Long-Term Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infectiousness Among Three Immunocompromised Patients: From Prolonged Viral Shedding to SARS-CoV-2 Superinfection.

Background: Guidelines for stopping coronavirus disease 2019 patient isolation are mainly symptom-based, with isolation for 10 to 20 days depending on their condition.

Methods: In this study, we describe 3 deeply immunocompromised patients, each with different clinical evolutions. We observed (1) the patients' epidemiological, clinical, and serological data, (2) infectiousness using viral culture, and (3) viral mutations accumulated over time.