Antibodies and antigen kinetics in patients with COVID-19 (preprint)

The antigen and antibody kinetics of SARS-CoV-2 infected patients remains unclear, and the clinical values of the serological test have not been completely elucidated. A total of 154 serum samples from 13 patients with COVID-19 infection were collected at about three-day intervals during hospitalization. Samples were screened for SARS-CoV-2-specific total antibodies (TAb), IgA, IgM, IgG, and antigen (Ag) using chemiluminescent microparticle immunoassays (CMIA). The overall seroconversion and/or four-fold increase rates of TAb, IgA, IgM, and IgG during hospitalization were 92.31%, 92.31%, 84.62%, and 92.31%, respectively. However, within a week of onset, antibodies were present in <50% of the patients. The combination of “Ag and/or TAb” maintained the positive rate at 81.82% during the first three days after symptom onset and quickly enhanced to 92.31% during 4–6 days after the symptom onset. The seropositive median day of Ag was two days after symptom onset. Among patients who underwent IgM and IgG seroconversion, the seroconversion median days of IgA, TAb, IgM, and IgG were 9.5 days, 10 days, 11 days, and 11.5 days after the symptom onset, respectively. Serological testing, especially virus-specific antigen testing, may be helpful for early identification of suspected patients and asymptomatic infections.

The strategies of perioperative management in orthopedic department during the pandemic of COVID-19 (preprint)

Background: Coronavirus disease 2019 (COVID-19) broken out and spread rapidly nationwide at the beginning of 2020, which has brought huge impacts to people and work. The current situation of prevention and control is severe and urge guidance for clinicians, especially for medical systems. In the hope of providing a reference and recommendation for the prevention and control of the COVID-19, we carried out research to improve the quality of patients care and prevention during this epidemic. Methods: : All of the staff were trained rapidly to master personal protection in our department. We reviewed the patients’ discharged records who underwent surgery in our department during January 1st to March 1st in 2019 and January 1st to March 1st in 2020. The managements of the surgery patients and flow charts were described and analyzed. Post-operation outcomes of the patients including duration, complications, surgical site infection (SSI), system infection, re-operation, and mortality. Both chi-squared test and Student’s t-test were performed to determine the relationship between the two periods in term of post-operation outcomes. Results: : Descriptive statistics analysis revealed that demographic of the patients between the two periods is similar. We had been benefited from the strict flow charts, smart robot and protection equipment in management of perioperative for orthopedic patients. With the help of the strict flow charts and smart equipment, post-operation outcomes of the patients revealed that the rates of the complications and re-operation had been reduced significantly ( p ＜0.05), while duration of operation, SSI and system infection had no significantly difference between two periods ( p ＞0.05). No patient and staff caught COVID-19 infection or mortality during the epidemic. Conclusions: : Our study indicated that medical quality and efficiency were affected little with the help of strategies described above during the epidemic, which could be a reference tool for medical staff in routine clinical practice for admission of patients around the world. What’s more, the provided strategies, which may evolve over time, could be used as empirical guidance and reference for orthopedic peers to get through the pandemic and ensure the normal operation of the hospital.