Coronavirus disease 2019
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 29 September 2020, more than 33.3 million cases have been reported across 188 countries and territories with more than 1 million deaths; more than 23.1 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 one to fourteen days.The disease spreads between people most often when they are physically close. It spreads very easily and sustainably through the air, primarily via small droplets or particles such as aerosols, produced after an infected person breathes, coughs, sneezes, talks or sings. It may also be transmitted via contaminated surfaces, although this has not been conclusively demonstrated. It can spread for up to two days prior to symptom onset, and from people who are asymptomatic. People remain infectious for 7–12 days in moderate cases, and up to two weeks in severe cases. 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 along with sneezes, 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 in certain settings, such as on public transport and in shops. 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 yet, though several are in development. 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.Longer-term damage to organs (in particular lungs and heart) has been observed, and there is concern about a significant number of patients who have recovered from the acute phase of the disease but continue to experience a range of effects including severe fatigue, memory loss and other cognitive issues, low grade fever, muscle weakness, breathlessness and other symptoms for months afterwards.