Follow-up testing of viral nucleic acids in patients with COVID-19 in Dazu district, Chongqing, China

ABSTRACT

To investigate the recurrence rate of coronavirus disease 2019(COVID-19) after discharge and type of SARS-CoV-Z nucleic acid-positive samples from patients with recurrence of SARS-CoV-Z in Dazu District, Chongqing, China, all patients were kept in isolation for 14 days, then quarantined at home for 4 weeks after discharge, during which time nasopharyngeal swabs, oropharyngeal swabs, feces, saliva, and urine were collected to test for SARS-CoV-Z nucleic acids by RT-PCR, and symptoms and signs were documented. Results showed that there were no symptoms or signs during isolation for any patient. However, specimens from three patients were confirmed positive for SARS-CoV-Z nucleic acids 3 to 14 days after discharge. SARS- CoV-Z nucleic acids were detected in saliva samples from two patients with recurrence of SARS-CoV-Z. The present study suggested that there is a relatively high incidence of positive tests for SARS-CoV-Z nucleic acids in patients after discharge. This is the first time that SARS-CoV-Z nucleic acids were detected in saliva samples. Whether the virus is infectious in these patients requires further study.