key: cord-0948721-34vyocgr authors: Sexton, Donal J.; O’Connor, Patrick; McBrearty, Eileen; Mellotte, George title: The impact of a national surgical mask wearing policy on COVID-19 transmission in Haemodialysis units in the Republic of Ireland. date: 2021-01-01 journal: Kidney Int Rep DOI: 10.1016/j.ekir.2020.12.031 sha: 6cd8def9a6473939422aab0426cf267883481698 doc_id: 948721 cord_uid: 34vyocgr nan In late 2019 a novel betacoronavirus named SARS-CoV-2 was reported in China, and subsequently spread rapidly to cause a global pandemic. 1 SARS-CoV-2 is primarily spread through respiratory droplets typically released by coughing, sneezing, breathing or speaking and may be aerosolized by singing, ventilation or the use of nebulisers. 1 The most common symptoms of COVID-19 infection include fever, cough, fatigue, anorexia, myalgia and diarrhoea, 2 however severe illness occurs in a subset of individuals and usually begins approximately 1 week after the onset of symptoms. 2 Dialysis patients were requested to wear these surgical masks prior to arriving at the dialysis unit and to continue wearing the masks throughout the entire time in the dialysis unit. In addition eating on dialysis was not permitted to limit time without masking, and healthcare workers were instructed to wear surgical masks at all times while in clinical areas. We questioned whether the introduction of universal surgical mask wearing in all dialysis units nationally was associated with a decline in COVID-19 transmission in dialysis patients in Ireland. There was a significant net slope change after the period of mask policy introduction. Median positivity rate in the pre-intervention period was 0.16% (IQR 0.15%), and 0.10% (0.05%) in the post intervention period (after mask introduction) P=0.02 (Figure 1) . Results were not different while accounting for a lag effect of 5 to 7 days following the interventon dates for either intervention. Forecasting suggested a projected static COVID-19 positive case rate for the period following April 7 th 2020. It would appear that the introduction of universal mask policy altered this projected course since cases fell in the intervention period defined by national universal masking in dialysis units rather than being static. Results were not different while accounting for a lag effect of 5 to 7 days following he interventon dates for either intervention. At the time of writing there is now emerging evidence from multiple studies worldwide that wearing facemasks does indeed appear to curb the spread of COVID-19. 7 However there are few reports pertaining to the application of surgical mask wearing policies to the specific environment of the haemodialysis unit. In Ireland, the NRO, mandated a national policy of surgical face mask wearing by patients and healthcare staff in all dialysis units nationwide on April 7 th 2020. This was due to cognizance that dialysis patients were vulnerable to complications from COVID-19 infection and also evidence from Italy of possible transmission from dialysis units out into the community. 3, 4 In addition, dialysis patients could not shelter in place due to the fact that they must attend the dialysis unit three times per week often while sharing transport with other dialysis patients. Our study design precludes the identification of definitive causal relationships. While, it appears as though the COVID-19 case rate declined progressively after the introduction of a mandatory surgical mask wearing policy in HD units nationwide we cannot conclude this definitively and it is possible that other factors may have also contributed. Our reported trends were consistent while also accounting for a two weeks Frequency count represents total number of cases per day from 17/03/2020 onward. Based on case count prior to the surgical mask policy, forecasting suggested a relatively static case count. Mild or Moderate Covid-19 Severe Covid-19 Presentation and Outcomes of Patients with ESKD and COVID-19 Outcomes of patients with end-stage kidney disease hospitalized with COVID-19 Spread of SARS-CoV-2 in the Icelandic Population Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis "Supplementary information is available at KI Report's website."