Cases were initially identified in Wuhan, capital of Hubei province in China in December 2019. Cases reported outside China have predominantly been in people who have recently travelled to Mainland China, however a few cases of local transmission have also occurred. More than 2,000 deaths have been reported in Mainland China, and 8 deaths in other parts of the world.
It is primarily spread between people via respiratory droplets from the coughs and sneezes. Officials in Shanghai confirmed several transmission modes, including direct transmission, contact transmission and aerosol transmission, the latter two involving transmission when someone touches a surface contaminated with tainted respiratory droplets and inhalation of air contaminated with tainted respiratory droplets.
An epidemiological study of the first 72,314 cases suggested that there may have been a "continuous common source" of the outbreak in December 2019, which would imply that several animal to human zoonotic events occurred at the Huanan Seafood Wholesale Market. According to this theory, the primary source of infection became human-to-human transmission in early January 2020.
Diagnostic guidelines released by Zhongnan Hospital of Wuhan University suggested methods for detecting infections based upon clinical features and epidemiological risk. These involved identifying patients who had at least two of the following symptoms in addition to a history of travel to Wuhan or contact with other infected patients: fever, imaging features of pneumonia, normal or reduced white blood cell count, or reduced lymphocyte count.
Global health organisations have published preventive measures to reduce the chances of infection. Recommendations are similar to those published for other coronaviruses and include: frequent washing of hands with soap and water; not touching the eyes, nose, or mouth with unwashed hands; and practicing good respiratory hygiene.
The use of masks by healthy members of the public is not recommended outside of China.
To prevent transmission, the CDC recommends that infected individuals stay at home except to get medical care; call ahead before visiting a healthcare provider; wear a facemask (especially in public); cover coughs and sneezes with a tissue; regularly wash hands with soap and water; and avoid sharing personal household items.
No vaccine currently exists against SARS-CoV-2.
There are no specific antiviral medications approved for this disease. Symptoms are managed with supportive care. The WHO has published detailed treatment recommendations for hospitalized patients with severe acute respiratory infection (SARI) when a SARS-CoV-2 infection is suspected. The WHO also recommended volunteers take part in randomized controlled trials for testing the effectiveness and safety of potential treatments.
The Beijing branch of China's National Health Commission suggested the use of lopinavir/ritonavir as part of treatment plans in the absence of an approved drug for this indication. The lopinavir/ritonavir combination and interferon can now be claimed for via health insurance in some countries.
Infected individuals may experience distress from quarantine, travel restrictions, side effects of treatment, or fear of the infection itself. To address these concerns, the National Health Commission of China published a national guideline for psychological crisis intervention on 27 January 2020.
Chinese health authorities recommend the use of traditional Chinese medicine (TCM) to prevent or treat the disease. On 22 January, National Health Commission put TCM into the third issue of the COVID diagnostic and treatment plan. On 2 February, Wuhan officials ordered all patients to be put on a specific TCM treatment. On 14 February, Wuhan opened a TCM-oriented temporary hospital. The efficacy and safety of TCM has not been established in coronavirus infections.
According to WHO, based on analysis of 44,000 cases of COVID-19 in Hubei province, around 80% of patients only have a mild form of the disease, 14% developed more severe disease such as pneumonia, 5% have critical disease, and 2% of cases are fatal. Of those who died, many had preexisting conditions, including hypertension, diabetes, or cardiovascular disease.
In early cases that resulted in death, the median time of disease was found to be 14 days, with a total range from six to 41 days.
Overall mortality and morbidity rates due to infection are not well established; while the case fatality rate changes over time in the current outbreak, the proportion of infections that progress to diagnosable disease remains unclear. However, preliminary research has yielded case fatality rate numbers between 2% and 3%; in January 2020 the WHO suggested that the case fatality rate was approximately 3%, and 2% in February 2020 in Hubei. An unreviewed Imperial College preprint study among 55 fatal cases noted that early estimates of mortality may be too high as asymptomatic infections are missed. They estimated a mean infection fatality ratio (the mortality among infected) ranging from 0.8% when including asymptomatic carriers to 18% when including only symptomatic cases from Hubei province.
Antiviral medications are being tested, including both new medications and those already approved for other infections.
Research into potential treatments for the disease was initiated in January 2020, and several antiviral drugs are already in clinical trials. Although completely new drugs may take until 2021 to develop, several of the drugs being tested are already approved for other antiviral indications, or are already in advanced testing. Antivirals being tested include the RNA polymerase inhibitor remdesivir,interferon beta,triazavirin,chloroquine, the lopinavir/ritonavir combination (Kaletra) and others. Other drugs being tested include galidesivir, a broad-spectrum antiviral that is a nucleoside RNA polymerase inhibitor; REGN3048-3051 (Regeneron), a combination of two neutralizing monoclonal antibodies; darunavir/cobicistat, an approved drug for HIV, and PRO 140, a Research into potential treatments for the disease was initiated in January 2020, and several antiviral drugs are already in clinical trials. As it has effects against other coronaviruses and modes of action that suggest they may be effective, the lopinavir/ritonavir combination already has been the target of significant research and analysis.
The World Health Organization on 11 February 2020 announced that "COVID-19" will be the official name of the disease. World Health Organization chief Tedros Adhanom Ghebreyesus said "co" stands for "corona", "vi" for "virus" and "d" for "disease", while "19" was for the year, as the outbreak was first identified on December 31. Tedros said the name had been chosen to avoid references to a specific geographical location (i.e. China), animal species or group of people in line with international recommendations for naming aimed at preventing stigmatisation.
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