The virus is primarily spread between people during close contact,[a] often via small droplets produced by coughing,[b] sneezing, or talking. While these droplets are produced when breathing out, they usually fall to the ground or onto surfaces rather than being infectious over long distances. People may also become infected by touching a contaminated surface and then their face. The virus can survive on surfaces for up to 72 hours. It is most contagious during the first three days after the onset of symptoms, although spread may be possible before symptoms appear and in later stages of the disease.
As is common with infections, there is a delay between the moment when a person is infected with the virus and the time when they develop symptoms. This is called the incubation period. The incubation period for COVID-19 is typically five to six days but may range from two to 14 days. 97.5% of people who develop symptoms will do so within 11.5 days of infection.
Reports indicate that not all who are infected develop symptoms. The role of these asymptomatic carriers in transmission is not yet fully known; however, preliminary evidence suggests that they may contribute to the spread of the disease. The proportion of infected people who do not display symptoms is currently unknown and being studied, with the Korea Centers for Disease Control and Prevention (KCDC) reporting that 20% of all confirmed cases remained asymptomatic during their hospital stay. China's National Health Commission began including asymptomatic cases in its daily cases on 1April; of the 166 infections on that day, 130 (78%) were asymptomatic.
Some details about how the disease is spread are still being determined. The WHO and the U.S. Centers for Disease Control and Prevention (CDC) say it is primarily spread during close contact and by small droplets produced when people cough, sneeze or talk; with close contact being within 1–3 m (3 ft 3 in–9 ft 10 in). A study in Hong Kong observed that the virus was present in most patients' saliva in quantities reaching 100 million virus strands per 1mL. Loud talking releases more droplets than normal talking. A study in Singapore found that an uncovered cough can lead to droplets travelling up to 4.5 meters (15 feet). A second study, produced during the 2020 pandemic, found that advice on the distance droplets could travel might be based on old research conducted in the 1930s which ignored the protective effect and speed of the warm moist outbreath surrounding the droplets. This study found that an uncovered cough or sneeze can travel up to 8.2 metres (27 feet).
Respiratory droplets may also be produced while breathing out, including when talking. Though the virus is not generally airborne, the National Academy of Science has suggested that bioaerosol transmission may be possible and air collectors positioned in the hallway outside of people's rooms yielded samples positive for viral RNA. The droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs. Some medical procedures such as intubation and cardiopulmonary resuscitation (CPR) may cause respiratory secretions to be aerosolised and thus result in airborne spread. It may also spread when one touches a contaminated surface, known as fomite transmission, and then touches one's eyes, nose or mouth. While there are concerns it may spread via feces, this risk is believed to be low.
The virus is most contagious when people are symptomatic; while spread may be possible before symptoms emerge, the risk is low. The European Centre for Disease Prevention and Control (ECDC) says while it is not entirely clear how easily the disease spreads, one person generally infects two to three others.
Severe acute respiratory syndrome coronavirus2 (SARS-CoV-2) is a novel severe acute respiratory syndrome coronavirus, first isolated from three people with pneumonia connected to the cluster of acute respiratory illness cases in Wuhan. All features of the novel SARS-CoV-2 virus occur in related coronaviruses in nature.
Outside the human body, the virus is killed by household soap, which bursts its protective bubble.
SARS-CoV-2 is closely related to the original SARS-CoV. It is thought to have a zoonotic origin. Genetic analysis has revealed that the coronavirus genetically clusters with the genus Betacoronavirus, in subgenus Sarbecovirus (lineage B) together with two bat-derived strains. It is 96% identical at the whole genome level to other bat coronavirus samples (BatCov RaTG13). In February 2020, Chinese researchers found that there is only one amino acid difference in certain parts of the genome sequences between the viruses from pangolins and those from humans; however, whole-genome comparison to date found that at most 92% of genetic material was shared between pangolin coronavirus and SARS-CoV-2, which is insufficient to prove pangolins to be the intermediate host.
The lungs are the organs most affected by COVID-19 because the virus accesses host cells via the enzyme angiotensin-converting enzyme 2 (ACE2), which is most abundant in the type II alveolar cells of the lungs. The virus uses a special surface glycoprotein called a "spike" (peplomer) to connect to ACE2 and enter the host cell. The density of ACE2 in each tissue correlates with the severity of the disease in that tissue and some have suggested that decreasing ACE2 activity might be protective, though another view is that increasing ACE2 using angiotensin II receptor blocker medications could be protective and these hypotheses need to be tested. As the alveolar disease progresses, respiratory failure might develop and death may follow.
Systemic inflammation results in vasodilation, allowing inflammatory lymphocytic and monocytic infiltration of the lung and the heart. In particular, pathogenic GM-CSF-secreting T-cells were shown to correlate with the recruitment of inflammatory IL-6-secreting monocytes and severe lung pathology in COVID-19 patients. Lymphocytic infiltrates have also been reported at autopsy.
Diagnostic guidelines released by Zhongnan Hospital of Wuhan University suggested methods for detecting infections based upon clinical features and epidemiological risk. These involved identifying people who had at least two of the following symptoms in addition to a history of travel to Wuhan or contact with other infected people: fever, imaging features of pneumonia, normal or reduced white blood cell count or reduced lymphocyte count.
Along with laboratory testing, chest CT scans may be helpful to diagnose COVID-19 in individuals with a high clinical suspicion of infection but is not recommended for routine screening. Bilateral multilobar ground-glass opacities with a peripheral, asymmetric and posterior distribution are common in early infection. Subpleural dominance, crazy paving (lobular septal thickening with variable alveolar filling), and consolidation may appear as the disease progresses.
Inhibiting new infections to reduce the number of cases at any given time—known as "flattening the curve"—allows healthcare services to better manage the same volume of patients. Conversely, increasing healthcare capacity—called raising the line—such as by increasing bed count, personnel, and equipment, can help to meet increased demand.
Inadequate mitigation, such as premature relaxation of physical distancing rules or stay-at-home orders, can result in a resurgence of pandemics.
Preventive measures to reduce the chances of infection include staying at home, avoiding crowded places, washing hands with soap and water often and for at least 20 seconds, practising good respiratory hygiene and avoiding touching the eyes, nose or mouth with unwashed hands. The CDC recommends covering the mouth and nose with a tissue when coughing or sneezing and recommends using the inside of the elbow if no tissue is available. They also recommend proper hand hygiene after any cough or sneeze.Social distancing strategies aim to reduce contact of infected persons with large groups by closing schools and workplaces, restricting travel and cancelling large public gatherings. Distancing guidelines also include that people stay at least 6 feet (1.8 m) apart. There is no medication known to be effective at preventing COVID-19.
As a vaccine is not expected until 2021 at the earliest, a key part of managing COVID-19 is trying to decrease the epidemic peak, known as "flattening the curve". This is done by slowing the infection rate to decrease the risk of health services being overwhelmed, allowing for better treatment of current cases and delaying additional cases until effective treatments or a vaccine become available.
According to the WHO, the use of masks is recommended only if a person is coughing or sneezing or when one is taking care of someone with a suspected infection.[needs update] Some countries also recommend healthy individuals to wear face masks, including China,Hong Kong,Thailand, Czech Republic, and Austria. In order to meet the need for masks, the WHO estimates global production will need to increase by 40%. Hoarding and speculation have worsened the problem, with the price of masks increasing sixfold, N95 respirators tripled, and gowns doubled. Some health experts consider wearing non-medical grade masks and other face coverings like scarves or bandanas a good way to prevent people from touching their mouths and noses, even if non-medical coverings would not protect against a direct sneeze or cough from an infected person.
Those diagnosed with COVID-19 or who believe they may be infected are advised by the CDC to stay home except to get medical care, call ahead before visiting a healthcare provider, wear a face mask before entering the healthcare provider's office and when in any room or vehicle with another person, cover coughs and sneezes with a tissue, regularly wash hands with soap and water and avoid sharing personal household items. The CDC also recommends that individuals wash hands often with soap and water for at least 20 seconds, especially after going to the toilet or when hands are visibly dirty, before eating and after blowing one's nose, coughing or sneezing. It further recommends using an alcohol-based hand sanitiser with at least 60% alcohol, but only when soap and water are not readily available.
Precautions must be taken to minimise the risk of virus transmission, especially in healthcare settings when performing procedures that can generate aerosols, such as intubation or hand ventilation. For healthcare professionals caring for people with COVID-19, the CDC recommends placing the person in an Airborne Infection Isolation Room (AIIR) in addition to using standard precautions, contact precautions and airborne precautions.
When available, respirators (instead of facemasks) are preferred. N95 respirators are approved for industrial settings but the FDA has authorised the masks for use under an Emergency Use Authorisation (EUA). They are designed to protect from airborne particles like dust but effectiveness against a specific biological agent is not guaranteed for off-label uses. When masks are not available, the CDC recommends using face shields or, as a last resort, homemade masks.
Severe cases are most common in older adults (those older than 60 years, and especially those older than 80 years). Many developed countries do not have enough hospital beds per capita, which limits a health system's capacity to handle a sudden spike in the number of COVID-19 cases severe enough to require hospitalisation. This limited capacity is a significant driver behind calls to “flatten the curve” — to lower the speed at which new cases occur and thus keep the number of persons sick at any one time lower. One study in China found 5% were admitted to intensive care units, 2.3% needed mechanical support of ventilation, and 1.4% died. In China, approximately 30% of people in hospital with COVID-19 are eventually admitted to ICU.
Research into potential treatments started in January 2020, and several antiviral drugs are in clinical trials. Remdesivir appears to be the most promising. Although new medications may take until 2021 to develop, several of the medications being tested are already approved for other uses or are already in advanced testing. Antiviral medication may be tried in people with severe disease. The WHO recommended volunteers take part in trials of the effectiveness and safety of potential treatments.
The FDA has granted temporary authorisation to convalescent plasma as an experimental treatment in cases where the person's life is seriously or immediately threatened. It has not undergone the clinical studies needed to show it is safe and effective for the disease.
In February 2020, China launched a mobile app to deal with the disease outbreak. Users are asked to enter their name and ID number. The app is able to detect 'close contact' using surveillance data and therefore a potential risk of infection. Every user can also check the status of three other users. If a potential risk is detected, the app not only recommends self-quarantine, it also alerts local health officials.
Big data analytics on cellphone data, facial recognition technology, mobile phone tracking and artificial intelligence are used to track infected people and people whom they contacted in South Korea, Taiwan and Singapore. In March 2020, the Israeli government enabled security agencies to track mobile phone data of people supposed to have coronavirus. The measure was taken to enforce quarantine and protect those who may come into contact with infected citizens. Also in March 2020, Deutsche Telekom shared aggregated phone location data with the German federal government agency, Robert Koch Institute, in order to research and prevent the spread of the virus. Russia deployed facial recognition technology to detect quarantine breakers. Italian regional health commissioner Giulio Gallera said he has been informed by mobile phone operators that "40% of people are continuing to move around anyway". German government conducted a 48 hours weekend hackathon with more than 42.000 participants. Also the president of Estonia, Kersti Kaljulaid, made a global call for creative solutions against the spread of coronavirus.
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.
The severity of diagnosed COVID-19 cases in China
Case fatality rates by age group. Data through 24 March 2020
Case fatality rate in China depending on other health problems. Data through 11 February 2020.
The number of deaths vs total cases by country and approximate case fatality rate
The severity of COVID-19 varies. The disease may take a mild course with few or no symptoms, resembling other common upper respiratory diseases such as the common cold. Mild cases typically recover within two weeks, while those with severe or critical diseases may take three to six weeks to recover. Among those who have died, the time from symptom onset to death has ranged from two to eight weeks.
Children are susceptible to the disease, but are likely to have milder symptoms and a lower chance of severe disease than adults; in those younger than 50 years, the risk of death is less than 0.5%, while in those older than 70 it is more than 8%.Pregnant women may be at higher risk for severe infection with COVID-19 based on data from other similar viruses, like SARS and MERS, but data for COVID-19 is lacking.
In some people, COVID-19 may affect the lungs causing pneumonia. In those most severely affected, COVID-19 may rapidly progress to acute respiratory distress syndrome (ARDS) causing respiratory failure, septic shock or multi-organ failure. Complications associated with COVID-19 include sepsis, abnormal clotting and damage to the heart, kidneys and liver. Clotting abnormalities, specifically an increase in prothrombin time, have been described in 6% of those admitted to hospital with COVID-19, while abnormal kidney function is seen in 4% of this group. Approximately 20-30% of people who present with COVID-19 demonstrate elevated liver enzymes (transaminases). Liver injury as shown by blood markers of liver damage is frequently seen in severe cases.
Availability of medical resources and the socioeconomics of a region may also affect mortality. Estimates of the mortality from the condition vary because of those regional differences, but also because of methodological difficulties. The under-counting of mild cases can cause the mortality rate to be overestimated. However, the fact that deaths are the result of cases contracted in the past can mean the current mortality rate is underestimated.
Note: The lower bound includes all cases. The upper bound excludes cases that were missing data.
Estimate of infection fatality rates and probability of severe disease course (%) by age based on cases from China
Total infection fatality rate is estimated to be 0.66% (0.39–1.3). Infection fatality rate is fatality per all infected individuals, regardless of whether they were diagnosed or had any symptoms. Numbers in parentheses are 95% credible intervals for the estimates.
As of March 2020, it was unknown if past infection provides effective and long-term immunity in people who recover from the disease. Immunity is seen as likely, based on the behaviour of other coronaviruses, but cases in which recovery from COVID-19 have been followed by positive tests for coronavirus at a later date have been reported. These cases are believed to be worsening of a lingering infection rather than re-infection.
The virus is thought to be natural and have an animal origin, through spillover infection. The actual origin is unknown, but by December 2019 the spread of infection was almost entirely driven by human-to-human transmission. A study of the first 41 cases of confirmed COVID-19, published in January 2020 in The Lancet, revealed the earliest date of onset of symptoms as 1December 2019. Official publications from the WHO reported the earliest onset of symptoms as 8December 2019.
Several measures are commonly used to quantify mortality. These numbers vary by region and over time and are influenced by the volume of testing, healthcare system quality, treatment options, time since initial outbreak and population characteristics such as age, sex and overall health. In late 2019, WHO assigned the emergency ICD-10 disease codes U07.1 for deaths from lab-confirmed SARS-CoV-2 infection and U07.2 for deaths from clinically or epidemiologically diagnosed COVID-19 without lab-confirmed SARS-CoV-2 infection.
The death-to-case ratio reflects the number of deaths divided by the number of diagnosed cases within a given time interval. Based on Johns Hopkins University statistics, the global death-to-case ratio is 6.4% (126,681/1,981,239) as of 15 April 2020. The number varies by region.
Other measures include the case fatality rate (CFR), which reflects the percent of diagnosed individuals who die from a disease, and the infection fatality rate (IFR), which reflects the percent of infected individuals (diagnosed and undiagnosed) who die from a disease. These statistics are not time bound and follow a specific population from infection through case resolution. A number of academics have attempted to calculate these numbers for specific populations. In the epicentre of the outbreak in Italy, Castiglione d'Adda, a small village of 4500, 80 (1.8%) are already dead. Most people in the village appear to have developed antibodies and plausible immunity, most did so without being diagnosed, and many did not have symptoms. An investigation is underway to test the entire population to learn more about the disease.
In the German region of Gangelt, where 0.06% (more than currently in any country as a whole) of the population has died, 14% have antibodies and are now considered immune (15% have been infected and 2% were currently infectious). In Gangelt, the disease was spread by Carnival festivals, and spread to younger people, causing a relatively lower mortality, and not all COVID-19 deaths may have been formally classified as such. Furthermore, the German health system has not been overwhelmed.
Total confirmed cases over time
Total deaths over time
Total confirmed cases of COVID-19 per million people, 10 April 2020
Total confirmed deaths due to COVID-19 per million people, 10 April 2020
Society and culture
The World Health Organization announced in February 2020 that COVID-19 is the official name of the disease. World Health Organisation chief Tedros Adhanom Ghebreyesus explained that CO stands for corona, VI for virus and D for disease, while 19 is for when the outbreak was first identified: 31 December 2019. The name had been chosen to avoid references to a specific geographical location (e.g. China), animal species or group of people, in line with international recommendations for naming aimed at preventing stigmatisation. For example, there are attempts to lay blame on the China government for the problem, using the words "Wuhan Pneumonia" to assign fault.
During the initial outbreak in Wuhan, China, the virus and disease were commonly referred to as "coronavirus" and "Wuhan coronavirus". In January 2020, WHO recommended 2019-nCov and 2019-nCoV acute respiratory disease as interim names for the virus and disease in accordance with 2015 guidance against using locations in disease and virus names. The official names COVID-19 and SARS-CoV-2 were issued on 11 February 2020.
Due to capacity limitations in the standard supply chains, some digital manufacturers are printing healthcare material such as nasal swabs and ventilator parts. In one example, when an Italian hospital urgently required a ventilator valve, and the supplier was unable to deliver in the timescale required, a local startup reverse-engineered and printed the required 100 valves overnight.
Humans appear to be capable of spreading the virus to some other animals. A domestic cat in Liège tested positive after it started showing symptoms (diarrhoea, vomiting, shortness of breath) a week later than its owner, who was also positive.Tigers at the Bronx Zoo tested positive for the virus and showed symptoms of COVID-19, including a dry cough and loss of appetite.
A study on domesticated animals inoculated with the virus found that cats and ferrets appear to be "highly susceptible" to the disease, while dogs appear to be less susceptible, with lower levels of viral replication. The study failed to find evidence of viral replication in pigs, ducks, and chickens.
No medications or vaccine is approved to treat the disease. International research on vaccines and medicines in COVID-19 are underway by government organisations, academic groups and industry researchers. In March, the World Health Organization initiated the "SOLIDARITY Trial" to assess treatment effects of four existing antiviral compounds with the most promise of efficacy.
There is no available vaccine, but various agencies are actively developing vaccine candidates. Previous work on SARS-CoV is being utilised because SARS-CoV and SARS-CoV-2 both use the ACE2 receptor to enter human cells. There are three vaccination strategies being investigated. First, researchers aim to build a whole virus vaccine. The use of such a virus, be it inactive or dead, aims to elicit a prompt immune response of the human body to a new infection with COVID-19. A second strategy, subunit vaccines, aims to create a vaccine that sensitises the immune system to certain subunits of the virus. In the case of SARS-CoV-2, such research focuses on the S-spike protein that helps the virus intrude the ACE2 enzyme receptor. A third strategy is that of the nucleic acid vaccines (DNA or RNA vaccines, a novel technique for creating a vaccination). Experimental vaccines from any of these strategies would have to be tested for safety and efficacy.
On 16 March 2020, the first clinical trial of a vaccine started with four volunteers in Seattle. The vaccine contains a harmless genetic code copied from the virus that causes the disease.
The COVID-19 Clinical Research Coalition has goals to 1) facilitate rapid reviews of clinical trial proposals by ethics committees and national regulatory agencies, 2) fast-track approvals for the candidate therapeutic compounds, 3) ensure standardised and rapid analysis of emerging efficacy and safety data and 4) facilitate sharing of clinical trial outcomes before publication. A dynamic review of clinical development for COVID-19 vaccine and drug candidates was in place, as of April 2020.
Chloroquine, previously used to treat malaria, was studied in China in February 2020, with preliminary results. However, there are calls for peer review of the research. The Guangdong Provincial Department of Science and Technology and the Guangdong Provincial Health and Health Commission issued a report stating that chloroquine phosphate "improves the success rate of treatment and shortens the length of person's hospital stay" and recommended it for people diagnosed with mild, moderate and severe cases of novel coronavirus pneumonia.
On 17 March, the Italian Pharmaceutical Agency included chloroquine and hydroxychloroquine in the list of drugs with positive preliminary results for treatment of COVID-19. Korean and Chinese Health Authorities recommend the use of chloroquine. However, the Wuhan Institute of Virology, while recommending a daily dose of one gram, notes that twice that dose is highly dangerous and could be lethal. On 28 March 2020, the FDA issued an emergency use authorisation for hydroxychloroquine and chloroquine at the discretion of physicians treating people with COVID-19.
The Chinese 7th edition guidelines also include interferon, ribavirin or umifenovir for use against COVID-19. Preliminary data indicate that high doses of ribavirin are necessary to inhibit SARS-CoV-2 in vitro. Since studies have been inconsistent with respect to ribavirin's efficacy against other novel coronaviruses (e.g., SARS, MERS) and its significant toxicity, this suggests its role in treating COVID-19 is limited and its best chance of being effective is being a part of combination therapy.
In 2020, a trial found that lopinavir/ritonavir was ineffective in the treatment of severe illness.Nitazoxanide has been recommended for further in vivo study after demonstrating low concentration inhibition of SARS-CoV-2.
Studies have demonstrated that initial spike protein priming by transmembrane protease serine2 (TMPRSS2) is essential for entry of SARS-CoV-2 via interaction with the ACE2 receptor. These findings suggest the TMPRSS2 inhibitor camostat approved for use in Japan for inhibiting fibrosis in liver and kidney disease might constitute an effective off-label treatment.
In February 2020, favipiravir was being studied in China for experimental treatment of the emergent COVID-19 disease.
In April 2020 ivermectin is being studied in Australia for a possible treatment for COVID-19 and has been shown to stop viral growth within 48 hours in vitro.
There are mixed results as of 3 April 2020 as to the effectiveness of hydroxychloroquine as a treatment for COVID-19, with some studies showing little or no improvement. The studies of chloroquine and hydroxychloroquine with or without azithromycin have major limitations that have prevented the medical community from embracing these therapies without further study.
Oseltamivir does not inhibit SARS-CoV-2 in vitro and has no known role in COVID-19 treatment.
Lenzilumab, an anti-GM-CSF monoclonal antibody, has been shown to be protective in murine models for CAR T cell induced CRS and neurotoxicity and is a viable therapeutic option due to the observed increase of pathogenic GM-CSF secreting T-cells in hospitalised patients with COVID-19.
^Han X, Cao Y, Jiang N, Chen Y, Alwalid O, Zhang X, et al. (March 2020). "Novel Coronavirus Pneumonia (COVID-19) Progression Course in 17 Discharged Patients: Comparison of Clinical and Thin-Section CT Features During Recovery". Clinical Infectious Diseases. doi:10.1093/cid/ciaa271. PMID32227091.
^ abcdHui DS, I Azhar E, Madani TA, Ntoumi F, Kock R, Dar O, et al. (February 2020). "The continuing 2019-nCoV epidemic threat of novel coronaviruses to global health—The latest 2019 novel coronavirus outbreak in Wuhan, China". Int J Infect Dis. 91: 264–66. doi:10.1016/j.ijid.2020.01.009. PMID31953166.
^ abcdeSalehi, Sana; Abedi, Aidin; Balakrishnan, Sudheer; Gholamrezanezhad, Ali (14 March 2020). "Coronavirus Disease 2019 (COVID-19): A Systematic Review of Imaging Findings in 919 Patients". American Journal of Roentgenology: 1–7. doi:10.2214/AJR.20.23034. ISSN0361-803X. PMID32174129.
^ abWei, Xiao-Shan; Wang, Xuan; Niu, Yi-Ran; Ye, Lin-Lin; Peng, Wen-Bei; Wang, Zi-Hao; Yang, Wei-Bing; Yang, Bo-Han; Zhang, Jian-Chu; Ma, Wan-Li; Wang, Xiao-Rong; Zhou, Qiong (26 February 2020). "Clinical Characteristics of SARS-CoV-2 Infected Pneumonia with Diarrhea". doi:10.2139/ssrn.3546120.
^Chen N, Zhou M, Dong X, Qu J, Gong F, Han Y, et al. (February 2020). "Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study". Lancet. 395 (10223): 507–513. doi:10.1016/S0140-6736(20)30211-7. PMID32007143.
^Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, et al. (February 2020). "Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China". Lancet. 395 (10223): 497–506. doi:10.1016/S0140-6736(20)30183-5. PMID31986264.
^Letko M, Marzi A, Munster V (2020). "Functional assessment of cell entry and receptor usage for SARS-CoV-2 and other lineage B betacoronaviruses". Nature Microbiology. 5 (4): 562–569. doi:10.1038/s41564-020-0688-y. PMID32094589.
^Hamming, I.; Timens, W.; Bulthuis, M. L. C.; Lely, A. T.; Navis, G. J.; Goor, H. van (2004). "Tissue distribution of ACE2 protein, the functional receptor for SARS coronavirus. A first step in understanding SARS pathogenesis". The Journal of Pathology. 203 (2): 631–637. doi:10.1002/path.1570. ISSN1096-9896. PMID15141377.
^ abBarton L, Duval E, Stroberg E, Ghosh S, Mukhopadhyay S (April 2020). "COVID-19 autopsies, Oklahoma, USA". American Journal of Clinical Pathology. doi:10.1093/ajcp/aqaa062. PMID32275742.
^Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, et al. (February 2020). "Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China". Lancet. 395 (10223): 497–506. doi:10.1016/S0140-6736(20)30183-5. PMID31986264.
^Lillicrap, David (1 April 2020). "Disseminated intravascular coagulation in patients with 2019-nCoV pneumonia". Journal of Thrombosis and Haemostasis: JTH. 18 (4): 786–787. doi:10.1111/jth.14781. PMID32212240.
^Mitra, Anupam; Dwyre, Denis M.; Schivo, Michael; Thompson, George R.; Cohen, Stuart H.; Ku, Nam; Graff, John P. (25 March 2020). "Leukoerythroblastic reaction in a patient with COVID-19 infection". American Journal of Hematology. doi:10.1002/ajh.25793. PMID32212392.
^ abcdAnderson RM, Heesterbeek H, Klinkenberg D, Hollingsworth TD (March 2020). "How will country-based mitigation measures influence the course of the COVID-19 epidemic?". Lancet. 395 (10228): 931–934. doi:10.1016/S0140-6736(20)30567-5. PMID32164834. A key issue for epidemiologists is helping policy makers decide the main objectives of mitigation—e.g. minimising morbidity and associated mortality, avoiding an epidemic peak that overwhelms health-care services, keeping the effects on the economy within manageable levels, and flattening the epidemic curve to wait for vaccine development and manufacture on scale and antiviral drug therapies.
^"For different groups of people: how to choose masks". NHC.gov.cn. National Health Commission of the People's Republic of China. 7 February 2020. Retrieved 22 March 2020. Disposable medical masks: Recommended for: · People in crowded places · Indoor working environment with a relatively dense population · People going to medical institutions · Children in kindergarten and students at school gathering to study and do other activities[permanent dead link]
^Kuhakan, Jiraporn (12 March 2020). "'Better than nothing': Thailand encourages cloth masks amid surgical mask shortage". Reuters. Archived from the original on 21 March 2020. Retrieved 22 March 2020. Thailand's health authorities are encouraging people to make cloth face masks at home to guard against the spread of the coronavirus amid a shortage of surgical masks.... The droplet from coughing and sneezing is around five microns and we have tested already that cloth masks can protect against droplets bigger than one micron.
^"WHO-recommended handrub formulations". WHO Guidelines on Hand Hygiene in Health Care: First Global Patient Safety Challenge Clean Care Is Safer Care. World Health Organization. 19 March 2009. Retrieved 19 March 2020.
^Kui L, Fang YY, Deng Y, Liu W, Wang MF, Ma JP, et al. (February 2020). "Clinical characteristics of novel coronavirus cases in tertiary hospitals in Hubei Province". Chinese Medical Journal: 1. doi:10.1097/CM9.0000000000000744. PMID32044814.
^Xiang YT, Yang Y, Li W, Zhang L, Zhang Q, Cheung T, et al. (March 2020). "Timely mental health care for the 2019 novel coronavirus outbreak is urgently needed". The Lancet. Psychiatry. 7 (3): 228–29. doi:10.1016/S2215-0366(20)30046-8. PMID32032543.
^Kang L, Li Y, Hu S, Chen M, Yang C, Yang BX, et al. (March 2020). "The mental health of medical workers in Wuhan, China dealing with the 2019 novel coronavirus". The Lancet. Psychiatry. 7 (3): e14. doi:10.1016/S2215-0366(20)30047-X. PMID32035030.
^Zhou F, Yu T, Du R, Fan G, Liu Y, Liu Z, et al. (2020). "Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study". The Lancet. Elsevier BV. 395 (10229): 1054–1062. doi:10.1016/s0140-6736(20)30566-3. ISSN0140-6736. PMID32171076.
^Xu L, Liu J, Lu M, Yang D, Zheng X (March 2020). "Liver injury during highly pathogenic human coronavirus infections". Liver International. doi:10.1111/liv.14435. PMID32170806.
^Wang W, Tang J, Wei F (April 2020). "Updated understanding of the outbreak of 2019 novel coronavirus (2019-nCoV) in Wuhan, China". Journal of Medical Virology. 92 (4): 441–47. doi:10.1002/jmv.25689. PMID31994742.
^Ji Y, Ma Z, Peppelenbosch MP, Pan Q (February 2020). "Potential association between COVID-19 mortality and health-care resource availability". Lancet Global Health. 8 (4): e480. doi:10.1016/S2214-109X(20)30068-1. PMID32109372.
^Li XQ, Cai WF, Huang LF, Chen C, Liu YF, Zhang ZB, et al. (March 2020). "[Comparison of epidemic characteristics between SARS in2003 and COVID-19 in 2020 in Guangzhou]". Zhonghua Liu Xing Bing Xue Za Zhi = Zhonghua Liuxingbingxue Zazhi (in Chinese). 41 (5): 634–637. doi:10.3760/cma.j.cn112338-20200228-00209. PMID32159317.
^"ICD-10 Version:2019". World Health Organization. 2019. Archived from the original on 31 March 2020. Retrieved 31 March 2020. U07.2—COVID-19, virus not identified—COVID-19 NOS—Use this code when COVID-19 is diagnosed clinically or epidemiologically but laboratory testing is inconclusive or not available. Use additional code, if desired, to identify pneumonia or other manifestations
^Ko WC, Rolain JM, Lee NY, Chen PL, Huang CT, Lee PI, Hsueh PR (March 2020). "Arguments in favor of remdesivir for treating SARS-CoV-2 infections". International Journal of Antimicrobial Agents: 105933. doi:10.1016/j.ijantimicag.2020.105933. PMID32147516.
^multicenter collaboration group of Department of Science Technology of Guangdong Province Health Commission of Guangdong Province for chloroquine in the treatment of novel coronavirus pneumonia (February 2020). "[Expert consensus on chloroquine phosphate for the treatment of novel coronavirus pneumonia]". Zhonghua Jie He He Hu Xi Za Zhi = Zhonghua Jiehe He Huxi Zazhi = Chinese Journal of Tuberculosis and Respiratory Diseases. 43: E019. doi:10.3760/cma.j.issn.1001-0939.2020.0019. PMID32075365.