First considerations on the SARS-CoV-2 epidemic in the Dialysis Units of Piedmont and Aosta Valley, Northern Italy

This paper describes the epidemiological data about the first month of SARS-CoV2 pandemic among the patients in renal replacement therapy and the operators of the Piedmont and Aosta Valley nephrology units. The prevalence of SARS-CoV-2 positivity was the same in RRT patients and nephrology staff: 2.2%. This is much higher than the rates for the general population in Piedmont and Aosta Valley (7782 subjects affected by SARS-CoV-2, i.e., 0.17% of the population), with an odds ratio of 13.43, 95% CI 11.27 to 16.00; z score p < 0.0001 for RRT patients, and of 12.80 (95% CI 8.67 to 18.89; z score p < 0.0001) for staff. Of these patients, 74.6% have been hospitalised. Being under RRT did not preclude per se admission to the intensive care unit (ICU). However, the incidence of ICU admission was higher in transplanted than dialysis patients, presumably due to lower comorbidity burden that favoured accessibility to intensive care. Anyway, the difference was not statistically significant (20.8% vs 8.2%; z-score p = 0.086). The death rate was 24.6%, much higher than that observed in the whole SARS-CoV-2-positive population of the same area in the same period (8.19%; 637 deaths in 7,782 confirmed subjects affected by SARS-CoV-2). The Odds Ratio for death in RRT patients vs the general population was 3.80 (95% CI: 2.53 to 5.72; z score, p < 0.0001).