Biosafety risk assessment and risk control of clinical laboratory in designated hospitals for treating COVID-19 in Chongqing, China.

BACKGROUND: If a nucleic acid preservation solution containing viral inactivators is used, the biosafety risk in the process of detecting the nucleic acid of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will be low. Patients infected with SARS-CoV-2 are sent to designated hospitals for treatment in China, except for detecting nucleic acid of SARS-CoV-2, other laboratory tests such as bacterial culture may also be carried out while the patients are being treated. However, in addition to nucleic acid testing, biosafety risks in the testing of these items for patients with coronavirus disease 2019 (COVID-19) might be ignored. Therefore, we identified and evaluated risks in these detection processes and formulated appropriate, but not excessive control measures for biosafety risk, to improve the work efficiency and prevent biosafety accidents. METHODS: Biosafety risks in all laboratory tests for COVID-19 patients were identified and evaluated according to the risk severity and occurrence probability. Subsequently, the corresponding control measures for biosafety risk were formulated according to the identified risk. Hereafter, risk monitoring was carried out. RESULTS: More than 32 risks in the entire laboratory testing process were identified and evaluated, and the residual risk after the implementation of the control measures was acceptable. CONCLUSIONS: The biosafety risk assessment of laboratories in designated hospitals for treating COVID-19 should be re-implemented before testing specimens for COVID-19 patients. Risk management by risk monitoring is even more important, as it can prevent the occurrence of biosafety incidents and can continuously improve risk management.

Antibody responses to SARS-CoV-2 in patients with COVID-19.

We report acute antibody responses to SARS-CoV-2 in 285 patients with COVID-19. Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion. Serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections.