key: cord-0853839-gq9mfztv
authors: Gray, Simon; Clough, Toni; Mcgee, Yvonne; Murphy, Tracey; Donne, Rosemary; Poulikakos, Dimitrios
title: Occupational exposure of healthcare workers to COVID-19 and infection prevention control measures in haemodialysis facilities in North West of England.
date: 2021-06-05
journal: Infection prevention in practice
DOI: 10.1016/j.infpip.2021.100150
sha: 0a4f5c5cb210ca62b2a0be53b79695378791b4b6
doc_id: 853839
cord_uid: gq9mfztv

COVID-19 infection rates in haemodialysis (HD) facilities are extremely high and are attributed to the high burden of comorbidities of HD patients coupled with inability to self-isolate needing thrice weekly attendance for HD treatment. Healthcare workers (HCW) in HD facilities are at risk of occupational exposure to COVID-19. Infection prevention control (IPC) measures were introduced during the pandemic aiming at reducing transmission and occupational exposure risk of COVID-19. Here we describe the results of our baseline and follow up occupational exposure audit in a renal centre in the North West of England following the implementation of a multifaceted IPC bundle.

Healthcare workers (HCW) involved in patient facing activities, and in particular those caring for patients suffering from COVID-19, are at increased risk of COVID-19 infection exposure based on data from the first wave of the pandemic in the UK (1) . HD facilities are high risk areas of transmission of COVID-19. Patients receiving in centre HD have suffered from high infection and mortality rates from COVID-19 due to being both clinically extremely vulnerable due to comorbidities and unable to self-isolate having to attend HD facilities for thrice weekly life-sustaining dialysis treatment. By August 2020 11.7% (2339 patients) of the total in centre HD population in England had suffered from COVID-19 and 2.6 % (538 patients) had died (2) . Isolation, treatment and infection control policy (IPC) pathways were developed rapidly to minimise the risk of COVID-19 transmission in HD units, effectively isolate, provide HD treatment to COVID-19 infected patients and decrease the risk of occupational exposure to HCW.

Renal departments reconfigured their services to establish designated COVID-19 areas and assigned dedicated nursing workforce for the treatment of suspected or confirmed cases for COVID-19. The risk of patient to staff transmission of COVID-19 in these designated areas J o u r n a l P r e -p r o o f is related to necessary staff to patient interaction during HD treatment. Initiating HD treatment often requires close proximity with the patient's airways especially when connecting, manipulating or disconnecting a tunnelled dialysis neck line or placing and removing dialysis needles on upper arm arteriovenous fistulas or grafts. HD patients also often present with cough and shortness of breath due to fluid overload thus increasing the risk of aerosol generation in the context of COVID-19 infection (3) .

We previously reported the results of an audit of occupational exposure in our haemodialysis (HD) services in North West of England, showing increased risk of COVID-19 in healthcare workers (HCW) in direct contact with COVID-19 infected patients (4) during the first wave of the pandemic. Following this audit we established a quality improvement project implementing a bundle of IPC measures aiming at minimising COVID-19 transmission in patients and staff in the HD units. Here we present the evolution of the response to the pandemic and our follow up audit at the peak of the second wave of the pandemic in our region that provides reassurance about the effectiveness of the IPC bundle.

The setting and results of our initial audit have been previously reported (4). Our department was caring for 402 HD patients dialysing in one main and 4 satellite HD units at the beginning of the pandemic. In brief, during the first wave of the pandemic we designated the main hospital HD unit for isolation and HD treatment of patients with suspected or confirmed COVID-19. The designated COVID-19 unit was covered by a dedicated nursing team of 26 HCW and two satellite units (A and B) were supported by 48 HCWs caring for 232 patients.

In the remaining two satellite units the nursing staff are managed by our industry partner, we do not have access to occupational exposure data and they were not included in the audit.

Nursing staff were not allowed to move between COVID-19 positive and negative units from J o u r n a l P r e -p r o o f 4 19 th March until 29 th June 2020 when our HD programme was reconfigured. During this initial period selected HD patients were switched to twice weekly HD treatment to reduce the risk of exposure (5) . Following the reconfiguration in June 2020, the vast majority of HD patients returned to thrice weekly treatment and the main unit was segregated into a completely spatially separated COVID-19 designated area and a COVID free area to repatriate patients who originally dialysed in the main unit.

All patients were screened for symptoms before entering the HD units. Symptomatic subjects or patients sharing the same household with COVID-19 cases were transferred directly to the designated COVID-19 unit where they underwent COVID-19 RT-PCR nasopharyngeal swab (NP RT-PCR), medical assessment and HD treatment. Patients who tested positive or where deemed to be close household contacts continued to dialyse at the designated unit for a minimum period of 2 weeks and were de-isolated after a negative NP RT-PCR. Symptomatic patients with negative NP RT-PCR on admission to the designated COVID-19 zone underwent a second NP RT-PCR on the subsequent dialysis session and if it was also negative they could be de-isolated following medical review.

Public Health England PPE guidance (6) was followed for staff caring for suspected and confirmed COVID-19 cases entailing surgical masks, plastic aprons, protective eyewear and gloves and there were no shortages in PPE supplies. Surgical masks for all HD patients and the universal use of the above level of PPE for HCW in dialysis units irrespective of COVID-19 status of patients was implemented following Renal Association guidance on 5 April 2020 J o u r n a l P r e -p r o o f (7) . Use of face masks for all HCW in non-clinical areas was introduced 9 June 2020. In addition, since 2 April 2020 enhanced PPE (FFP3 and long sleeved gowns) was used when obtaining NP RT-PCR. Testing with NP RT-PCR for symptomatic HCWs not requiring hospital admission was introduced on 30 March 2020. Prior to this date symptomatic HCWs were advised to self-isolate for 7 days. Timeline of IPC interventions is depicted in Figure 1 .

Occupational exposure data for HCW were retrieved by the divisional absence record and information in relation to contacts, result of NP RT-PCR and lateral flow antigen testing were obtained from the HCW by the line managers.

Data regarding the status of patients dialysed in the COVID-19 designated area were obtained from the COVID-19 designated zone database that has been updated on a weekly basis by TC. Data were confirmed against information included in the electronic patient record data by SG.

During this period 52 symptomatic HD patients who tested positive by NP RT-PCR, 66 symptomatic HD patients who tested negative, 38 HD patients with close contact out of whom one subsequently tested positive by NP RT-PCR and six patients with COVID-19 induced AKI post ICU discharge were dialysed in the designated COVID-19 unit. (Table 1) . 

In June 2020 we established a quality improvement project aiming at minimising COVID-19 transmission in HD units. A quality improvement project team was formed including all dialysis unit managers, HD Consultants, representatives from the hospital Infection Control team, administrative team and quality improvement team. The group was meeting at weekly intervals from 9/06/2020 until 14/7/2020 when the frequency was reduced to fortnightly up to date. The main drivers of the project evaluated at each meeting were the following: 7. Surveillance screening with NP RT-PCR on a fortnightly basis since 7 September 2020 that increased to weekly from 14 th December.

Qualitative Test) for HCW twice weekly implemented 26 November 2020.

Implementation timeline of diagnostics and IPC measures for COVID-19 is depicted in Figure 1 .

In total in the second wave 304 HD patients were dialysed in the designated COVID-19 area from 01/07/2020 until 04/02/21 (Table 1) (Table 1 ).There were four asymptomatic HCW with positive lateral flow tests that where not confirmed with NP RT-PCR (false positives) ( Table 1 ).

The results of the occupational audit show that the implementation of the IPC bundle has been effective in minimising exposure to COVID-19 in HCW deployed in the COVID-19 designated areas. In addition, none of the HCW diagnosed with COVID-19 during the second wave in the satellite units required hospitalisation possibly reflecting decreased viral loads at the time of transmission due to the embedded IPC protocols.

The results also highlight the usefulness of routine surveillance lateral flow antigen testing for COVID-19 for HCW for early detection and isolation of positive HCW cases. All positive cases following the introduction of surveillance with lateral flow testing where detected promptly at home with the lateral flow antigen point of care devices.

Routine screening with NP RT-PCR for asymptomatic HD patients identified 55 cases who were promptly isolated underscoring the value of surveillance NP RT-PCR testing to reduce risk of transmission in HD facilities.

The limitations of this study include the lack of antibody data for HCW to evaluate occupational exposure not detected via NP RT-PCR especially during the first wave of the pandemic when testing capacity was limited. The infection rates in the two groups of HCW during the second wave cannot be directly compared due to the likely presence of relative protection to reinfection in 16% (six out of 37) of HCW working in the COVID-19 unit due to previous infection during the first wave. It was also not possible to estimate the relative potential contribution of staff to staff transmission during the initial period when surgical face mask wearing was not mandatory at all times in hospitals. Despite these limitations, are results provide reassurance that the implementation of the IPC bundle has been effective in minimising occupational exposure to COVID-19.

By 10 th February 2021 81% of our total in centre HD cohort and 74% of HD nurses has received the first dose of COVID-19 vaccination. However, due to lack of data at this point in 

This is an occupational exposure audit following a quality improvement project that did not require ethical approval or informed consent from patients. 

Covid-19: risks to healthcare workers and their families

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