The 2019–20 coronavirus pandemic is an ongoing 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, Hubei, China in December 2019, and was recognized as a pandemic by the World Health Organization (WHO) on 11 March 2020. As of 21 March, more than 276,000 cases of COVID-19 have been reported in over 180 countries and territories, resulting in more than 11,300 deaths and 88,000 recoveries.


The virus primarily spreads between people via respiratory droplets produced during coughing. It may also be spread from touching contaminated surfaces and then touching one's face. It is considered most contagious when people are symptomatic, although spread may be possible before symptoms appear. The time between exposure and symptom onset is typically around five days, but may range from two to fourteen days.

Common symptoms include fever, cough, and shortness of breath. Complications may include pneumonia and acute respiratory distress syndrome. There is no vaccine or specific antiviral treatment; although the FDA has approved remdesivir for compassionate use. Primary treatment is symptomatic and supportive therapy. Recommended preventive measures include hand washing, covering the mouth when coughing, maintaining distance from other people, and monitoring and self-isolation for people who suspect they are infected.

Efforts to prevent spreading include travel restrictions, quarantines, curfews, event postponements and cancellations, and facility closures. These include a quarantine of Hubei, nationwide quarantines in multiple European countries, Colombia and Jordan, curfew measures in China and South Korea, various border closures or incoming passenger restrictions, screening at airports and train stations, and travel advisories regarding regions with community transmission. Schools and universities have closed either on a nationwide or local basis in at least 115 countries, affecting more than 1.2 billion students.

The pandemic has led to global socioeconomic disruption, the postponement or cancellation of sporting and cultural events, and widespread fears of supply shortages which have spurred bulk buying of goods. Misinformation and conspiracy theories about the virus have spread online, and there have been incidents of xenophobia and racism against Chinese and other East or Southeast Asian people.

Death

The case fatality rate of COVID-19 (that is, the fatality rate among the subset of infected individuals with symptoms) has been estimated at 1.4%.

Among those who died from the disease, the time from development of symptoms to death was between six and 41 days, with a median of 14 days. As of 20 March 2020, more than 10,200 deaths have been attributed to COVID-19. Most of those who died were elderly—about 80% of deaths were in those over 60, and 75% had pre-existing health conditions including cardiovascular diseases and diabetes.

The first confirmed death was on 9 January 2020 in Wuhan. The first death outside China occurred on 1 February in the Philippines, and the first death outside Asia was in France. By 28 February, outside mainland China, more than a dozen deaths were recorded in each of Iran, South Korea, and Italy. By 13 March, over 40 countries and territories had reported deaths, on every continent except Antarctica.

Symptoms

Symptoms of COVID-19 are non-specific and those infected may either be asymptomatic or develop flu-like symptoms such as fever, cough, fatigue, shortness of breath, or muscle pain. The typical signs and symptoms and their prevalence are shown in the corresponding table.

Further development can lead to severe pneumonia, acute respiratory distress syndrome, sepsis, septic shock and death. Some of those infected may be asymptomatic, returning test results that confirm infection but show no clinical symptoms, so researchers have issued advice that those with close contact to confirmed infected people should be closely monitored and examined to rule out infection.

The usual incubation period (the time between infection and symptom onset) ranges from one to fourteen days; it is most commonly five days. In one case, it may have had an incubation period of 27 days.

Transmission

The primary mode of transmission is via respiratory droplets that people exhale, for example, when coughing or sneezing. Droplets stay suspended in the air for only a short time in air at 65% relative humidity and 21 to 23 °C (70 to 73 °F), but may stay viable and contagious on a metal, cardboard, glass or plastic surface. The stability of the SARS-CoV-2 virus in the air and on various surfaces is believed to be comparable to that of other coronaviruses, some of which can survive for up to nine days at room temperature. Its similarity to SARS-CoV-1 in particular was confirmed in laboratory tests that found both viruses could survive up to or beyond 72 hours on plastic and stainless steel. A survey of research on the inactivation of other coronaviruses using various biocidal agents suggests that disinfecting surfaces contaminated with SARS-CoV-2 may also be achieved using similar solutions (within one minute of exposure on a stainless steel surface), including 62–71% ethanol, 50–100% isopropanol, 0.1% sodium hypochlorite, 0.5% hydrogen peroxide, and 0.2–7.5% povidone-iodine; benzalkonium chloride and chlorhexidine gluconate are less effective.

The WHO has stated that the risk of spread from someone without symptoms is "very low". However, if someone has early symptoms and a mild cough, there is a risk of transmission. An analysis of infections in Singapore and Tianjin, China revealed that coronavirus infections may be spread by people who have recently caught the virus and have not yet begun to show symptoms.

Estimates of the basic reproduction number (the average number of people an infected person is likely to infect) range from 2.13 to 4.82. This is similar to the measure typical of severe acute respiratory syndrome-related coronavirus (SARS-CoV).

Credit: https://en.wikipedia.org/wiki/2019%E2%80%9320_coronavirus_pandemic