SARS-CoV-2 late shedding may be infectious between immunocompromised hosts.

Background: Immunocompromised patients shed SARS-CoV-2 for extended periods, but to our knowledge person-to-person transmission from late shedding has not been reported.

The Case: We present a case in which a COVID-19 patient infected another over 28 days after the patient's initial symptoms, past current guideline recommendations of 20 days for length of isolation in immunocompromised patients. Whole genome sequencing of their viruses was performed to ascertain the transmission.

Discussion: Severely immunocompromised patients, whose clearance of the virus is impaired, may remain infectious for extended periods. Caution should be taken particularly in hospital settings where lapses in isolation procedures might pose increased risk, especially to other immunocompromised patients.