The COVID-19 pandemic, also known as the Coronavirus pandemic, is an ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first identified in December 2019 in Wuhan, China. In these first 50 days of the COVID-19 pandemic, despite the virus having spread to two more countries outside China, most of the global community was not particularly worried, as the perception was that only those who had come into contact with the Wuhan seafood market, where the first case was thought to have occurred, had the highest probability of being infected. The World Health Organization declared the outbreak a Public Health Emergency of International Concern in January 2020 and a pandemic in March 2020. As of 21 March 2021, more than 122 million cases have been confirmed, with more than 2.71 million deaths attributed to COVID-19, making it one of the deadliest pandemics in history.
Symptoms of COVID-19 are highly variable, ranging from none to life-threatening illness. The virus spreads mainly through the air when people are near each other. It leaves an infected person as they breathe, cough, sneeze, or speak and enters another person via their mouth, nose, or eyes. It may also spread via contaminated surfaces. People remain infectious for up to two weeks, and can spread the virus even if they do not show symptoms.
Recommended preventive measures include social distancing, wearing face masks in public, ventilation and air-filtering, hand washing, covering one's mouth when sneezing or coughing, disinfecting surfaces, and monitoring and self-isolation for people exposed or symptomatic. Several vaccines are being developed and distributed. Current treatments focus on addressing symptoms while work is underway to develop therapeutic drugs that inhibit the virus. Authorities worldwide have responded by implementing travel restrictions, lockdowns, workplace hazard controls, and facility closures. Many places have also worked to increase testing capacity and trace contacts of the infected.
The responses to the pandemic have resulted in significant global social and economic disruption, including the largest global recession since the Great Depression. The pandemic led to widespread supply shortages exacerbated by panic buying, agricultural disruption and food shortages, and decreased emissions of pollutants and greenhouse gases, while responses included the postponement or cancellation of many events. Many educational institutions and public areas have been partially or fully closed. Misinformation has circulated through social media and mass media. The pandemic has raised issues of racial and geographic discrimination, health equity, and the balance between public health imperatives and individual rights.
Although it is still unknown exactly where the outbreak first started, many early cases of COVID-19 have been attributed to people who have visited the Huanan Seafood Wholesale Market, located in Wuhan, Hubei, China. On 11 February 2020, the World Health Organization (WHO) named the disease "COVID-19", which is short for coronavirus disease 2019. The virus that caused the outbreak is known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a newly discovered virus closely related to bat coronaviruses, pangolin coronaviruses, and SARS-CoV. Scientific consensus is that COVID-19 is a zoonotic virus that arose from bats in a natural setting.
The earliest known person with symptoms was later discovered to have fallen ill on 1 December 2019, and that person did not have visible connections with the later wet market cluster. However, an earlier case of infection could have occurred on 17 November. Of the early cluster of cases reported that month, two thirds were found to have a link with the market. There are several theories about when and where the very first case (the so-called patient zero) originated.