People Who Test Positive for COVID-19 After Recovering Aren't Infectious
By Julia Ries
Around the world, there have been several cases of people recovering from COVID-19 only to later test positive again and appear to have another infection.
Such cases have had doctors and researchers puzzling over whether recovered people continue to be contagious, and if they could get a second infection.
Now, new research published by the Korea Centers for Disease Control and Prevention has found that recovered COVID-19 patients who test positive again aren't infectious.
The study also found that most patients who recover have neutralizing antibodies — the type of antibody that confers immunity and protects people from getting sick again.
"This study addresses the question of whether patients who have recovered from COVID-19 are still infectious, and which is a question that has been troubling us for some time," said Dr. Heidi J. Zapata, a Yale Medicine infectious disease doctor. "This study suggests that patients that are recovered are no longer contagious."
The Viral Material in Re-Positive Cases Isn’t Infectious
The Korean study examined 285 patients who tested positive again for the new coronavirus after they recovered from COVID-19, which had been confirmed via a negative test result.
The researchers swabbed the patients and examined the viral material to determine whether it was still actively infectious.
The team was unable to isolate live viral material, indicating that the positive diagnostic tests were picking up dead virus particles.
"[This] may speak for the fact that the virus may be dead or not be fit enough to grow — therefore the virus may not be fit enough to infect a new host," said Dr. Andres Romero, an infectious disease specialist at Providence Saint John's Health Center in Santa Monica, California.
The researchers also tested 790 people who'd been in close contact with the "re-positive" patients. Of the 27 who tested positive, no cases appeared to be caused from exposure to someone who appeared to have a reinfection.
The report also found that the vast majority of recovered patients (96 percent) had neutralizing antibodies, indicating that they conferred immunity.
"Whether this is indicative of a completely protective response remains to be proven. If this study holds true, then people who have recovered can get back to work," Zapata said.
In response to the new findings, South Korea eliminated a policy requiring discharged patients to isolate for 2 weeks.
Conducting and Interpreting PCR Tests
The tests widely used to diagnose COVID-19 are called polymerase chain reaction (PCR) tests.
The tests swab a person's nose or throat and try to pick up the virus's genetic material, or RNA.
According to guidance from the U.S. Centers for Disease Control and Prevention (CDC), a positive result on a PCR test doesn't "necessarily mean infectious virus is present or that the patient is contagious."
Infectious disease experts have suspected that the test kits aren't picking up actively infectious viral material in recovered patients who test positive again, but rather dead remnants of the virus.
We see this occur with other viruses, too.
"We know other viruses like parainfluenza, human metapneumovirus, or RSV [respiratory syncytial virus] may linger for months in certain patients, and that does not represent infectious state," Romero said. "Coronavirus may be the same."
We Still Need to Practice Caution
While the findings are promising, infectious disease experts say we still need to practice caution.
More research is needed to validate these findings and determine whether they apply to distinct parts of the population, such as those who are immunocompromised.
It's common for immunocompromised patients — such as those with cancer — to continue testing positive for a virus for longer, since it takes their immune system more time to clear the virus out of their body.
"I don't think we can be 100 percent certain of whether each recovered person is no longer contagious. Again, this may differ with distinct population groups," Zapata said.
Physicians are seeing some hospitalized patients testing positive for a month after they were first swabbed for COVID-19. It's unclear whether these patients still shed infectious virus, according to Zapata.
Everyone's body mounts a distinct immune response based on their age and overall health. Different individuals will clear the virus out at different speeds, according to Zapata.
Until we have more data and a preventive vaccine, it's crucial to continue adhering to the safety precautions laid out by the CDC.
"The reality is that moving forward, the best approach will be keeping social/physical distancing, wearing a mask, and frequent hand hygiene in order to control the spread of the virus," Romero said.
The Bottom Line
Doctors and researchers have been unsure whether people who recover from COVID-19 who test positive again continue to be contagious, or if they could get a second infection.
New research published by the Korea Centers for Disease Control and Prevention has found that recovered COVID-19 patients who test positive again aren't infectious.
The study also found that most patients who recover have neutralizing antibodies that protect them from getting sick again.
Though the study is promising, health experts say we need more data to validate the findings and determine whether they apply to all patient populations.
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By Victoria Masterson
Using one of the world's problems to solve another is the philosophy behind a Norwegian start-up's mission to develop affordable housing from 100% recycled plastic.
Sustainable Homes<p>UN-Habitat says an <a href="https://unhabitat.org/un-habitat-aims-to-use-plastic-waste-to-support-housing-for-all" target="_blank">estimated 60% of people living in urban areas of Africa are in informal settlements</a>. At the same time, between 1990 and 2017, African countries imported around 230 metric tonnes of plastic, "which mostly ended up in dump sites creating a massive environmental challenge," the agency adds.</p><p>UN-Habitat deputy executive director, Victor Kisob, said the aim of the partnership with Othalo was to "promote adequate, sustainable and affordable housing for all."</p>
Artist's impression of an Othalo community, imagined by architect Julien De Smedt. Othalo<p>Othalo's process involves shredding plastic waste and mixing it with other elements, including non-flammable materials. Components are used to build up to four floors, with a home of 60 square metres using eight tons of recycled plastic. A factory with one production line can produce 2,800 housing units annually.</p><p>Following successful laboratory tests, Othalo's factory in Estonia has started producing components to build three demonstration homes for Kenya's capital, Nairobi; Yaoundé, the capital of Cameroon and Dakar, the capital of Senegal.</p><p>Othalo founder Frank Cato Lahti has been developing and testing the technology since 2016 in partnership with <a href="https://www.sintef.no/en/" target="_blank">SINTEF</a>, a 70-year-old independent research organization in Trondheim, Norway, and experts at Norway's <a href="https://en.uit.no/startsida" target="_blank" rel="noopener noreferrer">University of Tromsø</a>.</p>
Othalo founder Frank Cato Lahti. Othalo<p>Almost <a href="https://www.un.org/development/desa/publications/2018-revision-of-world-urbanization-prospects.html" target="_blank">seven out of every 10 people in the world are expected to live in urban areas by 2050</a>. More than 90% of this growth will take place in Africa, Asia, Latin America, and the Caribbean.</p><p>"In the absence of effective urban planning, the consequences of this rapid urbanization will be dramatic," UN-Habitat warns.</p><p>Lack of proper housing and growth of slums, inadequate and outdated infrastructure, escalating poverty and unemployment, and pollution and health issues, are just some of the effects.</p><p>Mindsets, policies, and approaches towards urbanization need to change for the growth of cities and urban areas to be turned into opportunities that will leave nobody behind, UN-Habitat says.</p>
Pioneers of Change<p>Reimagining cities and communities for greater resilience and sustainability was a key topic at the<a href="https://www.weforum.org/events/pioneers-of-change-summit-2020" target="_blank"> World Economic Forum's Pioneers of Change Summit 2020</a>.</p><p>The digital event brought together innovators and stakeholders from around the world to explore solutions to the challenges facing enterprises, governments and society.</p><p>Opening the summit, <a href="https://www.weforum.org/events/pioneers-of-change-summit-2020/sessions/opening-plenary-8f731cbc65" target="_blank">Stephan Mergenthaler, the Forum's Head of Strategic Intelligence and a member of the Executive Committee</a>, said: "We need to change the way we produce, the way we live and interact in our cities to make this transition to net-zero emissions a reality…</p><p>"And as this year has illustrated so dramatically, we need to make every effort that we keep populations healthy, if we want to avoid jeopardizing all this progress."</p><p><em>Reposted with permission from </em><em><a href="https://www.weforum.org/agenda/2020/11/un-africa-recycled-plastic-housing/" target="_blank">World Economic Forum</a>.</em><a href="https://www.ecowatch.com/r/entryeditor/2649069252#/" target="_self"></a></p>
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By Dolf Gielen and Morgan Bazilian
John Kerry helped bring the world into the Paris climate agreement and expanded America's reputation as a climate leader. That reputation is now in tatters, and President-elect Joe Biden is asking Kerry to rebuild it again – this time as U.S. climate envoy.
Energy Is at the Center of the Climate Challenge<p>The <a href="https://science2017.globalchange.gov/chapter/1/" target="_blank">effects of climate change</a> are already evident across the globe, from <a href="https://theconversation.com/100-degrees-in-siberia-5-ways-the-extreme-arctic-heat-wave-follows-a-disturbing-pattern-141442" target="_blank">extreme heat waves</a> to <a href="https://science2017.globalchange.gov/chapter/12/" target="_blank">sea level rise</a>. But while the challenge is daunting, there is hope. Solar and wind power have become the <a href="https://www.irena.org/publications/2020/Jun/Renewable-Power-Costs-in-2019" target="_blank">cheapest forms of power generation globally</a>, and technology progress and innovation continue apace to support a transition to clean energy.</p><p>In the U.S. under a Biden administration, long-term national climate legislation will depend on who controls the Senate, and that won't be clear until after two run-off elections in Georgia in January.</p><p>But there is no shortage of <a href="https://www.bloomberg.com/features/2020-biden-climate-change-advice/" target="_blank">ideas for ways Biden</a> could still take action even if his proposals are blocked in Congress. For example, he could use executive orders and direct government agencies to tighten regulations on greenhouse gas emissions; increase research and development in clean energy technologies; and empower states to exceed national standards, <a href="https://www.reuters.com/article/us-autos-emissions-california/defying-trump-california-locks-in-vehicle-emission-deals-with-major-automakers-idUSKCN25D2CH" target="_blank" rel="noopener noreferrer">as California did in the past with auto emission standards</a>. A focus on a just and equitable transition for communities and people affected by the decline of fossil fuels will also be key to creating a sustainable transition.</p><p>The U.S. position as the world's largest oil and gas producer and consumer creates political challenges for any administration. U.S. forays into European energy security are often treated with suspicion. Recently, France blocked <a href="https://www.wsj.com/articles/frances-engie-backs-out-of-u-s-lng-deal-11604435609" target="_blank">a multi-billion dollar contract</a> to buy U.S. liquefied natural gas because of concerns about limited emissions regulations in Texas.</p><p>Strengthening cooperation and partnerships with like-minded countries will be critical to bring about a transition to cleaner energy as well as sustainability in agriculture, forestry, water and other sectors of the global economy.</p>
Creating a Global Sustainable Transition<p>How the world recovers from COVID-19's economic damage could help drive a lasting shift in the global energy mix.</p><p>Nearly one-third of Europe's US$2 trillion economic relief package <a href="https://www.bloomberg.com/news/articles/2020-07-21/eu-approves-biggest-green-stimulus-in-history-with-572-billion-plan" target="_blank" rel="noopener noreferrer">involves investments that are also good for the climate</a>. The European Union is also strengthening its 2030 climate targets, though each country's energy and climate plans will be critical for successfully implementing them. The <a href="https://joebiden.com/clean-energy/" target="_blank" rel="noopener noreferrer">Biden plan</a> – including a $2 trillion commitment to developing sustainable energy and infrastructure – is aligned with a global energy transition, but its implementation is also uncertain.</p><p>Once Biden takes office, Kerry will be joining ongoing <a href="https://www.un.org/en/conferences/energy2021/about#:%7E:text=The%20overarching%20goal%20of%20the,2030%20Agenda%20for%20Sustainable%20Development.&text=Accelerate%20delivery%20of%20United%20Nations,related%20issues%20at%20all%20levels." target="_blank" rel="noopener noreferrer">high-level discussions on the energy transition</a> at the U.N. General Assembly and other gatherings of international leaders. With the U.S. no longer obstructing work on climate issues, the G-7 and G-20 have more potential for progress on energy and climate.</p><p>Lots of technical details still need to be worked out, including international trade frameworks and standards that can help countries lower greenhouse gas emissions enough to keep global warming in check. <a href="https://www.carbonpricingleadership.org/what" target="_blank" rel="noopener noreferrer">Carbon pricing</a> and <a href="https://www.csis.org/analysis/how-can-europe-get-carbon-border-adjustment-right" target="_blank" rel="noopener noreferrer">carbon border adjustment taxes</a>, which create incentive for companies to reduce emissions, may be part of it. A consistent and comprehensive set of national energy transition plans will also be needed.</p><p>The global shift to <a href="https://www.irena.org/publications/2019/Jan/A-New-World-The-Geopolitics-of-the-Energy-Transformation" target="_blank">clean energy will also have geopolitical implications for countries and regions</a>, and this will have a profound impact on wider international relations. Kerry, with his experience as secretary of state in the Obama administration, and Biden's plan to make the climate envoy position part of the National Security Council, may help mend these relations. In doing so, the U.S. may again join the wider community of countries willing to lead.</p>
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As we approach the holidays I, like most people, have been reflecting on everything 2020 has given us (or taken away) while starting to look ahead to 2021.