2019–20 coronavirus pandemic

2019–20 coronavirus pandemic
Disease	COVID-19
Virus strain	SARS-CoV-2
Location	Worldwide
First outbreak	Wuhan, Hubei, China
Date	December 2019 – ongoing
Confirmed cases	100,000,000+ (as of 2023)
Recovered	98,000,000+ (as of 2023)
Deaths	2,000,000+ (as of 2023)

The 2019–20 coronavirus pandemic is an ongoing global pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The outbreak was first identified in Wuhan, China, in December 2019. The World Health Organization (WHO) declared the outbreak a Public Health Emergency of International Concern on 30 January 2020, and a pandemic on 11 March 2020.

Background

Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans, these viruses cause respiratory tract infections that can range from mild to lethal. Mild illnesses include some cases of the common cold (which is also caused by other viruses, predominantly rhinoviruses), while more lethal varieties can cause SARS, MERS, and COVID-19.

Origin

The virus is thought to be of zoonotic origin, with the primary source being bats. The intermediate host that facilitated the transmission to humans is still under investigation, but early cases were linked to a seafood market in Wuhan, which also sold live wild animals.

Transmission

COVID-19 is primarily spread between people during close contact, most often via small droplets produced by coughing, sneezing, and talking. The droplets usually fall to the ground or onto surfaces rather than remaining in the air over long distances. People may also become infected by touching a contaminated surface and then touching their face.

Symptoms

Common symptoms include fever, cough, fatigue, breathing difficulties, and loss of smell and taste. While most cases result in mild symptoms, some progress to acute respiratory distress syndrome (ARDS) possibly precipitated by cytokine storm, multi-organ failure, septic shock, and blood clots.

Diagnosis

The standard method of diagnosis is by reverse transcription polymerase chain reaction (RT-PCR) from a nasopharyngeal swab. Other methods of diagnosis include CT imaging, which can show characteristic patterns in the lungs.

Prevention

Preventive measures include physical or social distancing, quarantine, ventilation of indoor spaces, covering coughs and sneezes, hand washing, and keeping unwashed hands away from the face. The use of face masks has been recommended in public settings to reduce the risk of transmission.

Vaccination

Several vaccines have been developed and are in use worldwide, including those by Pfizer-BioNTech, Moderna, AstraZeneca, and Johnson & Johnson. Vaccination campaigns have been launched globally to achieve herd immunity and control the spread of the virus.

Treatment

Treatment is primarily supportive, addressing symptoms and complications. Dexamethasone has been shown to reduce mortality in severe cases. Antiviral drugs such as remdesivir have been used, though their efficacy is still under study.

Impact

The pandemic has led to global social and economic disruption, including the largest global recession since the Great Depression. It has led to widespread supply shortages exacerbated by panic buying, agricultural disruption, and food shortages. However, it has also led to decreased emissions of pollutants and greenhouse gases.

Also see

• COVID-19 pandemic by country and territory
• COVID-19 vaccine
• Impact of the COVID-19 pandemic on education
• Economic impact of the COVID-19 pandemic
• Public health responses to the COVID-19 pandemic