2019–20 coronavirus pandemic

2019–20 coronavirus pandemic


he 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).The outbreak started in Wuhan, Hubei province, China, in December 2019. The World Health Organization (WHO) declared the outbreak to be a Public Health Emergency of International Concern on 30 January 2020 and recognized it as a pandemic on 11 March 2020. As of 4 April 2020, more than 1.18 million cases of COVID-19 have been reported in more than 200 countries and territories,[5] resulting in more than 63,900 deaths. More than 244,000 people have recovered. The virus is mainly spread during close contact,[c] and by small droplets produced during coughing,[d] sneezing, or talking. These small droplets may also be produced during breathing, but rapidly fall to the ground or surfaces and are not generally spread through the air over large distances.People may also catch COVID-19 by touching a contaminated surface and then their face. The virus can survive on surfaces up to 72 hours. It is most contagious during the first 3 days after symptom onset, although spread may be possible before symptoms appear and in later stages of the disease. The time between exposure and symptom onset is typically around five days, but may range from 2 to 14 days. Common symptoms include fever, cough, and shortness of breath.Complications may include pneumonia and acute respiratory distress syndrome. There is no known vaccine or specific antiviral treatment.Primary treatment is symptomatic and supportive therapy. 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. Efforts to prevent the virus spread include travel restrictions, quarantines, curfews, workplace hazard controls, event postponements and cancellations, and facility closures. These include national or regional quarantines throughout the world (starting with the quarantine of Hubei), curfew measures in mainland China and South Korea, various border closures or incoming passenger restrictions,screening at airports and train stations, and outgoing passenger travel bans. The pandemic has led to severe global socioeconomic disruption, the postponement or cancellation of sporting, religious, and cultural events, and widespread fears of supply shortages resulting in panic buying.Schools and universities have closed either on a nationwide or local basis in more than 160 countries, affecting nearly 90 percent of the world’s student population. Misinformation about the virus has spread online, and there have been incidents of xenophobia and discrimination against Chinese people and people of East and Southeast Asian descent and appearance, as well as against people from emergent hotspots around the globe. Health authorities in Wuhan, the capital of Hubei province, China, reported a cluster of pneumonia cases of unknown cause on 31 December 2019, and an investigation was launched in early January 2020. The cases mostly had links to the Huanan Seafood Wholesale Market and so the virus is thought to have a zoonotic origin. The virus that caused the outbreak is known as SARS-CoV-2, a newly discovered virus closely related to bat coronaviruses, pangolin coronaviruses, and SARS-CoV. 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. Of the early cluster of cases reported in December 2019, two-thirds were found to have a link with the market.[314][315][316] On 13 March 2020, an unverified report from the South China Morning Post suggested that a case traced back to 17 November 2019, in a 55-year-old from Hubei province, may have been the first. On 26 February 2020, the WHO reported that, as new cases reportedly declined in China but suddenly increased in Italy, Iran, and South Korea, the number of new cases outside China had exceeded the number of new cases within China for the first time. There may be substantial underreporting of cases, particularly among those with milder symptoms. By 26 February, relatively few cases had been reported among youths, with those 19 and under making up 2.4% of cases worldwide. Government sources in Germany and the United Kingdom estimate that 60–70% of the population will need to become infected before effective herd immunity can be achieved. 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.[326] The number of people infected with COVID-19 will likely be much higher, as many of those with only mild or no symptoms may not have been tested. As of 23 March, no country had tested more than 3% of its population, and many countries have had official policies not to test those with only mild symptoms, such as Italy, the Netherlands, Spain, and Switzerland. The time from development of symptoms to death has been between 6 and 41 days, with the most common being 14 days.[18] As of 4 April 2020, approximately 63,900[4] deaths had been attributed to COVID-19. In China, as of 5 February about 80% of deaths were in those over 60, and 75% had pre-existing health conditions including cardiovascular diseases and diabetes. The first confirmed death was on 9 January 2020 in Wuhan. The first death outside mainland China occurred on 1 February in the Philippines, and the first death outside Asia was in France on 14 February. By 28 February, outside mainland China, more than a dozen deaths each were recorded in Iran, South Korea, and Italy. By 13 March, more than forty countries and territories had reported deaths, on every continent except Antarctica. 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. 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 5.4% (63,902/1,181,825) as of 4 April 2020.[4] 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. Some researchers have also attempted to estimate the IFR for the pandemic as a whole. In China, estimates for the "crude CFR", i.e. the death-to-case ratio decreased from 17.3% (for those with symptom onset 1–10 January 2020) to 0.7% (for those with symptom onset after 1 February 2020). The WHO asserts that the pandemic can be controlled. 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". However, the Chinese government’s senior medical adviser Zhong Nanshan argued that "it could be over by June" if all countries can be mobilized to follow the WHO’s advice on measures to stop the spread of the virus. Adam Kucharski of the London School of Hygiene & Tropical Medicine stated that SARS-CoV-2 "is going to be circulating, potentially for a year or two".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)". 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. Symptoms of COVID-19 can be relatively non-specific and infected people may be asymptomatic. The two most common symptoms are fever (88%) and dry cough (68%). Less common symptoms include fatigue, respiratory sputum production (phlegm), loss of the sense of smell, shortness of breath, muscle and joint pain, sore throat, headache, chills, vomiting, hemoptysis, diarrhea, or cyanosis. The WHO states that approximately one person in six becomes seriously ill and has difficulty breathing.[357] 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. Further development of the disease can lead to severe pneumonia, acute respiratory distress syndrome, sepsis, septic shock and death. 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.Chinese estimates of the asymptomatic ratio range from few to 44%. The usual incubation period (the time between infection and symptom onset) ranges from one to 14 days; it is most commonly five days. As an example of uncertainty, estimates of loss of smell for people with COVID-19 were 30%, and then estimates fell to 15%. Some details about how the disease is spread are still being determined. The disease is believed to be primarily spread during close contact and by small droplets produced during coughing, sneezing, or talking;[9][10][12] with close contact being within 1 to 2 metres (3 to 6 feet). Studies have found that an uncovered coughing can lead to droplets travelling up to 4.5 metres (15 feet) to 8.2 metres (27 feet). Respiratory droplets may also be produced during breathing out, including when talking, though the virus is not generally airborne. The droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.[369] Some medical procedures such as intubation and cardiopulmonary resuscitation (CPR) may cause respiratory secretions to be aerosolized and thus result in airborne spread. It may also spread when one touches a contaminated surface and then touches their eyes, nose, or mouth.[9] While there are concerns it may spread by feces, this risk is believed to be low.[9][10] The Government of China denied the possibility of fecal-oral transmission of SARS-CoV-2. The virus is most contagious during the first 3 days after onset of symptoms, although spread may be possible before symptoms appear and in later stages of the disease.People have tested positive for the disease up to 3 days before onset of symptoms suggesting transmission is possible before developing significant symptoms. Only few reports of laboratory-confirmed asymptomatic cases exist, but asymptomatic transmission has been identified by some countries during contact tracing investigations. The European Centre for Disease Prevention and Control (ECDC) states that while it is not entirely clear how easily the disease spreads, one person generally infects two to three others.The virus survives for hours to days on surfaces. Specifically, the virus was found to be detectable for up to three days on plastic and stainless steel, for one day on cardboard, and for up to four hours on copper. This, however, varies based on the humidity and temperature. However, pets or other livestock may test positive but can’t pass on coronavirus to humans, as there were reported cases of infected pets such as a cat in Belgium and two dogs in Hong Kong. There have been reports were those diagnosed with coronavirus and seemingly recovered, have been readmitted to hospitals after testing positive for the virus a second time. These cases are believed to be worsening of a lingering infection rather than re-infection. Severe acute respiratory syndrome coronavirus 2 (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 at most 92% of genetic material shared between pangolin coronavirus and SARS-CoV-2, which is insufficient to prove pangolins to be the intermediate host. 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. A study comparing PCR to CT in Wuhan has suggested that CT is significantly more sensitive than PCR, though less specific, with many of its imaging features overlapping with other pneumonias and disease processes. 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". The WHO has published several RNA testing protocols for SARS-CoV-2, with the first issued on 17 January. Testing uses real-time reverse transcription polymerase chain reaction (rRT-PCR). The test can be done on respiratory or blood samples. Results are generally available within a few hours to days. A person is considered at risk if they have travelled to an area with ongoing community transmission within the previous 14 days, or have had close contact with an infected person. Common key indicators include fever, coughing, and shortness of breath. Other possible indicators include fatigue, myalgia, anorexia, sputum production, and sore throat. Characteristic imaging features on radiographs and computed tomography (CT) of people who are symptomatic include asymmetric peripheral ground glass opacities and absent pleural effusions. The Italian Radiological Society is compiling an international online database of imaging findings for confirmed cases. Due to overlap with other infections such as adenovirus, imaging without confirmation by PCR is of limited specificity in identifying COVID-19. However, 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.[395] Artificial intelligence-based convolutional neural networks have been developed to detect imaging features of the virus with both radiographs and CT. 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. Physical distancing measures are also recommended to prevent transmission. Many governments have restricted or advised against all non-essential travel to and from countries and areas affected by the outbreak. However, the virus has reached the stage of community spread in large parts of the world. This means that the virus is spreading within communities, and some community members don’t know where or how they were infected. Health care providers taking care of someone who may be infected are recommended to use standard precautions, contact precautions, and eye protection.
Contact tracing is an important method for health authorities to determine the source of an infection and to prevent further transmission. Misconceptions are circulating about how to prevent infection; for example, rinsing the nose and gargling with mouthwash are not effective. There is no COVID-19 vaccine, though many organizations are working to develop one. 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. CDC further recommended using an alcohol-based hand sanitizer with at least 60% alcohol by volume when soap and water are not readily available.[398] The WHO advises people to avoid touching the eyes, nose, or mouth with unwashed hands. 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% ethanol, 50–100% isopropanol, 0.1% sodium hypochlorite, 0.5% hydrogen peroxide, and 0.2–7.5% 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 daycare, 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. Health organizations 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. Surgical masks are recommended for those who may be infected, as wearing a mask can limit the volume and travel distance of expiratory droplets dispersed when talking, sneezing, and coughing. The WHO has issued instructions on when and how to use masks. According to Stephen Griffin, a virologist at the University of Leeds, "Wearing a mask can reduce the propensity [of] people to touch their faces, which is a major source of infection without proper hand hygiene." Masks have also been recommended for use by those taking care of someone who may have the disease. The WHO has recommended the wearing of masks by healthy people only if they are at high risk, such as those who are caring for a person with COVID-19, although they also acknowledge that wearing masks may help people avoid touching their face. Several countries have started to encourage the use of face masks by members of the public. China has specifically recommended the use of disposable medical masks by healthy members of the public, particularly when coming into close contact (≤1 metre) with other people. Hong Kong recommends wearing a surgical mask when taking public transport or staying in crowded places. Thailand’s health officials are encouraging people to make face masks at home out of cloth and wash them daily. The Czech Republic and Slovakia banned going out in public without wearing a mask or covering one’s nose and mouth. The Austrian government mandated that everyone entering a grocery store must wear a face mask. Israel has asked all residents to wear face masks when in public. Taiwan, which has been producing ten million masks per day since mid-March, required passengers on trains and intercity buses to wear face masks on 1 April.Panama has asked its citizens to wear a face mask. Face masks have also been widely used in Japan, South Korea, Malaysia, and Singapore. Social distancing (also known as physical distancing) includes infection control actions intended to slow the spread of disease by minimizing 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. Many governments are now mandating or recommending social distancing in regions affected by the outbreak. The maximum gathering size recommended by government bodies and health organizations 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. On 22 March 2020, Germany banned public gatherings of more than two people. 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. 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. The government in Ireland released sexual health guidelines during the pandemic. These included recommendations to only have sex with someone you live with, who does not have the virus or symptoms of the virus. In late March 2020, it was reported that for more than 70 million people in India, who live in clustered slums and comprise of about one sixth of the total urban population, social distancing is not only physically impossible, but economically too. The reported reproduction rate of the COVID-19 disease could be 20% higher in Indian slums due to impenetrable living conditions, as compared to the global ratio, i.e. 2 to 3 percent.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. Many governments have mandated or recommended self-quarantine for entire populations living in affected areas.] 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.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. Suppression requires more extreme measures so as to reverse the pandemic by reducing the basic reproduction number to less than 1. Part of managing an infectious disease outbreak is trying to decrease the epidemic peak, known as flattening the epidemic curve.[457] This decreases the risk of health services being overwhelmed and provides more time for vaccines and treatments to be developed. 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. 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. Other countries also adopted a variety of measures aimed at limiting the spread of the virus. South Korea introduced mass screening and localized 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 penalized hoarding of medical supplies. 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, if that comes first), as transmission otherwise quickly rebounds when measures are relaxed. Long-term intervention to suppress the pandemic causes social and economic costs. 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, drinking fluids, and resting may help alleviate symptoms. Depending on the severity, oxygen therapy, intravenous fluids, and breathing support may be required. The use of steroids may worsen outcomes.Several compounds that were previously approved for treatment of other viral diseases are being investigated for use in treating COVID-19. The World Health Organization also stated that some “traditional and home remedies” that can provide relief of the symptoms caused by SARS-CoV-19. Increasing capacity and adapting healthcare for the needs of COVID-19 patients is described by the WHO as a fundamental outbreak response measure.[469] 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.

en.wikipedia.org/wiki/2019–20_coronavirus_pandemic

Posted by bernawy hugues kossi huo on 2020-06-09 19:45:57

Tagged: , ventilators , primary , healthcare , services , COVID-19 , positive , patients , elective , procedures , oxygen therapy , intravenous fluids , antiviral , medications , contact , tracing , social , distancing , basic , reproduction , number , virulence , mortality , Containment , mitigation , system , personal , preventive , measures , cancelling , mass , gathering , events , coronavirus