ContentsSynopsisCodesLook ForDiagnostic PearlsDifferential Diagnosis & PitfallsBest TestsManagement PearlsTherapyReferencesView all Images (96)
Potentially life-threatening emergency
Other Resources UpToDate PubMed
Potentially life-threatening emergency


Contributors: Paritosh Prasad MD, Eric Ingerowski MD, FAAP, David Peritz MD, Jeffrey M. Cohen MD, Susan Burgin MD, Lowell A. Goldsmith MD, MPH
Other Resources UpToDate PubMed


Updated February 10, 2021. The situation is rapidly changing. Refer to the US Centers for Disease Control and Prevention (CDC) (Information for Healthcare Professionals) for the most current information.

Clinicians should immediately implement recommended infection prevention and control practices if a patient is suspected of having COVID-19. Minimize the number of personnel that interact with a suspected or positive COVID-19 patient and record all personnel who have entered the room.

Per the CDC, health care providers should immediately notify their local or state health department in the event of the identification of a person under investigation (PUI) for COVID-19. See Diagnostic Pearls and Best Tests for more information on evaluating and reporting suspected cases.

Per the CDC:
  • Preferred Personal Protective Equipment (PPE): Adhere to Standard, Contact, and Airborne Precautions, including the use of Eye Protection (ie, gowns, gloves, National Institute for Occupational Safety and Health [NIOSH]-certified disposable N95 respirator, eye protection).
  • Acceptable Alternative Personal Protective Equipment (PPE): Adhere to Standard, Contact, and Droplet Precautions, including the use of Eye Protection (ie, gowns, gloves, facemask [non-N95], eye protection) for COVID+ or COVID PUI patients not undergoing aerosol-generating procedures (intubation, extubation, bilevel positive airway pressure [BiPAP], continuous positive airway pressure [CPAP], etc). N95 or higher respirators should be used in the setting of aerosol-generating procedures.
  • Isolate the patient under investigation for COVID-19 in an Airborne Infection Isolation Room (AIIR) for aerosol-generating procedures, if available.
The CDC has also provided interim guidance (as of April 13) on infection prevention and control to reduce facility risk, isolate symptomatic patients as soon as possible, and protect health care personnel.

Contrary to CDC recommendations, the World Health Organization (WHO) does not recommend use of Airborne Precautions unless the patient is undergoing high-risk interventions for aerosolization (intubation, induced sputum, etc). Currently, all US providers should follow CDC recommendations.

Finally, it is imperative that providers caring for patients being evaluated for or found to have COVID-19 practice regular hand hygiene before and after patient contact.

About COVID-19
Coronavirus disease 2019 (COVID-19), previously known as 2019 novel coronavirus (2019-nCoV), is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a new coronavirus and the responsible agent for an outbreak of pneumonia cases in Wuhan City, Hubei Province, China, initially reported to the WHO on December 31, 2019, and reportedly linked to a large seafood and animal market. Coronaviruses are a family of viruses, some of which cause infection in humans and others in animals such as camels, cats, and bats. When animal coronaviruses evolve, on rare occasion they can become infectious to and spread between humans (a zoonotic infection) as has occurred with Middle East respiratory syndrome (MERS) and SARS. This animal-to-human spread has been postulated to have occurred with SARS-CoV-2 with subsequent person-to-person transmission.


Person-to-person spread in the community is occurring in many countries, including the United States. The virus is transmitted primarily via infectious secretions (respiratory droplets and sputum) between individuals in close contact (within 6 feet for a total of 15 minutes or more over a 24-hour period [including multiple short exposures]). It is possible that, in addition, the virus can be transmitted by saliva, urine, and stool. Transmission of SARS-CoV-2 from asymptomatic or presymptomatic persons can occur.

Previously, the WHO and CDC stated that airborne transmission of the SARS-CoV-2 virus can only occur during aerosol-generating medical interventions (such as endotracheal intubation or extubation, for example), but there has been some controversy, and guidance has been updated.
  • The CDC states that although the spread of SARS-CoV-2 is believed to be primarily via respiratory droplets, airborne transmission from more than 6 feet away is possible, particularly in enclosed spaces with inadequate circulation or under circumstances where the infectious individual is breathing heavily, such as while exercising or singing.
  • The WHO states that airborne transmission of SARS-CoV-2 in crowded, indoor locations with poor ventilation cannot be ruled out.
Clinical features:

Clinical features primarily include fever and symptoms of lower respiratory tract illness (eg, cough, shortness of breath), although many patients also report associated gastrointestinal complaints (nausea, vomiting). Reported cases have ranged from mild to severe; some cases have been fatal. Some individuals with infection can be relatively asymptomatic.

An association exists between the risk of severe COVID-19 and a multigene locus at 3p21.31 and the ABG blood group locus at 9q34.2. Mutations in type I interferon pathway genes have been associated with severe disease.

Severity breakdown rates per the Chinese Center for Disease Control and Prevention:
  • Mild to moderate (mild symptoms up to mild pneumonia): 81%
  • Severe (dyspnea, hypoxia, or > 50% lung involvement on imaging): 14%
  • Critical (respiratory failure, shock, or multiorgan system dysfunction): 5%
Preventive measures:
  • Every person should wash hands often; the CDC recommends washing with soap and water for at least 20 seconds, or using an alcohol-based hand sanitizer if soap and water are not available.
  • Per the CDC, mitigation strategies to control transmission of the disease and protect individuals at increased risk for severe illness (including older adults and persons of any age with underlying health conditions) include physical distancing measures such as staying at home and avoiding gatherings or other situations of potential exposures, including travel, and generally maintaining distance (at least 6 feet or 2 meters) from others when possible. Mitigation strategies can be scaled up or down depending on evolving local circumstances.
  • The CDC recommends universal mask use outside of people's homes and especially in indoor spaces where social distancing cannot be maintained. The CDC also recommends mask use at home when a member of the household has been infected or potentially exposed to the virus.

Multiple variants of the virus are circulating globally, including in the United States. Per the CDC, these variants (the "UK variant" [B.1.1.7], the "South African variant" [B.1.351], and the "Brazil variant" [P1]) seem to spread more easily and quickly.

Related topic: community-acquired pneumonia


U07.1 – COVID-19

840539006 – Disease caused by 2019 novel coronavirus

Look For

Subscription Required

Diagnostic Pearls

Subscription Required

Differential Diagnosis & Pitfalls

The differential diagnosis includes other etiologies of lower respiratory tract infection (depending on season).

Note: Viral coinfections (eg, dengue) have been reported in patients with COVID-19; thus, diagnosis of an alternative respiratory virus does not exclude SARS-CoV-2 virus infection. In addition, patients with COVID-19 have been reported presenting with concurrent community-acquired bacterial pneumonia.

Viral infection:
Bacterial pneumonia, eg:
Atypical bacterial pneumonia, eg:
Skin manifestations (based on a Spanish study of 375 patients):

Best Tests

Subscription Required

Management Pearls

Subscription Required


Subscription Required


Subscription Required

Last Reviewed:10/29/2020
Last Updated:02/10/2021
Copyright © 2021 VisualDx®. All rights reserved.
Potentially life-threatening emergency
Copyright © 2021 VisualDx®. All rights reserved.