麻豆传媒

Viable SARS-CoV-2 virus was detected in immunocompromised cancer patients with COVID-19 for up to two months after symptom onset, a small study found.

Out of 20 cancer patients with COVID-19 and suppressed immune function, three continued to shed culturable virus for more than 20 days, reported Mini Kamboj, MD, of Memorial Sloan Kettering Cancer Center in New York City, and colleagues.

One of these patients still had viable coronavirus isolated at day 61, Kamboj and colleagues wrote in a

"The current guidelines for COVID-19 isolation precautions may need to be revisited for immunocompromised patients," they wrote, adding that current CDC guidelines for this population "are based on limited data."

Indeed, these guidelines state that "persons with more severe to critical illness or severe immunocompromise after symptom onset." While shedding "detectable SARS-CoV-2 RNA" may continue for up to 3 months, the guidelines continue, the levels are "in ranges where replication-competent virus has not been reliably recovered and infectiousness is unlikely."

Kamboj and colleagues used cell cultures to detect viable virus in serially collected respiratory samples from 18 recipient cancer patients who received hematopoietic stem-cell transplants or CAR T-cell therapy, and two with lymphoma. Fifteen of the patients were receiving active treatment or chemotherapy. COVID-19 illness was severe in 11.

Viral RNA was detected for up to 78 days following onset of symptoms, and viable virus in 10 of 14 nasopharyngeal samples on the first day of laboratory testing. Three of five patients with follow-up samples grew virus in culture for more than 20 days (25, 26 and 61 days). These patients received either allogeneic hematopoietic stem-cell transplants or CAR T-cell therapy in the last 6 months and were seronegative for antibodies to viral nuclear protein.

Two of these patients had severe COVID-19 and received investigational treatments, Kamboj and colleagues noted.

Genomic analysis of viral RNA in patient samples showed no major changes over time, indicating that the study's "findings were consistent with persistent infection," the group said.

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