COVID-19

Coronavirus disease 2019
(COVID-19)
Other namesCOVID, (the) coronavirus
Transmission and life-cycle of SARS-CoV-2, which causes COVID-19
Pronunciation
SpecialtyInfectious disease
SymptomsFever, cough, fatigue, shortness of breath, vomiting, loss of taste or smell; some cases asymptomatic[2][3]
ComplicationsPneumonia, sepsis, ARDS, kidney failure, respiratory failure, pulmonary fibrosis, CKS, MIS-C, long COVID
Usual onset2–14 days (typically 5)
after infection
Duration5 days to chronic
CausesSARS-CoV-2
Diagnostic methodRT‑PCR testing, CT scan, rapid antigen test
PreventionVaccination, face coverings, quarantine, social distancing, ventilation, hand washing
TreatmentSymptomatic and supportive
Frequency774,834,237[4] confirmed cases (true case count is expected to be much higher[5])
Deaths
  • 7,037,007[4] (reported)
  • 18.2–33.5 million[6] (estimated)

Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. The first known case was identified in Wuhan, China, in December 2019.[7] The disease quickly spread worldwide, resulting in the ongoing COVID-19 pandemic.

The symptoms of COVID‑19 are variable but often include fever,[8] fatigue, cough, breathing difficulties, loss of smell, and loss of taste.[9][10][11] Symptoms may begin one to fourteen days after exposure to the virus. At least a third of people who are infected do not develop noticeable symptoms.[12][13] Of those who develop symptoms noticeable enough to be classified as patients, most (81%) develop mild to moderate symptoms (up to mild pneumonia), while 14% develop severe symptoms (dyspnea, hypoxia, or more than 50% lung involvement on imaging), and 5% develop critical symptoms (respiratory failure, shock, or multiorgan dysfunction).[14] Older people are at a higher risk of developing severe symptoms. Some complications result in death. Some people continue to experience a range of effects (long COVID) for months or years after infection, and damage to organs has been observed.[15] Multi-year studies are underway to further investigate the long-term effects of the disease.[16]

COVID‑19 transmission occurs when infectious particles are breathed in or come into contact with the eyes, nose, or mouth. The risk is highest when people are in close proximity, but small airborne particles containing the virus can remain suspended in the air and travel over longer distances, particularly indoors. Transmission can also occur when people touch their eyes, nose or mouth after touching surfaces or objects that have been contaminated by the virus. People remain contagious for up to 20 days and can spread the virus even if they do not develop symptoms.[17]

Testing methods for COVID-19 to detect the virus's nucleic acid include real-time reverse transcription polymerase chain reaction (RT‑PCR),[18][19] transcription-mediated amplification,[18][19][20] and reverse transcription loop-mediated isothermal amplification (RT‑LAMP)[18][19] from a nasopharyngeal swab.[21]

Several COVID-19 vaccines have been approved and distributed in various countries, many of which have initiated mass vaccination campaigns. Other preventive measures include physical or social distancing, quarantining, ventilation of indoor spaces, use of face masks or coverings in public, covering coughs and sneezes, hand washing, and keeping unwashed hands away from the face. While drugs have been developed to inhibit the virus, the primary treatment is still symptomatic, managing the disease through supportive care, isolation, and experimental measures.

  1. ^ "Covid-19". Oxford English Dictionary (Online ed.). Oxford University Press. April 2020. Retrieved 15 April 2020. (Subscription or participating institution membership required.)
  2. ^ "Symptoms of Coronavirus". U.S. Centers for Disease Control and Prevention (CDC). 13 May 2020. Archived from the original on 17 June 2020. Retrieved 18 June 2020.
  3. ^ "Q&A on coronaviruses (COVID-19)". World Health Organization (WHO). 17 April 2020. Archived from the original on 14 May 2020. Retrieved 14 May 2020.
  4. ^ a b Ritchie H, Mathieu E, Rodés-Guirao L, Appel C, Giattino C, Ortiz-Ospina E, Hasell J, Macdonald B, Beltekian D, Dattani S, Roser M (2020–2022). "Coronavirus Pandemic (COVID-19)". Our World in Data. Retrieved 28 March 2024.
  5. ^ Mathieu E, Ritchie H, Rodés-Guirao L, Appel C, Giattino C, Hasell J, Macdonald B, Dattani S, Beltekian D, Ortiz-Ospina E, Roser M (5 March 2020). "Coronavirus Pandemic (COVID-19)". Our World in Data. Archived from the original on 24 February 2024. Retrieved 24 February 2024.
  6. ^ "The pandemic's true death toll". The Economist. 28 August 2023 [2 November 2021]. Retrieved 28 August 2023.
  7. ^ Page J, Hinshaw D, McKay B (26 February 2021). "In Hunt for Covid-19 Origin, Patient Zero Points to Second Wuhan Market – The man with the first confirmed infection of the new coronavirus told the WHO team that his parents had shopped there". The Wall Street Journal. Retrieved 27 February 2021.
  8. ^ Islam MA (April 2021). "Prevalence and characteristics of fever in adult and paediatric patients with coronavirus disease 2019 (COVID-19): A systematic review and meta-analysis of 17515 patients". PLOS ONE. 16 (4): e0249788. Bibcode:2021PLoSO..1649788I. doi:10.1371/journal.pone.0249788. PMC 8023501. PMID 33822812.
  9. ^ Saniasiaya J, Islam MA (April 2021). "Prevalence of Olfactory Dysfunction in Coronavirus Disease 2019 (COVID-19): A Meta-analysis of 27,492 Patients". The Laryngoscope. 131 (4): 865–878. doi:10.1002/lary.29286. ISSN 0023-852X. PMC 7753439. PMID 33219539.
  10. ^ Saniasiaya J, Islam MA (November 2020). "Prevalence and Characteristics of Taste Disorders in Cases of COVID-19: A Meta-analysis of 29,349 Patients" (PDF). Otolaryngology–Head and Neck Surgery. 165 (1): 33–42. doi:10.1177/0194599820981018. PMID 33320033. S2CID 229174644.
  11. ^ Agyeman AA, Chin KL, Landersdorfer CB, Liew D, Ofori-Asenso R (August 2020). "Smell and Taste Dysfunction in Patients With COVID-19: A Systematic Review and Meta-analysis". Mayo Clin. Proc. 95 (8): 1621–1631. doi:10.1016/j.mayocp.2020.05.030. PMC 7275152. PMID 32753137.
  12. ^ Wang B, Andraweera P, Elliott S, Mohammed H, Lassi Z, Twigger A, Borgas C, Gunasekera S, Ladhani S, Marshall HS (March 2023). "Asymptomatic SARS-CoV-2 Infection by Age: A Global Systematic Review and Meta-analysis". The Pediatric Infectious Disease Journal. 42 (3): 232–239. doi:10.1097/INF.0000000000003791. PMC 9935239. PMID 36730054. Retrieved 15 November 2023.
  13. ^ Oran DP, Topol EJ (January 2021). "The Proportion of SARS-CoV-2 Infections That Are Asymptomatic: A Systematic Review". Annals of Internal Medicine. 174 (5): M20-6976. doi:10.7326/M20-6976. PMC 7839426. PMID 33481642.
  14. ^ "Interim Clinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19)". U.S. Centers for Disease Control and Prevention (CDC). 6 April 2020. Archived from the original on 2 March 2020. Retrieved 19 April 2020.
  15. ^ Cite error: The named reference davis was invoked but never defined (see the help page).
  16. ^ CDC (11 February 2020). "Post-COVID Conditions". U.S. Centers for Disease Control and Prevention (CDC). Retrieved 12 July 2021.
  17. ^ "Coronavirus disease (COVID-19): How is it transmitted?". www.who.int. Retrieved 13 April 2023.
  18. ^ a b c "Overview of Testing for SARS-CoV-2, the virus that causes COVID-19". U.S. Centers for Disease Control and Prevention (CDC). 11 February 2020. Retrieved 31 July 2022.
  19. ^ a b c "Nucleic Acid Amplification Tests (NAATs)". U.S. Centers for Disease Control and Prevention (CDC). 11 February 2020. Retrieved 31 July 2022.
  20. ^ Gorzalski AJ, Tian H, Laverdure C, Morzunov S, Verma SC, VanHooser S, Pandori MW (August 2020). "High-Throughput Transcription-mediated amplification on the Hologic Panther is a highly sensitive method of detection for SARS-CoV-2". Journal of Clinical Virology. 129: 104501. doi:10.1016/j.jcv.2020.104501. PMC 7286273. PMID 32619959.
  21. ^ Cite error: The named reference pmid32621814 was invoked but never defined (see the help page).