Duration of infectious virus shedding of SARS-CoV-2 Omicron variant among immunocompromised patients

The duration of viral shedding and criteria for de-isolation in the hospital among immunocompromised patients with coronavirus disease 2019 (COVID-19) remain unclear. This study aimed to evaluate viral shedding duration in immunocompromised patients infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2.

A prospective cohort study was performed at 2 tertiary medical centers in Japan during the Omicron epidemic waves from July 2022 to January 2023. Nasopharyngeal swabs were serially collected from immunocompromised patients with COVID-19, including those with hematological malignancies, solid tumors, autoimmune diseases, and human immunodeficiency virus infection. Patients were classified as severely or moderately immunocompromised according to the Japanese national guidelines for tixagevimab-cilgavimab. The relationship between patient characteristics, immune status, duration of viral RNA presence, and infectious virus shedding were assessed using Mann-Whitney U and Fisher's exact tests.

Among 41 patients (163 samples), 9 (47 samples) were severely and 32 (116 samples) were moderately immunocompromised. In the severely and moderately immunocompromised groups, 87.2 % and 75.0 % of the samples were viral RNA-positive, while 36.2 % and 35.3 % were culture-positive, respectively. Five culture-positive samples after day 20 were from 2 severely immunocompromised patients on B cell depletion therapy. No culture-positive samples were found for the moderately immunocompromised patients after day 10.

Long-term viral shedding should be closely monitored in severely immunocompromised patients with COVID-19.