Coronavirus disease 2019 (COVID-19) epidemic is still spreading rapidly around the world. Recent cases with prolonged detection of SARS-CoV-2 RNA have been successively reported and the phenomenon of false-negative real-time polymerase chain reaction (RT-PCR) results of SARS-CoV-2 RNA or “repositive” was also described in patients with COVID-19.
A 69-year-old female with hypertension, total hysterectomy for hysteromyoma and suspected lung tumor presented with moderate COVID-19 symptoms was testing positive for SARS-CoV-2 RNA by RT-PCR when she travelled from USA to China. The patient required second and third re-hospitalization due to repositive SARS-CoV-2 test results of throat swaps during post-charge solitary isolation and observation. The serum SARS-CoV-2-IgG decayed rapidly and disappeared on illness day 139 when the throat swab was still positive for SARS-CoV-2 RNA. Finally the virus shedding lasted at least146 days (the last positive test result of throat swap on illness day 146 and the first true-negative test result on illness day 151) from her initial positive test.
Prolonged viral shedding of SARS-CoV RNA is prone to occur in an immunocompromised host. With the change of host immune status, SARS-CoV-2 detection can be repeatedly positive. The SARS-CoV-2-IgG may decrease rapidly and disappear before the virus removal, indicating there may be certain limitations on the protective effect of antibody against SARS-CoV-2 which deserves attention of clinicians.