View source for COVID-19 overview

__NOTOC__
{{COVID-19}}
{{CMG}}{{AE}}{{Sab}}; {{HK}}

== Overview ==

Coronavirus, named due to the "crown" like appearance of its surface projections, was first isolated from chickens in 1937. The etiological agent, a novel coronavirus, [[SARS-CoV-2|severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)]], named for the similarity of its symptoms to those induced by the severe acute respiratory syndrome, causing coronavirus disease 2019 (COVID-19), is a [[virus]] identified as the cause of an outbreak of [[respiratory illness]] first detected in Wuhan, China. On March 12, 2020 the World Health Organization declared the COVID-19 outbreak a pandemic. [[SARS-CoV-2|Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)]], the [[Etiology|etiological]] agent of coronavirus disease 2019 (COVID-19), can be categorized into two major types, '''L''', the major type (~70%) and '''S''', the minor type (~30%). Coronavirus disease 2019 (COVID-19) is caused by [[SARS-CoV-2|severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)]], a novel coronavirus named for the similarity of its [[Symptom|symptoms]] to those caused by the [[severe acute respiratory syndrome]]. Unlike SARS-CoV, transmission of COVID-19 takes place during the [[Prodrome|prodromal period]] when those infected are mildly ill and are carrying on with their usual activities. This contributes to the spread of [[infection]]. The main [[pathogenesis]] of COVID-19 is severe [[pneumonia]], RNAemia, combined with the [[incidence]] of ground-glass opacities, and [[Acute (medicine)|acute]] [[Heart|cardiac]] [[injury]]. Person-to-person transmission occurs primarily via direct contact or through droplets spread by [[Cough|coughing]] or [[Sneeze|sneezing]] from an infected individual. Coronavirus disease 2019 (COVID-19) is caused by [[SARS-CoV-2|severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)]]. Coronavirus disease 2019 (COVID-19) should be differentiated from other [[Disease|diseases]] presenting with [[cough]], [[fever]], [[shortness of breath]], and [[tachypnea]]. Globally, 952,100 cases of COVID-19 have been reported with 48,300 deaths. In the US greater than 200,000 cases have been reported with 5,100 deaths in country. Due rapidly evolving data at this point, the exact [[Incidence (epidemiology)|incidence rate]] of Coronavirus disease 2019 (COVID-19) can not be approximated. Prevalent in all the continents of the world, [[World Health Organization|World Health Organization (WHO)]] has declared COVID-19 [[outbreak]] a [[pandemic]]. Due to inconsistent reporting and lack of organized data, an exact and universal case-fatality rate of COVID-19 is yet to be established. Middle aged and elderly population seem to be the most commonly affected with a [[median]] age of 49 - 56 years. COVID-19 is affecting males more than females. Majority of the cases of COVID-19 have been reported in China and at this point the disease has spread to all the continents of the world. Similar to all [[Viral disease|viral illnesses]], exposure is considered the most significant [[risk factor]] for [[infection]] with Coronavirus disease 2019 (COVID-19). Individuals at risk for the severe form of the [[disease]] include [[Old age|elderly]] (those aged 60+), [[cardiovascular disease]] [[Patient|patients]], [[Diabetic|diabetics]], [[Chronic (medical)|chronic]] [[respiratory disease]] [[Patient|patients]], [[Hypertension|hypertensive]] [[Patient|patients]], [[Cancer patient|cancer patients]], and individuals in long term care facilities. Currently, there are no recommended [[Medical guideline|guidelines]] in place for the routine [[Screening (medicine)|screening]] for Coronavirus disease 2019 (COVID-19). Some of the clinical and non-clinical features related to COVID-19 being used to [[Screening (medicine)|screen]] suspected individuals are history of international travel, history of exposure to a confirmed COVID-19 case, [[fever]], [[cough]], [[fatigue]], and [[Dyspnea|shortness of breath]]. In [[symptomatic]] [[Patient|patients]], the clinical features of the [[disease]] usually start within a week, consisting of [[fever]], [[cough]], [[nasal congestion]], [[fatigue]], and other [[Medical sign|signs]] of [[Upper respiratory tract infection|upper respiratory tract infections]]. Disease progression and severity is manifested by [[dyspnea]] and severe [[chest]] [[Symptom|symptoms]] corresponding to [[pneumonia]] in approximately 75% of the [[Patient|patients]]. The World Health Organization has published a diagnostic criteria that helps identify patients requiring confirmation of COVID-19 through either PCR or antibody detection tests. This criteria includes several epidemiological and clinical criteria that the patient has to fulfill in order to be either a suspected or confirmed case of COVID-19. History of [[Patient|patients]] [[Infection|infected]] with Coronavirus disease 2019 (COVID-19) can include international travel to where COVID-19 is highly [[Prevalence|prevalent]]. The most common [[Symptom|symptoms]] that can appear 2 - 14 days after exposure include [[fever]], [[cough]], [[fatigue]], and [[Dyspnea|shortness of breath]]. The [[pathognomonic]] [[physical examination]] findings in [[Patient|patients]] [[Infection|infected]] with coronavirus include [[fever]], [[Flu|flu-like-symptoms]], [[cough]], and [[body aches]]. General appearance of the [[patient]] [[Infection|infected]] with coronavirus depends on the [[incubation period]] of the [[illness]]. Laboratory tests can be done to confirm whether illness may be caused by human coronaviruses. Specific laboratory tests include serology for viral antigen, molecular testing and viral culture. All these tests can be used to confirm infection with coronavirus. Non-specific laboratory findings in COVID-19 include [[lymphocytopenia]], [[thrombocytopenia]], elevated [[C-reactive protein|C-Reactive protein]], elevated [[liver function tests]] ([[Alanine transaminase|ALT]], [[Aspartate transaminase|AST]]), increased [[creatine kinase]], increased [[D-dimer|D-Dimer]] and an increase in the levels of markers of cell damage e.g. [[troponin]], [[lactate dehydrogenase]], [[interleukin-4]], [[procalcitonin]]. There are no specific [[ECG]] findings associated with coronavirus [[infection]]. Non specific findings can include [[sinus tachycardia]], ST-elevation and diffuse [[T wave]] inversion. The [[Chest X-ray|chest x ray]] findings in a suspected case of coronavirus [[infection]] can mimic the findings in [[pneumonia]]. Severe cases of COVID-19 progressing to acute respiratory distress syndrome (ARDS) can show a typical "white-out" on chest x-ray. There are no specific [[echocardiography]]/ultrasound findings associated with coronavirus infection. Non specific [[Echocardiography|echocardiographic]] findings can include left ventricular systolic dysfunction and [[pericardial effusion]]. [[Chest]] [[Computed tomography|CT scan]] findings in [[Patient|patients]] [[Infection|infected]] with coronavirus can include unilateral or bilateral [[pneumonia]], mottling and ground glass opacity, focal or multifocal opacities, [[Consolidation (medicine)|consolidation]], and septal thickening with subpleural and lower lobe involvement more likely. There are no specific [[MRI]] findings associated with coronavirus [[infection]]. [[MRI]] can aide in making the [[diagnosis]] on the basis of exclusion. There are no other [[imaging]] findings associated with COVID-19. Research laboratories have used isolation methods, [[electron microscopy]], [[serology]] and [[PCR|PCR-based assays]] to diagnose coronavirus infections for surveillance studies. Treatment of coronavirus [[infection]] includes supportive measures and [[Symptomatic treatment|symptomatic management]]. No specific treatment is available. Given the emergence of the cases during the [[influenza]] season, all [[Patient|patients]] presenting with COVID-19 were given [[oral]] and [[intravenous]] [[antibiotics]] and [[Oseltamivir]] (75 mg twice daily via oral route) empirically. [[Corticosteroids]] ([[methylprednisolone]] 40 - 120 mg/day) were given as a combined regimen if severe [[community-acquired pneumonia]] was [[Diagnosis|diagnosed]]. Oxygen support (e.g., via nasal cannula and invasive mechanical ventilation) was given to [[Patient|patients]] indicated by the severity of [[hypoxemia]]. [[Surgery]] is not [[Indication|indicated]] in the management of COVID-19. There is currently no [[vaccine]] to prevent COVID-19. The best way to prevent [[infection]] is to avoid being exposed to this [[virus]]. The fact that it is currently [[flu]] and [[respiratory disease]] season, [[Centers for Disease Control and Prevention|CDC]] recommends getting a [[flu vaccine]], taking everyday preventive actions to help stop the spread of [[Germ|germs]], and taking [[flu]] [[antivirals]] if prescribed. [[Health care provider|Healthcare providers]] are advised to be on the look-out for people who recently traveled from China and have [[fever]] and [[Respiratory system|respiratory]] [[Symptom|symptoms]].

== Historical Perspective ==
Coronavirus, named due to the "crown" like appearance of its surface projections, was first isolated from chickens in 1937. The etiological agent, a novel coronavirus, [[SARS-CoV-2|severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)]], named for the similarity of its symptoms to those induced by the severe acute respiratory syndrome, causing coronavirus disease 2019 (COVID-19), is a [[virus]] identified as the cause of an outbreak of [[respiratory illness]] first detected in Wuhan, China. On March 12, 2020 the World Health Organization declared the COVID-19 outbreak a pandemic.

== Classification ==
[[SARS-CoV-2|Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)]], the [[Etiology|etiological]] agent of coronavirus disease 2019 (COVID-19), can be categorized into two major types, '''L''', the major type (~70%) and '''S''', the minor type (~30%).

== Pathophysiology ==
Coronavirus disease 2019 (COVID-19) is caused by [[SARS-CoV-2|severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)]], a novel coronavirus named for the similarity of its [[Symptom|symptoms]] to those caused by the [[severe acute respiratory syndrome]]. Unlike SARS-CoV, transmission of COVID-19 takes place during the [[Prodrome|prodromal period]] when those infected are mildly ill and are carrying on with their usual activities. This contributes to the spread of [[infection]]. The main [[pathogenesis]] of COVID-19 is severe [[pneumonia]], RNAemia, combined with the [[incidence]] of ground-glass opacities, and [[Acute (medicine)|acute]] [[Heart|cardiac]] [[injury]]. Person-to-person transmission occurs primarily via direct contact or through droplets spread by [[Cough|coughing]] or [[Sneeze|sneezing]] from an infected individual.

== Causes ==
Coronavirus disease 2019 (COVID-19) is caused by [[SARS-CoV-2|severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)]].

== Differential Diagnosis ==
Coronavirus disease 2019 (COVID-19) should be differentiated from other [[Disease|diseases]] presenting with [[cough]], [[fever]], [[shortness of breath]], and [[tachypnea]].

== Epidemiology and Demographics ==
Globally, 952,100 cases of COVID-19 have been reported with 48,300 deaths. In the US greater than 200,000 cases have been reported with 5,100 deaths in country. Due rapidly evolving data at this point, the exact [[Incidence (epidemiology)|incidence rate]] of Coronavirus disease 2019 (COVID-19) can not be approximated. Prevalent in all the continents of the world, [[World Health Organization|World Health Organization (WHO)]] has declared COVID-19 [[outbreak]] a [[pandemic]]. Due to inconsistent reporting and lack of organized data, an exact and universal case-fatality rate of COVID-19 is yet to be established. Middle aged and elderly population seem to be the most commonly affected with a [[median]] age of 49 - 56 years. COVID-19 is affecting males more than females. Majority of the cases of COVID-19 have been reported in China and at this point the disease has spread to all the continents of the world.

== Risk Factors ==
Similar to all [[Viral disease|viral illnesses]], exposure is considered the most significant [[risk factor]] for [[infection]] with Coronavirus disease 2019 (COVID-19). Individuals at risk for the severe form of the [[disease]] include [[Old age|elderly]] (those aged 60+), [[cardiovascular disease]] [[Patient|patients]], [[Diabetic|diabetics]], [[Chronic (medical)|chronic]] [[respiratory disease]] [[Patient|patients]], [[Hypertension|hypertensive]] [[Patient|patients]], [[Cancer patient|cancer patients]], and individuals in long term care facilities.

== Screening ==
Currently, there are no recommended [[Medical guideline|guidelines]] in place for the routine [[Screening (medicine)|screening]] for Coronavirus disease 2019 (COVID-19). Some of the clinical and non-clinical features related to COVID-19 being used to [[Screening (medicine)|screen]] suspected individuals are history of international travel, history of exposure to a confirmed COVID-19 case, [[fever]], [[cough]], [[fatigue]], and [[Dyspnea|shortness of breath]]. 

== Natural History, Complications and Prognosis ==
In [[symptomatic]] [[Patient|patients]], the clinical features of the [[disease]] usually start within a week, consisting of [[fever]], [[cough]], [[nasal congestion]], [[fatigue]], and other [[Medical sign|signs]] of [[Upper respiratory tract infection|upper respiratory tract infections]]. Disease progression and severity is manifested by [[dyspnea]] and severe [[chest]] [[Symptom|symptoms]] corresponding to [[pneumonia]] in approximately 75% of the [[Patient|patients]]. 

== Diagnosis ==

=== Diagnostic study of choice ===
The World Health Organization has published a diagnostic criteria that helps identify patients requiring confirmation of COVID-19 through either PCR or antibody detection tests. This criteria includes several epidemiological and clinical criteria that the patient has to fulfill in order to be either a suspected or confirmed case of COVID-19. 

=== History and symptoms ===
History of [[Patient|patients]] [[Infection|infected]] with Coronavirus disease 2019 (COVID-19) can include international travel to where COVID-19 is highly [[Prevalence|prevalent]]. The most common [[Symptom|symptoms]] that can appear 2 - 14 days after exposure include [[fever]], [[cough]], [[fatigue]], and [[Dyspnea|shortness of breath]].

=== Physical Examination ===
The [[pathognomonic]] [[physical examination]] findings in [[Patient|patients]] [[Infection|infected]] with coronavirus include [[fever]], [[Flu|flu-like-symptoms]], [[cough]], and [[body aches]]. General appearance of the [[patient]] [[Infection|infected]] with coronavirus depends on the [[incubation period]] of the [[illness]].

=== Laboratory findings ===
Laboratory tests can be done to confirm whether illness may be caused by human coronaviruses. Specific laboratory tests include serology for viral antigen, molecular testing and viral culture. All these tests can be used to confirm infection with coronavirus. Non-specific laboratory findings in COVID-19 include [[lymphocytopenia]], [[thrombocytopenia]], elevated [[C-reactive protein|C-Reactive protein]], elevated [[liver function tests]] ([[Alanine transaminase|ALT]], [[Aspartate transaminase|AST]]), increased [[creatine kinase]], increased [[D-dimer|D-Dimer]] and an increase in the levels of markers of cell damage e.g. [[troponin]], [[lactate dehydrogenase]], [[interleukin-4]], [[procalcitonin]].

=== Electrocardiogram ===
There are no specific [[ECG]] findings associated with coronavirus [[infection]]. Non specific findings can include [[sinus tachycardia]], ST-elevation and diffuse [[T wave]] inversion.

=== Chest X-ray ===
The [[Chest X-ray|chest x ray]] findings in a suspected case of coronavirus [[infection]] can mimic the findings in [[pneumonia]]. Severe cases of COVID-19 progressing to acute respiratory distress syndrome (ARDS) can show a typical "white-out" on chest x-ray.

=== Echocardiography ===
There are no specific [[echocardiography]]/ultrasound findings associated with coronavirus infection. Non specific [[Echocardiography|echocardiographic]] findings can include left ventricular systolic dysfunction and [[pericardial effusion]].

=== CT scan ===
[[Chest]] [[Computed tomography|CT scan]] findings in [[Patient|patients]] [[Infection|infected]] with coronavirus can include unilateral or bilateral [[pneumonia]], mottling and ground glass opacity, focal or multifocal opacities, [[Consolidation (medicine)|consolidation]], and septal thickening with subpleural and lower lobe involvement more likely.

=== MRI ===
There are no specific [[MRI]] findings associated with coronavirus [[infection]]. [[MRI]] can aide in making the [[diagnosis]] on the basis of exclusion.

=== Other Imaging Findings ===
There are no other [[imaging]] findings associated with COVID-19.

=== Other Diagnostic Studies ===
Research laboratories have used isolation methods, [[electron microscopy]], [[serology]] and [[PCR|PCR-based assays]] to diagnose coronavirus infections for surveillance studies.

== Treatment ==

=== Medical Therapy ===
Treatment of coronavirus [[infection]] includes supportive measures and [[Symptomatic treatment|symptomatic management]]. No specific treatment is available. Given the emergence of the cases during the [[influenza]] season, all [[Patient|patients]] presenting with COVID-19 were given [[oral]] and [[intravenous]] [[antibiotics]] and [[Oseltamivir]] (75 mg twice daily via oral route) empirically. [[Corticosteroids]] ([[methylprednisolone]] 40 - 120 mg/day) were given as a combined regimen if severe [[community-acquired pneumonia]] was [[Diagnosis|diagnosed]]. Oxygen support (e.g., via nasal cannula and invasive mechanical ventilation) was given to [[Patient|patients]] indicated by the severity of [[hypoxemia]].

=== Surgery ===
[[Surgery]] is not [[Indication|indicated]] in the management of COVID-19.

=== Primary Prevention ===
There is currently no [[vaccine]] to prevent COVID-19. The best way to prevent [[infection]] is to avoid being exposed to the [[virus]]. As a precaution against coinfection during the [[flu]] and [[respiratory disease]] season, [[Centers for Disease Control and Prevention|CDC]] recommends getting a [[flu vaccine]], taking everyday preventive actions to help stop the spread of [[Germ|germs]], and taking [[flu]] [[antivirals]] if prescribed. [[Health care provider|Healthcare providers]] are advised to be on the look-out for people who recently traveled from China and have [[fever]] and [[Respiratory system|respiratory]] [[Symptom|symptoms]].