COVID-19 Rapid Antigen Test Screening in Patients on Hemodialysis

Gaetano Alfano; Roberta Scarmignan; Niccolò Morisi; Francesco Fontana; Silvia Giovanella; Giulia Ligabue; Laura Rofrano; William Gennari; Monica Pecorari; Mariacristina Gregorini; Gianni Cappelli; Riccardo Magistroni; Gabriele Donati

doi:10.1155/2022/4678717

COVID-19 Rapid Antigen Test Screening in Patients on Hemodialysis

Int J Nephrol. 2022 Sep 14:2022:4678717. doi: 10.1155/2022/4678717. eCollection 2022.

Authors

Affiliations

¹ Nephrology, Dialysis and Transplant Unit, University Hospital of Modena, Modena, Italy.
² Surgical, Medical and Dental Department of Morphological Sciences, Section of Nephrology, University of Modena and Reggio Emilia, Via Del Pozzo 71, Modena 41124, Italy.
³ Clinical and Experimental Medicine Program, University of Modena and Reggio Emilia, Via Del Pozzo 71, Modena 41124, Italy.
⁴ Clinical Microbiology Unit, University Hospital of Modena, Modena, Italy.
⁵ Molecular Microbiology and Virology Unit, Department of Laboratory Medicine and Pathological Anatomy, Azienda Ospedaliero Universitaria di Modena, Modena, Italy.
⁶ Nephrology and Dialysis, AUSL-IRCCS Reggio Emilia, Reggio Emilia, Italy.

Abstract

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 15^th to December 26^th, 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.