Persistent viral RNA positivity during the recovery period of a patient with SARS-CoV-2 infection

Abstract

As an emerging infectious disease, the clinical course and virological course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remain to be further investigated. In this case report, we described a case of SARS-CoV-2 infection with the clinical course for more than 2 months. This patient had recovered from pneumonia after treatment. The viral RNA of throat swabs became negative and the viral-specific antibodies were produced during the recovery period. However, the viral RNA reappeared and additionally persisted in throat swabs for more than 40 days. In addition, the viral RNA was detected in multiple types of specimens with extremely high titers in the saliva. In conclusion, these findings indicate that SARS-CoV-2 can cause a long clinical course. The coexistence of viral RNA and viral-specific antibodies may imply an immune evasion of SARS-CoV-2 from the host's immune system.

Keywords: SARS-CoV-2; coronavirus; saliva; virus shedding.

Figure 1

The virological course of SARS‐CoV‐2 infection in the patient. The curve presents the changes in throat swab viral RNA. To visually reflect the relative quantification of viral RNA, the cycle threshold (C _t, red points) values showed on the curve were converted according to the equation of log₂ (40 − x), x = C _t value. The C _t of 40 is the lower limit of detection on the RT‐qPCR assay. The red‐dash line describes putative changes in viral RNA before detection. The last two dictions of throat swab were reported as qualitative analyses (positive) in another hospital. The symptoms and main therapies are listed under the timeline. The time points of CT scan are labeled as blue arrows. CT, computed tomography; IgG, immunoglobulin G; IgM, immunoglobulin M; RT‐qPCR, reverse‐transcription quantitative polymerase chain reaction; SARS‐CoV‐2, severe acute respiratory syndrome coronavirus 2