Advanced searches left 3/3
Search only database of 8 mil and more summaries

Saliva Based Covid Test

Summarized by PlexPage
Last Updated: 02 July 2021

* If you want to update the article please login/register

General | Latest Info

Science S COVID - 19 reporting is supported by the Pulitzer Center and the Heising - Simons Foundation. First, technician pushes a pencil - length swab to the very back of your nasal passages. Then you pay 100 or more, and wait days for an answer. But faster, cheaper, more pleasant ways to test for novel coronavirus are coming online. This month, US Food and Drug Administration Grant Emergency Use Authorization for two tests that sample Saliva instead of nasal fluid, and more innovations are likely after FDA relaxed rules to allow new tests to be adopted more quickly. One candidate was announced last week: experimental test, potentially faster and cheaper, that analyzes saliva in a new way. There is real promise here, says Anne Wyllie, microbiologist at Yale University who helped develop one of the new tests authorized this month. Takanori Teshima, chief of Laboratory Medicine at Hokkaido University, who also Report successful results testing Saliva, agree. It will have a big impact worldwide. When SARS - CoV - 2, respiratory virus that causes COVID - 19, emerges in December 2019, researchers will scramble to develop tests to detect the virus. Initially, they turn to a long - trusted technique for diagnosing respiratory infections: looking for viral genetic material in mucosal fluid, thought to be best hunting ground for respiratory viruses collected from deep in patients ' nasal passages. That is where 15 - centimeter swab comes in. The swab goes into a plastic tube with a chemical mixture that stabilizes the virus during transport to the Diagnostics lab. There, technicians extract its genetic material and load it into a machine to carry out polymerase chain reaction, which amplifies snippets of genetic material unique to the virus. The procedure accurately identifies infections about 95% of the time. But the testing is uncomfortable and, because collecting swabs requires close contact with patients, it puts medical personnel at risk of contracting virus. Nobody wants to do that job, Teshima say. Testing Saliva for SARS - CoV - 2 was no sure thing. Studies with other respiratory diseases show Saliva tests identify only about 90% of people for whom swab tests indicate infection. But the appeal of an easier and safer test for new coronavirus led researchers to try. It People being tested simply drool into a bar - cod plastic tube, seal it, and drop it in pouch that is shipped to the lab for PCR analysis. Because the procedure directly tests fluid responsible for transmitting viruses between people, it may give better indication of who is most contagious, said Paul Hergenrother, chemist at University of Illinois, Urbana - Champaign, who leads his Universitys Saliva Test development. As early as 12 February, researchers in Hong Kong and China Report in Clinical Infectious Diseases that they could identify SARS - CoV - 2 from Saliva in 11 of 12 patients whose swabs show virus. Since then, groups in the United States, Singapore, and Japan have confirmed and further simplified procedures, cutting out costly steps such as adding specialized reagents to stabilize viruses during transport and extracting genetic material.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Infected = Infectious

Its gross simplification: infectiousness depends on viral burden. The more viruses you have in your airways, we believe more likely you are to transmit to others. Viral burden rise steeply in days immediately following exposure. The typical infected person begins to shed large, transmissible quantities of viruses starting around Day 3 after exposure. Symptoms, if they emerge, will follow around Day 5. By Day 8, whether or not symptoms have emerge, viral burden and infectiousness are both in steady decline. All these numbers will vary from person to person, of course, but the general lesson is this: there is a roughly 5 - day window of maximum transmissibility, stretching from Day 3 to Day 8 following exposure. Another useful simplification: viral burden is also associated with the likelihood that antigen - base test will pick up presence of infection. More viruses in the airway, greater likelihood of positive antigen result. What that means is thatconvenientlythere is a high degree of overlap between the period of maximal infectiousness and the period during which antigen - base test is most likely to yield positive results. And, just as importantly, antigen - base testing is highly specific: unlike its PCR counterpart, antigen test isnt fooled by faint signals of lingering viral matter outside period of infectiousness. For purposes of surveillance screening, those antigen - base negatives worrying FDA arent false negatives at all; those are true negatives for disease transmission. Far from being problematic, in the context of outbreak containment, antigen tests limit window of sensitivity is major asset. The Antigen test is ideally suited to yielding positive results precisely when the infected individual is maximally infectious. Contrast that with PCR, whose performance barely depends at all on viral load. In principle, PCR can detect just a few copies of viral RNA. Pcr starts to pick up scent on Day 2 and continues to return positive results for as many as 6 - 12 weeks after exposure. That is great if youre interested in knowing if someone was infected in the past several weeks to months; but it is a problem if you are interested in knowing if someone is infectious right now. Pcr continues to produce positive results long after person has ceased to pose any real risk of transmission to others, Some data say up to 12 weeks longer! As test of infectiousness, PCR test is far too prone to false positives. These false positives clog up testing and contact tracing infrastructure and needlessly ground lot of people WHO pose no transmission risk to others. Pcr is the wrong tool for surveillance job. There are a thousand little details that our clinical colleagues would add to this narrative. But the main message is this: For purposes of containing outbreaks, problem is decidedly not false negatives associated with antigen testing; rather, problem is false positives associated with PCR testing. If your goal is to suss out infectiousness and prevent outbreaks, antigen test is the tool you want to reach for first.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Welcome!

The new test for coronavirus is so simple and straightforward, almost anyone could do it: Spit a glob of saliva into a cup, close the lid and hand it over. While not as fast to process as the speediest swab tests, saliva tests could transform diagnosis of COVID - 19. If manufactured in enough numbers and processed by enough labs across the country, they could alleviate Diagnostic shortages that have hampered containment of pandemics and offer a less onerous way for companies to see if workers are infect. The first saliva - base test, already being offered in parts of New Jersey, detects genetic material from viruses just as existing tests do, but it avoids long swabs that reach disturbingly far up persons nose. For saliva - base, health care workers do not need to wear and discard precious gowns and masks. And early evidence suggests it is just as sensitive, if not more so, than swabs. Because the saliva test relies on equipment that is widely available, it also offers hope of nationwide rollout without encountering supply problems that have plague swabs. Starting about two weeks ago, New Jersey has offered saliva tests at walk - up site in New Brunswick; drive - through sites in Somerset and Edison; state Department of Corrections; 30 long - term care facilities; and even American Dream mall. Experts not involved with the test praise it as a welcome solution to Diagnostic shortages across the country. If people are going back to work, and theyre going to be tested presumably on a regular basis, we really do need to have less invasive sampling methods than swabs, says Angela Rasmussen, virologist at Columbia University. To have to do nasopharyngeal swabs twice a week? No, thanks. The next step would be an at - home saliva test kit that does even need to go to the walk - in Center, said Dr. Amesh Adalja, senior scholar at Johns Hopkins University Center for Health Security. Dr. Adalja noted that LabCorp, one of the nation's largest commercial laboratories, now offers at - home tests that people can use to swab their own nose. If we can do nasal swabs unsupervised, there is no reason why we ca do these tests unsupervised as well, he say. On April 13, Food and Drug Administration granted emergency - use authorization, waiving some usual requirements, for saliva test made by Rutgers University lab, RUCDR Infinite Biologics. Rutgers lab has already processed close to 90 000 tests, according to its chief executive, Andrew Brooks, and expects to ramp up eventually to 30 000 tests per day. Results are available within 72 hours, although they could be speeded up to just a few hours with enough infrastructure in place. By contrast, some rapid tests that rely on swabs deliver results in minutes. Other States are expressing interest.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Sources

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

logo

Plex.page is an Online Knowledge, where all the summaries are written by a machine. We aim to collect all the knowledge the World Wide Web has to offer.

Partners:
Nvidia inception logo

© All rights reserved
2021 made by Algoritmi Vision Inc.

If you believe that any of the summaries on our website lead to misinformation, don't hesitate to contact us. We will immediately review it and remove the summaries if necessary.

If your domain is listed as one of the sources on any summary, you can consider participating in the "Online Knowledge" program, if you want to proceed, please follow these instructions to apply.
However, if you still want us to remove all links leading to your domain from Plex.page and never use your website as a source, please follow these instructions.