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Post by Admin on Apr 7, 2020 6:24:42 GMT
New research appears to show that coronavirus is passed to people more easily than previously thought. New studies, coupled with the high number of potentially asymptomatic people, prompted the CDC to recommend that all Americans wear cloth masks in public. New guidance sent to the White House suggests that COVID-19 could be aerosol-transmitted, which means the tiny particles that carry the virus stay in the air much longer than previously thought. “There are micro-droplets and they can stay in the air for a while,” said Dr. Scott Miscovich, with Hawaii’s coronavirus task force. “That’s why you have to quarantine. That’s why social distancing is important.” The science is still too early to be conclusive, but some researchers say it is alarming. “There’s been advice given and guidance given out for a while, the whole time pretty much, that we need to social distance at six feet and a lot of that was based on research that was done, hate to say it, nearly 100 years ago,” said Kim Prather, University of California San Diego chemistry professor. Professor Prather says when a person coughs or sneezes, those germs travel about 6 feet. However, she says germs that carry viruses can travel much farther by simply breathing or talking. "If the breeze is blowing and you're 20 feet away, it can blow right to you,” Prather said. University of Hawaii Epidemiologist Dewolfe Miller says that’s possible, but the science on it still isn’t solid. “It may have some merit, but we have to have a great deal of more evidence before I go and say I am going to part ways with what has been settled on pretty well,” said Miller. Nevertheless, most doctors will agree wearing masks or simply staying home will save lives. “Some countries have historically worn masks when they think they’re sick. Places like Taiwan for example. If you look at their rate of death, their rate of cases, it’s nothing compared to us who don’t wear masks when we’re sick,” Prather said. The CDC said it’s especially important to wear masks in tight quarters like grocery stores or pharmacies, especially since people can be sick and not show signs. “It is a significant concern and another reason why people should wear masks when they’re needed and avoid being too close to others. You should assume you’re infected and everyone else is infected around you,” said Bruce Anderson, state Health Department director. The World Health Organization says they have reviewed the reports about transmission, but say more peer-reviewed testing is needed before they change their social distancing guidelines. “Maybe we’re over cautious, but at the end of the day, if we’re over cautious, we will save lives,” Prather said.
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Post by Admin on Apr 7, 2020 20:06:48 GMT
A report1 from the National Academy of Science, Engineering and Medicine to the White House Office of Science and Technology Policy released on April 1 states that based on current research, SARS-CoV-2 may be spread through aerosols. The letter cites a recent study2 at the University of Nebraska Medical Center that found “widespread evidence of viral RNA in isolation rooms where patients with SARS-CoV-2 were receiving care” in air and surface samples. Even air collectors that were more than six feet away from patients detected the RNA, calling into question whether current social distancing guidelines are sufficient to prevent the spread of the disease. To date, the Centers for Disease Control and Prevention (CDC) has stated that larger respiratory droplets expelled when infected people cough or sneeze are the primary means of transmitting the coronavirus, reports Science, but the possibility that SARS-CoV-2 could be airborne implies that recommendations about mask wearing in public may need to be revised. “In the mind of scientists working on this, there’s absolutely no doubt that the virus spreads in the air,” aerosol scientist Lidia Morawska of the Queensland University of Technology in Australia tells Nature. “This is a no-brainer.” A study3 from the University of Hong Kong that has not yet been peer-reviewed detected rhinovirus, influenza, and human coronaviruses (not including SARS-CoV-2) in respiratory droplets and aerosols, and found that surgical masks worn by sick patients reduced the detection of coronavirus RNA in both transmission forms, according to the NASEM report. Another preprint4 conducted in two Wuhan, China, hospitals indicates that staff movement, floor cleaning, and the removal of personal protective equipment could transmit the virus through the re-suspension of virus-contaminated aerosols. “[I’m] relieved to see aerosolization is accepted,” says Kimberly Prather, an aerosol chemist at the University of California, San Diego, in remarks to Science. “This added airborne pathway helps explain why it is spreading so fast.” Virologist Leo Poon of the University of Hong Kong tells Nature that evidence for the airborne transmission of SARS-CoV-2 isn’t yet sufficient, and Nature reports that a study from an outbreak center in Singapore found no evidence of the virus in air samples. The World Health Organization (WHO) states that airborne transmission may be possible during certain medical procedures such as intubation or open suctioning, but cautions that a recent study published in the New England Journal of Medicine5 that used a high-powered nebulizer to generate aerosols is not the same as real-life situations of people coughing. “Further studies are needed to determine whether it is possible to detect COVID-19 virus in air samples from patient rooms where no procedures or support treatments that generate aerosols are ongoing.” Michael Osterholm, an infectious disease epidemiologist at the University of Minnesota, tells Nature that definitive research on the airborne transmission of SARS-CoV-2 may take years, and that we shouldn’t “let perfect be the enemy of convincing.” Despite the uncertainty regarding the transmission of the coronavirus, public policy appears to be shifting. Los Angeles mayor Eric Garcetti tweeted today that residents should wear face coverings made of bandanas, scarves, or other fabric, and Science reports that the CDC may be preparing to recommend that all people in the United States wear cloth facemasks in public. 1. www.nap.edu/read/25769/chapter/12. www.medrxiv.org/content/10.1101/2020.03.23.20039446v23. www.nature.com/articles/s41591-020-0843-24. www.biorxiv.org/content/10.1101/2020.03.08.982637v15. www.the-scientist.com/news-opinion/sars-cov-2-can-live-on-plastic-and-steel-for-2-3-days-67260
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Post by Admin on Apr 8, 2020 8:17:43 GMT
New York, Detroit, and New Orleans—three metropolitan areas with some of the highest number of Covid-19 cases in the US—may all be hitting their peak number of hospital beds needed within the next week. “If mitigation in New York worked—and we believe it is working—the cases are going to start to go down, but the mortality will be a lag behind that because of the co-morbidities and other conditions,” said Deborah Birx, the coronavirus response coordinator for the White House Coronavirus Task Force, in a press briefing on Saturday. Birx and her team base these predictions on epidemiological models—in particular, those created by the Institute for Health Metrics and Evaluation (IHME) based at the University of Washington’s School of Medicine. When you hear of the pandemic “peaking” in these cities, what people are likely referring to is peak medical resource utilization. Many of these models, including the one from IHME, predict hospitalization rates, ICU admission rates, ventilator use, and deaths. In part, that’s because it’s simply easier to obtain that data—as opposed to, say, infection rates, which are impossible to know in the US since such little testing has been done. Thanks to what IHME’s director calls “a massive infusion of new data,” the model’s creators can feel increasingly confident in the accuracy of those kinds of predictions, which were updated on Sunday. But not every model agrees with IHME. In the absence of a single, definitive national epidemiological model, states and many other organizations have been left to create their own, so that public health officials can apply the right mitigation strategies and hospitals can prepare for how many patients they expect to receive. Models can disagree based on the assumptions of their creators. At the beginning of an outbreak, epidemiologists use estimates for how many people might be susceptible to the disease, how long a person stays sick, how long it takes for an infected person to develop symptoms, how likely a person is to contract the disease if they come into contact with someone who has it, and how likely someone is to be hospitalized or die from it. All that information is in very short supply when a disease is new, so researchers start with educated guesses. “In early stages you use a lot of assumptions, then you refine models over time using real data,” says Glen Mays, a public health expert at the Colorado School of Public Health at the University of Colorado. For the first coronavirus models in the US, epidemiologists had to rely on data from other countries, which may have varied because of differences in socialization patterns or underlying health conditions. For example, it’s much more common for men in China to smoke than it is for men in the US, which may have affected estimates of hospitalization rates. But now that more data is available, models can still vary widely. The IHME model, for example, predicts that Colorado has already hit its peak number of hospitalizations, while state-made models say the peak is yet to come. “Models are approximations of reality and all predictions should be approached cautiously. There is a great deal of uncertainty in model predictions and it is important to communicate this uncertainty, as well as model limitations and assumptions, alongside any model projections,” says Eva A. Enns, an associate professor of health policy at the University of Minnesota School of Public Health.
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Post by Admin on Apr 9, 2020 5:07:07 GMT
Claim: ‘Face masks don’t work’ Wearing a face mask is certainly not an iron-clad guarantee that you won’t get sick – viruses can also transmit through the eyes and tiny viral particles, known as aerosols, can penetrate masks. However, masks are effective at capturing droplets, which is a main transmission route of coronavirus, and some studies have estimated a roughly fivefold protection versus no barrier alone (although others have found lower levels of effectiveness).
If you are likely to be in close contact with someone infected, a mask cuts the chance of the disease being passed on. If you’re showing symptoms of coronavirus, or have been diagnosed, wearing a mask can also protect others. So masks are crucial for health and social care workers looking after patients and are also recommended for family members who need to care for someone who is ill – ideally both the patient and carer should have a mask.
However, masks will probably make little difference if you’re just walking around town or taking a bus so there is no need to bulk-buy a huge supply.
Claim: ‘It is mutating into a more deadly strain’ All viruses accumulate mutations over time and the virus that causes Covid-19 is no different. How widespread different strains of a virus become depends on natural selection – the versions that can propagate quickest and replicate effectively in the body will be the most “successful”. This doesn’t necessarily mean most dangerous for people though, as viruses that kill people rapidly or make them so sick that they are incapacitated may be less likely to be transmitted.
Genetic analysis by Chinese scientists of 103 samples of the virus, taken from patients in Wuhan and other cities, suggests that early on two main strains emerged, designated L and S. Although the L strain appeared to be more prevalent than the S strain (about 70% of the samples belonged to the former), the S branch of the virus was found to be the ancestral version.
The team behind this research suggested that this may indicate the L strain is more “aggressive”, either transmitting more easily or replicating faster inside the body. However, this theory is speculative at this stage – there haven’t yet been direct comparisons to see whether people who catch one version of the virus are more likely to pass it on or suffer more severe symptoms.
Claim: ‘It is no more dangerous than winter flu’ Many individuals who get coronavirus will experience nothing worse than seasonal flu symptoms, but the overall profile of the disease, including its mortality rate, looks more serious. At the start of an outbreak the apparent mortality rate can be an overestimate if a lot of mild cases are being missed. But Bruce Aylward, a WHO expert, who led an international mission to China to learn about the virus and the country’s response, said this has not been the case with Covid-19. The evidence did not suggest that we were only seeing the tip of the iceberg. If borne out by further testing, this could mean that current estimates of a roughly 1% fatality rate are accurate. This would make Covid-19 about 10 times more deadly than seasonal flu, which is estimated to kill between 290,000 and 650,000 people a year globally.
Claim: ‘It only kills the elderly, so younger people can relax’ Most people who are not elderly and do not have underlying health conditions will not become critically ill from Covid-19. But the illness still has a higher chance of leading to serious respiratory symptoms than seasonal flu and there are other at-risk groups – health workers, for instance, are more vulnerable because they are likely to have higher exposure to the virus. The actions that young, healthy people take, including reporting symptoms and following quarantine instructions, will have an important role in protecting the most vulnerable in society and in shaping the overall trajectory of the outbreak.
Claim: ‘You need to be with an infected person for 10 minutes’ For flu, some hospital guidelines define exposure as being within six feet of an infected person who sneezes or coughs for 10 minutes or longer. However, it is possible to be infected with shorter interactions or even by picking the virus up from contaminated surfaces, although this is thought to be a less common route of transmission.
Claim: ‘A vaccine could be ready within a few months’ Scientists were quick out of the gates in beginning development of a vaccine for the new coronavirus, helped by the early release of the genetic sequence by Chinese researchers. The development of a viable vaccine continues apace, with several teams now testing candidates in animal experiments. However, the incremental trials required before a commercial vaccine could be rolled out are still a lengthy undertaking – and an essential one to ensure that even rare side-effects are spotted. A commercially available vaccine within a year would be quick.’
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Post by Admin on Apr 10, 2020 2:17:48 GMT
Two separate research projects suggest that the novel coronavirus may have been circulating in New York City earlier than thought and the earliest cases likely originated with travelers coming from Europe and other parts of the United States, not Asia. The new data come from the Icahn School of Medicine at Mount Sinai and the NYU Grossman School of Medicine. 'It's all hands on deck now' Now new data from NYU Langone Health suggests that the novel coronavirus has been spreading in New York for a couple of months now -- long before testing started -- and a genetic analysis of viral samples in the city indicate that they originated in Europe, according to an announcement from the academic medical center on Thursday. The announcement notes that this early data was based on examining the genetic material of the novel coronavirus taken from 75 patients in New York City. Nasal swab samples were collected from the patients at Tisch Hospital, NYU Winthrop Hospital and NYU Langone Hospital Brooklyn. "As viruses evolve during transmission from person to person, their sequences can help researchers to zero in on the provenance, or place of origin, of that specific infection," Dr. Matija Snuderl, leader of the clinical testing team and director of molecular pathology and diagnostics at NYU Grossman School of Medicine, said in the announcement. The new data has not been published yet in a report, pre-print paper, study or peer-reviewed journal. "We're just starting this project, but will soon be sequencing 192 viral samples per week with the goal of offering thousands of sequences for analysis in the near future," Adriana Heguy, leader of the research team and director of the Genome Technology Center at NYU Langone Health, said in the announcement. Heguy added in an email on Thursday that "we want the whole community to have access as soon as we have the data. It's all hands on deck now." The 'dynamics of the pandemic' Separately, a pre-print study from Mount Sinai, published online Thursday at medRxiv and not yet peer-reviewed, involved sequencing and analyzing 90 complete coronavirus genomes from 84 Covid-19 patients who sought care in the Mount Sinai Health System between February 29 and March 18. The cases came from two towns in Westchester county and 21 New York City neighborhoods across Manhattan, Bronx, Queens and Brooklyn. Those cases were analyzed along with 2,363 publicly available coronavirus genomes from around the world. The Mount Sinai study traced the cases in the city and found there is "limited evidence" supporting that the virus was directly introduced there from China, where the coronavirus originated. China was under the United States' early travel restrictions in February. "With increased testing, we observed the emergence of community acquired infections with the majority of the community cases caused by viral isolates from clades that are of European origin," the researchers wrote in the Mount Sinai study. "Taken together, we provide a first analysis of the SARS-CoV-2 viral genotypes collected from patients seeking medical care," the researchers wrote. "We find that New York City, as an international hub, provides not only a snapshot of the diversity of disease-causing SARS-CoV-2 at the global level but also informs on the dynamics of the pandemic at the local level."
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