ABSTRACT
Nucleic acid testing and antibody testing data from 143 recovered COVID-19 patients during the convalescent phase were retrospectively analyzed. A total of 23 (16.1%) recovered patients re-tested positive for SARS-CoV-2 RNA by RT-PCR. Three months after symptom onset, 100% and 99.3% of the patients remained positive for total and IgG antibodies, and the antibody levels remained high. IgM antibodies declined rapidly, with a median time to seroconversion of 67 (95% CI: 59, 75) days after onset. Approximately 25% of patients were seronegative for IgA antibodies at three months after onset. There was no statistically significant difference in antibody kinetics between patients with and without re-positive RT-PCR results during the convalescent phase.
Subject(s)
Antibodies, Viral/blood , COVID-19/immunology , Convalescence , SARS-CoV-2/immunology , Adult , COVID-19/diagnosis , COVID-19 Testing , Female , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Kinetics , Male , Middle Aged , RNA, Viral/genetics , Retrospective Studies , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , SeroconversionABSTRACT
Objectives: Research on recovering COVID-19 patients could be helpful for containing the pandemic and developing vaccines, but we still do not know much about the clinical features, recovery process, and antibody reactions during the recovery period. Methods: We retrospectively analysed the epidemiological information, discharge summaries, and laboratory results of 324 patients. Results: In all, 15 (8.62%) patients experienced chest distress/breath shortness, where 8 of the 15 were severely ill. This means severely ill patients need an extended amount of time to recover after discharge; next, 20 (11.49%) patients experienced anxiety and 21 (12.07%) had headache/insomnia and a small fraction of them complained of anosmia/ageusia, indicating that these patients need treatment for mental and psychological health issues. Regarding the re-positive patients, their CT and laboratory test results showed no obvious evidence of illness progress or infectivity but a high anti-SARS-CoV-2 antibody expression. Conclusion: Recovered COVID-19 patients need psychological and physiological care and treatment, re-positivity can occur in any person, but juveniles, females, and patients with mild/moderate existing symptoms have higher rates of re-positivity, While there is no evidence that turning re-positive has an impact on their infectivity, but it still alerted us that we need differentiate them in the following managements.