Testing, Laboratory, and Therapeutics

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Interim COVID-19 Testing Guidance for Healthcare Providers

Test all patients with symptoms consistent with COVID-19.

Rapidly test all patients with COVID-19 symptoms. Testing informs patient management and is a critical first step in identifying and isolating cases, quarantining their close contacts, and preventing community spread.

COVID-19 patients may present with:

  • Cough
  • Shortness of breath or difficulty breathing
  • Fever
  • Chills
  • Muscle pain
  • Sore throat
  • New loss of taste or smell
  • Atypical presentations have been described

Children have similar symptoms as adults and generally have milder illness.

Older adults and persons with medical comorbidities may have delayed presentation of fever and respiratory symptoms and older persons may have new confusion, with delirium or falls. 

A new syndrome associated with COVID-19 has been described called Multisystem Inflammatory Syndrome in Children (“MIS-C”). Patients aged <21 years may have fever, laboratory evidence of inflammation, and evidence of clinically severe illness requiring hospitalization, with multisystem organ involvement. Healthcare providers should immediately report any patient who meets the MIS-C case definition to the local health department by the most rapid means.

Report all cases to VDH.

Report all clinically suspected COVID-19 cases using  VDH’s online morbidity portal at the earliest point COVID-19 is suspected. Reporting complete information, including demographics like race and ethnicity, is critical to help prevent health disparities. 

While PPE and tests are in limited supply, reserve testing for selected asymptomatic people. 

The prevalence of asymptomatic and presymptomatic infection is not well understood, but may play a role in the transmission of SARS-CoV-2. If adequate supplies are available, consider testing asymptomatic people for: 

  • Medical purposes
    • Women who are pregnant and present in labor;  additional considerations here
    • Neonates born to women with confirmed or suspected COVID-19; additional considerations here.
    • People undergoing aerosol-generating procedures, within 48 hours of procedure, with limited PPE at the facility; additional considerations here.
    • People undergoing major time-sensitive surgeries, within 48 hours of procedure; additional considerations here
    • Immunocompromised people admitted to the hospital; additional considerations here
    • Undergoing immunosuppressive procedures; additional considerations here
  • Contact investigations*
    • People who have had close contact** with a lab-confirmed case without proper use of PPE, including exposed healthcare personnel; additional considerations here.
    • People who work or reside in a nursing home; additional considerations here.
    • People who work or reside in a congregate setting other than a nursing home that is experiencing an outbreak.

*Testing should ideally occur 5-7 days following exposure. If a close contact tests negative, the person still needs to remain in quarantine for 14 days after their last date of exposure. 

**A close contact is any individual within 6 feet of an infected person for at least 15 minutes starting from 2 days before the person became sick (or 2 days before specimen collection if asymptomatic) until the person was isolated.

Print and display ‘VDH COVID-19 Testing Algorithm’ in your healthcare facility or office. 

In general, send specimens to commercial laboratories.

In general, healthcare providers should send specimens for COVID-19 testing to commercial, private, or hospital laboratories. VDH recommends providers work with laboratories using viral tests granted an EUA by the FDA. Always evaluate test performance measures. 

Many community sites are conducting specimen collection and either performing point of care tests or sending specimens to a private or reference laboratory for testing. To find a site for your patient, visit Virginia COVID-19 Testing Sites. Each site has different policies and procedures for testing and billing.

For certain situations, send specimens to Virginia’s public health laboratories. Specifically, specimens collected from:

  • Persons identified in contact and outbreak investigations
  • Residents and workers with COVID-19 symptoms in, or newly arriving to, congregate settings (e.g., long-term care facilities, prisons, or jails, or behavioral health facilities)
  • Un- or underinsured persons with COVID-19 symptoms
  • Public health monitoring, including point prevalence surveys  and special programs (e.g., TB patients, etc.)
  • Sentinel surveillance and seroprevalence studies
  • Community testing clinics

Clinicians may request public health testing for these scenarios by contacting their local health department.  Submitters using public health testing must be willing and capable of collecting and packaging specimens, and either delivering them to a DCLS courier site or shipping them via commercial courier (e.g, FedEx).

The COVID-19 Uninsured Program Portal has been launched by the federal government to allow healthcare providers who have conducted COVID-19 testing or provided COVID-19 treatment for uninsured persons on or after February 4, 2020 to submit claims for reimbursement. Providers can access the portal at COVIDUninsuredClaim.HRSA.gov.

Test patients using a diagnostic test for COVID-19.

The preferred diagnostic test for COVID-19 is a PCR-based test. These tests detect the presence of SARS-CoV-2 RNA.

    • A positive result indicates current infection.
      • Recommendation: The person should self-isolate until the criteria to discontinue home isolation for a  symptom-based strategy (i.e., time-since-illness-onset and time-since-recovery strategy) or a test-based strategy are met. Close contacts of this person should self-quarantine for at least 14 days from the date of last exposure, as specified in other COVID-19 guidance.
      • Caveats: A positive PCR does not necessarily mean viable virus is present (i.e., that the person is infectious); viral RNA can persist in the respiratory tract. Immune competent persons with a previously positive PCR test who have a repeat positive PCR test, regardless of the duration of time elapsed between tests, are not subject to re-isolation provided they meet the symptom-based or time-based criteria. Persons with repeat positive PCR tests who are severely immunocompromised should consult with their healthcare provider in addition to meeting the test-based criteria because these persons might actually have prolonged viral shedding and be infectious longer than 10 days after onset (or specimen collection date) and may require additional PCR testing. For more information from CDC about persistently positive PCR results, see here
    • A negative result indicates no active infection
      • Recommendation: If the person had a known exposure to someone with COVID-19, the person should continue to self-quarantine until 14 days after the last known exposure. If the person did not have a known exposure to someone with COVID-19, the person should self-isolate until at least 24 hours after symptoms resolve (if symptomatic) or follow protective measures in place in the community (if asymptomatic).  
      • Caveats: Virus or antigen may not have been detected either because the person is not currently infected, the virus caused the illness but is no longer detectable or present in the upper respiratory tract, or an inadequate specimen was collected.

Get helpful advice on informing your patients of COVID-19 test results. Provide additional guidance and education to patients with confirmed or suspected COVID-19. 

An antigen test is another type of diagnostic test. It detects the presence of SARS-CoV-2 nucleocapsid protein antigen.  Antigen can be detected in upper respiratory specimens during the acute phase of infection. Antigen tests are known to be less sensitive than PCR-based tests and might generate false negative results. Antigen test results may be interpreted similarly to PCR-based tests, except that a negative result is considered presumptive for the currently FDA EUA authorized tests. A presumptive negative result should be  confirmed using a PCR-based test. If using an antigen test, select one that has been authorized by the U.S. Food and Drug Administration (FDA) under an Emergency Use Authorization (EUA)

Serology, or antibody, tests are not recommended for making a diagnosis of COVID-19. Serology tests identify the body’s immune response to exposure to SARS-CoV-2. These tests could be useful to determine how widespread infection has been in different populations, identify people with antibodies who can donate plasma, for serosurveys in populations to determine true infection rates, and learn more about the antibody response to SARS-CoV-2 and its relationship with symptom history. 

    • A positive result indicates that the person may have been exposed to the virus at some point in the past.
      • Recommendation: Test with PCR or antigen test if clinically indicated.
      • Caveat: Detection of antibodies does not mean the person is infectious or immune to SARS-CoV-2. A false positive is possible if the test cross-reacts with commonly circulating coronaviruses.
    • A negative result means that antibodies to SARS-CoV-2 were not detected in serum.
      • Recommendation: Retest if antibody status is needed or test with PCR or antigen if clinically indicated.
      • Caveat: This could indicate that the person has not been infected, that antibodies had not yet developed at the time of specimen collection, antibody levels are too low for the test to detect, or the immune system has not mounted a response to the exposure (e.g., because of immunosuppression).

Learn more about Interpreting COVID-19 Test Results. Read a helpful report on Interpreting Diagnostic Tests for SARS-CoV-2 or watch a brief VDH video about Informing Patients of COVID-19 Test Results

Utilize VDH Factors to Consider When Offering Community-Based Testing for COVID-19 for more information

Collect and test specimens safely. 

For initial diagnostic testing for SARS-CoV-2, collect and test one of the following acceptable upper respiratory specimens. To conserve PPE, consider diagnostic tests that use specimens that can be collected using minimal PPE. These include a specimen from a nasal swab that can be self-collected by the patient. VDH developed a brief video: Patient Self-Collecting Nasal Swab for COVID-19.

Verify with your diagnostic laboratory to determine which specimens are appropriate for the tests they offer. Follow directions on the laboratory’s test menu for specific specimen collection instructions, submission forms, and shipping requirements.

The Virginia Emergency Support Team (VEST) has coordinated with Amazon to provide a portal for healthcare professionals to purchase PPE in varied amounts and types at a reasonable price. As a reminder, CDC recommends that all healthcare providers implement universal source control with face coverings for everyone entering a healthcare facility, regardless of symptoms.

General guidance for the preferred types of specimen collection*

Specimen Type PPE Equipment Instructions
Nasopharyngeal (NP) collected by healthcare professional (HCP) N95 or higher-level respirator (or facemask if a respirator is not available), eye protection, gloves, and a gown  Flocked, synthetic fiber mini-tip swabs with plastic or wire shafts Insert minitip swab through the nostril parallel to the palate (not upwards) until resistance is encountered or the distance is equivalent to that from the ear to the nostril of the patient, indicating contact with the nasopharynx. Swab should reach depth equal to distance from nostrils to outer opening of the ear. Gently rub and roll the swab. Leave swab in place for several seconds to absorb secretions. Slowly remove swab while rotating it.
Nasal mid-turbinate swab (Deep Nasal Swab) collected by HCP N95 or higher-level respirator (or facemask if a respirator is not available), eye protection, gloves, and a gown Flocked tapered swab Tilt patient’s head back 70 degrees. While gently rotating the swab, insert swab less than one inch (about 2 cm) into nostril (until resistance is met at turbinates). Rotate the swab several times against nasal wall and repeat in other nostril using the same swab.
Nasal mid-turbinate swab (Deep Nasal Swab) collected by patient while medically-supervised with HCP standing >6 feet away Standard precautions, gloves, universal source control at all times in healthcare facilities  Flocked tapered swab Patient should tilt head back 70 degrees. While gently rotating the swab, insert swab less than one inch (about 2 cm) into nostril (until resistance is met at turbinates). Rotate the swab several times against nasal wall and repeat in other nostril using the same swab.
Nasal swab (anterior nares) collected by HCP N95 or higher-level respirator (or facemask if a respirator is not available), eye protection, gloves, and a gown  Use flocked or spun polyester swab Insert the swab at least 1 cm (0.5 inch) inside the nostril (naris) and firmly sample the nasal membrane by rotating the swab and leaving in place for 10 to 15 seconds. Sample both nostrils with the same swab.
Nasal swab (anterior nares) collected by patient while medically-supervised with HCP standing >6 feet away Standard precautions, gloves, universal source control at all times in healthcare facilities  Use flocked or spun polyester swab Patient should insert the swab at least 1 cm (0.5 inch) inside the nostril (naris) and firmly sample the nasal membrane by rotating the swab and leaving in place for 10 to 15 seconds. Sample both nostrils with the same swab.
Nasopharyngeal wash/aspirate or nasal wash/aspirate (NW) collected by HCP N95 or higher-level respirator (or facemask if a respirator is not available), eye protection, gloves, and a gown Use catheter attached to suction apparatus Have the patient sit with head tilted slightly backward. Instill 1 mL-1.5 mL of non-bacteriostatic saline (pH 7.0) into one nostril. Insert the tubing into the nostril parallel to the palate (not upwards). Catheter should reach depth equal to distance from nostrils to outer opening of ear. Begin gentle suction/aspiration and remove catheter while rotating it gently. Place specimen in a sterile viral transport media

*Oropharyngeal (OP) swabs should only be collected if nasal or NP is not available. HCP collecting OP swabs should wear the same PPE as used when collecting NP swabs. Testing lower respiratory tract specimens is also an option. 

For more information, read CDC Guidelines for Clinical Specimens.

Refresher on useful epidemiology terminology about test performance:

  • Sensitivity - measures the ability of a test to correctly identify persons who have SARS-CoV-2. Calculated by:  [a/a+c]*100
  • Specificity - measures the ability of the test to correctly identify persons who do not have SARS-CoV-2. Calculated by: [d/b+d]*100
  • Cross-reactivity -        
    • PCR – reagents used for SARS-CoV-2 test react with non-SARS-CoV-2 organisms by either actual lab testing or by theoretical sequence analysis
    •  Antigen – reagents react with related pathogens, high prevalence organisms or normal flora likely to be encountered in a clinical specimen
    • Serology - detection of other related antibodies (e.g., produced by past infection with other coronaviruses) which would produce a false-positive results. Researchers (Gorse et. al) estimate that 90% of persons age 50 or older have antibodies to common non-SARS-CoV-2 human coronaviruses HKU1, NL63, OC43, or 229E. 
  • Prevalence - proportion of population that have been infected with SARS-CoV-2.
  • Positive predictive value (PPV) - probability a person with a positive SARS-CoV-2 test result actually has SARS-CoV-2 and was infected. Calculated by: [a/a+b]*100; PPV goes up  as prevalence increases and down as prevalence decreases
  • Negative predictive value (NPV) - probability a person with a negative SARS-CoV-2 test result does not actually have SARS-CoV-2 and was not infected. Calculated by: [d/c+d]*100; As prevalence increases, NPV decreases and as prevalence decreases, NPV increases

    Disease + Disease -
Test + a=true positive b=false positive
Test - c=false negative d =true negative

Page last reviewed: June 9th, 2020