Testing is our window onto the pandemic and how it is spreading. Without testing we have no way of understanding the pandemic. It is one of our most important tools in the fight to slow and reduce the spread and impact of the virus.
Tests allow us to identify infected individuals, guiding the medical treatment that they receive. It enables the isolation of those infected and the tracing and quarantining of their contacts. In addition, testing for COVID also informs our understanding of the pandemic and the risks it poses in different populations.
This knowledge is important if we are to properly assess the interventions that should be implemented, including very costly interventions such as social distancing and the shutdown of entire regions and industries. The testing data we present below relates to the former kind of test. Here you can find a video that explains how this kind of test works.
The second kind of test — serological tests — are generally still in the research stage of development. This kind of test will be central to establishing how far the coronavirus has spread across the broader population. The Centre for Health Security at Johns Hopkins University provide up to date information on serology tests that are in development or available for use — whether for diagnosis, or only for research purposes.
A helpful summary of the current state of testing technologies and their implementation — as of 8 April — can be found in this editorial published in Nature Biomedical Engineering. Without data we cannot respond appropriately to the threat; neither as individuals nor as a society. Nor can we learn where countermeasures against the pandemic are working.
But the confirmation of a case is based on a test. Reliable data on testing is therefore necessary to assess the reliability of the data that informs us about the spread of the pandemic: the data on cases and deaths. Some countries present comprehensive, detailed and regularly updated data. Iceland here is one of these countries.
Estonia here goes even further, showing breakdowns by age, gender and region. For many countries however, available data on testing is either incomplete or else completely unavailable. This makes it impossible for their citizens and for researchers to assess the extent and significance of their testing efforts.
Our current knowledge of COVID testing — and more importantly of the pandemic itself — would be greatly improved if all countries were able to report all the testing data available to them in the way shown by the best examples. Those countries that do publish testing data often do not provide the required documentation to make it clear what the provided numbers precisely mean, and this is crucial for meaningful comparisons between countries and over time.
The key questions that any data description on testing data should answer are given in the following checklist. Clear answers to these questions are what is needed to properly interpret and compare published numbers. For citizens to trust and understand the published data and for countries to learn from each other, it is crucial that every country provides the data on testing in a clearly documented way.
We hope this checklist offers helpful guidance. Many countries are not yet providing official figures. Others do not do so on a regular basis. The first question to ask, then, is if there is any testing data for a given country. Equally important is to make the available data findable. Currently, the available data is often not easy to find, because some countries are releasing figures at unpredictable intervals in ad-hoc locations including social media or press conferences.
The number of tests performed is different to the number of individuals tested. The reason for this is that it is common for COVID testing that the same person is tested more than once. It needs to be clear whether or not figures for the total number of tests performed, or the number of people tested, include negative test results, as well as the number of tests that are pending results.
To be reliably included in test counts, it needs to be explicit whether such categories reflect the number of people who are awaiting test results or have tested negatively. Figures reported by countries may only be partial if not all laboratories are reporting to the central authority.
The scope of testing data should be made explicit by the source.Limited global testing for coronavirus yellow has led researchers to try to estimate the prevalence of infection within specific communities. Widespread antibody testing in a Californian county has revealed a much higher prevalence of coronavirus infection than official figures suggested.
The findings also indicate that the virus is less deadly than current estimates of global case and death counts suggest. But some scientists have raised concerns about the accuracy of kits used in such studies because most have not been rigorously assessed to confirm they are reliable. The work has not yet been peer reviewed.
Many surveys are using commercial antibody kits to detect antibodies against the virus in blood samples. The presence of SARS-CoVspecific antibodies reveals that a person had been infected for at least a week earlier, even if they have had no symptoms. This is especially important for an infection such as SARS-CoV-2, for which some people show no symptoms, or only mild ones, she says.
When combined with information about age, gender, symptoms, co-morbidities and socioeconomic status, these surveys can also help to answer questions about factors such as the role of children in spreading the infection, and the portion of cases that are asymptomatic. News of the Santa Clara analysis follows preliminary results from a similar study in Germany, released on 9 April, that tested some people in a village of more than 12, and found that one in seven had been infected with SARS-CoV The fact that both studies detected much higher rates of infection than official figures suggest is not surprising, says Peter Collignon, a physician and microbiologist at the Australian National University in Canberra.
The virus had been spreading in the United States and parts of Europe for at least a month before it was detected as spreading in the community. But Collignon notes that the commercial antibody tests used in both studies were evaluated onusing only a small number of people, which could also affect the accuracy of the survey results.
Kits are also being marketed for testing whether individuals have had the disease. Sero-surveys can also provide a better estimate of how deadly a virus is, using a measure known as the infection fatality rate IFR — the proportion of all infections, not just those confirmed through clinical testing, that result in death.
An accurate IFR can improve models being used to decide public-health responses. If a disease turns out to be less deadly than previously estimated, this could reframe discussions around the measures being introduced to contain it, and their economic and social impact, says Neeraj Sood, a health economist at the University of Southern California in Los Angeles, who is leading a separate antibody study in Los Angeles and is also a co-author in the Santa Clara study.
As of 10 April, the county's official death count was 50 people. In another study, the same group estimated an IFR for China of 0. Figures vary in different places for several reasons, including the age distribution of the population and the extent of testing. Fatality rate estimates have been revised down over time as more people have been tested and researchers have gained more insight into less-severe cases, as happened with swine flu insays Eran Bendavid, a population-health researcher at Stanford University who led the Santa Clara study.
But scientists have concerns about the reliability of antibody tests, particularly in regards to the number of false positives they produce, which could inflate infection rate estimates. According to the preprint, the manufacturer's kit performance data noted 2 false positives out of true negative samples.
But with that ratio of false positives to true cases, a large number of the positive cases reported in the study — 50 out of tests — could be false positives, says Marm Kilpatrick, an infectious disease researcher at the University of California Santa Cruz.
To ensure a test is sensitive enough to pick up only true SARS-CoV-2 infections, it needs to be evaluated on hundreds of positive cases of COVID and thousands of negative ones, says Michael Busch, an infectious-diseases researcher and director of the Vitalant Research Institute in San Francisco, California, who is also leading a sero-prevalence survey.The Food and Drug Administration sent a warning letter Thursday ordering Jones to stop falsely claiming that toothpaste, mouth wash and other products sponsored by his show can help prevent COVID Jones, known for pushing conspiracy theories about school shootings and the Sept.
The agency states that by making these claims Jones is promoting illegal, unapproved drugs, which can carry financial penalties and risk product seizures by government agents. FDA warnings are not legally binding, but the agency can take individuals to court if they are ignored. The FDA has not approved any treatments or vaccines against the coronavirus, and the National Institutes of Health says no scientific evidence exists to suggest alternative remedies help.
The FDA warning follows earlier government warnings against Jones last month.
C.D.C. Recommends Wearing Masks in Public; Trump Says, ‘I’m Choosing Not to Do It’
The AP is solely responsible for all content. Listen Live. Mostly Cloudy. The latest top stories. The latest traffic report. On Thursday, April 9,the U. Food and Drug Administration sent a warning letter ordering Jones to stop falsely claiming that toothpaste, mouth wash and other products sponsored by his show can help prevent COVID Scott Applewhite. FDA warns Alex Jones to stop pitching bogus virus remedies.
Updated: April 10 PM. Read More. The Latest News Headlines. Coronavirus live updates: Global deaths soar pastas US death toll tops 39, More than 2.
In the four months since the virus was first identified in Wuhan, China, it has infected at least 2, people worldwide.This briefing has ended. Read our global live coverage on the coronavirus pandemic here. The C. They suggested for a period of time. But this is voluntary. These face coverings can be easily washed or reused. I want to emphasize that the C. The new mask guidelines also do not replace C. I think wearing a face mask as I greet presidents, prime ministers, dictators, kings, queens.
President Trump said on Friday that the Centers for Disease Control and Prevention was urging all Americans to wear a mask when they leave their homes, but he immediately undercut the message by repeatedly calling the recommendation voluntary and saying that he would not wear one himself. I am choosing not to do it. It may be good. It is only a recommendation, voluntary.
And it came at a particularly contentious briefing where the president insulted reporters, jousted with his own administration and returned to pugilistic form. Trump again dismissed the recommendation of Dr. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, for a national stay-at-home order, saying he would leave such demands to the governors. The mask debate has played out in public and in private.
Trump said Americans who choose to comply with the C. Senior officials at the C. Miller, is a former federal prosecutor who spent nine years as the inspector general of the General Services Administration. Miller was nominated for that post in by President George W. The position will be closely scrutinized as lawmakers from both parties have been calling for Mr.
Trump to fill the role expeditiously to ensure that the stimulus money is doled out with transparency and that fraud and favoritism are avoided. The president alarmed some in Congress last week when, after signing the legislation, he released a statement that suggested he had the power to decide what information the inspector general could share with Congress. Miller joined the White House, where he is a special assistant to the president and a senior associate counsel, in December That role is expected to be a red flag for Mr.
Attorney General William P.You are now logged in. Forgot your password? Preliminary results are out from a COVID case cluster study in one of the regions worst hit by Germany's coronavirus epidemic. They are somewhat reassuring. One often-heard statistic is the "case fatality rate"—that is, the percentage of people diagnosed with a disease who will die of it. This afternoon that figure stands at 3.
What we really need to know is the infection fatality rate: the percentage of all the people infected who eventually die of the disease. That's what the German study attempts to do. Over the last two weeks, German virologists tested nearly 80 percent of the population of Gangelt for antibodies that indicate whether they'd been infected by the coronavirus. Around 15 percent had been infectedallowing them to calculate a COVID infection fatality rate of about 0.
The researchers also concluded that people who recover from the infection are immune to reinfection, at least for a while.
Antibody tests suggest that coronavirus infections vastly exceed official counts
For comparison, the U. For seasonal flu, the rate typically averages around 0. Basically, the German researchers found that the coronavirus kills about four times as many infected people than seasonal flu viruses do. The German researchers caution that it would be wrong to extrapolate these regional results to the whole country. But they also believe these findings show that lockdowns can begin to be lifted, as long as people maintain high levels of hygiene to keep COVID under control.
Josh Blackman 4.
Katherine Mangu-Ward From the May issue. Ilya Somin 4. Eugene Volokh 4. Scott Shackford 4. Possible really good news from a population screening antibody test study in Santa Clara County, California.Far more people may have been infected with Covid than have been confirmed by health officials in Santa Clara County, California, according to a study released Friday in preprint.
The study used an antibody blood test to estimate how many people had been infected with Covid in the past. Other tests, like those performed with nasal swabs or saliva, test for the virus' genetic material, which does not persist long after recovery, as antibodies do.
Jay Bhattacharya, a professor of medicine at Stanford University and one of the paper's authors. The study estimated that 2. This represents between 48, and 81, people, which is 50 to 85 times what county officials recorded by that date: confirmed cases.
A preprint study is a draft version of a study released to the public that hasn't been peer-reviewed for publication in a journal.
The National Institutes of Health has a similar effort underway as well. Bhattacharya said information from these studies will not only give researchers a better idea on antibody prevalence, but they will also vastly improve projections and disease modeling. Experts have said it's clear there have been more people infected than we've tested for, but it's unclear how much higher that number could be. That number depends on knowing how many people have had the infection -- not just actively have it now, but have had it and recovered from it," Bhattacharya said.
If 50 times more people have had the infection, the death rate could drop by that same factor, putting it "somewhere between 'little worse than the flu' to 'twice as bad as the flu' in terms of case fatality rate," Bhattacharya said.
But he cautioned that the flu and coronavirus are still quite different. For one, we don't yet have a vaccine for Covid Doctors suspect, though, and are still trying to prove beyond a doubt, that antibodies to Covid mean one is immune down the line. The study in Santa Clara County recruited participants largely using Facebook ads targeted by zip code to sample various parts of the community.
The study tested 3, adults and children. Sanjay Gupta on his podcast, "Coronavirus: Fact vs. Michael Nedelman, CNN.You are now logged in. Forgot your password? The gap between confirmed COVID cases and the actual number of infections, which is crucial in estimating the prevalence and lethality of the virus that causes the disease, may be far larger than most epidemiologists have assumed.
According to a recent analysis by two German researchers, the official numbers published by 40 national governments at the end of March represented just 6 percent of infections on average, meaning that "the true number of infected people worldwide may already have reached several tens of millions," as opposed to the current global tally of fewer than 2 million.
That is especially true when most carriers experience no symptoms or have symptoms so mild that they never seek treatment or testing, as appears to be the case with the COVID virus. The crude case fatality rate for COVID—reported deaths as a percentage of confirmed cases—varies widely by country, which suggests "vast differences in the quality of countries' case records," Vollmer and Bommer note.
To figure out how many infections might be missing from the official numbers, Vollmer and Bommer applied estimates from a Lancet Infectious Diseases study published on March That study, based on 24 COVID deaths in China and recoveries among citizens of other countries who returned from Wuhan after the outbreak there, estimated that the fatality rate was 1. Both of those rates rose with age, and the average time from symptom onset to death was 18 days.
As of March 31, Vollmer and Bommer calculate, confirmed cases represented just 3. In other words, the true number of infections was between 29 and 83 times as high as the official tallies in those countries. The countries with the highest estimated detection rates were South Korea nearly 50 percentNorway 38 percentJapan 25 percentand Germany 16 percent. With the exception of Japanall of those countries have tested a relatively large percentage of their populations.
The estimated prevalence of infection ranged from 0. Vollmer adds : "These results mean that governments and policy makers need to exercise extreme caution when interpreting case numbers for planning purposes. Such extreme differences in the amount and quality of testing carried out in different countries mean that official case records are largely uninformative and do not provide helpful information.
The country-specific infection fatality rates IFRs calculated by Vollmer and Bommer cover a wide range, from just 0. Their estimate for Germany is 1. Those tests, which covered 80 percent of the local population, found that 15 percent of residents had been infected and put the IFR at 0.
Vollmer and Bommer's estimated IFR for the United States is close to 1 percent, which is the high end of the range that federal public health officials consider reasonable and would make COVID about 10 times as deadly as the seasonal flu. That IFR implies a U. Vollmer and Bommer estimated that nearly 12 million Americans were already infected by March If the IFR is in fact about 1 percent, we would expect to see something likedeaths by now, nearly two weeks later, as opposed to the official tally of 22, or so.Dr. Anthony Fauci: Antibody tests are coming soon
Since Vollmer and Bommer are relying on the IFR estimates from the Lancet Infectious Diseases study, the accuracy of their numbers depends on the accuracy of that model. Furthermore, they adjusted only for age when they estimated the IFR for each country. For instance, it is possible that countries with very good health systems are more successful in treating patients than China.
According to the new calculationsthe detection rate in the United States as of March 30 was 6. The new estimates are also higher for other countries, including Italy 6. It turns out that it did improve, and therefore the estimated number of infections is much lower than under the assumption of a constant detection rate. The share of undetected cases is still quite sizeable, above 90 percent across these countries. The new estimate for the number of infections in the United States at the end of March is 2.
Based on the "expected infection fatality rate" of 0. Since the calculation of the detection rate is based on the expected IFR combined with the death toll and the estimated time to death, that is what you would expect.
Whether that IFR estimate will prove to be in the right ballpark is another question. Josh Blackman 4. Katherine Mangu-Ward From the May issue. Ilya Somin 4. Eugene Volokh 4.