Test-based De-isolation in COVID-19 Immunocompromised patients: Ct value versus SARS-CoV-2 viral cultures.

Background Immunocompromised COVID-19 patients have prolonged infectious viral shedding for more than 20 days. A test-based approach is suggested for de-isolation of these patients. Methods We evaluated this strategy by comparing SARS-CoV-2 viral load (Ct values) and viral cultures at the time of hospital discharge in a series of immunocompetent (6 patients) and immunocompromised (5 solid organ transplants, 1 patient with lymphoma and one patient with hepatocellular carcinoma) COVID-19 patients. Results 3/13 (23%) patients had positive viral cultures: one patient with lymphoma at day 16 and two immunocompetent patients at day 7 and 11. Of the patients, 80% had negative viral cultures and had mean Ct value 20.5. None of the solid organ transplants recipients had positive viral cultures. Conclusion The mean Ct values for negative viral cultures was 20.5 in our case series of immunocompromised patients. Unlike hematological malignancies, none of the solid organ transplants had positive viral cultures. Adopting the test-based approach for all immunocompromised patients may lead to prolonged quarantine. Large scale studies in disease specific populations are needed whether a test-based approach versus a symptom-based approach or a combination is applicable for the de-isolation of various immunocompromised patients.