# Covid-19

Coronavirus disease 2019 (COVID‑19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first identified in December 2019 in Wuhan, Hubei, China, and has resulted in an ongoing pandemic. As of 6 September 2020, more than 26.8 million cases have been reported across 188 countries and territories with more than 879,000 deaths; more than 17.9 million people have recovered.Common symptoms include fever, cough, fatigue, shortness of breath or breathing difficulties, and loss of smell and taste. While most people have mild symptoms, some people develop acute respiratory distress syndrome (ARDS) possibly precipitated by cytokine storm, multi-organ failure, septic shock, and blood clots. The incubation period may range from two to fourteen days.
The virus is spread primarily via small droplets from coughing, sneezing, and talking. The droplets are usually not airborne, however those standing closely may inhale them and become infected. People may also become infected by touching a contaminated surface and then touching their face. The transmission may also occur through aerosols that can suspend in the air for longer periods of time in enclosed spaces. It is most contagious during the first three days after the onset of symptoms, although spread is possible before symptoms appear, and from people who are asymptomatic. The standard method of diagnosis is by real-time reverse transcription polymerase chain reaction (rRT-PCR) from a nasopharyngeal swab. Chest CT imaging may also be helpful for diagnosis in individuals where there is a high suspicion of infection based on symptoms and risk factors, however guidelines do not recommend using it for routine screening.
Recommended measures to prevent infection include frequent hand washing, social distancing, quarantine, covering coughs, and keeping unwashed hands away from the face. The use of cloth face coverings such as a scarf or a bandana has been recommended by health officials in public settings to minimise the risk of transmissions, with some authorities requiring their use. Health officials also stated that medical-grade face masks, such as N95 masks, should be used only by healthcare workers, first responders, and those who directly care for infected individuals.
There are no proven vaccines or specific treatments for COVID-19. Management involves the treatment of symptoms, supportive care, isolation, and experimental measures. The World Health Organization (WHO) declared the COVID‑19 outbreak a public health emergency of international concern (PHEIC) on 30 January 2020 and a pandemic on 11 March 2020. Local transmission of the disease has occurred in most countries across all six WHO regions.