Background and Objectives: Seroprevalence estimation of COVID-19 is quite necessary for controlling the transmission of SARS-CoV-2 infection. Seroprevalence rate in recovered COVID-19 patients help us to identify individual with anti-SARS-CoV-2 antibodies and its protective nature. The objective of present study was to evaluate seroprevalence of SARS-CoV-2 among potential convalescent plasma donors and analysis of their deferral reasons. Materials and Methods: A total 400 potential convalescent plasma donors were enrolled over five-month period for this prospective study. Inclusion criteria were lab confirmed COVID-19 recovered patients and 14 days of symptoms free period. All prospective plasmapheresis donors were tested for IgG SARS-CoV-2 antibody through chemiluminescent microparticle immunoassay, CBC, serum protein, blood grouping along with other required test for normal blood donation as per Drugs & Cosmetics Act. After pre donation testing and medical examination if donor was found to be ineligible for plasmapheresis was deferred. Seroprevalence rate was calculated by positive IgG antibody test results among the potential plasma donors. Results: Seroprevalence rate was 87% for IgG SARS-CoV-2 antibodies in prospective convalescent plasma donors (recovered COVID-19 patients). There was no significant difference in seroprevalence rate between different sub-groups with respect to gender, age, blood groups, Rh factor, mode of treatment, day of Ab testing and repeat plasma donation. Most common reason for their deferral was absent IgG SARS-CoV-2 antibodies (13%) followed by absenteeism of eligible screen donors (6.7%), low Hb (1.7%) and poor veins for plasmapheresis (1.7%). Till five-month study period none of the plasmapheresis develop symptoms of reinfection with COVID-19. Conclusion: 13% recovered patients did not develop IgG antibodies after SARS-CoV-2 infection. SARS-CoV-2 IgG antibodies persist for quite some time and are protective against reinfection. More long-term serology studies are needed to understand better antibody response kinetics and duration of persistence of IgG antibodies.

Background and Objectives: An increasing prevalence of sexually transmitted infections especially Syphilis in blood donors may lead to increased donor deferrals and lessen the donor pool. Hence it is the need of the hour to device a structured screening methodology for Syphilis reactive donors. The aim of the study is to estimate the prevalence of syphilis in blood donors and to estimate the response rate of notified blood donors. Patients and Methods: This was a retrospective study, conducted in a Blood Centre (BC) on the blood donors visiting for donation from January 2020 to September 2021. The donors screened positive on chemiluminescence immunoassay were included after informed consent was obtained, and donor demographics and follow-up response rate were analyzed. Frequency and percentages were used to express descriptive statistics and Chi-square was used to test the relationship between categories (p<0.05 considered significant). Results: Out of 26,698 donations during the study period, 133 donors were screened positive for syphilis. 127 (96%) donors consented to postdonation. Out of 127, only 61 were notified regarding the infection and were advised about further followup. 52% of the donors who consented to postdonation counseling were not notified due to erroneous contact details. Out of 46 responders, only 17 underwent further testing. Conclusions: The prevalence rate of syphilis was found to be 0.49%. Among the donors notified, 75% responded back to the BC. Due to social stigma and inadequate knowledge about the disease, often, donors are hesitant to give a reliable exposure history. Adequate education and adapting to a structured screening methodology is the need of the hour to reduce the risk of transfusion-transmitted syphilis.