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93-474: Judges of the competition include ICC judges and officers, and teams have to present arguments based on a fictitious problem via the roles of prosecution counsel, defence counsel, government counsel, or victim's representative. The arguments made usually relate to pre-trial or appeal proceedings. Each team is given 20 minutes for the main submissions and 10 minutes for rebuttal/surebuttal. For the English edition of

186-426: A Coronavirus breathalyzer is a pre-screening test for people who have no or mild symptoms of COVID-19. A not negative result is followed by a PCR or LAMP test. In May 2021, Reuters reported that Dutch researchers at Wageningen University had shown that trained bees could detect the virus in infected samples in seconds and this could benefit countries where test facilities are in short supply. A two-month study by

279-496: A nasopharyngeal swab , sputum (coughed up material), throat swabs, deep airway material collected via suction catheter or saliva . Drosten et al. remarked that for 2003 SARS, "from a diagnostic point of view, it is important to note that nasal and throat swabs seem less suitable for diagnosis, since these materials contain considerably less viral RNA than sputum, and the virus may escape detection if only these materials are tested." Sensitivity of clinical samples by RT-PCR

372-494: A strain of coronavirus known as "severe acute respiratory syndrome coronavirus 2" ( SARS-CoV-2 ). COVID-19 is mainly transmitted when people breathe in air contaminated by droplets / aerosols and small airborne particles containing the virus. Infected people exhale those particles as they breathe, talk, cough, sneeze, or sing. Transmission is more likely the closer people are. However, infection can occur over longer distances, particularly indoors. The transmission of

465-534: A systemic inflammatory response syndrome . Among healthy adults not exposed to SARS-CoV-2, about 35% have CD4 T cells that recognise the SARS-CoV-2 S protein (particularly the S2 subunit) and about 50% react to other proteins of the virus, suggesting cross-reactivity from previous common colds caused by other coronaviruses. COVID-19 testing COVID-19 testing involves analyzing samples to assess

558-475: A PCR test. Because the loss of the sense of smell shows up before other symptoms, there has been a call for widespread sniff testing. Health care bureaucracies have generally ignored sniff tests even though they are quick, easy and capable of being self-administered daily. This has led some medical journals to write editorials supporting the adoption of sniff testing. Typical visible features on CT initially include bilateral multilobar ground-glass opacities with

651-419: A certain critical size, generally thought to be <100μm diameter, evaporate faster than they settle; due to that fact, they form respiratory aerosol particles that remain airborne for a long period of time over extensive distances. Infectivity can begin four to five days before the onset of symptoms. Infected people can spread the disease even if they are pre-symptomatic or asymptomatic . Most commonly,

744-404: A computerized tomography scan is a strong tool in the diagnosis of COVID-19, it is insufficient to identify COVID-19 alone due to the poor specificity and the difficulties that radiologists may experience in distinguishing COVID-19 from other viral pneumonia on chest computerized tomography scans. The standard blood test (quick scan) taken at the emergency room measures different values. By use of

837-419: A current infection, while positive antibody tests indicate a prior infection. Other techniques include a CT scan , checking for elevated body temperature, checking for low blood oxygen level, and detection by trained dogs . Detection of the virus is usually done either by looking for the virus's inner RNA , or pieces of protein on the outside of the virus. Tests that look for the viral antigens (parts of

930-543: A few hours. These tests are also referred to as molecular or genetic assays. Real-time PCR (qPCR) provides advantages including automation, higher-throughput and more reliable instrumentation. It has become the preferred method. The combined technique has been described as real-time RT-PCR or quantitative RT-PCR and is sometimes abbreviated qRT-PCR , rRT-PCR or RT-qPCR, although sometimes RT-PCR or PCR are used. The Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines propose

1023-422: A higher risk of developing severe symptoms. Some complications result in death. Some people continue to experience a range of effects ( long COVID ) for months or years after infection, and damage to organs has been observed. Multi-year studies are underway to further investigate the long-term effects of the disease. COVID‑19 transmission occurs when infectious particles are breathed in or come into contact with

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1116-412: A known viral protein, buffer reagents and specific, enzyme-labeled antibodies. The result is luminescent. A chemiluminescent microparticle immunoassay uses magnetic, protein-coated microparticles. Antibodies react to the viral protein, forming a complex. Secondary enzyme-labeled antibodies are added and bind to these complexes. The resulting chemical reaction produces light. The radiance is used to calculate

1209-822: A lab. These tests usually use whole blood , plasma , or serum samples. A plate is coated with a viral protein, such as a SARS-CoV-2 spike protein. Samples are incubated with the protein, allowing any antibodies to bind to it. The antibody-protein complex can then be detected with another wash of antibodies that produce a color/fluorescent readout. Neutralization assays assess whether sample antibodies prevent viral infection in test cells. These tests sample blood, plasma or serum. The test cultures cells that allow viral reproduction (e.g., Vero E6 cells). By varying antibody concentrations, researchers can visualize and quantify how many test antibodies block virus replication. Chemiluminescent immunoassays are quantitative lab tests. They sample blood, plasma, or serum. Samples are mixed with

1302-477: A peripheral or posterior distribution. COVID-19 can be identified with higher precision using CT than with RT-PCR. Subpleural dominance , crazy paving , and consolidation may develop as the disease evolves. Chest CT scans and chest x-rays are not recommended for diagnosing COVID-19. Radiologic findings in COVID-19 lack specificity. Chest X-rays, computed tomography scans and ultrasounds are all ways

1395-613: A positive result if they find only binding antibodies, these tests cannot indicate that the subject has generated protective NAbs that protect against re-infection. It is expected that binding antibodies imply the presence of NAbs and for many viral diseases total antibody responses correlate somewhat with NAb responses but this is not established for COVID-19. A study of 175 recovered patients in China who experienced mild symptoms reported that 10 individuals had no detectable NAbs at discharge, or thereafter. How these patients recovered without

1488-423: A range of effects, such as fatigue , for prolonged periods after an initial COVID-19 infection. This is the result of a condition called long COVID , which can be described as a range of persistent symptoms that continue for months or years. Long-term damage to organs has been observed after the onset of COVID-19. Multi-year studies are underway to further investigate the protracted effects of long COVID. Reducing

1581-524: A swab of the anterior nares , or from saliva (obtained by various methods including lollipop tests for children). The sample is then exposed to paper strips containing artificial antibodies designed to bind to coronavirus antigens. Antigens bind to the strips and give a visual readout. The process takes less than 30 minutes, can deliver results at point of care, and does not require expensive equipment or extensive training. Swabs of respiratory viruses often lack enough antigen material to be detectable. This

1674-537: A time per machine. RT-PCR tests are accurate but require too much time, energy and trained personnel to run the tests. "There will never be the ability on a [PCR] test to do 300 million tests a day or to test everybody before they go to work or to school," Deborah Birx , head of the White House Coronavirus Task Force , said on 17 April 2020. "But there might be with the antigen test." Samples may be collected via nasopharyngeal swab,

1767-555: A variety of healthcare settings. There are some downsides to using imaging, however. The equipment needed for computed tomography scans is not available in most hospitals, making it not as effective as some other tools used for detection of the coronavirus disease. One of the difficult tasks in a pandemic is manually inspecting each report, which takes numerous radiology professionals and time. There were several problems with early studies of using chest computerized tomography scans for diagnosing coronavirus. Some of these problems included

1860-404: Is 63% for nasal swab, 32% for pharyngeal swab, 48% for feces, 72–75% for sputum, and 93–95% for bronchoalveolar lavage . The likelihood of detecting the virus depends on collection method and how much time has passed since infection. According to Drosten tests performed with throat swabs are reliable only in the first week. Thereafter the virus may abandon the throat and multiply in the lungs. In

1953-744: Is a novel severe acute respiratory syndrome coronavirus. It was first isolated from three people with pneumonia connected to the cluster of acute respiratory illness cases in Wuhan. All structural features of the novel SARS-CoV-2 virus particle occur in related coronaviruses in nature, particularly in Rhinolophus sinicus (Chinese horseshoe bats). Outside the human body, the virus is destroyed by household soap which bursts its protective bubble . Hospital disinfectants, alcohols, heat, povidone-iodine , and ultraviolet -C (UV-C) irradiation are also effective disinfection methods for surfaces. SARS-CoV-2

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2046-430: Is a measure of how well a test can identify true negatives. For all testing, both diagnostic and screening, there is usually a trade-off between sensitivity and specificity, such that higher sensitivities will mean lower specificities and vice versa. A 90% specific test will correctly identify 90% of those who are uninfected, leaving 10% with a false positive result. Samples can be obtained by various methods, including

2139-614: Is a process that amplifies (replicates) a small, well-defined segment of DNA many hundreds of thousands of times, creating enough of it for analysis. Test samples are treated with certain chemicals that allow DNA to be extracted. Reverse transcription converts RNA into DNA. Reverse transcription polymerase chain reaction (RT-PCR) first uses reverse transcription to obtain DNA, followed by PCR to amplify that DNA, creating enough to be analyzed. RT-PCR can thereby detect SARS-CoV-2 , which contains only RNA. The RT-PCR process generally requires

2232-411: Is an urgent need for frequent surveillance and rapid availability of results. Test analysis is often performed in automated , high-throughput , medical laboratories by medical laboratory scientists . Rapid self-tests and point-of-care testing are also available and can offer a faster and less expensive method to test for the virus although with a lower accuracy. Positive viral tests indicate

2325-571: Is associated with COVID-19 and is reported in as many as 88% of symptomatic cases. Published data on the neuropathological changes related with COVID-19 have been limited and contentious, with neuropathological descriptions ranging from moderate to severe hemorrhagic and hypoxia phenotypes , thrombotic consequences, changes in acute disseminated encephalomyelitis (ADEM-type), encephalitis and meningitis . Many COVID-19 patients with co-morbidities have hypoxia and have been in intensive care for varying lengths of time, confounding interpretation of

2418-433: Is available, guidelines and recommendations for hypertensive patients remain. The effect of the virus on ACE2 cell surfaces leads to leukocytic infiltration, increased blood vessel permeability, alveolar wall permeability, as well as decreased secretion of lung surfactants. These effects cause the majority of the respiratory symptoms. However, the aggravation of local inflammation causes a cytokine storm eventually leading to

2511-402: Is because pregnant women with COVID‑19 appear to be more likely to develop respiratory and obstetric complications that can lead to miscarriage , premature delivery and intrauterine growth restriction . Fungal infections such as aspergillosis , candidiasis , cryptococcosis and mucormycosis have been recorded in patients recovering from COVID‑19. COVID‑19 is caused by infection with

2604-522: Is closely related to the original SARS-CoV . It is thought to have an animal ( 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 ). The structural proteins of SARS-CoV-2 include membrane glycoprotein (M), envelope protein (E), nucleocapsid protein (N), and

2697-476: Is contained in a unit of convalescent plasma, for COVID-19 treatment, or to verify if a given vaccine generates an adequate immune response. SARS-CoV-2 antibodies' potency and protective period have not been established. Therefore, a positive antibody test may not imply immunity to a future infection. Further, whether mild or asymptomatic infections produce sufficient antibodies for a test to detect has not been established. Antibodies for some diseases persist in

2790-617: Is detected a median 14 days after symptom onset. IgG levels significantly decline after two or three months. Genetic tests verify infection earlier than antibody tests. Only 30% of those with a positive genetic test produced a positive antibody test on day 7 of their infection. RDTs typically use a small, portable, positive/negative lateral flow assay that can be executed at point of care. RDTs may process blood samples, saliva samples, or nasal swab fluids. RDTs produce colored lines to indicate positive or negative results. ELISAs can be qualitative or quantitative and generally require

2883-435: Is especially true for asymptomatic patients who have little if any nasal discharge . Viral proteins are not amplified in an antigen test. A Cochrane review based on 64 studies investigating the efficacy of 16 different antigen tests determined that they correctly identified COVID-19 infection in an average of 72% of people with symptoms, compared to 58% of people without symptoms. Tests were most accurate (78%) when used in

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2976-438: Is needed. The body responds to a viral infection by producing antibodies that help neutralize the virus. Blood tests (also called serology tests or serology immunoassays ) can detect the presence of such antibodies. Antibody tests can be used to assess what fraction of a population has once been infected, which can then be used to calculate the disease's mortality rate . They can also be used to determine how much antibody

3069-470: Is not advised for routine screening of COVID-19. Patients with asymptomatic to mild symptoms are not recommended to be tested via chest computerized tomography scans. However, it is still crucial to use, particularly when determining complications or disease progression. Chest imaging also is not always the first route to take with patients who have high risk factors for COVID. High risk patients that had mild symptoms, chest imaging findings were limited. Although

3162-564: Is not as available as chest x-ray, but still only takes about 15 minutes per patient. Computerized tomography has been a known routine scanning for pneumonia diagnosis, therefore can also be used to diagnose coronavirus disease. Computerized tomography scans may help with ongoing illness monitoring throughout treatment. Patients who had low-grade symptoms and high body temperatures revealed significant lung indications on their chest computed tomography scans. They emphasized how important chest computerized tomography scans are for determining how serious

3255-595: Is the cause of the bud release and the formation of the viral envelope. The N and E protein are accessory proteins that interfere with the host's immune response. Human angiotensin converting enzyme 2 (hACE2) is the host factor that SARS-CoV-2 virus targets causing COVID‑19. Theoretically, the usage of angiotensin receptor blockers (ARB) and ACE inhibitors upregulating ACE2 expression might increase morbidity with COVID‑19, though animal data suggest some potential protective effect of ARB; however no clinical studies have proven susceptibility or outcomes. Until further data

3348-469: Is the viral component that attaches to the host receptor via the ACE2 receptors. It includes two subunits: S1 and S2. Studies have shown that S1 domain induced IgG and IgA antibody levels at a much higher capacity. It is the focus spike proteins expression that are involved in many effective COVID‑19 vaccines. The M protein is the viral protein responsible for the transmembrane transport of nutrients. It

3441-938: The Alpha variant (B.1.1.7, formerly called the UK variant), first found in London and Kent, the Beta variant (B.1.351, formerly called the South Africa variant), the Gamma variant (P.1, formerly called the Brazil variant), the Delta variant (B.1.617.2, formerly called the India variant), and the Omicron variant (B.1.1.529), which had spread to 57 countries as of 7 December. On December 19, 2023,

3534-755: The COVID-19 pandemic . The symptoms of COVID‑19 are variable but often include fever, fatigue, cough, breathing difficulties , loss of smell , and loss of taste . Symptoms may begin one to fourteen days after exposure to the virus. At least a third of people who are infected do not develop noticeable symptoms . Of those who develop symptoms noticeable enough to be classified as patients, most (81%) develop mild to moderate symptoms (up to mild pneumonia ), while 14% develop severe symptoms ( dyspnea , hypoxia , or more than 50% lung involvement on imaging), and 5% develop critical symptoms ( respiratory failure , shock , or multiorgan dysfunction ). Older people are at

3627-588: The Spanish flu , Middle East respiratory syndrome , and Zika virus . In January 2020, the World Health Organization (WHO) recommended 2019-nCoV and 2019-nCoV acute respiratory disease as interim names for the virus and disease per 2015 guidance and international guidelines against using geographical locations or groups of people in disease and virus names to prevent social stigma . The official names COVID‑19 and SARS-CoV-2 were issued by

3720-482: The small intestine . The virus can cause acute myocardial injury and chronic damage to the cardiovascular system . An acute cardiac injury was found in 12% of infected people admitted to the hospital in Wuhan, China, and is more frequent in severe disease. Rates of cardiovascular symptoms are high, owing to the systemic inflammatory response and immune system disorders during disease progression, but acute myocardial injuries may also be related to ACE2 receptors in

3813-710: The spike protein (S). The M protein of SARS-CoV-2 is about 98% similar to the M protein of bat SARS-CoV, maintains around 98% homology with pangolin SARS-CoV, and has 90% homology with the M protein of SARS-CoV; whereas, the similarity is only around 38% with the M protein of MERS-CoV . The many thousands of SARS-CoV-2 variants are grouped into either clades or lineages . The WHO, in collaboration with partners, expert networks, national authorities, institutions and researchers, have established nomenclature systems for naming and tracking SARS-CoV-2 genetic lineages by GISAID , Nextstrain and Pango . The expert group convened by

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3906-548: The B.1 lineage. Several notable variants of SARS-CoV-2 emerged throughout 2020. Cluster 5 emerged among minks and mink farmers in Denmark . After strict quarantines and the slaughter of all the country's mink , the cluster was assessed to no longer be circulating among humans in Denmark as of 1 February 2021. As of December 2021 , there are five dominant variants of SARS-CoV-2 spreading among global populations:

3999-542: The CNS, possibly within an infected white blood cell. Research conducted when Alpha was the dominant variant has suggested COVID-19 may cause brain damage. Later research showed that all variants studied (including Omicron) killed brain cells, but the exact cells killed varied by variant. It is unknown if such damage is temporary or permanent. Observed individuals infected with COVID-19 (most with mild cases) experienced an additional 0.2% to 2% of brain tissue lost in regions of

4092-506: The COVID-19 infection may have different symptoms, and their symptoms may change over time. Three common clusters of symptoms have been identified: a respiratory symptom cluster with cough, sputum , shortness of breath , and fever; a musculoskeletal symptom cluster with muscle and joint pain, headache, and fatigue; and a cluster of digestive symptoms with abdominal pain, vomiting, and diarrhea. In people without prior ear, nose, or throat disorders, loss of taste combined with loss of smell

4185-471: The SARS-CoV-2 virus entered into human populations through natural zoonosis , similar to the SARS-CoV-1 and MERS-CoV outbreaks, and consistent with other pandemics in human history. Social and environmental factors including climate change , natural ecosystem destruction and wildlife trade increased the likelihood of such zoonotic spillover . The disease quickly spread worldwide, resulting in

4278-716: The US FDA granted an emergency use authorization for a saliva test developed at Yale University that gives results in hours. On 4 January 2021, the US FDA issued an alert about the risk of false results, particularly false negative results, with the Curative SARS-Cov-2 Assay real-time RT-PCR test. Viral burden measured in upper respiratory specimens declines after symptom onset. Following recovery, many patients no longer have detectable viral RNA in upper respiratory specimens. Among those who do, RNA concentrations three days following recovery are generally below

4371-475: The WHO declared that another distinctive variant, JN.1, had emerged as a "variant of interest". Though the WHO expected an increase in cases globally, particularly for countries entering winter, the overall global health risk was considered low. The SARS-CoV-2 virus can infect a wide range of cells and systems of the body. COVID‑19 is most known for affecting the upper respiratory tract (sinuses, nose, and throat) and

4464-759: The WHO on 11 February 2020 with COVID-19 being shorthand for "coronavirus disease 2019". The WHO additionally uses "the COVID‑19 virus" and "the virus responsible for COVID‑19" in public communications. The symptoms of COVID-19 are variable depending on the type of variant contracted, ranging from mild symptoms to a potentially fatal illness. Common symptoms include coughing , fever , loss of smell (anosmia) and taste (ageusia), with less common ones including headaches , nasal congestion and runny nose , muscle pain , sore throat , diarrhea , eye irritation , and toes swelling or turning purple, and in moderate to severe cases, breathing difficulties . People with

4557-551: The WHO recommended the labelling of variants using letters of the Greek alphabet , for example, Alpha , Beta , Delta , and Gamma , giving the justification that they "will be easier and more practical to discussed by non-scientific audiences". Nextstrain divides the variants into five clades (19A, 19B, 20A, 20B, and 20C), while GISAID divides them into seven (L, O, V, S, G, GH, and GR). The Pango tool groups variants into lineages , with many circulating lineages being classed under

4650-474: The ability to reduce reinfection severity. Sudden loss of smell can be used to screen people on a daily basis for COVID-19. A study by the National Institutes of Health showed that those infected with SARS-CoV-2 could not smell a 25% mixture of ethanol and water. Because various conditions can lead to the loss of the sense of smell, a sniff test would not be definitive but indicate the need for

4743-522: The best track record in this competition, having reached the international championship final six times and winning it five times. This article about a criminal law topic is a stub . You can help Misplaced Pages by expanding it . COVID-19 Coronavirus disease 2019 ( COVID-19 ) is a contagious disease caused by the coronavirus SARS-CoV-2 . The first known case was identified in Wuhan , China, in December 2019. Most scientists believe

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4836-469: The blocking of steps in the replicative cycle up to and including membrane fusion. A non-neutralizing antibody either does not bind to the crucial structures on the virus surface or binds but leaves the virus particle infectious; the antibody may still contribute to the destruction of virus particles or infected cells by the immune system. It may even enhance infectivity by interacting with receptors on macrophages . Since most COVID-19 antibody tests return

4929-461: The blood quick scan the CoLab score is calculated with a developed algorithm based on how the coronavirus causes changes in the blood. The software is intended for use in emergency rooms to quickly rule out the presence of the disease in incoming patients. A not negative result is followed by a PCR ( polymerase chain reaction ) or LAMP ( loop-mediated isothermal amplification ) test. The breath test by

5022-680: The bloodstream for many years, while others fade away. The most notable antibodies are IgM and IgG . IgM antibodies are generally detectable several days after initial infection, although levels over the course of infection and beyond are not well characterized. IgG antibodies generally become detectable 10–14 days after infection and normally peak around 28 days after infection. This pattern of antibody development seen with other infections, often does not apply to SARS-CoV-2, however, with IgM sometimes occurring after IgG, together with IgG or not occurring at all. Generally, however, median IgM detection occurs 5 days after symptom onset, whereas IgG

5115-515: The brain connected to the sense of smell compared with uninfected individuals, and the overall effect on the brain was equivalent on average to at least one extra year of normal ageing; infected individuals also scored lower on several cognitive tests. All effects were more pronounced among older ages. The virus also affects gastrointestinal organs as ACE2 is abundantly expressed in the glandular cells of gastric , duodenal and rectal epithelium as well as endothelial cells and enterocytes of

5208-591: The brain found as complications leading to death in people infected with COVID‑19. Infection may initiate a chain of vasoconstrictive responses within the body, including pulmonary vasoconstriction – a possible mechanism in which oxygenation decreases during pneumonia. Furthermore, damage of arterioles and capillaries was found in brain tissue samples of people who died from COVID‑19. COVID‑19 may also cause substantial structural changes to blood cells , sometimes persisting for months after hospital discharge. A low level of blood lymphocytess may result from

5301-428: The brains of those who have died from COVID‑19, but these results need to be confirmed. While virus has been detected in cerebrospinal fluid of autopsies, the exact mechanism by which it invades the CNS remains unclear and may first involve invasion of peripheral nerves given the low levels of ACE2 in the brain. The virus may also enter the bloodstream from the lungs and cross the blood–brain barrier to gain access to

5394-409: The clear jelly liquid found in lung autopsies of people who died of COVID-19. One possibility addressed in medical research is that hyuralonic acid (HA) could be the leading factor for this observation of the clear jelly liquid found in the lungs, in what could be hyuralonic storm, in conjunction with cytokine storm . One common symptom, loss of smell, results from infection of the support cells of

5487-516: The coronavirus disease can be detected. A chest x-ray is a portable lightweight machine. This machine is typically more available than polymerase chain reaction and computerized tomography scans. it only takes approximately 15 seconds per patient. This makes chest-x ray readily accessible and inexpensive. It also has quick turnaround time and can be crucial to the clinical equipment in the detection of coronavirus disease. Computerized tomography scans involve looking at 3D images from various angles. This

5580-439: The coronavirus disease infection is. Ultrasound can be another tool to detect coronavirus disease. An ultrasound is a type of imaging exam that produces images using sound waves. Unlike computerized tomography scans and x-rays, ultrasound does not use radiation. Moreover, it is inexpensive, simple to use, repeatable, and has several additional advantages. Using a hand-held mobile machine, ultrasound examinations can be performed in

5673-500: The current or past presence of SARS-CoV-2 , the virus that cases COVID-19 and is responsible for the COVID-19 pandemic . The two main types of tests detect either the presence of the virus or antibodies produced in response to infection. Molecular tests for viral presence through its molecular components are used to diagnose individual cases and to allow public health authorities to trace and contain outbreaks. Antibody tests (serology immunoassays) instead show whether someone once had

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5766-406: The data. Of people who show symptoms, 81% develop only mild to moderate symptoms (up to mild pneumonia ), while 14% develop severe symptoms ( dyspnea , hypoxia , or more than 50% lung involvement on imaging) that require hospitalization, and 5% of patients develop critical symptoms ( respiratory failure , septic shock , or multiorgan dysfunction ) requiring ICU admission. At least a third of

5859-425: The disease severity characters being different in severe and hospitalized cases. The criteria for doing a chest computerized tomography scan were not defined. There was also no characterization of positive chest computerized tomography scans results. The computerized tomography scans findings were not the same as positive computerized tomography scans findings of coronavirus. In a typical clinical setting, chest imaging

5952-660: The disease. They are less useful for diagnosing current infections because antibodies may not develop for weeks after infection. It is used to assess disease prevalence, which aids the estimation of the infection fatality rate . Individual jurisdictions have adopted varied testing protocols, including whom to test, how often to test, analysis protocols, sample collection and the uses of test results. This variation has likely significantly impacted reported statistics, including case and test numbers, case fatality rates and case demographics. Because SARS-CoV-2 transmission occurs days after exposure (and before onset of symptoms), there

6045-721: The expression of ACE-2, thereby facilitating the SARS-Cov2 virus to enter cells and to replicate. A competition of negative feedback loops (via protective effects of interferon alpha) and positive feedback loops (via upregulation of ACE-2) is assumed to determine the fate of patients suffering from COVID-19. Additionally, people with COVID‑19 and acute respiratory distress syndrome (ARDS) have classical serum biomarkers of CRS, including elevated C-reactive protein (CRP), lactate dehydrogenase (LDH), D-dimer , and ferritin . Systemic inflammation results in vasodilation , allowing inflammatory lymphocytic and monocytic infiltration of

6138-428: The eyes, nose, or mouth. The risk is highest when people are in close proximity, but small airborne particles containing the virus can remain suspended in the air and travel over longer distances, particularly indoors. Transmission can also occur when people touch their eyes, nose or mouth after touching surfaces or objects that have been contaminated by the virus. People remain contagious for up to 20 days and can spread

6231-525: The face. While drugs have been developed to inhibit the virus, the primary treatment is still symptomatic , managing the disease through supportive care , isolation , and experimental measures . During the initial outbreak in Wuhan , the virus and disease were commonly referred to as "coronavirus" and "Wuhan coronavirus", with the disease sometimes called "Wuhan pneumonia". In the past, many diseases have been named after geographical locations, such as

6324-538: The first week after symptoms first developed, likely because people have the most virus in their system in the first days after they are infected. While some scientists doubt whether an antigen test can be useful against COVID-19, others have argued that antigen tests are highly sensitive when viral load is high and people are contagious, making them suitable for public health screening. Routine antigen tests can quickly identify when asymptomatic people are contagious, while follow-up PCR can be used if confirmatory diagnosis

6417-523: The heart. ACE2 receptors are highly expressed in the heart and are involved in heart function. A high incidence of thrombosis and venous thromboembolism occurs in people transferred to intensive care units with COVID‑19 infections, and may be related to poor prognosis. Blood vessel dysfunction and clot formation (as suggested by high D-dimer levels caused by blood clots) may have a significant role in mortality, incidents of clots leading to pulmonary embolisms , and ischaemic events (strokes) within

6510-480: The help of NAbs and whether they were at risk of re-infection was not addressed. An additional source of uncertainty is that even if NAbs are present, viruses such as HIV can evade NAb responses. Studies have indicated that NAbs to the original SARS virus (the predecessor to the current SARS-CoV-2) can remain active for two years and are gone after six years. Nevertheless, memory cells including memory B cells and memory T cells can last much longer and may have

6603-503: The host cell. Following viral entry, COVID‑19 infects the ciliated epithelium of the nasopharynx and upper airways. Autopsies of people who died of COVID‑19 have found diffuse alveolar damage , and lymphocyte-containing inflammatory infiltrates within the lung. From the CT scans of COVID-19 infected lungs, white patches were observed containing fluid known as ground-glass opacity (GGO) or simply ground glass. This tended to correlate with

6696-528: The infection, children may develop paediatric multisystem inflammatory syndrome , which has symptoms similar to Kawasaki disease , which can be fatal. In very rare cases, acute encephalopathy can occur, and it can be considered in those who have been diagnosed with COVID‑19 and have an altered mental status. According to the US Centers for Disease Control and Prevention , pregnant women are at increased risk of becoming seriously ill from COVID‑19. This

6789-454: The lower respiratory tract (windpipe and lungs). The lungs are the organs most affected by COVID‑19 because the virus accesses host cells via the receptor for the enzyme angiotensin-converting enzyme 2 (ACE2), which is most abundant on the surface of type II alveolar cells of the lungs. The virus uses a special surface glycoprotein called a " spike " to connect to the ACE2 receptor and enter

6882-409: 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 people with COVID‑19. Lymphocytic infiltrates have also been reported at autopsy. Multiple viral and host factors affect the pathogenesis of the virus. The S-protein , otherwise known as the spike protein,

6975-447: The moment a person first becomes infected and the appearance of the first symptoms. The median delay for COVID-19 is four to five days possibly being infectious on 1–4 of those days. Most symptomatic people experience symptoms within two to seven days after exposure, and almost all will experience at least one symptom within 12 days. Most people recover from the acute phase of the disease. However, some people continue to experience

7068-563: The moot, each country can only send a limited number of teams to participate; depending on the rules for the year, regional or national rounds may be organised to select the teams that will compete in the international rounds. To date, such rounds have been held for the Americas and Caribbean, Brazil, China, Georgia, Germany, India, Iran, Israel, and the Netherlands. For the international rounds, in 2013, semi-final rounds were introduced for

7161-474: The number of antibodies. This test can identify multiple types of antibodies, including IgG, IgM, and IgA . Most if not all large scale COVID-19 antibody testing looks for binding antibodies only and does not measure the more important neutralizing antibodies (NAb). A NAb is an antibody that neutralizes the infectivity of a virus particle by blocking its attachment to or entry into a susceptible cell; enveloped viruses, like e.g. SARS-CoV-2, are neutralized by

7254-480: The olfactory epithelium , with subsequent damage to the olfactory neurons . The involvement of both the central and peripheral nervous system in COVID‑19 has been reported in many medical publications. It is clear that many people with COVID-19 exhibit neurological or mental health issues . The virus is not detected in the central nervous system (CNS) of the majority of COVID-19 patients with neurological issues . However, SARS-CoV-2 has been detected at low levels in

7347-488: The peak viral load in upper respiratory tract samples occurs close to the time of symptom onset and declines after the first week after symptoms begin. Current evidence suggests a duration of viral shedding and the period of infectiousness of up to ten days following symptom onset for people with mild to moderate COVID-19, and up to 20 days for persons with severe COVID-19, including immunocompromised people. Severe acute respiratory syndrome coronavirus   2 (SARS-CoV-2)

7440-411: The people who are infected with the virus do not develop noticeable symptoms at any point in time. These asymptomatic carriers tend not to get tested and can still spread the disease. Other infected people will develop symptoms later (called "pre-symptomatic") or have very mild symptoms and can also spread the virus. As is common with infections, there is a delay, or incubation period , between

7533-659: The point-of-care or as self-tests. Self-tests are rapid tests that can be taken at home or anywhere, are easy to use, and produce rapid results. Antigen tests can be performed on nasopharyngeal, nasal swab, or saliva specimens. Antigen tests that can identify SARS-CoV-2 offer a faster and less expensive method to test for the virus. Antigen tests are generally less sensitive than real-time reverse transcription polymerase chain reaction (RT-PCR) and other nucleic acid amplification tests (NAATs). Antigen tests may be one way to scale up testing to much greater levels. Isothermal nucleic acid amplification tests can process only one sample at

7626-538: The range in which replication-competent virus has been reliably isolated. No clear correlation has been described between length of illness and duration of post-recovery shedding of viral RNA in upper respiratory specimens. Isothermal nucleic acid amplification tests also amplify the virus's genome. They are faster than PCR because they do not involve repeated heating and cooling cycles. These tests typically detect DNA using fluorescent tags , which are read out with specialized machines. CRISPR gene editing technology

7719-416: The respiratory tract, people with severe COVID‑19 have symptoms of systemic hyperinflammation. Clinical laboratory findings of elevated IL‑2 , IL‑6 , IL‑7 , as well as the following suggest an underlying immunopathology: Interferon alpha plays a complex, Janus-faced role in the pathogenesis of COVID-19. Although it promotes the elimination of virus-infected cells, it also upregulates

7812-859: The risk of long COVID includes staying up to date on the most recent COVID-19 vaccine, practicing good hygiene, maintaining clean indoor air, and physical distancing from people infected with a respiratory virus. Complications may include pneumonia , acute respiratory distress syndrome (ARDS), multi-organ failure , septic shock , and death. Cardiovascular complications may include heart failure, arrhythmias (including atrial fibrillation ), heart inflammation , thrombosis , particularly venous thromboembolism , and endothelial cell injury and dysfunction. Approximately 20–30% of people who present with COVID‑19 have elevated liver enzymes , reflecting liver injury. Neurologic manifestations include seizure , stroke, encephalitis , and Guillain–Barré syndrome (which includes loss of motor functions ). Following

7905-615: The second week, sputum or deep airways collection is preferred. Collecting saliva may be as effective as nasal and throat swabs, although this is not certain. Sampling saliva may reduce the risk for health care professionals by eliminating close physical interaction. It is also more comfortable for the patient. Quarantined people can collect their own samples. A saliva test's diagnostic value depends on sample site (deep throat, oral cavity, or salivary glands). Some studies have found that saliva yielded greater sensitivity and consistency when compared with swab samples. On 15 August 2020,

7998-414: The term RT-qPCR , but not all authors adhere to this. Average sensitivity for rapid molecular tests depend on the brand. For ID NOW, the average sensitivity was 73.0% with an average specificity of 99.7%; for Xpert Xpress the average sensitivity was 100% with an average specificity of 97.2%. In a diagnostic test, sensitivity is a measure of how well a test can identify true positives and specificity

8091-477: The top nine teams, with the top three teams proceeding to the championship final. In 2015, the number of preliminary rounds were increased from three to six, and in 2016 quarter-final rounds were introduced for the top 27 teams. In 2020, the oral rounds were cancelled due to COVID-19 , and in 2021 and 2022, the competition adopted an online format. Since 2022, seeding and choice of side have been randomised. Singapore Management University , which debuted in 2015, has

8184-566: The viral surface. In the case of a coronavirus , these are usually proteins from the surface spikes . SARS-CoV-2 antigens can be detected before onset of COVID-19 symptoms (as soon as SARS-CoV-2 virus particles) with more rapid test results, but with less sensitivity than PCR tests for the virus. COVID-19 rapid antigen tests are lateral flow immunoassays that detect the presence of a specific viral antigen , which indicates current viral infection. Antigen tests produce results quickly (within approximately 15–30 minutes), and most can be used at

8277-464: The virus acting through ACE2-related entry into lymphocytes. Another common cause of death is complications related to the kidneys . Early reports show that up to 30% of hospitalised patients both in China and in New York have experienced some injury to their kidneys, including some persons with no previous kidney problems. Although SARS-CoV-2 has a tropism for ACE2-expressing epithelial cells of

8370-752: The virus even if they do not develop symptoms. Testing methods for COVID-19 to detect the virus's nucleic acid include real-time reverse transcription polymerase chain reaction (RT‑PCR), transcription-mediated amplification , and reverse transcription loop-mediated isothermal amplification (RT‑LAMP) from a nasopharyngeal swab . Several COVID-19 vaccines have been approved and distributed in various countries, many of which have initiated mass vaccination campaigns . Other preventive measures include physical or social distancing , quarantining , ventilation of indoor spaces, use of face masks or coverings in public, covering coughs and sneezes, hand washing , and keeping unwashed hands away from

8463-509: The virus is carried out through virus-laden fluid particles, or droplets, which are created in the respiratory tract, and they are expelled by the mouth and the nose. There are three types of transmission: "droplet" and "contact", which are associated with large droplets, and "airborne", which is associated with small droplets. If the droplets are above a certain critical size, they settle faster than they evaporate , and therefore they contaminate surfaces surrounding them. Droplets that are below

8556-579: The virus) are called antigen tests . There are multiple types of tests that look for the virus by detecting the presence of the virus's RNA. These are called nucleic acid or molecular tests, after molecular biology . As of 2021 , the most common form of molecular test is the reverse transcription polymerase chain reaction (RT-PCR) test. Other methods used in molecular tests include CRISPR , isothermal nucleic acid amplification , digital polymerase chain reaction , microarray analysis , and next-generation sequencing . Polymerase chain reaction (PCR)

8649-530: Was modified to perform the detection: if the CRISPR enzyme attaches to the sequence, it colors a paper strip. The researchers expect the resulting test to be cheap and easy to use in point-of-care settings. The test amplifies RNA directly, without the RNA-to-DNA conversion step of RT-PCR. An antigen is the part of a pathogen that elicits an immune response . Antigen tests look for antigen proteins from

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