Coronavirus Pandemic (2019-2020)

A picture of the coronavirus molecule.

The Coronavirus Pandemic is an ongoing conflict that has caused lot of stress and worry around the world and might even cause the Hot Contest to be postponed or even cancelled. The virus was first discovered on December 31, 2019 but is thought to have actually started in September 2019. As the rest of the world was celebrating the new year and decade little did they know that what was about to happen would be one of the worst events of the 21st century. As of September 11, 2020 the virus has killed over 150,000 people worldwide, and infected at least 2 million. The United States alone has had over 192,000 deaths as of September 11, 2020 and over 6,420,000 cases. People expect that the total deaths will at least 2 million and that the United States alone will have around 200,000.

## More Info

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).[a] The outbreak was identified in Wuhan, China, in December 2019.[4] The World Health Organization declared the outbreak to be a Public Health Emergency of International Concern on 30 January 2020, and recognised it as a pandemic on 11 March 2020.[7][8] As of 20 April 2020, more than 2.41 million cases of COVID-19 have been reported in 185 countries and territories, resulting in more than 165,000 deaths. More than 632,000 people have recovered,[5] although there may be a possibility of relapse or reinfection.[9][10]

The virus is primarily spread between people during close contact,[c] often via small droplets produced by coughing,[d] sneezing, or talking.[11][12][14] While these droplets are produced when breathing out, they usually fall to the ground or onto surfaces rather than remain in the air over long distances.[11][15][16] People may also become infected by touching a contaminated surface and then touching their eyes, nose, or mouth.[11][12] The virus can survive on surfaces for up to 72 hours.[17]
 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.[18] Common symptoms include fever, cough and shortness of breath.[19] Complications may include pneumonia and acute respiratory distress syndrome.[20] The time from exposure to onset of symptoms is typically around five days, but may range from two to fourteen days.[19][21] There is no known vaccine or specific antiviral treatment.[11] Primary treatment is symptomatic and supportive therapy.[22]

Recommended preventive measures include hand washing, covering one's mouth when coughing, maintaining distance from other people, and monitoring and self-isolation for people who suspect they are infected.[11][23] Authorities worldwide have responded by implementing travel restrictions, quarantines, curfews and stay-at-home orders, workplace hazard controls, and facility closures. Many places have also worked to increase testing capacity and trace contacts of infected persons.

The pandemic has led to severe global socioeconomic disruption,[24] the postponement or cancellation of sporting, religious, political and cultural events,[25] and widespread shortages of supplies exacerbated by panic buying.[26][27] The pandemic has led to one of the largest global recessions in history, with more than a third of the global population being in lockdown.[28] Schools, universities and colleges have closed
 either on a nationwide or local basis in 197 countries, affecting
approximately 99.9 per cent of the world's student population.[29][e] Misinformation about the virus has spread online,[30][31] and there have been incidents of xenophobia and discrimination against Chinese people and against those perceived as being Chinese, or as being from areas with high infection rates.[32][33][34] Due to reduced travel and closures of heavy industry, there has been a decrease in air pollution and carbon emissions.[35][36]

Play media

Video summary (script) on the coronavirus disease

## Contents

* 1 Epidemiology
	+ 1.1 Cases
	+ 1.2 Deaths
	+ 1.3 Duration
* 2 Signs and symptoms
* 3 Cause
	+ 3.1 Transmission
	+ 3.2 Virology
* 4 Diagnosis
	+ 4.1 Viral testing
	+ 4.2 Imaging
* 5 Prevention
	+ 5.1 Hand washing
	+ 5.2 Surface cleaning
	+ 5.3 Face masks and respiratory hygiene
	+ 5.4 Social distancing
	+ 5.5 Self-isolation
* 6 Management
	+ 6.1 Containment and mitigation
	+ 6.2 Health care
	+ 6.3 Treatment
* 7 History
* 8 Domestic responses
	+ 8.1 Asia
	+ 8.2 Europe
	+ 8.3 North America
	+ 8.4 South America
	+ 8.5 Africa
	+ 8.6 Oceania
* 9 International responses
	+ 9.1 Travel restrictions
	+ 9.2 Evacuation of foreign citizens
	+ 9.3 International aid
	+ 9.4 WHO response measures
	+ 9.5 Economic and social policy responses
* 10 Impact
	+ 10.1 Politics
	+ 10.2 Education
	+ 10.3 Socioeconomics
	+ 10.4 Culture
	+ 10.5 Environment and climate
	+ 10.6 Xenophobia and racism
	+ 10.7 Domestic violence
* 11 Information dissemination
	+ 11.1 Misinformation
* 12 See also
* 13 Notes
* 14 References
* 15 External links
	+ 15.1 Health agencies
	+ 15.2 Directories
	+ 15.3 Data and graphs
	+ 15.4 Medical journals

## Epidemiology

Main articles: 2019–20 coronavirus pandemic by country and territory, cases, and deaths

Health authorities in Wuhan, Hubei, China, reported a cluster of viral pneumonia cases of unknown cause on 31 December 2019,[346][347] and an investigation was launched in early January 2020.[348] The cases mostly had links to the Huanan Seafood Wholesale Market and so the virus is thought to have a zoonotic origin.[349] The virus that caused the outbreak is known as SARS-CoV-2, a newly discovered virus closely related to bat coronaviruses,[350] pangolin coronaviruses,[3][351] and SARS-CoV.[352]

The current scientific consensus is that COVID-19 has a natural origin.[353][354][355][356]

The earliest known person with symptoms was later discovered to
have fallen ill on 1 December 2019, and that person did not have visible
 connections with the later wet market cluster.[357][358] Of the early cluster of cases reported in December 2019, two-thirds were found to have a link with the market.[359][360][361] On 13 March 2020, an unverified report from the *South China Morning Post* suggested a case traced back to 17 November 2019, in a 55-year-old from Hubei, may have been the first.[362][363]

### Cases

Cases refers to the number of people who have been tested for COVID-19, and whose test has been confirmed positive according to official protocols.[364]
 As of 20 April, the countries that made public their testing data have
on average performed an amount of tests equal to only 1.1 per cent of
their population, while no country has tested samples equal to more than
 12.5 per cent of its population.[365] Many countries (for example, Italy and Switzerland, as well as the Netherlands[366] and Spain[367][368]) have had official policies not to test those with only mild symptoms.[369]
 An analysis of the early phase of the outbreak up to 23 January
estimated 86 per cent of COVID-19 infections had not been detected, and
that these undocumented infections were the source for 79 per cent of
documented cases.[370]
 Several other studies, using a variety of methods, have estimated that
numbers of infections in many countries are likely to be considerably
greater than the reported cases.[371][372]

On 9 April 2020, preliminary results of testing showed that 15 per cent of people tested in Gangelt, the centre of a major infection cluster in Germany, had apparent immunity to SARS-COV-2.[373]
 Screening for COVID-19 in pregnant women in New York City, and blood
donors in the Netherlands, has also found that the numbers of infections
 are substantially higher than reported cases.[374][375]

Analysis by age in China indicates that a relatively low proportion of cases occur in individuals under 20 years of age.[376]
 However, it is not yet clear whether this is because young people are
actually less likely to be infected, or less likely to develop serious
symptoms, and thus seek medical attention and be tested.[377]

Initial estimates of the basic reproduction number ("R0") for COVID-19 in January were between 1.4 and 2.5,[378] but a subsequent analysis has concluded that it may be about 5.7 (with a 95% confidence interval of 3.8 to 8.9).[379] After the implementation of social distancing and stay-at-home orders, some regions have been able to sustain an effective transmission rate ("Rt") of less than one, meaning that the disease is in remission there.[380][381]

* Total confirmed cases of COVID-19 per million people[382]
* Epidemic curve of COVID-19 by date of report
* Semi-log graph showing the change in total (cumulative) count from the first reported date for the ten most affected countries[383]
* Semi-log plot of daily new cases of Covid-19 (three-day average) in the world and top five countries (mean with deaths)
* Semi-log plot of cases in some countries with high growth rates

(post-China) with doubling times and three-day projections based on the
exponential growth rates

* Daily confirmed cases by country[384]

### Deaths

Further information: List of deaths due to coronavirus disease 2019

Most people with COVID-19 recover. For the rest, the time from first
symptom to death is between 6 and 41 days, typically 14 days.[385] As of 20 April 2020, approximately 165,000[5] deaths had been attributed to COVID-19. In China, as of 5 February
 about 80 per cent of deaths were in those over 60, and 75 per cent had
pre-existing health conditions including cardiovascular diseases and
diabetes.[386] Deaths among people under 65 years of age without an underlying predisposing condition are uncommon.[387]

The first confirmed death was in Wuhan on 9 January 2020.[388] The first death outside mainland China occurred on 1 February in the Philippines,[389] and the first death outside Asia was in France on 14 February.[390] By 28 February, outside mainland China, more than a dozen deaths each were recorded in Iran, South Korea, and Italy.[391][392][393] By 13 March, more than forty countries and territories had reported deaths, on every continent except Antarctica.[394]

Official deaths from the COVID-19 generally refer to people who
died after testing positive according to official protocols. This may
ignore deaths of people who die without testing, e.g. at home or in
nursing homes.[395] Conversely, deaths of people who had underlying conditions may lead to overcounting.[396] There are indications of undercounting of deaths in Brazil,[397] China[*citation needed*], Iran,[398] North Korea,[399] Russia,[400] the UK,[401] and the U.S.,[402] and overcounting in Belgium.[403]

Several measures are commonly used to quantify mortality.[404]
 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.[405]

The death-to-case ratio reflects the number of deaths attributed
to COVID-19 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 6.9 per cent (165,939 deaths for 2,416,135 cases) as of 20 April 2020.[5] The number varies by region.[406]

Other measures include the case fatality rate
 (CFR), which reflects the percentage of diagnosed people who die from a
 disease, and the infection fatality rate (IFR), which reflects the
percentage of infected (diagnosed and undiagnosed) who die from a
disease. These statistics are not timebound and follow a specific
population from infection through case resolution. The University of Oxford's Centre for Evidence-Based Medicine (CEBM) estimates a global CFR of 0.72% and IFR of 0.1% to 0.36%.[407] According to CEBM, random antibody testing in Germany suggests an IFR of 0.37%.[407]

* Total confirmed deaths due to COVID-19 per million people[408]
* Semi-log plot of daily deaths due to Covid-19 (three-day average) in the world and top five countries (mean with cases)
* Case fatality rate of COVID-19 by country and confirmed cases
* Ongoing case fatality rate of COVID-19 by country

### Duration

The WHO asserts that the pandemic can be controlled.[8] The peak and ultimate duration of the outbreak are uncertain and may differ by location. Maciej Boni of Penn State University
 stated, "Left unchecked, infectious outbreaks typically plateau and
then start to decline when the disease runs out of available hosts. But
it's almost impossible to make any sensible projection right now about
when that will be".[409] The Chinese government's senior medical adviser Zhong Nanshan
 argued that "it could be over by June" if all countries can be
mobilised to follow the WHO's advice on measures to stop the spread of
the virus.[409] On 17 March, Adam Kucharski of the London School of Hygiene & Tropical Medicine said SARS-CoV-2 "is going to be circulating, potentially for a year or two".[410] According to the Imperial College study led by Neil Ferguson, physical distancing and other measures will be required "until a vaccine becomes available (potentially 18 months or more)".[411] William Schaffner of Vanderbilt University
 stated, "I think it's unlikely that this coronavirus—because it's so
readily transmissible—will disappear completely" and it "might turn into
 a seasonal disease, making a comeback every year". The virulence of the comeback would depend on herd immunity and the extent of mutation.[412]

## Signs and symptoms

Main article: Coronavirus disease 2019

Symptoms of COVID-19[413]

Symptoms of COVID-19 can be relatively non-specific and infected people may be asymptomatic. The two most common symptoms are fever (88 per cent) and dry cough (68 per cent). Less common symptoms include fatigue, respiratory sputum production (phlegm), loss of the sense of smell (initially estimated at 30 per cent[414] but later at only 15 per cent[415]), shortness of breath, muscle and joint pain, sore throat, headache, chills, vomiting, hemoptysis, and diarrhoea.[2][416]

The WHO says approximately one person in five becomes seriously ill and has difficulty breathing.[11]
 The U.S. Centers for Disease Control and Prevention (CDC) lists
emergency symptoms as difficulty breathing, persistent chest pain or
pressure, sudden confusion, difficulty waking, and bluish face or lips;
immediate medical attention is advised if these symptoms are present.[417]

Further development of the disease can lead to potentially fatal complications including pneumonia, acute respiratory distress syndrome, sepsis, septic shock, and kidney failure.[418]

Some of those infected may be asymptomatic, with no clinical
symptoms but test results that confirm infection, so researchers have
issued advice that those with close contact to confirmed infected people
 should be closely monitored and examined to rule out infection.[419] Chinese estimates of the asymptomatic ratio range from few to 44 per cent.[420] The usual incubation period (the time between infection and symptom onset) ranges from one to 14 days; it is most commonly five days.[421][11]

## Cause

### Transmission

Further information: Fomite and Contact tracing

Respiratory droplets, produced during a sneeze

Play media

A video discussing the basic reproduction number and case fatality rate in the context of the pandemic

Some details about how the disease is spread are still being determined.[12] The disease is believed to be primarily spread during close contact and by small droplets produced during coughing, sneezing, or talking;[11][12][14] with close contact being within 1 to 2 metres (3 to 6 feet).[11][12] Both sputum and saliva can carry large viral loads.[422] Studies have found that an uncovered cough can lead to droplets travelling up to 4.5 metres (15 feet) to 11.4 metres (37 feet).[423][424][13]
 Some have proposed the virus may also be transmitted by small droplets
that stay for more prolonged periods in the air, as may be generated
during speech.[425]

Respiratory droplets may also be produced during breathing out, including when talking, though the virus is not generally airborne.[11][426] The droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.[427] Some medical procedures such as intubation and cardiopulmonary resuscitation (CPR) may cause respiratory secretions to be aerosolised and thus result in airborne spread.[426] It may also spread when one touches a contaminated surface, including skin, and then touches their eyes, nose, or mouth.[11] While there are concerns it may spread by faeces, this risk is believed to be low.[11][12] The Government of China denied the possibility of faecal–oral transmission of SARS-CoV-2.[428]

The virus is most contagious during the first three days after
onset of symptoms, although spread may be possible before symptoms
appear and in later stages of the disease.[12][429]
 People have tested positive for the disease up to three days before
onset of symptoms, suggesting transmission is possible before developing
 significant symptoms.[429][430]
 Only a few reports of laboratory-confirmed asymptomatic cases exist,
but asymptomatic transmission has been identified by some countries
during contact tracing investigations.[*citation needed*] 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.[14]

The virus survives for hours to days on surfaces.[14][431] Specifically, the virus was found to be detectable for up to three days on plastic (polypropylene) and 304 stainless steel, for one day on cardboard, and for up to four hours on copper.[17] This, however, varies based on the humidity and temperature.[432]

Pets and other animals have tested positive for COVID-19. There is no evidence animals can pass the virus on to humans,[433]
 though British authorities advise washing one's hands after contact
with animals, like after contact with other potentially contaminated
surfaces.[434][435]

### Virology

Main article: Severe acute respiratory syndrome coronavirus 2

Illustration of SARSr-CoV virion

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel virus, first isolated from three people with pneumonia connected to the cluster of acute respiratory illness cases in Wuhan.[352] All features of the novel SARS-CoV-2 virus occur in related coronaviruses in nature.[436]

SARS-CoV-2 is closely related to SARS-CoV, and is thought to have a zoonotic origin.[350] SARS-CoV-2 genetically clusters with the genus *Betacoronavirus*, and is 96 per cent identical at the whole genome level to other bat coronavirus samples[2] and 92 per cent identical to pangolin coronavirus.[437]

## Diagnosis

Main article: COVID-19 testing

Demonstration of a swab for COVID-19 testing

Infection by the virus can be provisionally diagnosed on the basis of symptoms, though confirmation is ultimately by reverse transcription polymerase chain reaction (rRT-PCR) of infected secretions or CT imaging.[438][439] A study comparing PCR to CT in Wuhan
 suggests CT is significantly more sensitive than PCR, though less
specific, with many of its imaging features overlapping with other
pneumonias and disease processes.[439] As of March 2020, the American College of Radiology recommends that "CT should not be used to screen for or as a first-line test to diagnose COVID-19".[440]

### Viral testing

The WHO has published several RNA testing protocols for SARS-CoV-2, with the first issued on 17 January.[441][442][443] The test uses real-time reverse transcription polymerase chain reaction (rRT-PCR).[444] The test can be done on respiratory or blood samples.[445] Results are generally available within a few hours to days.[446][447] Generally this test is carried out on a nasopharyngeal swab though a throat swab may also be used.[448]

A number of laboratories and companies are developing serological tests, which detect antibodies.[449] As of 6 April 2020, none of these has been proved sufficiently accurate to be approved for widespread use.[450] In the U.S. a serological test developed by Cellex has been approved for emergency use by certified laboratories only.[451]

### Imaging

A CT scan of the chest of a person with COVID‑19. It shows light patches in the lungs.

Characteristic imaging features on radiographs and computed tomography (CT) of people who are symptomatic include asymmetric peripheral ground glass opacities and absent pleural effusions.[452] The Italian Radiological Society is compiling an international online database of imaging findings for confirmed cases.[453] Due to overlap with other infections such as adenovirus, imaging without confirmation by PCR is of limited specificity in identifying COVID-19.[452]
 A large study in China compared chest CT results to PCR and
demonstrated that though imaging is less specific for the infection, it
is faster and more sensitive, suggesting its consideration as a screening tool in epidemic areas.[439] Artificial intelligence-based convolutional neural networks have been developed to detect imaging features of the virus with both radiographs[454] and CT.[455]

## Prevention

Further information: Workplace hazard controls for COVID-19, Pandemic prevention, and Preparation to COVID-19

Infographic by the United States CDC, describing how to stop the spread of germs

Strategies for preventing transmission of the disease include
maintaining overall good personal hygiene, washing hands, avoiding
touching the eyes, nose, or mouth with unwashed hands, and coughing or
sneezing into a tissue and putting the tissue directly into a waste
container. Those who may already have the infection have been advised to
 wear a surgical mask in public.[456][457][458] Physical distancing measures are also recommended to prevent transmission.[459][460] Health care providers taking care of someone who may be infected are recommended to use standard precautions, contact precautions, and eye protection.[461]

Many governments have restricted or advised against all
non-essential travel to and from countries and areas affected by the
outbreak.[462]
 However, the virus is already spreading within communities in large
parts of the world, with many not knowing where or how they were
infected.[427]

Misconceptions are circulating about how to prevent infection;
for example, rinsing the nose and gargling with mouthwash are not
effective.[463] There is no COVID-19 vaccine, though many organisations are working to develop one.[464]

### Hand washing

Main article: Hand washing

Hand washing is recommended to prevent the spread of the disease. The
 CDC recommends that people wash hands often with soap and water for at
least twenty seconds, especially after going to the toilet or when hands
 are visibly dirty; before eating; and after blowing one's nose,
coughing, or sneezing. This is because outside the human body, the virus
 is killed by household soap, which bursts its protective bubble.[23] CDC further recommended using an alcohol-based hand sanitiser with at least 60 per cent alcohol by volume when soap and water are not readily available.[456] The WHO advises people to avoid touching the eyes, nose, or mouth with unwashed hands.[457][465]

### Surface cleaning

Surfaces may be decontaminated with a number of solutions (within one
 minute of exposure to the disinfectant for a stainless steel surface),
including 62–71 per cent ethanol, 50–100 per cent isopropanol, 0.1 per cent sodium hypochlorite, 0.5 per cent hydrogen peroxide, and 0.2–7.5 per cent povidone-iodine. Other solutions, such as benzalkonium chloride and chrohexidine gluconate,
 are less effective. The CDC recommends that if a COVID case is
suspected or confirmed at a facility such as an office or day care, all
areas such as offices, bathrooms, common areas, shared electronic
equipment like tablets, touch screens, keyboards, remote controls, and
ATM machines used by the ill persons, should be disinfected.[466][467]

### Face masks and respiratory hygiene

Main article: Face masks during the 2019–20 coronavirus pandemic

Taiwanese President Tsai Ing-wen (left) wearing a mask

Health organisations recommended that people cover their mouth and
nose with a bent elbow or a tissue when coughing or sneezing, and
disposing of any tissue immediately.[457] Surgical masks are recommended for those who may be infected,[468] as wearing a mask can limit the volume and travel distance of expiratory droplets dispersed when talking, sneezing, and coughing.[469] The WHO has issued instructions on when and how to use masks.[468]

Masks have also been recommended for use by those taking care of someone who may have the disease.[468]
 The WHO has recommended healthy people wear masks only if they are at
high risk, such as those who are caring for a person with COVID-19.[468]
 China and the United States, among other countries, have encouraged the
 use of face masks or cloth face coverings more generally by members of
the public to limit the spread of the virus by asymptomatic individuals.[470][471][472] Several national and local governments have made wearing masks mandatory.[473][474] Varying recommendations for wearing masks have been a subject of debate.[475]

### Social distancing

Main article: Social distancing measures related to the 2019–20 coronavirus pandemic

Physical distancing in Toronto, with limited number of customers allowed inside the store

Social distancing (also known as physical distancing) includes infection control
 actions intended to slow the spread of disease by minimising close
contact between individuals. Methods include quarantines; travel
restrictions; and the closing of schools, workplaces, stadiums,
theatres, or shopping centres. Individuals may apply social distancing
methods by staying at home, limiting travel, avoiding crowded areas,
using no-contact greetings, and physically distancing themselves from
others.[457][476] Many governments are now mandating or recommending social distancing in regions affected by the outbreak.[477][478]
 The maximum gathering size recommended by U.S. government bodies and
health organisations was swiftly reduced from 250 people (if there was
no known COVID-19 spread in a region) to 50 people, and later to 10
people.[479] On 22 March 2020, Germany banned public gatherings of more than two people.[480]
 A Cochrane review found that early quarantine with other public health
measures are effective in limiting the pandemic, but the best manner of
adopting and relaxing policies are uncertain, as local conditions vary.[481]

The pandemic in Peru resulted in curfews enforced by the Peruvian Armed Forces.

Older adults and those with underlying medical conditions such as diabetes, heart disease, respiratory disease, hypertension, and compromised immune systems
 face increased risk of serious illness and complications and have been
advised by the CDC to stay home as much as possible in areas of
community outbreak.[482][483]

In late March 2020, the WHO and other health bodies began to
replace the use of the term "social distancing" with "physical
distancing", to clarify that the aim is to reduce physical contact while
 maintaining social connections, either virtually or at a distance. The use of the term "social distancing" had led to implications that people should engage in complete social isolation, rather than encouraging them to stay in contact with others through alternative means.[484][485][486]

Some authorities have issued sexual health guidelines for use
during the pandemic. These include recommendations to have sex only with
 someone you live with, and who does not have the virus or symptoms of
the virus.[487][488]

### Self-isolation

Transmission of COVID-19 depends on many factors, most obviously physical distance.

Self-isolation
 at home has been recommended for those diagnosed with COVID-19 and
those who suspect they have been infected. Health agencies have issued
detailed instructions for proper self-isolation.[489][490]

Many governments have mandated or recommended self-quarantine for entire populations living in affected areas.[491][492]
 The strongest self-quarantine instructions have been issued to those in
 high risk groups. Those who may have been exposed to someone with
COVID-19 and those who have recently travelled to a country or region
with widespread transmission have been advised to self-quarantine for 14
 days from the time of last possible exposure.[11][19][493][494]

## Management

Further information: Coronavirus disease 2019 § Management, and Pandemic § Management

### Containment and mitigation

Further information: Flatten the curve

Goals of mitigation include delaying and reducing peak burden on healthcare (*flattening the curve*) and lessening overall cases and health impact.[495][496] Moreover, progressively greater increases in healthcare capacity (*raising the line*) such as by increasing bed count, personnel, and equipment, helps to meet increased demand.[497]

If
 mitigation is inadequate in strictness or duration—such as through
premature relaxation of physical distancing rules or stay-at-home
orders—there can be a resurgence after the initial surge and mitigation.[495][498]

Strategies in the control of an outbreak are containment or
suppression, and mitigation. Containment is undertaken in the early
stages of the outbreak and aims to trace and isolate those infected as
well as introduce other measures of infection control and vaccinations
to stop the disease from spreading to the rest of the population. When
it is no longer possible to contain the spread of the disease, efforts
then move to the mitigation stage: measures are taken to slow the spread
 and mitigate its effects on the healthcare system and society. A
combination of both containment and mitigation measures may be
undertaken at the same time.[499] Suppression requires more extreme measures so as to reverse the pandemic by reducing the basic reproduction number to less than 1.[411]

Part of managing an infectious disease outbreak is trying to decrease the epidemic peak, known as flattening the epidemic curve.[495]
 This decreases the risk of health services being overwhelmed and
provides more time for vaccines and treatments to be developed.[495]
 Non-pharmaceutical interventions that may manage the outbreak include
personal preventive measures, such as hand hygiene, wearing face masks,
and self-quarantine; community measures aimed at physical distancing
such as closing schools and cancelling mass gathering events; community
engagement to encourage acceptance and participation in such
interventions; as well as environmental measures such surface cleaning.[500]

More drastic actions aimed at containing the outbreak were taken
in China once the severity of the outbreak became apparent, such as
quarantining entire cities and imposing strict travel bans.[501]
 Other countries also adopted a variety of measures aimed at limiting
the spread of the virus. South Korea introduced mass screening and
localised quarantines, and issued alerts on the movements of infected
individuals. Singapore provided financial support for those infected who
 quarantined themselves and imposed large fines for those who failed to
do so. Taiwan increased face mask production and penalised hoarding of
medical supplies.[502]

Simulations for Great Britain and the United States show that
mitigation (slowing but not stopping epidemic spread) and suppression
(reversing epidemic growth) have major challenges. Optimal mitigation
policies might reduce peak healthcare demand by 2/3 and deaths by half,
but still result in hundreds of thousands of deaths and health systems
being overwhelmed. Suppression can be preferred but needs to be
maintained for as long as the virus is circulating in the human
population (or until a vaccine becomes available), as transmission
otherwise quickly rebounds when measures are relaxed. Long-term
intervention to suppress the pandemic has considerable social and
economic costs.[411]

#### Contact tracing

Contact tracing is an important method for health authorities to determine the source of an infection and to prevent further transmission.[503] The use of location data from mobile phones by governments for this purpose has prompted privacy concerns, with Amnesty International and more than a hundred other organisations issuing a statement calling for limits on this kind of surveillance.[504]

Various mobile apps have been implemented or proposed for voluntary use, and as of 7 April 2020 more than a dozen expert groups were working on privacy-friendly solutions such as using Bluetooth to log a user's proximity to other cellphones.[504]
 Users could then receive a message if they've been in close contact
with someone who has subsequently tested positive for COVID-19.[504]

On 10 April 2020 Google and Apple, jointly announced an initiative for privacy-preserving contact tracing based on Bluetooth technology and cryptography.[505][506]
 The system is intended to allow governments to create official
privacy-preserving coronavirus tracking apps, with the eventual goal of
integration of this functionality directly into the iOS and Android mobile platforms.[507]

### Health care

An army-constructed field hospital outside Östra sjukhuset (*Eastern hospital*) in Gothenburg, Sweden, contains temporary intensive care units for COVID-19 patients.

See also: Flatten the curve, list of countries by hospital beds, and Shortages related to the 2019–20 coronavirus pandemic

Increasing capacity and adapting healthcare for the needs of COVID-19
 patients is described by the WHO as a fundamental outbreak response
measure.[508] The ECDC and the European regional office of the WHO have issued guidelines for hospitals and primary healthcare services for shifting of resources at multiple levels, including focusing laboratory services towards COVID-19 testing, cancelling elective procedures whenever possible, separating and isolating COVID-19 positive patients, and increasing intensive care capabilities by training personnel and increasing the number of available ventilators and beds.[508][509]

Due to capacity limitations in the standard supply chains, some manufacturers are 3D printing healthcare material such as nasal swabs and ventilator parts.[510][511]
 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.[512][513] However, the startup later received legal threats due to alleged patent infringement.[514]

### Treatment

There are no specific antiviral medications approved for COVID-19, but development efforts are underway, including testing of existing medications. Taking over-the-counter cold medications,[515] drinking fluids, and resting may help alleviate symptoms.[456] Depending on the severity, oxygen therapy, intravenous fluids, and breathing support may be required.[516] The use of steroids may worsen outcomes.[517]
 Several compounds which were previously approved for treatment of other
 viral diseases are being investigated for use in treating COVID-19.[518]

## History

Main article: Timeline of the 2019–20 coronavirus pandemic

Cases by country plotted on a logarithmic scale[519]

There are various theories about where the very first case (the so-called patient zero) may have originated.[520] The first known case may trace back to 1 December 2019 in Wuhan, Hubei, China.[357] Within a month, the number of coronavirus cases in Hubei gradually increased. These were mostly linked to the Huanan Seafood Wholesale Market, which also sold live animals, and one theory is that the virus came from one of these animals; or, in other words, has a zoonotic origin.[349]

A pneumonia cluster of unknown cause was observed on 26 December
and treated by the doctor Zhang Jixian in Hubei Provincial Hospital, who
 informed the Wuhan Jianghan CDC on 27 December.[521][522]
 On 30 December, a group of doctors at Wuhan Central Hospital alerted
their colleagues of a "SARS-like coronavirus". The Wuhan Municipal
Health Commission released a public notice on 31 December.[346][523][524] Eight of these doctors, including Li Wenliang,[525] were then admonished by the police for spreading supposedly false rumours, and another, Ai Fen, was reprimanded by her superiors for raising the alarm.[526]
 Enough cases of unknown pneumonia had been reported to health
authorities in Wuhan to trigger an investigation in early January.[348]

During the early stages of the outbreak, the number of cases doubled approximately every seven and a half days.[527] In early and mid-January 2020, the virus spread to other Chinese provinces, helped by the Chinese New Year migration and Wuhan being a transport hub and major rail interchange.[2] On 20 January, China reported nearly 140 new cases in one day, including two people in Beijing and one in Shenzhen.[528] Later official data shows that 6,174 people had already developed symptoms by 20 January 2020.[529]

By 26 March, the United States had overtaken China and Italy with the highest number of confirmed cases in the world.[530] Research on coronavirus genomes indicates the majority of COVID-19 cases in New York came from European travellers, rather than directly from China or any other Asian country.[531]

As of 12 April 2020, more than 2.41 million cases have been
reported worldwide; more than 165,000 people have died and more than
632,000 have recovered.[532][533]

## Domestic responses

Main articles: Curfews and lockdowns related to the 2019–20 coronavirus pandemic, 2019–20 coronavirus pandemic by country and territory, and National responses to the 2019–20 coronavirus pandemic

Further information: Criticism of response to the 2019–20 coronavirus pandemic

Map of national and subnational lockdowns as of 30 March 2020 (table; more details)

National lockdown

Subnational lockdown

No lockdown

Around 200 countries and territories have had at least one case.[533] Due to the pandemic in Europe, many countries in the Schengen Area have restricted free movement and set up border controls.[534] National reactions have included containment measures such as quarantines and curfews (known as stay-at-home orders, shelter-in-place orders, or lockdowns).[535]

As of 12 April, nearly 300 million people, or about 90 per cent of the population, are under some form of lockdown in the United States,[536] more than 50 million people are in lockdown in the Philippines,[537] about 59 million people are in lockdown in South Africa,[538] and 1.3 billion people are in lockdown in India.[539][540] On 26 March, 1.7 billion people worldwide were under some form of lockdown,[541] which increased to 3.9 billion people one week later—more than half of the world's population.[542][543]

### Asia

Main article: 2019–20 coronavirus pandemic in Asia

As of 16 April 2020, cases have been reported in all Asian countries except for Tajikistan[544] and Turkmenistan, although some suspect such countries also have cases.[545][546]

#### Mainland China

Main article: 2019–20 coronavirus pandemic in mainland China

Confirmed cases of COVID-19 per 100,000 inhabitants by province, as of 13 April

Semi-log graph of new cases and deaths in China during the COVID-19 epidemic showing the lockdown and lifting

Wuhan Leishenshan Hospital, an emergency speciality field hospital built in response to the 2019–20 coronavirus pandemic

A temporary hospital for treating mild cases of COVID-19 in Wuhan, one of more than 10 such hospitals in the city[547]

The first confirmed case of COVID-19 has been traced back to 1 December 2019 in Wuhan;[357] one unconfirmed report suggests the earliest case was on 17 November.[362] Doctor Zhang Jixian observed a cluster of pneumonia cases of unknown cause on 26 December, upon which her hospital informed Wuhan Jianghan CDC on 27 December.[548][549] Initial genetic testing of patient samples on 27 December 2019 indicated the presence of a SARS-like coronavirus.[548] A public notice was released by Wuhan Municipal Health Commission on 31 December.[524] The WHO was informed on the same day.[346] As these notifications occurred, doctors in Wuhan were warned by police for "spreading rumours" about the outbreak.[550] The Chinese National Health Commission initially claimed there was no "clear evidence" of human-to-human transmission.[551]

On 20 January, the Chinese National Health Commission announced
that human-to-human transmission of the coronavirus had already
occurred.[552] During the Chinese New Year travel period in late January, Chinese authorities instigated a lockdown of the City of Wuhan.[553] However, travellers from Wuhan had already transported the virus to some Asian countries,[554][555][556] the Chinese government launched a radical campaign described on 10 February by the Chinese Communist Party general secretary Xi Jinping as a "people's war" to contain the spread of the virus.[557] In what has been described as "the largest quarantine in human history",[558] a *cordon sanitaire* was announced on 23 January stopping travel in and out of Wuhan,[559][560] which was extended to a total of 15 cities in Hubei, affecting a total of about 57 million people.[561] Private vehicle use was banned in the city.[562] Chinese New Year (25 January) celebrations were cancelled in many places.[563] The authorities also announced the construction of a temporary hospital, Huoshenshan Hospital, which was completed in 10 days.[564] Another hospital, Leishenshan Hospital, was built afterwards to handle additional patients.[565]
 In addition to newly constructed hospitals, China also converted 14
other facilities in Wuhan, such as convention centres and stadiums, into
 temporary hospitals.[566]

On 26 January, the government instituted further measures to
contain the COVID-19 outbreak, including issuing health declarations for
 travellers[567] and extending the Spring Festival holiday.[568] Universities and schools around the country were also closed.[569][570][571] The regions of Hong Kong and Macau instituted several measures, particularly in regard to schools and universities.[572] Remote working measures were instituted in several Chinese regions.[573] Travel restrictions were enacted in and outside of Hubei.[573][574] Public transport was modified,[575] and museums throughout China were temporarily closed.[573][576][577]
 Control of public movement was applied in many cities, and it has been
estimated that 760 million people (more than half the population) faced
some form of outdoor restriction.[578] In January and February 2020, during the height of the epidemic in Wuhan, about 5 million people lost their jobs.[579] Many of China's nearly 300 million rural migrant workers have been stranded at home in inland provinces or trapped in Hubei province.[580][581]

After the outbreak entered its global phase in March, Chinese
authorities took strict measures to prevent the virus re-entering China
from other countries. For example, Beijing imposed a 14-day mandatory
quarantine for all international travellers entering the city.[582] At the same time, a strong anti-foreigner sentiment quickly took hold,[583] and foreigners experienced harassment by the general public[584] and forced evictions from apartments and hotels.[34][585]

On 23 March, mainland China had only one case transmitted
domestically in the five days prior, in this instance via a traveller
returning to Guangzhou from Istanbul. On 24 March 2020, Chinese Premier Li Keqiang
 reported that the spread of domestically transmitted cases has been
basically blocked and the outbreak has been controlled in China.[586] The same day travel restrictions were eased in Hubei, apart from Wuhan, two months after the lockdown was imposed.[587]

The Chinese Ministry of Foreign Affairs announced on 26 March
2020 that entry for visa or residence permit holders would be suspended
from 28 March onwards, with no specific details on when this policy
would end. Those wishing to enter China must to apply for visas in
Chinese embassies or consulates.[588][589]
 The Chinese government encouraged businesses and factories to re-open
on 30 March, and provided monetary stimulus packages for firms.[590]

The State Council declared a day of mourning to begin with a national three-minute moment of silence on 4 April, coinciding with Qingming Festival, although the central government asked families to pay their respects online in observance of physical distancing to avoid a renewed COVID-19 outbreak.[591]

#### South Korea

Main article: 2020 coronavirus pandemic in South Korea

A banner in Seoul shares coronavirus infection prevention tips.

A drive-through test centre at the Gyeongju
 Public Health Centre allows people to be screened for COVID-19 without
leaving their vehicles. The collection process takes less than 10
minutes.[592]

COVID-19 was confirmed to have spread to South Korea on 20 January
2020 from China. The nation's health agency reported a significant
increase in confirmed cases on 20 February,[593] largely attributed to a gathering in Daegu of the Shincheonji Church of Jesus.[593][594] Shincheonji devotees visiting Daegu from Wuhan were suspected to be the origin of the outbreak.[595][596] As of 22 February, among 9,336 followers of the church, 1,261 or about 13 per cent reported symptoms.[597]

South Korea declared the highest level of alert on 23 February 2020.[598] On 28 February, more than 2,000 confirmed cases were reported,[599] rising to 3,150 on 29 February.[600] All South Korean military bases were quarantined after tests showed three soldiers had the virus.[595] Airline schedules were also changed.[601][602]

South Korea introduced what was considered the largest and
best-organised programme in the world to screen the population for the
virus, isolate any infected people, and trace and quarantine those who
contacted them.[603][604] Screening methods included mandatory self-reporting of symptoms by new international arrivals through mobile application,[605] drive-through testing for the virus with the results available the next day,[606] and increasing testing capability to allow up to 20,000 people to be tested every day.[607] South Korea's programme is considered a success in controlling the outbreak without quarantining entire cities.[603][608]

South Korean society was initially polarised on President Moon Jae-in's
 response to the crisis. Many Koreans signed petitions either calling
for Moon's impeachment over what they claimed to be government
mishandling of the outbreak, or praising his response.[609] On 23 March, it was reported that South Korea had the lowest one-day case total in four weeks.[607] On 29 March it was reported that beginning 1 April all new overseas arrivals will be quarantined for two weeks.[610] Per media reports on 1 April, South Korea has received requests for virus testing assistance from 121 different countries.[611]