arid peninsula to the Ukrainian Soviet Socialist Republic to manage rebuilding after the second world war. The waterway allowed for the cultivation of arable land and helped transform Crimea into a haven for tourists.

“The canal symbolises the stupidity of the Kremlin in occupying Crimea. They didn’t weigh the consequences at a moment of electoral euphoria that was fed by their own propaganda,” said Oleksiy Reznikov, Ukraine’s deputy prime minister in charge of reintegration policies for the occupied territories.

“Why didn’t you think about water?” he asked.

The North Crimean Canal is seen with a low level of water
The severely depleted North Crimean Canal previously provided up to 85% of the peninsula’s water supplies © Pierre Crom/Getty

Workers collect potatoes on the North Crimean Canal
Workers collect potatoes on the North Crimean Canal. Ukraine blocked the irrigation channel after Russia’s 2014 annexation of Crimea © Pierre Crom/Getty

Russia, while pressing Ukraine to reopen the waterway, has launched a Rbs50bn ($680m) programme to bolster Crimea’s supplies, repairing crumbling infrastructure, drilling wells, adding storage and desalination capacity.

Russian prosecutors last week filed a lawsuit in the European Court of Human Rights accusing Ukraine of “flagrant violations” over the issue. Crimea’s governor plans to file a separate complaint demanding up to Rbs1.5tn in compensation.

“Kyiv has essentially used Crimea’s infrastructure dependence on Ukraine, which came about in the Soviet era, as a weapon of mass destruction against all Crimeans. The water blockade is an act of state terrorism and ecocide, but the international community is failing to notice the Kyiv regime’s crimes,” Sergei Aksyonov, the peninsula’s governor, said in written comments to the Financial Times.

Reznikov said Russia, as the occupation force, was responsible under the Geneva Conventions for securing water and other basic needs for local the population. Ukraine has filed its own multi-billion-dollar claims against Russia, citing losses caused by what it describes as an illegal land grab.

With tensions rising, Russia deployed tens of thousands of troops and advanced weapons to Crimea this spring, as well as to the border of the two breakaway eastern regions where Moscow-backed separatists have battled government troops into an eighth year.

Col Kyrylo Budanov, chief of Ukraine’s army intelligence unit, said Russia was looking to seize the canal as well as adjacent territory to connect Crimea with the breakaway regions. Russian troops could advance on Nova Kakhovka, the Dnipro river town where the canal begins.

Some Crimean Tatars, an indigenous ethnic group whose members largely opposed Russia’s annexation, have set up a makeshift camp near the dams to make sure the water flow does not resume.

A Crimean Tatar activist on the North Crimean Canal
A Crimean Tatar activist enters his base on the North Crimean Canal. Tatars have set up camp to make sure the water flow does not resume © Pierre Crom/Getty

A Ukraine military vehicle drives past a Soviet monument marking the entrance to Brylivka
A Ukraine military vehicle drives past a Soviet monument marking the entrance to Brylivka, a village on the North Crimean Canal © Pierre Crom/Getty

“It will be a full-scale war,” said a 55-year-old activist who gave his name as Alibaba. He said he and his fellow activists were willing to take up arms to defend the blockaded canal. “There will be nowhere to hide in these fields. Let them try,” he added.

At the Kalanchak border crossing near the new dam, Russian and Ukrainian troops have dug trench positions a few hundred meters apart.

Tensions have also flared in the Black Sea, not just with Ukraine but also with western navies. Russia fired warning shots in the path of a British destroyer sailing through contested waters off Crimea last month. Sevastopol, Crimea’s largest city, is home to Russia’s Black Sea fleet.

Moscow has insisted it would not go to war over Crimea’s water supplies, even as it conceded that Ukraine was unlikely to restore them. “All these hysterical statements from Ukrainian politicians are completely baseless — they’re just stupid, aggressive propaganda aimed at inciting hatred between the Russian and Ukrainian people. There won’t be any ‘water war’,” Crimea governor Aksyonov said.

Reznikov, the Ukrainian minister, said Kyiv was ready to provide Crimea with humanitarian assistance, including drinking water, which it already does for the separatist-run eastern territories, but no request had been made.

“For Russia to admit they’re weak is very difficult . . . it would amount to an admission that they made the wrong decision,” he said.



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