UW Medicine Laboratory Medicine has been a national leader in the development of testing for SARS-CoV-2, the virus that causes COVID-19. Early access to a test with a rapid turnaround time has helped UW Medicine hospitals and clinics to continue to provide safe and effective care for patients. Starting today, the Lab Medicine team is now providing access to an antibody test for SARS-CoV-2. This laboratory test will help public health and research colleagues learn more about how many people in the community may have had COVID-19 in the past and how many people remain uninfected. This information is critical to help determine the extent of the epidemic so far. More important details below.
Status Update: While the number of COVID-19 patients in our hospitals continues slowly to trend down, state, national and global numbers indicate that this is not true in all areas.
UW Medicine COVID-19 Daily Inpatient Census
State, National and Global Updates
Washington: Washington state reported 12,085 cases and 652 deaths as of April 19. Approximately 141,000 tests had been performed and 8.6% of those tests were positive.
United States: The Centers for Disease Control and Prevention reports 776,093 COVID-19 cases and 41,758 deaths as of today. While other parts of the country are seeing different levels of COVID-19 activity, the United States nationally continues to be in the acceleration phase of the pandemic.
Global: The WHO COVID-19 Situation Report for April 21 reports more than 2.3 million confirmed COVID-19 cases and nearly 163,000 deaths. No new country/territory/area reported cases of COVID-19 in the past 24 hours.
NEW: COVID-19 Serology Testing Available Effective April 21
The test for IgG antibodies to SARS-CoV-2 virus is now available as a routine orderable test (mnemonic NCVIGG) through UW Laboratory Medicine in EPIC and ORCA. Serological testing is NOT indicated for diagnosis of acute infection. The UW test is a qualitative test (reported as positive/negative) that detects IgG antibodies to the nucleocapsid protein of SARS-CoV-2 in serum and plasma from people who have been infected with SARS-CoV-2.
- A positive result indicates previous or current infection, with over 99% specificity. The median time to seroconversion is about 10 days after symptom onset in moderately ill patients and 14 days in severely ill patients. Almost all infected patients develop antibodies by 25 days. Antibodies start to develop while patients are still infected; therefore, a positive serology test cannot distinguish between active or past SARS-CoV-2 infection. If there is concern for active infection, molecular testing (PCR) with a nasopharyngeal swab should be performed.
- A negative result indicates that a person has not been infected with SARS-CoV-2, or there has been an infection without a detectable level of antibody. Explanations for infection in the absence of antibody response may include a very recent infection or the immune response has decreased below the detectable level. A negative result does not absolutely rule out current or past infection with SARS-CoV-2.
- The medical indications for ordering this test remain uncertain. Testing patients who were previously symptomatic with COVID-19 compatible symptoms but who did not have positive molecular testing (PCR) results may be indicated.
- Both serum and plasma are acceptable with routine specimen handling (more information is available in the Online Test Guide). The turnaround time is expected to be within 24 hours but may change.
Current UW COVID-19 Clinical Research
The UW Medicine Institute of Translational Health Sciences is compiling a list of clinical research projects with information valuable to interested scientists and participants. You can learn about these projects and the criteria for enrolling patients at Current UW COVID-19 Clinical Research.
Thank you, as always, for your valuable contributions to these efforts and to patient care throughout the region.
Sincerely,
John Lynch, MD, MPH
Medical Director, Infection Prevention & Control
Associate Medical Director, Harborview Medical Center
Division of Allergy & Infectious Diseases, UW School of Medicine
