SARS-CoV-2 persistence in immunocompromised children

We evaluated the length of time immunocompromised children (ICC) remain positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), identified factors associated with viral persistence, and determined cycle threshold (C_T ) values of children with viral persistence as a surrogate of viral load.

We conducted a retrospective cohort study of ICC at a pediatric hospital from March 2020 to March 2021. Immunocompromised status was defined as primary, secondary, or acquired due to medical comorbidities/immunosuppressive treatment. The primary outcome was time to first of two consecutive negative SARS-CoV-2 polymerase chain reaction (PCR) tests at least 24 hours apart. Testing of sequential clinical specimens from the same subject was conducted using the Centers for Disease Control (CDC) 2019-nCoV real-time reverse transcriptase (RT)-PCR Diagnostic Panel assay. Descriptive statistics, Kaplan-Meier curve median event times and log-rank tests were used to compare outcomes between groups.

Ninety-one children met inclusion criteria. Median age was 15.5 years (interquartile range [IQR] 8-18), 64% were male, 58% were White, and 43% were Hispanic/Latinx. Most (67%) were tested in outpatient settings and 58% were asymptomatic. The median time to two negative tests was 42 days (IQR 25.0-55.0), with no differences in median time by illness presentation or level of immunosuppression. Seven children had more than one sample available for repeat testing, and five of seven (71%) children had initial C_T values of <30 (moderate to high viral load); four children had C_T values of <30, 3-4 weeks later, suggesting persistent moderate to high viral loads.

Most ICC with SARS-CoV-2 infection had mild disease, with prolonged viral persistence >6 weeks and moderate to high viral load.