+ What advice should be given to patients with known or presumed COVID-19 managed at home?

For most patients with COVID-19 who are managed at home, we advise the following:

●Supportive care with antipyretics/analgesics (eg, acetaminophen) and hydration

●Close contact with their health care provider

●Monitoring for clinical worsening, particularly the development of dyspnea, which should prompt clinical evaluation and possible hospitalization

●Separation from other household members, including pets (eg, staying in a separate room when possible and wearing a mask when in the same room)

●Frequent hand washing for all family members

●Frequent disinfection of commonly touched surfaces

+ How long should patients cared for at home stay isolated?

Th#e optimal duration of home isolation is uncertain. The United States Centers for Disease Control and Prevention (CDC) has issued recommendations on discontinuation of home isolation, which include both test-based and non-test-based strategies. The choice of strategy must be determined on a case-by-case basis, since each strategy has potential limitations.

When a test-based strategy is used, patients may discontinue home isolation when there is:

• Resolution of fever without the use of fever-reducing medications AND

• Improvement in respiratory symptoms (eg, cough, shortness of breath) AND

• Negative results of a US Food and Drug Administration (FDA) emergency use authorized molecular assay for COVID-19 from at least two consecutive respiratory specimens collected ≥24 hours apart (total of two negative specimens)

When a symptom-based strategy is used, patients may discontinue home isolation when the following criteria are met:

• At least 10 days have passed since symptoms first appeared AND

• At least 24 hours have passed since recovery of symptoms (defined as resolution of fever without the use of fever-reducing medications and improvement in respiratory symptoms [eg, cough, shortness of breath])

In some cases, patients may have had laboratory-confirmed COVID-19 but they did not have any symptoms when they were tested. In such patients, home isolation may be discontinued using a test-based strategy or a time-based strategy (when at least 10 days have passed since the date of their first positive COVID-19 test) as long as there was no evidence of subsequent illness.

+ How is SARS-CoV-2 (the virus that causes COVID-19) transmitted Person to Person?

Via respiratory droplets. resembling the spread of influenza.

With droplet transmission, virus released in the respiratory secretions when a person with infection coughs, sneezes, or talks can infect another person if it makes direct contact with the mucous membranes.

Infection can also occur if a person touches a contaminated surface and then touches his or her eyes, nose, or mouth.

+ What is the incubation period for COVID-19?

The incubation period for COVID-19 is thought to be within 14 days following exposure, with most cases occurring approximately four to five days after exposure.

+ What are the clinical presentation and natural history of COVID-19?

The spectrum of illness associated with COVID-19 is wide, ranging from asymptomatic infection to life-threatening respiratory failure.

When symptoms are present, they typically arise approximately 4-5 days after exposure.

Symptoms are mild in approximately 80 percent of cases and often include fever, fatigue, and dry cough.

Smell and taste disorders have also been reported in patients with COVID-19; whether these symptoms are distinguishing features is unknown.

Gastrointestinal symptoms are not frequently reported but may be the presenting feature in some patients. Headache, rhinorrhea, and sore throat are less common.

Dyspnea affects approximately 20 to 30 percent of patients, typically arising five to eight days after symptom onset.

Progression from dyspnea to acute respiratory distress syndrome (ARDS) can be rapid; thus, the onset of dyspnea is generally an indication for hospital evaluation and management.

Pneumonia is the most common manifestation

The overall case fatality rate is estimated to be between 2 and 3 percent.

+ Is there a way to distinguish COVID-19 clinically from other respiratory illnesses, particularly influenza?

No, the clinical features of COVID-19 overlap substantially with influenza and other respiratory viral illnesses. There is no way to distinguish among them without testing.

+ When should patients with confirmed or suspected COVID-19 be advised to stay at home? Go to the hospital?

Home management is appropriate for most patients with mild symptoms (eg, fever, cough, and/or myalgias without dyspnea), provided they can be adequately isolated, monitored, and supported in the outpatient setting. However, there should be a low threshold to clinically evaluate patients who have any risk factor for more severe illness, even if they have only mild symptoms.

+ What are the different types of tests for COVID-19?

There are two major types of tests for COVID-19

• Nucleic acid amplifications tests (NAATs; eg, reverse transcription polymerase chain reaction [RT-PCR]) – RT-PCR for SARS-CoV-2 is the primary test used to diagnose active COVID-19. The test is typically performed on nasopharyngeal swabs, but can also be performed on other respiratory tract specimens (eg, oropharyngeal swabs, lower respiratory tract samples).

Sensitivity and specificity are generally high, although performance varies based on the specific assay used, specimen quality, and duration of illness.

• Serology – Serologic tests measure antibodies to SARS-CoV-2 and are primarily used to identify patients who have had COVID-19 in the past. Sensitivity and specificity are highly variable and cross-reactivity with other coronaviruses has been reported. While some serologic assays can help identify patients with acute infection, they are not as reliable as RT-PCR and not recommended for this purpose.

+ How accurate is RT-PCR for SARS-CoV-2? Should two tests be performed or one?

Tests for COVID-19 are new, and determining their accuracy is challenging.

A positive RT-PCR for SARS-CoV-2 generally confirms the diagnosis of COVID-19.

However, false-negative tests from upper respiratory specimens have been well documented. If initial testing is negative, but the suspicion for COVID-19 remains, and determining the presence of infection is important for management or infection control, we suggest repeating the test.

Antigen tests can also be used to diagnosis active infection and are typically performed on nasopharyngeal or nasal swabs. While data on their performance are limited, they are generally considered less sensitive than NAATs.