BACKGROUND: Although reports have documented prolonged SARS-CoV-2 RNA detection in immunocompromised patients, few studies have systematically analyzed data on duration of SARS-CoV-2 in respiratory specimens of immunocompromised patients. METHODS: A systematic review was undertaken to describe SARS-CoV-2 RNA and infectious virus detection in immunocompromised patients from published data between January 1, 2020 and July 1, 2022. Patients were included if there was ≥ 1 positive SARS-CoV-2 RNA result in respiratory specimens collected > 20 days since symptom onset or first positive SARS-CoV-2 RT-PCR result. RESULTS: Of the 183 patients, 175 were symptomatic with 83 (47.4%) that experienced intermittent relapsing symptoms, while pneumonia was reported in 122 (66.7%). Immunocompromising conditions represented were hematologic malignancy treatment (89, 48.6%), solid organ transplant (47, 25.7%), autoimmune disease treatment (14, 7.7%), solid tumor treatment (3, 1.6%), HIV infection (15, 8.2%), and primary immunodeficiency (15, 8.2%). Median duration from the first to the last positive SARS-CoV-2 RT-PCR result was 56 days in upper respiratory and 60 days in lower respiratory tract specimens. Significant differences in median duration of SARS-CoV-2 RNA detection were observed between patients with and without pneumonia and for patients with hematologic malignancies compared to solid organ transplant patients. Among patients with viral culture performed, median duration of replication-competent SARS-CoV-2 was 60.5 days from symptom onset (maximum 238 days) and 59 days from first RT-PCR positive result (maximum 268 days). CONCLUSIONS: Immunocompromised persons can have replication-competent SARS-CoV-2 in respiratory tissues for months, including while asymptomatic. Serial SARS-CoV-2 testing can inform the duration of isolation for immunocompromised patients with SARS-CoV-2 infection.

Severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) is a novel human coronavirus that was identified in 2019. SARS-CoV-2 infection results in an acute, severe respiratory disease called coronavirus disease 2019 (COVID-19). The emergence and rapid spread of SARS-CoV-2 has led to a global public health crisis, which continues to affect populations across the globe. Real time reverse transcription polymerase chain reaction (rRT-PCR) is the reference standard test for COVID-19 diagnosis. Serological tests are valuable tools for serosurveillance programs and establishing correlates of protection from disease. This study evaluated the performance of one in-house enzyme linked immunosorbent assay (ELISA) utilizing the pre-fusion stabilized ectodomain of SARS-CoV-2 spike (S), two commercially available chemiluminescence assays Ortho VITROS Immunodiagnostic Products Anti-SARS-CoV-2 Total Reagent Pack and Abbott SARS-CoV-2 IgG assay and one commercially available Surrogate Virus Neutralization Test (sVNT), GenScript USA Inc., cPass SARS-CoV-2 Neutralization Antibody Detection Kit for the detection of SARS-CoV-2 specific antibodies. Using a panel of rRT-PCR confirmed COVID-19 patients' sera and a negative control group as a reference standard, all three immunoassays demonstrated high comparable positivity rates and low discordant rates. All three immunoassays were highly sensitive with estimated sensitivities ranging from 95.4-96.6 %. ROC curve analysis indicated that all three immunoassays had high diagnostic accuracies with area under the curve (AUC) values ranging from 0.9698 to 0.9807. High positive correlation was demonstrated among the conventional microneutralization test (MNT) titers and the sVNT inhibition percent values. Our study indicates that independent evaluations are necessary to optimize the overall utility and the interpretation of the results of serological tests. Overall, we demonstrate that all serological tests evaluated in this study are suitable for the detection of SARS-CoV-2 antibodies.

BACKGROUND: SARS-CoV-2, the virus that causes COVID-19 disease, was first identified in Wuhan, China in December 2019, with subsequent worldwide spread. The first U.S. cases were identified in January 2020. METHODS: To determine if SARS-CoV-2 reactive antibodies were present in sera prior to the first identified case in the U.S. on January 19, 2020, residual archived samples from 7,389 routine blood donations collected by the American Red Cross from December 13, 2019 to January 17, 2020, from donors resident in nine states (California, Connecticut, Iowa, Massachusetts, Michigan, Oregon, Rhode Island, Washington, and Wisconsin) were tested at CDC for anti-SARS-CoV-2 antibodies. Specimens reactive by pan-immunoglobulin (pan Ig) enzyme linked immunosorbent assay (ELISA) against the full spike protein were tested by IgG and IgM ELISAs, microneutralization test, Ortho total Ig S1 ELISA, and receptor binding domain / Ace2 blocking activity assay. RESULTS: Of the 7,389 samples, 106 were reactive by pan Ig. Of these 106 specimens, 90 were available for further testing. Eighty four of 90 had neutralizing activity, 1 had S1 binding activity, and 1 had receptor binding domain / Ace2 blocking activity >50%, suggesting the presence of anti-SARS-CoV-2-reactive antibodies. Donations with reactivity occurred in all nine states. CONCLUSIONS: These findings suggest that SARS-CoV-2 may have been introduced into the United States prior to January 19, 2020.