COVID-19 Rapid Antigen Test Screening in Patients on Hemodialysis

• Published in: International journal of nephrology 2022-09, Vol.2022, p.4678717-5
• Main Authors: Alfano, Gaetano, Scarmignan, Roberta, Morisi, Niccolò, Fontana, Francesco, Giovanella, Silvia, Ligabue, Giulia, Rofrano, Laura, Gennari, William, Pecorari, Monica, Gregorini, Mariacristina, Cappelli, Gianni, Magistroni, Riccardo, Donati, Gabriele
• Format: Article
• Language: English
• Subjects: Analysis; Antigens; Asymptomatic; Coronaviruses; Cost analysis; COVID-19; COVID-19 diagnostic tests; Disease transmission; Health aspects; Hemodialysis; Infections; Medical tests; Patients; Severe acute respiratory syndrome coronavirus 2
• ISSN: 2090-214X; 2090-2158; 2090-2158
• DOI: 10.1155/2022/4678717

Introduction. Patients receiving in-center hemodialysis are extremely vulnerable to COVID-19. It is unclear if routine screening of asymptomatic hemodialysis patients is an effective strategy to prevent COVID-19 outbreaks within the dialysis unit. Methods. We conducted a retrospective analysis of in-center hemodialysis patients who underwent bimonthly COVID-19 rapid antigen test screening from February 15th to December 26th, 2021. Nasal rapid antigen testing was performed in all asymptomatic patients. All rapid antigen-positive tests were confirmed by RT-PCR nasopharyngeal swab. Besides universal rapid antigen screening, RT-PCR testing was conducted in all symptomatic patients and contacts of COVID-19 subjects. Results. Overall, 4079 rapid antigen tests were performed in 277 hemodialysis patients on chronic hemodialysis with a mean age of 68.4 ± 14.6 years. Thirty-eight (0.9%) rapid antigen tests resulted positive. Only five (13.8%) positive-rapid antigen tests were also positive by RT-PCR testing. During the same period, 219 patients regularly screened by rapid antigen tests bimonthly underwent 442 RT-PCR nasopharyngeal swabs for clinical reasons. RT-PCR testing yielded a positive result in 13 (5.9%) patients. The time elapsed between PCR and the negative-rapid antigen test was 7.7 ± 4.6 days (range 1.8–13.9 days). At the end of the follow-up, 6.4% of the population on in-center hemodialysis contracted COVID-19, and routine rapid antigen tests detected only 5 out of 18 (27.7%) COVID-19 cases. No outbreaks of COVID-19 were identified within the dialysis unit. Conclusion. Bimonthly rapid antigen screening led to the early diagnosis of COVID-19 in less than one-third of cases. The short incubation period of the new SARS-CoV-2 variants makes bimonthly test screening inadequate for an early diagnosis of COVID-19. More frequent tests are probably necessary to improve the utility of COVID-19 nasal rapid antigen test in patients on hemodialysis.