Are Standard COVID-19 Isolation Protocols Appropriate in Haemodialysis Units? A Description of a Novel SARSCoV-2 Coronavirus Outbreak in a Haemodialysis Unit in Johannesburg, South Africa

Background: Recipients of outpatient haemodialysis are at an increased risk of acquiring severe SARS-CoV-2 infection. Isolation of infected patients reduces in-centre transmission, but protocols extrapolated from the general population may not be applicable in this setting. We describe the kinetics of an outbreak in a tertiary dialysis centre in Johannesburg, South Africa, to suggest an appropriate isolation strategy. Methods: Retrospective analysis of a clinical database employed to facilitate isolation of exposed and infected patients was undertaken. Modes of transmission, incubation and recovery periods in patients developing SARS-CoV-2 infection were assessed. The effects of factors modulating immune function on incubation and recovery periods were modelled using sigma-restricted partial least squares linear regression. Severity of infection and the outcomes thereof were described to assess the efficacy of the isolation protocols employed. Results: SARS-CoV-2 infection was diagnosed in 24.7% of patients receiving outpatient haemodialysis. Contact with an infected healthcare worker was the leading indication for surveillance swabbing in this cohort (49.12%). Forty per cent of all positive cases had antecedent contact with an infected healthcare worker, and possible patient-to-patient transmission occurred in one case. The median time to the diagnosis of infection following known exposure was 16.5 days. Comorbid diabetes and increasing dialysis vintage were associated with a shorter incubation period. The median time to clearance of infection was 33.5 days. The clinical disease severity prolonged the recovery period. No patient required mechanical ventilation, and there were no deaths during the study period. Conclusion: Haemodialysis patients manifest prolonged incubation and recovery periods. Serial monitoring with RT-PCR swabs may be required to ensure effective isolation.