Test for Corona-Virus( SARS-CoV-2)
How to get tested for Corona-virus?
In case you feel your symptoms are specific to the corona-virus, your healthcare provider can get in touch with CDC or the local healthcare departments for testing instructions. There are specific labs set up for conducting corona-virus tests, so you may be directed to one of these labs.
There are different types of corona-virus tests that can be done:
- Swab Test – In this case, a special swab is used to take a sample from your nose or throat
- Nasal aspirate – In this case, a saline solution will be injected into your nose and, then a sample is taken with a light suction
- Tracheal aspirate – In this case, a thin tube with a torch, also known as a bronchoscope, is put into your mouth to reach your lungs from where a sample is collected.
- Sputum Test – Sputum is thick mucus that gets accumulated in the lungs and comes out with a cough. During this test, you’re required to cough up sputum in a special cup or a swab is used to take a sample from your nose.
- Blood test – In this case, a blood sample is taken from a vein in the arm.
A rapid test has also been started for the COVID-19, which involves taking samples from the nose, throat, and lungs. This ensures a speedy, and accurate diagnosis and is used in all CDC-approved.
Before the test, the concerned health professionals may request you to wear a mask during the test. In case there are any other steps that need to be taken, the healthcare professional can communicate that to you.
What are the risks associated while testing for Corona virus?
During the test, you may feel a gagging sensation when the swab will be inserted in your nose and throat. The nasal aspirate may especially seem a bit uncomfortable. However, all of these effects are temporary and will go away shortly after the test. In some cases of tracheal aspirate, there may be bleeding or infection. In the case of the blood test, no risks are observed. There may be a slight swell and pain in the area where the needle was inserted, however it goes away pretty soon.
1) What is PCR testing?
“At the moment the majority of the current Covid-19 tests that all the reports are coming from are using PCR,” says University of Sussex senior lecturer in microbiology Dr Edward Wright. “They detect the genetic information of the virus, the RNA. That’s only possible if the virus is there and someone is actively infected.”
PCR tests are used to directly detect the presence of an antigen, rather than the presence of the body’s immune response, or antibodies. By detecting viral RNA, which will be present in the body before antibodies form or symptoms of the disease are present, the tests can tell whether or not someone has the virus very early on.
“PCR gives us a good indication of who is infected. They can be isolated and get in contact with people they’ve been in touch with so they can be quarantined too, just in case. That’s the true advantage of the current major diagnostic tests, you can break that transmission chain and get a clearer picture of what’s happening,” says Wright.
By scaling PCR testing to screen vast swathes of nasopharyngeal swab samples from within a population, public health officials can get a clearer picture of the spread of a disease like Covid-19 within a population.
It’s worth noting that PCR tests can be very labour intensive, with several stages at which errors may occur between sampling and analysis. False negatives can occur up to 30% of the time with different PCR tests, meaning they’re more useful for confirming the presence of an infection than giving a patient the all-clear.
2) What is serologic testing?
Wright says: “An antibody test tells us what proportion of the population has been infected. It won’t tell you who is infected, because the antibodies are generated after a week or two, after which time the virus should have been cleared from the system. But it tells you who’s been infected and who should be immune to the virus.”
It’s not yet clear how long any immunity period after a Covid-19 infection will turn out to be. Historical studies have indicated that people who survived the 2003 – 2003 sudden acute respiratory syndrome (SARS) outbreak had antibodies in their blood for years after recovery. Both SARS and Covid-19 are caused by coronaviruses, but it’s too early to say if Covid-19 will generate a similar immune response. Reports also indicate that some people have been infected with the virus twice over, meaning these particular patients didn’t develop any immunity at all.
All that said, if public health officials can get a handle on what proportion of the population are theoretically immune to the virus, the information could help lift the social distancing restrictions on movement.
3) Rapid in-clinic antigen testing
Bosch has also taken an innovative approach to Covid-19, developing a point of care swab test designed to produce results in under two and a half hours.
Running on Bosch’s pre-existing Vivalytic analysis device, the company says the test is one of the world’s first fully automated molecular diagnostic tests that can be used directly by all medical institutions.
Vivalytic consists of an analyser device and matching test cartridges. There are biological components in each of the cartridges that are used to prove whether a sample contains SARS-CoV-2 or nine other respiratory viruses. This eliminates the need for further tests if a patient doesn’t have Covid-19, but is presenting with one of the nine other infections.
The will be made available in Germany in April, with other European markets to follow.
A Bosch spokesperson says: “The Covid-19 quick test from Bosch is one of the world’s first fully automated molecular diagnostic tests that is able to determine an infection with SARS-CoV-2 and nine other respiratory viruses within 2.5 hours. It is therefore an antigen test.”
The more testing, the clearer the picture
If quick-response antigen tests like the ones from Sona and Bosch are effectively deployed across the worldwide healthcare ecosystem, they could play a crucial role in stopping the spread of Covid-19. Antibody tests will still be vital in determining any immunity that develops among the population, but these antigen tests can be used to confirm cases of active SARS-CoV-2 infection without PCR’s arduous process of laboratory testing. While Bosch’s Vivalytic system isn’t designed to leave healthcare settings, Sona’s is suitable for home use. What counts now is that these tests and others like them are actually able to make their way to the patients that need them.
“The more testing you do the clearer the picture is on who is infected and thus who needs to be isolated,” says Wright. “Singapore, South Korea, Germany, they seem to have had a better course of the pandemic so far than other countries who don’t have such a high testing capability. That can help alleviate some of the restrictions on movement sooner and give a better idea of what’s going on. It’s vital that testing, whether it’s PCR or antibodies, is ramped up as much as possible to provide clear evidence on what is happening and where we should be going.”