A coronavirus patient's phlegm or poop could still have live virus in it even after they recover and test negative, new research suggests
The new coronavirus typically spreads via airborne particles from an infected patient's coughs or sneezes. But some research suggests the virus can spread via fecal matter — studies have found traces of the virus in infected patients' poop. A new study found that the virus lingers in recovered patients' phlegm and poop for weeks after diagnostic tests using swabs from their nose and throats came back negative. This could mean doctors are discharging patients from the hospital who have tested negative for COVID-19 but are still shedding viral particles. Visit Business Insider's homepage for more stories.
The coronavirus typically spreads via airborne particles: When an infected person coughs or sneezes, viral particles can land on someone else's nose or mouth or get inhaled, then infect the new host. But a growing body of research also suggests the new coronavirus can spread via poop particles. A new study published in the Annals of Internal Medicine suggests that even after samples from recovering coronavirus patients' noses and throats came back negative for the COVID-19 virus, the patients were still shedding the virus in their sputum (phlegm) and poop. "These findings raise concern about whether patients with negative pharyngeal swabs are truly virus-free, or sampling of additional body sites is needed," the authors of the study wrote. The problem is that the only means of diagnosing a coronavirus patient to date is a test that utilizes nose and throat swabs to scan for the virus' genetic code. Right now, two back-to-back pharyngeal tests that come back negative — from samples collected at least 24 hours apart — are part of the criteria that tells doctors whether to discharge recovered COVID-19 patients. But the new research raises doubts about whether that's conclusive enough. Some patients tested negative for the coronavirus but had virus-laden poop and phlegm The new study analyzed 133 COVID-19 patients admitted to Beijing Ditan Hospital in China between January 20 and February 27. From that group, the researchers identified 22 people who tested negative based on throat and nose swabs but had phlegm and poop that still tested positive for the coronavirus. The researchers found that the sputum and feces from those patients still tested positive for the coronavirus up to 39 days and 13 days, respectively, after the patients' pharyngeal samples tested negative. However, according to experts, some viral shedding after recovery is normal. "It's been long know that, for many viral diseases, for a period of time after you recover you can still excrete some virus, but usually pretty low levels of it," William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt Medical University, told Business Insider. Just because a patient's phlegm and poop still have live coronavirus in them, that doesn't mean the viral particles can infect others. "The question is whether that virus that sheds is actually culturable. Is it something that you could grow in a lab? Is it something that we think could actually transmit to someone?" Megan Coffee, an infectious disease clinician in New York City, told Business Insider. "Sometimes viruses shed and it's simply the genetic material. It's not actually a virus that could actually infect someone," she added.
Nevertheless, the authors of the new study point out, diagnoses based on a patient's nose and throats swabs are pivotal in a doctor's decisions about whether to discharge them from a hospital and whether they need to continue self-isolating. If a patient is still shedding the virus when they resume normal behavior, they might pose a risk to others. The virus can spread through poop Several studies have found virus particles in infected people's poop. A study of three coronavirus patients in Singapore revealed that the coronavirus showed up in their stool — samples taken from the toilet bowls and sinks in their rooms came back positive. Researchers from the Chinese Center for Disease Control and Prevention also detected viable virus particles in coronavirus patients' feces. But Schaffner said the presence of the virus in feces "is likely to play a very small role, if any, in its transmission in the US." "I don't think it's going to be a problem here, where we literally flush the fecal material with the virus down the drain," he said.
But Schaffner added that the lingering presence of viral particles in phlegm is more concerning. "That may contribute to a small amount of transmission in hospital settings," he said, since that's where patients with severe cases are clustered close together and expelling phlegm. Aria Bendix contributed reporting to this story.Join the conversation about this story » NOW WATCH: Drugmakers are developing coronavirus vaccines in record time — but it will still be months before one is available
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The coronavirus' average incubation is 5 days, and people may be most contagious a day before symptoms. Here's what that means for Trump's contacts.
Summary List Placement After President Donald Trump announced that he and Melania Trump had been diagnosed...Summary List Placement After President Donald Trump announced that he and Melania Trump had been diagnosed with the coronavirus, public-health experts started doing some simple math. The president tweeted about his positive test result at 1 a.m. ET on Friday. Researchers know that on average, it takes five days for coronavirus symptoms to show up after a person gets infected. That's also how long it might take for a test to come back positive after exposure. So the president likely got exposed sometime in the last week. Several studies have also found that that coronavirus patients are often contagious before showing symptoms — in fact, the average patient is most infectious the day they start showing symptoms and the day or two prior. Here's what the research shows about the virus' incubation period, when a person is most likely to transmit it, and what that means for everyone who recently interacted with Trump. The virus' incubation period is between 2 and 14 days The coronavirus' incubation period — the length of time between when a person gets infected and when they first show symptoms or test positive — is between two and 14 days, according to the Centers for Disease Control and Prevention. Similarly, a March study of coronavirus patients in China earlier this year reported that the incubation period for 97.5% of infected people was less than 12 days. But on average, it takes four to five days for symptoms like fatigue, cough, and fever to start. Trump developed symptoms, including a cough, fever, and lethargy on Friday, the New York Times reported. In the afternoon, he was transferred to Walter Reed National Military Medical Center for testing. He will remain at the hospital for a few days, according to the Associated Press. This timeline suggests Trump may have gotten infected last weekend. However, because it takes a couple of days for people to start shedding viral particles after infection, Trump most likely did not spread the virus to any attendees at Judge Amy Coney Barrett's Supreme Court nomination on Saturday. "It's safe to say that it would be exceedingly rare for anyone to transmit the virus earlier than two days post exposure; however, at some point after that, the risk would begin to rise significantly," an article on the MIT Medical website says. According to Monica Gandhi, an infectious-disease expert at the University of California, San Francisco, anyone who has recently been around Trump, Melania, or White House adviser Hope Hicks (who tested positive Thursday) could test positive in the days ahead, even if they've recently had a negative test. "This entire week would be a risky period," Gandhi told Business Insider. Trump was probably infectious a day before his symptoms started Amesh Adalja, a senior scholar at the Johns Hopkins University Center for Health Security, told Business Insider that the president was infectious "probably about a day before symptoms started." How contagious a given patient is has to do with their viral load: how many viral particles they're carrying and shedding into the environment. One April study showed that patients had the highest viral load in their throat swabs at the time their symptoms started. "Models show the highest infectious period, the period at which you're spewing the most virus, is your onset of symptoms and possibly the day before," Gandhi said. That's why pre-symptomatic coronavirus transmission is so common. And it's why contact tracers usually track people's contacts back "about 24 hours before symptom onset," Adalja said. He added that an infected person's period of peak viral load can persist into "the very first days of symptoms" as well. That means the 100 or so people Trump came into contact with at his Thursday fundraiser in Bedminster, New Jersey, may have been exposed to the president at his most infectious time. Trump's campaign sent all fundraiser attendees an email on Friday urging them to contact a medical provider if they develop COVID-19 symptoms. The timeline could shift, however, if Trump turns out to have been feeling mild symptoms before Friday. Bloomberg reported that his aides suspected he wasn't feeling 100% as early as Wednesday. If that's true, the president might have been at his most infectious point on Tuesday, when he was debating former Vice President Joe Biden in Cleveland, Ohio. Even though Trump's COVID-19 test came back negative on Tuesday, Adalja said, a person "could be infectious and test negative." Trump's contacts who test negative Friday aren't 'in the clear' Biden and his wife, Jill, tested negative for the coronavirus on Friday, after which he announced he'd be resuming cross-country campaigning. But health experts caution that the negative result doesn't mean Biden can rest easy yet. "Reminder that testing COVID-19 negative today does not mean that those exposed to POTUS/FLOTUS/Hope Hicks are in the clear," Anne Rimoin, an epidemiologist at University of California, Los Angeles, tweeted on Friday. The virus' four- to five-day average incubation period means that if Biden was infected at the debate, he would most likely not start to show symptoms or test positive until this weekend. Although Biden and Trump stood about 10 feet apart onstage, the event was held inside and neither man wore a mask as they vigorously debated. Studies have shown that talking loudly and forcefully exhaling can lead a person to spew viral droplets farther than 6 feet. Gandhi said I think that is not unreasonable to be concerned about Biden's potential exposure. "The concerning part is that Trump yelled straight for 90 minutes," she said, adding, "I would advise Biden, certainly, to get tested." Morgan McFall-Johnsen contributed reporting to this story.SEE ALSO: The coronavirus' average incubation period is 5 days, a study shows — but in 1% of cases, it may last longer than the standard 2-week quarantine Join the conversation about this story » NOW WATCH: What we know about immunity for the coronavirus
There are 8 tests for the novel coronavirus that you can take at home. They work...There are 8 tests for the novel coronavirus that you can take at home. They work by collecting samples from the nose or mouth. Then, they're shipped to laboratories, where a process called "nucleic acid amplification" finds the virus' genetic material. The hope of at-home testing is to get tests in the hands of people who might otherwise struggle to find tests; rural areas and ZIP codes with more people of color tend to have less testing sites per capita. They cost anywhere from $0 to $150, and some of the companies accept funds from health savings accounts. Visit Business Insider's homepage for more stories. Among the hundreds of tests out there for the novel coronavirus, just a handful have received emergency authorization from the US Food and Drug Administration to ship them to people's homes. With at-home tests, people self-collect their samples and ship them back to the testing company for analysis. Many of the companies have their own labs and tests, or partner with other groups to run the samples, according to the FDA and Business Insider's reporting. Over the past few months states have started reopening and testing supplies have increased. Even so, coronavirus tests may still be hard to find for many, according to the Centers for Disease Control and Prevention. There's fewer testing sites in areas that are at least 75% people of color, and nearly two-thirds of rural counties have none at all, according to reporting by Axios and analysis by the nonprofit Surgo Foundation. At-home testing could make getting checked for coronavirus more accessible for those groups. They're also useful for people who feel sick and don't want to infect others, or are similarly afraid of getting infected by visiting a testing site or clinic. People seem to be taking these companies up on their at-home options. Testing company Everlywell has shipped nearly 75,000 coronavirus tests since March, according to a spokesperson. Fulgent Genetics, another testing group, said it's processing thousands of the tests per day. LabCorp, the first healthcare company to get the at-home kits authorized, has run more than 4 million diagnostic tests since March, though that number includes those carried out at testing locations as well, a spokesperson told BI. The at-home tests are similar in their sensitivity, or ability to detect coronavirus-positive samples, and specificity, or their ability to detect coronavirus-negative samples. To get tested, customers usually fill out some kind of questionnaire, get the testing kit, and ship it back for results. The price of the tests can range, with some tests costing as much as $150. Under the CARES Act, insurers have to provide coronavirus testing at no cost to members, but many of them are not doing so, healthcare executives told BI. Here are the eight emergency authorized coronavirus tests you can get at home. How at-home coronavirus tests work Unlike antibody tests, which measure for the body's immune response to the virus, these "diagnostic," "viral," or "molecular" tests detect the actual presence of the virus itself and, by extension, infection or very recent infection. They're how doctors tell patients who visit the hospital whether they have coronavirus or not. The tests work by a process called "nucleic acid amplification." That's when laboratory machines detect the genetic material of the virus by "amplifying" or copying it, according to Dr. Bobbi Pritt, a director in Mayo Clinic's Department of Laboratory Medicine and Pathology. Diagnostic tests work with a variety of samples from the upper respiratory tract. The best ones to use, according to Pritt, are nasopharyngeal swabs, which go way back in people's nasal passages until they reach the upper part of the throat behind the nose, called the nasopharynx. Viral loads tend to be heaviest there, Pritt said. Sometimes the tests used for at-home programs were studied in part with nasopharyngeal or other samples prior to getting the FDA's go-ahead, but the kits themselves use nasal and spit samples. While not ideal, it's easier for people to swab the insides of their mouths and noses than the back of their nasal passage; and they work about nine times out of 10, Pritt, who's developed diagnostic tests for other conditions, told BI. LabCorp Official name: COVID-19 RT-PCR Test Who makes the test: LabCorp makes the collection kit, and the test was developed in-house using devices and equipment from Roche, Thermo Fisher, and Integrated DNA Technologies, depending on how it's run, according to the FDA and a LabCorp spokesperson. Tests are carried out at the company's facilities. How it works: After a survey, LabCorp can file the cost of the test to people's insurance, or possibly cover it with federal funds, depending on eligibility, a spokesperson told BI. Then, the company sends a collection kit that includes a swab that's inserted into their noses to get samples, known as a nasal swab. The collection kits are sent via FedEx, and results are posted online. Accuracy: The test correctly identified 100% of 40 positive samples and 50 negative samples in an analysis posted with the FDA. Those results used nasopharyngeal swabs, compared to the nasal swab used in the at-home kit. Price: $0 upfront, according to the company. You can get one here. Rutgers University The device's official name: Rutgers Clinical Genomics Laboratory TaqPath SARS-CoV-2-Assay Who makes the test: The test was developed by a wing of Rutgers' genetics institute in partnership with testing companies Spectrum Solutions and Accurate Diagnostics, according to Rutgers. It uses a collection device made by Spectrum, and samples go to the Rutgers Clinical Genomics Laboratory in Piscataway, New Jersey, according to the FDA. The test requires parts from healthcare giants PerkinElmer and Thermo Fisher Scientific. How it works: When purchased from testing startup Vault Health, the doctor-ordered kits are sent to people's homes. Over Zoom, healthcare professionals supervise customers, who give the kits samples of their saliva. Results are posted within days after samples arrive at the lab. Other distributors, including testing companies ixLayer and Vitagene, also sell the test, according to Rutgers. Accuracy: The Rutgers test identified 100% of 60 positive and negative coronavirus samples when using swabs of saliva, according to data provided to BI by Rutgers. Price: $150 via Vault and $129 via Vitagene, though both allow you to pay via a health savings account or a flexible savings account. You can get one from Vault Health here and from Vitagene here. Everlywell Official name: Everlywell COVID-19 Test Home Collection Kit Who makes the test: Everlywell produces the kits that customers use to take samples, as well as the platform that, among other things, displays the results, a spokesperson told BI. The kits are analyzed by labs like Fulgent Genetics and Assurance Scientific, which use different diagnostic tests, according to the FDA. How it works: Depending on the shipping method, customers get their testing kits overnight or within 3 days. They go through a screening process, self-collect a nasal swab, and return the package to a drop-off location, according to Everlywell. The labs process them within 2 days. Accuracy: Both tests by Fulgent and Assurance correctly identified 100% of coronavirus samples as positive or negative in the clinical evaluations they shared with the FDA. Price: $109, which can usually be paid for using money in HSAs and FSAs, the spokesperson said. Everlywell also provides customers with the information they need to file claims with insurers. You can get one here. Fulgent Therapeutics Official name: Fulgent COVID-19 by RT-PCR Test Who makes the test: Fulgent Genetics, the parent company of Fulgent Therapeutics, makes the test and collection kit. It's also permitted to use another kit made by Everlywell. All samples are analyzed at Fulgent's laboratory in Temple City, California. How it works: Once folks complete an online screening, Fulgent's Picture Genetics mails them a kit. They ship back their nasal swabs in a pre-labeled box. Customers can see their results online and discuss them, if desired, with a medical professional virtually. Accuracy: Fulgent's test found 100% of negative and positive coronavirus samples taken with a variety of swabs, according to a company study on 94 specimens. Price: $119, with the option to file for reimbursement with health plans You can get one here. P23 Labs Official name: P23 Labs TaqPath SARS-CoV-2 Assay Who makes the test: P23's test uses parts from Thermo Fisher Scientific and works with collection kits made by testing companies Everlywell and OraSure Technologies, according to the FDA and a P23 spokesperson. Samples are tested in its lab in Little Rock, Arkansas. How it works: Once a clinician orders the test, it's shipped to people's homes. They take samples of their saliva with help from a healthcare worker online. The lab posts people's results to a website. It's sold by a handful of companies, including digital health companies Azova and ADx Healthcare, the spokesperson told BI. Accuracy: The tests are 98% sensitive and 99% specific, according to the company. Price: Between $109 and $129, depending on the kit and seller, the spokesperson said. You can get one here. PrivaPath Diagnostics Official name: LetsGetChecked Coronavirus (COVID-19) Test Who makes the test: PrivaPath, doing business as LetsGetChecked, makes the collection kit, but uses the molecular test made by Hologic, according to an FDA document and a spokesperson for the company. They're performed in PrivaPath labs. How it works: People fill out an online questionnaire, and doctors approve their requests. Testing packages include return labels, bags, nasal swabs, and a transport tube, according to the FDA. Once the lab gets the test, the company says that results are posted online within 24 hours. Throughout, users can track their symptoms with a mobile app. Accuracy: Hologic's test found 69 out of 69 positive samples and 109 out of 109 negative samples, according to the company's analysis on nasopharyngeal swabs. Price: $119, though folks can file claims for reimbursement with their health plans, and LetsGetChecked is offering a 20% discount. You can get one here. Phosphorus Diagnostics Official name: Phosphorus COVID-19 RT-qPCR Test Who makes the test: Phosphorus uses a kit made by OraSure Technologies to collect samples from customers, according to a spokesperson for the company; they're run in a Phosphorus lab in Secaucus, New Jersey, with tests made in-house. How it works: People can order the tests online after completing a questionnaire, which is reviewed by a doctor within 24 hours, the spokesperson said. Tests are shipped after approval and work via saliva samples. Physicians can chat about people's results with telemedicine. Accuracy: 97.1% sensitive and 98.2% specific, according to the company Price: $140, though people can seek reimbursement from their health plans You can get one here. Kaiser Permanente Mid-Atlantic States Official name: KPMAS COVID-19 Test Who makes the test: KPMAS, a health plan that's part of California-based Kaiser Permanente, makes the collection kit and runs the tests in a laboratory in Rockville, Maryland. The tests themselves, however, are made by Roche. How it works: KPMAS can send the kit to eligible members of the health plan, or have them pick it up, according to the FDA. It's used with supervision from a healthcare worker over video. People insert swabs into their noses to get samples, then place them in a tube, and ship it with FedEx. Results are posted to kp.org. Accuracy: Roche's PCR test found 100% of the 50 positive samples and 100% of the 100 negative samples tested in the company's evaluation using nasopharyngeal swabs, an FDA filing shows. Price: Unspecified, though Kaiser notes that testing is available at no cost to members. How to order: KPMAS kits have to be arranged by a provider.
Medical researchers are puzzled over why the coronavirus — which typically lasts about two weeks in...Medical researchers are puzzled over why the coronavirus — which typically lasts about two weeks in the body — endures far longer in some patients.