COVID-19 testing
COVID-19 testing can help find the SARS-CoV-2 virus. There are two types of test; one can find the virus (i.e. Polymerase chain reaction, also called PCR) and the other that can find antibodies produced in response to infection.
An accurate mortality rate of the disease and the level of herd immunity in the population can be found from the results of these tests. However, it is still not known how long immunity will last, and how effective it will be.[1]
Due to limited testing, as of March 2020, no countries had reliable data of the virus.[2]
Test methods
Demonstration of a nose swab (nasopharyngeal swab) for COVID‑19 testing
Demonstration of a throat swab for COVID‑19 testing
A PCR machine
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Detection Timing
- Viral burden (the amount of virus) measured in the respiratory tract declines after the start of illness.[3]
- At this time, replication-competent virus has not been successfully cultured more than nine days after the illness.[4]
- As isolating replication-competent virus lowers, anti-SARS-CoV-2 IgM and IgG can be found in an increasing number of persons recovering from infection.[5]
- Attempts to grow the virus from upper respiratory specimens have been largely unsuccessful[6]
- Following recovery from the illness, many patients no longer have detectable viral RNA in upper respiratory.[7]
- No clear link has been seen between length of illness and length of recovery. [8]
- Infectious virus has not been grown from urine or feces;[9] these possible sources have a very small risk of spreading infection.
WHO methods
| Date listed | Product name | Manufacturer |
|---|---|---|
| 3 April 2020 | Cobas SARS-CoV-2 qualitative assay for use on the cobas 6800/8800 Systems | Roche Molecular Systems |
| 7 April 2020 | Coronavirus (COVID-19) genesig rtPCR assay | Primerdesign |
| 9 April 2020 | Abbott Realtime SARS-CoV-2[10] | Abbott Molecular |
| 24 April 2020 | PerkinElmer SARS-CoV-2 Real-time RT-PCR Assay[10] | SYM-BIO LiveScience |
As of 7 April 2020, the WHO had accepted two diagnostic tests under the Emergency Use Listing procedure (EUL) for use during the COVID‑19 pandemic.[11] Both in vitro diagnostics, the tests are genesig Real-Time PCR Coronavirus (COVID‑19) created by Primerdesign, and cobas SARS-CoV-2 Qualitative assay for use on the cobas® 6800/8800 Systems by Roche Molecular Systems. Approval means that these tests can also be given away by the United Nations.
How accurate is this?
In March 2020 China[12] reported problems with accuracy in their test kits.
In the United States, the test kits developed by the CDC had "flaws".[13]
80% of test kits the Czech Republic purchased from China gave wrong results.[14][15]
Inventions
A group of scientists from Hokkaido University developed an antibody test that could detect avian flu antibodies in only 20 minutes. They said their test could be changed to detect SARS-CoV-2.[16][17]
COVID-19 Testing Media
Explanation of the underlying pathophysiology pertaining to diagnosis of COVID-19
Sensitivity and Specificity
COVID-19 Antigen Rapid Test Kit; the timer is provided by the user.
Mucus from nose or throat in a test liquid is placed onto a COVID-19 rapid antigen diagnostic test device.
COVID-19 rapid testing in Rwanda
Timeline of total number of tests in different countries
A Randox PCR home test kit in the UK, showing the swab, and multi-layer packaging to deliver it to the lab
Number of tests done per day in the US, as of April 2020[update].*Blue: CDC lab*Orange: Public health lab*Gray: Data incomplete due to reporting lag*Not shown: Testing at private labs; total exceeded 100,000 per day by 27 March.
A temporary drive-in testing site for COVID-19 set up with tents in a parking lot
Video of a nasopharyngeal swab for COVID-19 testing
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References
- ↑ Abbasi, Jennifer (17 April 2020). "The Promise and Peril of Antibody Testing for COVID-19". JAMA. JAMA Network. 323 (19): 1881–1883. doi:10.1001/jama.2020.6170. PMID 32301958. Retrieved 20 April 2020.
- ↑ Ioannidis, John P.A. (17 March 2020). A fiasco in the making? As the coronavirus pandemic takes hold, we are making decisions without reliable data. STAT. https://www.statnews.com/2020/03/17/a-fiasco-in-the-making-as-the-coronavirus-pandemic-takes-hold-we-are-making-decisions-without-reliable-data/. Retrieved 22 March 2020.
- ↑ Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced
- CDC unpublished data
- Midgley CM, Kujawski SA, Wong KK, Collins J, Epstein, Killerby ME, et al. (April 2020). "Clinical and virologic characteristics of the first 12 patients with coronavirus disease 2019 (COVID-19) in the United States". Nat. Med. 26 (6): 861–868. doi:10.1038/s41591-020-0877-5. PMID 32327757. S2CID 219648151.
- Young, Barnaby Edward; Ong, Sean Wei Xiang; Kalimuddin, Shirin; Low, Jenny G.; Tan, Seow Yen; Loh, Jiashen; Ng, Oon-Tek; Marimuthu, Kalisvar; Ang, Li Wei; Mak, Tze Minn; Lau, Sok Kiang; Anderson, Danielle E.; Chan, Kian Sing; Tan, Thean Yen; Ng, Tong Yong; Cui, Lin; Said, Zubaidah; Kurupatham, Lalitha; Chen, Mark I-Cheng; Chan, Monica; Vasoo, Shawn; Wang, Lin-Fa; Tan, Boon Huan; Lin, Raymond Tzer Pin; Lee, Vernon Jian Ming; Leo, Yee-Sin; Lye, David Chien (2020). "Epidemiologic Features and Clinical Course of Patients Infected With SARS-CoV-2 in Singapore". JAMA. 323 (15): 1488–1494. doi:10.1001/jama.2020.3204. ISSN 0098-7484. PMC 7054855. PMID 32125362.
- Zou, Lirong; Ruan, Feng; Huang, Mingxing; Liang, Lijun; Huang, Huitao; Hong, Zhongsi; Yu, Jianxiang; Kang, Min; Song, Yingchao; Xia, Jinyu; Guo, Qianfang; Song, Tie; He, Jianfeng; Yen, Hui-Ling; Peiris, Malik; Wu, Jie (2020). "SARS-CoV-2 Viral Load in Upper Respiratory Specimens of Infected Patients". New England Journal of Medicine. 382 (12): 1177–1179. doi:10.1056/NEJMc2001737. ISSN 0028-4793. PMC 7121626. PMID 32074444.
- Wölfel, Roman; Corman, Victor M.; Guggemos, Wolfgang; Seilmaier, Michael; Zange, Sabine; Müller, Marcel A.; Niemeyer, Daniela; Jones, Terry C.; Vollmar, Patrick; Rothe, Camilla; Hoelscher, Michael; Bleicker, Tobias; Brünink, Sebastian; Schneider, Julia; Ehmann, Rosina; Zwirglmaier, Katrin; Drosten, Christian; Wendtner, Clemens (2020). "Virological assessment of hospitalized patients with COVID-2019". Nature. 581 (7809): 465–469. Bibcode:2020Natur.581..465W. doi:10.1038/s41586-020-2196-x. ISSN 0028-0836. PMID 32235945. S2CID 214771224.
- ↑ Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced
- CDC unpublished data
- Wölfel et al. (2020)
- Arons, Melissa M.; Hatfield, Kelly M.; Reddy, Sujan C.; Kimball, Anne; James, Allison; Jacobs, Jesica R.; Taylor, Joanne; Spicer, Kevin; Bardossy, Ana C.; Oakley, Lisa P.; Tanwar, Sukarma; Dyal, Jonathan W.; Harney, Josh; Chisty, Zeshan; Bell, Jeneita M.; Methner, Mark; Paul, Prabasaj; Carlson, Christina M.; McLaughlin, Heather P.; Thornburg, Natalie; Tong, Suxiang; Tamin, Azaibi; Tao, Ying; Uehara, Anna; Harcourt, Jennifer; Clark, Shauna; Brostrom-Smith, Claire; Page, Libby C.; Kay, Meagan; Lewis, James; Montgomery, Patty; Stone, Nimalie D.; Clark, Thomas A.; Honein, Margaret A.; Duchin, Jeffrey S.; Jernigan, John A. (2020). "Presymptomatic SARS-CoV-2 Infections and Transmission in a Skilled Nursing Facility". New England Journal of Medicine. 382 (22): 2081–2090. doi:10.1056/NEJMoa2008457. ISSN 0028-4793. PMC 7200056. PMID 32329971.
- ↑ Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced Wölfel et al. (2020)
- ↑ "Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19". CDC. 3 May 2020. Archived from the original on 4 May 2020.
- ↑ Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced
- CDC unpublished data
- Young et al. (2020)
- ↑ Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced
- CDC unpublished data
- Midgley et al. (2020)
- ↑ Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced
- CDC unpublished data
- Midgley et al. (2020)
- Wölfel et al. (2020)
- ↑ 10.0 10.1 "WHO Emergency Use Listing for SARS‐CoV‐2 in vitro diagnostic products" (PDF). World Health Organization. Retrieved 4 May 2020.
- ↑ "WHO lists two COVID-19 tests for emergency use". World Health Organization. Retrieved 10 April 2020.
- ↑ Heartbreak in the Streets of Wuhan
- ↑ "State figures on testing raise questions about efforts to contain outbreak". The BostonGlobe.com.
flaws with the testing kits first distributed by the federal government and bureaucratic hurdles that held up testing by private labs at hospitals, universities and testing chains
- ↑ Morning, Prague (26 March 2020). "80% of Rapid COVID-19 Tests the Czech Republic Bought From China are Wrong".
- ↑ VOJTĚCH BLAŽEK (23 March 2020). "Úřad dopředu psal, kdy mohou rychlotesty selhat. I tak je stát nasadil" (in Czech). Zeznam Zprávy. https://www.seznamzpravy.cz/clanek/rychlotesty-neodhali-cerstve-nakazene-pacienty-varoval-zdravotni-ustav-95174. Retrieved 7 April 2020. "Indeed, the rapid tests that arrived from China a few days ago do not really reliably detect the infection at an early stage".
- ↑ Eurekalert.org (May 21, 2020). "New technology can detect anti-virus antibody in 20 minutes". Press release. https://www.eurekalert.org/pub_releases/2020-05/hu-nt052120.php. Retrieved May 26, 2020.
- ↑ Keine Nishiyama; Yohei Takeda; Masatoshi Maeki; Akihiko Ishida; Hirofumi Tani; Koji Shigemura; Akihide Hibara; Yutaka Yonezawa; Kunitoshi Imai; Haruko Ogawa; Manabu Tokeshi (August 1, 2020). "Rapid detection of anti-H5 avian influenza virus antibody by fluorescence polarization immunoassay using a portable fluorescence polarization analyzer". Sensors and Actuators B: Chemical. 316: 128160. doi:10.1016/j.snb.2020.128160. PMC 7172727. PMID 32322135.