NOTE: Information and guidelines may change rapidly. Check in with listed references in ‘Learn More – Primary Sources’ to best keep up to date. This summary has been updated with the latest CDC guidelines on when to end quarantine.

SUMMARY:

The novel coronavirus, named SARS-CoV-2, is the pathogen underlying the pandemic (a global outbreak of disease). The disease associated with this virus has been officially named COVID-19. Coronaviruses represent a large family of viruses. They can cause human illness, but many are found in animals and, rarely, animal coronaviruses can evolve and infect people as was the case in previous infectious outbreaks such as MERS and SARS.

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• COVID-19 Definitions
• Symptoms
• Those at Risk
• Travel Warnings
• Recommendations for Reporting, Testing, and Specimen Collection
• Healthcare Personnel: Infection Prevention
• Discontinuation of Transmission-Based Precautions
• Hospital Discharge
• Quarantine

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COVID-19 Definitions

• Mild Illness: Individuals who have
  • Any of the various signs and symptoms of COVID-19 (e.g., fever, cough, sore throat, malaise, headache, muscle pain) without shortness of breath, dyspnea, or abnormal chest imaging
• Moderate Illness: Individuals who have
  • Evidence of lower respiratory disease by clinical assessment or imaging and
  • Saturation of oxygen (SpO2) ≥94% on room air at sea level
• Severe Illness: Individuals who have
  • Respiratory frequency >30 breaths per minute
  • SpO2 <94% on room air at sea level (or, for patients with chronic hypoxemia, a decrease from baseline of >3%)
  • Ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) <300 mmHg
  • Lung infiltrates >50%
• Critical Illness: Individuals who have
  • Respiratory failure
  • Septic shock
  • Multiple organ dysfunction

Symptoms

• Incubation period
  • Time from exposure to development of symptoms: 2 to 14 days
  • 97.5% of persons with COVID-19 who develop symptoms will do so within 11.5 days of SARS-CoV-2 infection (see ‘Related ObG Topics’ below)
  • Median time from exposure to symptoms onset: 4-5 days

• Signs and Symptoms
  • Fever or chills
  • Cough
  • Shortness of breath or difficulty breathing
  • Fatigue
  • Muscle or body aches
  • Headache
  • New loss of taste or smell
  • Sore throat
  • Congestion or runny nose
  • Nausea or vomiting
  • Diarrhea
• Additional points regarding presentation
  • Older adults: Especially those with comorbidities may have delayed presentation of fever and respiratory symptoms
  • Fatigue, headache, and muscle aches (myalgia) are among the most commonly reported symptoms in people who are not hospitalized
  • Sore throat and nasal congestion or runny nose (rhinorrhea) also may be prominent symptoms
  • GI symptoms may be relatively common
    • Nausea, vomiting or diarrhea may occur prior to fever and lower respiratory tract signs and symptoms
  • Loss of smell (anosmia) or taste (ageusia) has been commonly reported, especially among women and younger or middle-aged patients

Those at Risk

CDC Currently Considers the Following Individuals to be at Higher Risk

• Age
  • Risk of severe illness increases with age
  • Approximately 80% of COVID-19 deaths have been in the ≥65 age group
• People of any age with certain underlying medical conditions are at increased risk for severe illness from COVID-19
  • Pregnancy
  • Cancer
  • Chronic kidney disease
  • COPD (chronic obstructive pulmonary disease)
  • Down Syndrome
  • Heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies
  • Immunocompromised state (weakened immune system) from solid organ transplant
  • Obesity (body mass index [BMI] of 30 kg/m2 or higher but < 40 kg/m2)
  • Severe Obesity (BMI ≥ 40 kg/m2)
  • Sickle cell disease
  • Smoking
  • Type 2 diabetes mellitus

Pediatric population: Medically complex conditions | Neurologic, genetic, metabolic conditions | Congenital heart disease

Those Who Might be at an Increased Risk

• Asthma (moderate-to-severe)
• Cerebrovascular disease (affects blood vessels and blood supply to the brain)
• Cystic fibrosis
• Hypertension or high blood pressure
• Immunocompromised state (weakened immune system) from blood or bone marrow transplant, immune deficiencies, HIV, use of corticosteroids, or use of other immune weakening medicines
• Neurologic conditions, such as dementia
• Liver disease
• Overweight (BMI > 25 kg/m2, but < 30 kg/m2)
• Pulmonary fibrosis (having damaged or scarred lung tissues)
• Smoking
• Thalassemia (a type of blood disorder)
• Type 1 diabetes mellitus

Travel Warnings

• Updated travelers’ warnings can be found within the CDC Novel Coronavirus Summary page below (‘Learn More – Primary Sources’)

KEY POINTS:

Recommendations for Reporting, Testing, and Specimen Collection

Diagnostic Testing – Specimen Collection

• Obtain an upper respiratory specimen for initial diagnostic testing
  • A nasopharyngeal (NP) specimen collected by a healthcare professional or
  • An oropharyngeal (OP) specimen collected by a healthcare professional or
  • A nasal mid-turbinate swab collected by a healthcare professional or by a supervised onsite self-collection (using a flocked tapered swab) or
  • An anterior nares (nasal swab) specimen collected by a healthcare professional or by onsite or home self-collection (using a flocked or spun polyester swab) or
  • Nasopharyngeal wash/aspirate or nasal wash/aspirate (NW) specimen collected by a healthcare professional
• Lower respiratory tract specimens
  • Collect and test sputum in patients who develop a productive cough | Induction of sputum is not recommended
  • Under certain clinical circumstances (e.g., those receiving invasive mechanical ventilation), a lower respiratory tract aspirate or bronchoalveolar lavage sample should be collected and tested as a lower respiratory tract specimen

Note: CDC does not recommend using antibody testing to diagnose acute infection | Use a viral (nucleic acid or antigen) test to diagnose acute infection

Healthcare Personnel: Infection Prevention

• Healthcare personnel: CDC advises use of
  • Gloves
  • Gowns
  • Airborne precautions
  • Eye protection (e.g., goggles or a face shield)
• Face masks are an acceptable alternative when the supply chain of N95 respirators (or similar respirators that filter inspired air and offer respiratory protection) cannot meet the demand
• If respirators are in short supply, priority should be given to aerosol-generating procedures
• CDC addresses alternatives in the setting of face mask shortages on the page entitled Strategies for Optimizing the Supply of Facemasks (see ‘Learn More – Primary Sources’)
  

Discontinuation of Transmission-Based Precautions: Now Symptom-Based

Patients with mild to moderate illness who are not severely immunocompromised

• ≥10 days since symptoms first appeared and
• ≥24 hours have passed since last fever without the use of fever-reducing medications and
• Symptoms (e.g., cough, shortness of breath) have improved

Note: For patients who are not severely immunocompromised and who were asymptomatic throughout their infection: Transmission-Based Precautions may be discontinued when ≥10 days have passed since the date of their first positive viral diagnostic test

Patients with severe to critical illness or who are severely immunocompromised

• ≥10 days and up to 20 days have passed since symptoms first appeared and
• ≥24 hours have passed since last fever without the use of fever-reducing medications and
• Symptoms (e.g., cough, shortness of breath) have improved
• Consider consultation with infection control experts

Note: Patients who are severely immunocompromised may produce replication-competent virus beyond 20 days after symptom onset or, for those who were asymptomatic throughout their infection, the date of their first positive viral test | Consultation with infectious diseases specialists is recommended | Use of a test-based strategy for determining when Transmission-Based Precautions may be discontinued could be considered

When to Consider Test-Based Strategy

• Test-based strategy can be considered for the following scenarios
  • Test-based strategy may release individual from isolation sooner
    • May be of limited utility due to prolonged viral shedding
    • Individuals who re severely immunocompromised (in discussion with ID expert) if concern that patient may be infection for more than 20 days

Test-Based Strategy

Patients who are symptomatic

• Resolution of fever without the use of fever-reducing medications and
• Symptoms (e.g., cough, shortness of breath) have improved and
• Results are negative from ≥2 consecutive respiratory specimens collected ≥24 hours apart (total of two negative specimens) tested using an FDA-authorized molecular viral assay to detect SARS-CoV-2 RNA

Patients who are not symptomatic

• Results are negative from ≥2 consecutive respiratory specimens collected ≥24 hours apart (total of two negative specimens) tested using an FDA-authorized molecular viral assay to detect SARS-CoV-2 RNA

Hospital Discharge

• Patient can be discharged from hospital with COVID-19 when clinically indicated even if not having met criteria for discontinuation of Transmission-Based Precautions
• If not yet met criteria for discontinuation of Transmission-Based Precautions
  • Decision should be made with clinical care team and local or state public health departments
  • Take in to consideration patient’s home situation and whether it is appropriate for home isolation recommendations (e.g., separate bedroom, appropriate caregivers, access to PPE, potential risk to others in the home who may be at risk)

Quarantine

• The purpose of quarantine is to separate someone who might have been exposed to COVID-19 with the goal of preventing transmission to others
• CDC recommends a 14 day quarantine period

2 ‘Acceptable’ CDC Options to Reduce Time Period to <14 Days

• Quarantine can end after Day 10 without testing
  • If no symptoms have been reported during daily monitoring
  • With this strategy, residual post-quarantine transmission risk is estimated to be about 1% with an upper limit of about 10%

• Quarantine can end after Day 7 if a diagnostic testing if
  • Testing is negative and if no symptoms were reported during daily monitoring
  • The specimen may be collected and tested within 48 hours before the time of planned quarantine discontinuation (e.g., in anticipation of testing delays)
  • Quarantine cannot be discontinued earlier than after Day 7
  • With this strategy, the residual post-quarantine transmission risk is estimated to be about 5% with an upper limit of about 12%.

Note: In both cases, additional criteria (e.g., continued symptom monitoring and masking through Day 14) must be met 

Learn More – Primary Sources:

CDC: 2019 Cases, Data, & Surveillance

CDC: COVID-19 and Older Adults

CDC: People of Any Age with Underlying Medical Conditions

CDC Coronavirus Disease 2019: Overview of Testing for SARS-CoV-2

CDC: Interim Clinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19)

CDC: Discontinuation of Transmission-Based Precautions and Disposition of Patients with COVID-19 in Healthcare Settings (Interim Guidance)

CDC Coronavirus Disease 2019: Guidelines for Clinical Specimens

CDC: Interim U.S. Guidance for Risk Assessment and Work Restrictions for Healthcare Personnel with Potential Exposure to COVID-19

CDC: Coronavirus Disease 2019 Information for Travel

CDC FAQs for Healthcare Professionals

CDC: Strategies for Optimizing the Supply of Facemasks

CDC: Disposition of Hospitalized Patients with COVID-19

CDC: Implementing Home Care

CDC: Options to Reduce Quarantine for Contacts of Persons with SARS-CoV-2 Infection Using Symptom Monitoring and Diagnostic Testing

WHO: Novel coronavirus Information Page

An ACP Physician’s Guide + Resources

JAMA: Coronavirus Disease 2019

FDA: Coronavirus Disease 2019

BMJ: Coronavirus Updates

Lancet: Coronavirus Hub

NEJM: 2019 Novel Coronavirus

Annals of Internal Medicine: Content Related to Coronavirus in Annals of Internal Medicine

CDC: Standard Precautions

CDC: Contact and Airborne Precautions

CDC: Middle East Respiratory Syndrome (MERS)

CDC: Severe acute respiratory syndrome (SARS)

JAMA: What Is a Pandemic?

Related ObG Topics: