Longitudinal Assessment of Solid Organ Transplant Recipients With SARS-CoV-2 Infection

Compared with immunocompetent individuals, those who are immunocompromised, including solid organ transplant (SOT) recipients, have higher SARS-CoV-2-related morbidity and mortality. We determined the duration of SARS-CoV-2 RNA positivity to evaluate viral persistence in SOT recipients.

This study prospectively followed SOT recipients who recently tested positive for SARS-CoV-2. The duration of viral RNA shedding in nasal swabs and stool samples was tracked, and viral genome sequencing was performed where possible. Persistent infection was defined as a positive nucleic acid amplification test (NAAT) for SARS-CoV-2 at 28 days or later after initial infection. This duration was chosen based on the U.S. Centers for Disease Control and Prevention (CDC) recommendation that immunocompromised individuals isolate for at least 20 days [1], compared with 10 days for non-immunocompromised individuals.

Of 30 SOT recipients, 12 (40%) had positive SARS-CoV-2 RNA in nasal swabs or stool (cycle threshold [Ct] < 40) at 28 or more days after the first positive SARS-CoV-2 test. Immunocompromised (IC) subject 015 had high viral loads (Ct < 30) at 28 days, with continued detection for 54 days.

In 12 of 30 SOT subjects, SARS-CoV-2 RNA was detected at or beyond 28 days post-detection (dpd), despite vaccination and antibody and/or antiviral treatment in most participants. Three subjects tested positive for SARS-CoV-2 RNA past 50 dpd. Viral persistence in the setting of host immune suppression, coupled with exposure to antiviral treatments, raises concern about the selection of unusual viral variants.