Evaluation of R-FIND SARS-CoV-2 Neutralizing Antibody ELISA and FREND COVID-19 SP Rapid Fluorescence Immunoassay.

BACKGROUND: Serology testing is useful to determine the past infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: We evaluated the comparative performance of a newly developed neutralizing antibody test (R-FIND SARS-CoV-2 Neutralizing Antibody ELISA, SG Medical, Seoul, Korea) and a rapid fluorescence immunoassay (FREND™ COVID-19 SP, NanoEntek, Hwaseong, Korea) for the detection of SARS-CoV-2 spike protein antibody. They were compared with cPass™ SARS-CoV-2 Neutralization Antibody Detection Kit (Genscript Biotech, Piscataway, NJ, USA) and ADVIA Centaur SARS-CoV-2 Total (COV2T) (Siemens Healthineers, Erlangen, Germany). Forty COVID-19 samples and 80 negative samples were collected after nucleic acid tests. RESULTS: The positive percent agreement (%) of the kit in samples from 6 - 7 days, 8 - 14 days, and 15 - 45 days after symptom onset were as follows: R-FIND (83.3, 76.9, 95.2), cPass (83.3, 69.2, 90.5), FREND (66.6, 84.6, 100), and COV2T (66.6, 69.2, 76.2). The negative percent agreement (%) was 100, 97.5, 92.5, and 100 for R-FIND, cPass, FREND, and COV2T. The total agreement rate between the neutralizing antibody kits (R-FIND and cPass) was 96.7%. FREND showed high agreement with two neutralizing antibody kits (96.7% for R-FIND and 93.3% for cPass). CONCLUSIONS: R-FIND Neutralizing Antibody and FREND COVID-19 SP showed comparable detecting ability to commercial tests.

Increased Healthcare Delays in Tuberculosis Patients During the First Wave of COVID-19 Pandemic in Korea: A Nationwide Cross-Sectional Study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic caused disruptions to healthcare systems, consequently endangering tuberculosis (TB) control. We investigated delays in TB treatment among notified patients during the first wave of the COVID-19 pandemic in Korea. METHODS: We systemically collected and analyzed data from the Korea TB cohort database from January to May 2020. Groups were categorized as 'before-pandemic' and 'during-pandemic' based on TB notification period. Presentation delay was defined as the period between initial onset of symptoms and the first hospital visit, and healthcare delay as the period between the first hospital visit and anti-TB treatment initiation. A multivariate logistic regression analysis was performed to evaluate factors associated with delays in TB treatment. RESULTS: Proportion of presentation delay > 14 days was not significantly different between two groups (48.3% vs. 43.7%, P = 0.067); however, proportion of healthcare delay > 5 days was significantly higher in the during-pandemic group (48.6% vs. 42.3%, P = 0.012). In multivariate analysis, the during-pandemic group was significantly associated with healthcare delay > 5 days (adjusted odds ratio = 0.884, 95% confidence interval = 0.715-1.094). CONCLUSION: The COVID-19 pandemic was associated with healthcare delay of > 5 days in Korea. Public health interventions are necessary to minimize the pandemic's impact on the national TB control project.

Impact of COVID-19 Pandemic on the National PPM Tuberculosis Control Project in Korea: the Korean PPM Monitoring Database between July 2019 and June 2020.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic caused disruptions to healthcare systems and endangered the control and prevention of tuberculosis (TB). We investigated the nationwide effects of COVID-19 on the national Public-Private Mix (PPM) TB control project in Korea, using monitoring indicators from the Korean PPM monitoring database. METHODS: The Korean PPM monitoring database includes data from patients registered at PPM hospitals throughout the country. Data of six monitoring indicators for active TB cases updated between July 2019 and June 2020 were collected. The data of each cohort throughout the country and in Daegu-Gyeongbuk, Seoul Metropolitan Area, and Jeonnam-Jeonbuk were collated to provide nationwide data. The data were compared using the χ² test for trend to evaluate quarterly trends of each monitoring indicator at the national level and in the prespecified regions. RESULTS: Test coverages of sputum smear (P = 0.622) and culture (P = 0.815), drug susceptibility test (P = 0.750), and adherence rate to initial standard treatment (P = 0.901) at the national level were not significantly different during the study period. The rate of loss to follow-up among TB cases at the national level was not significantly different (P = 0.088); however, the treatment success rate among the smear-positive drug-susceptible pulmonary TB cohort at the national level significantly decreased, from 90.6% to 84.1% (P < 0.001). Treatment success rate in the Seoul metropolitan area also significantly decreased during the study period, from 89.4% to 84.5% (P = 0.006). CONCLUSION: Our study showed that initial TB management during the COVID-19 pandemic was properly administered under the PPM project in Korea. However, our study cannot confirm or conclude a decreased treatment success rate after the COVID-19 pandemic due to limited data.