key: cord-0920384-65667aoa
authors: Dancer, Stephanie J.
title: Reducing the risk of COVID-19 transmission in hospitals: focus on additional infection control strategies
date: 2021-10-13
journal: Surgery (Oxf)
DOI: 10.1016/j.mpsur.2021.10.003
sha: 1a21d578561168ddf0164057a36f098b842bf44d
doc_id: 920384
cord_uid: 65667aoa

Hospitals under pressure from the COVID-19 pandemic have experienced an additional challenge due to clusters of hospital-acquired COVID-19 infection occurring on non-COVID-19 wards. These clusters have involved both staff and patients and compromise staffing, bed management and routine care, especially delivery of elective surgical procedures. They have also contributed towards the overall morbidity and mortality of the pandemic. COVID-19 infection rates are rising again, so it is important to consider implementing additional activities designed to impede transmission of SARS-CoV-2 in acute hospitals. These aim to protect staff, patients and visitors, and conserve safe and continued access for patients needing routine and emergency surgical interventions. Current infection prevention strategies include hand hygiene; patient and staff screening; surveillance; personal protective equipment; cohorting and isolation; and enhanced cleaning. Additional activities include restriction of staff and patient movement; COVID-19 pathways for wards, operating theatres and outpatient services; bathroom management; and ensuring fresh air in the absence of effective mechanical ventilation systems. Seasonal pressures and spread of more contagious and/or vaccine-tolerant variants will continue to disrupt routine and emergency care of non-COVID-19 patients, as well as increase the risk of COVID-19 infection for staff and patients. Supplementary practical and cost-effective actions to limit spread in hospitals are explored in this article.

The interruption of routine services has impacted on all specialties but especially elective surgery for a range of operations. In particular, waiting lists for cancer, cardiac and orthopaedic services have escalated and staff are struggling to resume normal services while dealing with the aftermath of the pandemic. Increased admissions of frail elderly patients for elective surgery offers a real challenge to busy hospitals also trying to prevent hospital-acquired infection.

SARS-CoV-2 is a novel virus and its major transmission pathways are still hotly debated.

Original guidance from the World Health Organisation (WHO) decreed droplet and fomite spread and excluded the possibility of airborne transmission outside the designated 1-2 metre zone. Since the virus has now been found in air far distant to affected patients, there has been a move to study both short and long-range spread of respiratory particles containing viable virus in hospital rooms. 2 Even normal speaking leads to airborne virus transmission in confined environments. If airborne spread enhances the risk of ward-based J o u r n a l P r e -p r o o f clusters of Covid-19, then current ventilation parameters in the healthcare environment require urgent review with the aim of reducing transmission between staff and patients as far as possible. 3 Given that the virus survives in air and on surfaces for hours, it is possible that transmission also occurs between people and contaminated surfaces. 4 Confirmation of effective preventive strategies has been impeded by technical difficulties with environmental sampling and viral culture. 5 SARS-Cov-2 is an enveloped RNA virus, which renders it particularly vulnerable to the usual methods of airborne capture. Both surface swabbing and tissue culture inoculation require highly specialised expertise and it is likely that reported environmental contamination and viability are a gross underestimate. 5 Matching genotypic strains between different environmental reservoirs and infected/colonised individuals would provide the evidence required to formulate effective infection prevention practices. 6 Unfortunately, much of what is advised at present is not supported by definitive proof. Therefore, infection prevention and control staff need to apply a package of procedures based on tried and tested principles until such time as new evidence is forthcoming.

This article summarises key components of infection prevention and control needed to reduce the risk of SARS-CoV-2 in hospitals, with more detailed focus on additional measures to protect routine clinical practices. While there is increasing emphasis on air exchange and quality in hospitals in the wake of this pandemic, there are ongoing issues that deserve further consideration, such as the risk of short range aerosol transmission in staff rooms, changing rooms, toilets and bathrooms. 7 The latter, in particular, has received little attention despite offering a potential transmission hub for all users. Other important actions include the safe management of operating theatres and outpatient clinics, and restricting staff and patient movement throughout the hospital. Table 1 shows the main components of current practices aimed at controlling COVID-19 in the healthcare environment. 6, [8] [9] [10] [11] [12] [13] These include the presence of an infection protection and control team (IP&C); staff and patient screening; ongoing surveillance; a managerial COVID-J o u r n a l P r e -p r o o f 19 risk-based strategy; emphasis on hand hygiene; isolation and cohorting of infected patients; surface and equipment cleaning/decontamination; personal protective equipment (PPE) including universal masking; and a staff vaccination programme. Despite implementing traditional IP&C activities, however, many hospitals have identified multiple outbreaks of healthcare-acquired clusters of SARS-CoV-2 infection among patients and staff. 1, 14 These have occurred on non-COVID-19 wards, which has entailed ward closures with consequent serious disruption of routine services. It is clear that usual IP&C practices are not sufficient to impede these clusters. Summarised below are some additional activities that could be implemented in order to reduce the risk of healthcare-acquired COVID-19

infection.

Hospital toilets and bathrooms may act as a contact hub point where healthcare transmission of SARS-CoV-2 occurs between users. 15 The mode of spread arises through three mechanisms: firstly, inhalation of faecal and/or urinary aerosol from an individual shedding SARS-CoV-2; secondly, airborne transmission of respiratory aerosols between users face-to-face or during short periods after use; and thirdly, from fomite transmission via frequent touch sites such as door handles, sink taps or toilet roll dispenser. Toilet facilities are often compact, inadequately ventilated, heavily used and subject to maintenance and cleaning issues. 15 In this respect, both patient and staff toilets could present a high risk of infection in the healthcare environment.

There are a number of activities aimed at reducing the potential transmission risk in toilets. with disposable paper towels rather than using air dryers. This is because automated hand dryers may encourage circulation and recirculation of contaminated air and/or fomites.

The cleaning frequency for toilet and hand touch sites in the bathroom can be increased, especially if heavily used. This is because the risk of acquisition is directly proportional to the frequency of touch. Cleaning staff should receive training in how to decontaminate a bathroom during an outbreak, as well as issued with all the requisite equipment and cleaning fluids to do the job. They also require training in self-protection, given the as yet unknown risk from toilet areas. All staff should be encouraged to report any maintenance or functional issues, especially blockages and/or flooding. Calls about malfunctioning or leaking toilets and sinks should be prioritised by Estates and/or plumbing personnel. 15 It may be possible to limit the number of users at any one time in multiple toilet bathrooms as well as ring-fence the time interval between users. This is especially important if the bathroom lacks windows or sufficient ingress of fresh air. While this helps to reduce droplet transmission by allowing infectious droplets to settle, it is unlikely to affect risks from aerosol transmission. 16 This is because the smallest virion carrying aerosols can remain airborne for several hours. One method for limiting users would be installation of an indicator at the entrance, e.g. a red/green light or sensor above the entrance to the bathroom. A green light permits entrance; a red light inhibits it. This system is currently employed by radiology departments to inhibit access during radiographic investigations. A simpler and cheaper way would be a notice on the door with user times, supported by a practical policy for the duration of non-use.

propping open doors to encourage air to circulate. The latter precludes designated fire doors and there should be no risk to privacy or security from inappropriate access. Not all toilets and bathrooms have windows, however, and some may also be used to change into/out of uniforms. It might be possible to leave doors (and any windows) open for short periods, along with managing additional 'trickle' or other type of vents, that may be present.

Kitchen-type extractor fans can be placed on the wall directly outside a poorly ventilated bathroom in non-clinical areas, to encourage egress of air towards the outside. 17 

A major risk for COVID-19 transmission is mask removal prior to eating and drinking. There is little that can be done for bed-bound patients in multi-bed bays other than improving the ventilation (see below), but a variety of measures could alleviate the risk for staff at leisure in staff rooms, offices and canteen. Staggering break times for staff is an option, with numbers per room allocated on a strict time basis. If windows are present in staff rooms, then opening these before break times can alleviate any lingering aerosol from prior Canteens and kitchens should mobilise window opening as far as possible, while recognising the need to conserve thermal energy during cold weather. There should be a hand hygiene station placed at each entry/exit, along with frequent cleaning of all hand-touch surfaces.

Again, staff numbers should be curtailed in order to allay crowding by use of a shift system if practicable. Visitors should be assigned a separate dining area from staff.

Staff changing rooms tend to be small and poorly ventilated and this represents an infection risk for healthcare personnel. Staff should retain or change their masks before changing into or out of uniforms and this merits provision of an appropriate clinical waste receptacle for discarded masks and any other disposable PPE. Dirty laundry bins should also be provided. boots and clogs should be stored appropriately and cleaned before and after use. Staff should never go home wearing used scrubs or uniforms (https://www.forbes.com/sites/joshuacohen/2020/04/05/wearing-medical-scrubs-inpublic-in-the-age-of-coronavirus/).

It is imperative to reduce staff and patient movement throughout the hospital, creating so called care bubbles wherever possible (https://www.nipcm.hps.scot.nhs.uk/scottish-covid-19-infection-prevention-and-control-addendum-for-acute-settings/#a2752). If patients are admitted through Accident & Emergency, they should be tested and accommodated in an admission or holding ward while waiting for COVID-19 test results. Transfer to another ward will depend on the result, although emergency intervention should not be withheld whatever their COVID-19 status. Elective patients should be tested directly before admission and sent straight to the appropriate ward if negative. Patients should not be transferred between wards unless their condition warrants immediate transfer, e.g. move to critical care. Patients needing specialist interventions, such as radiological investigations, should wear masks during transportation and visits staggered so that they do not have to wait in waiting areas and departments can be cleaned between patients.

Staff should stay on their base ward or department throughout their shift other than canteen visits. Meetings may be conducted electronically rather than face-to-face. Porters represent a critical work force responsible for patient and equipment transportation and must adopt safety measures to protect themselves and others. They should be issued with wipes and hand gels and asked to clean items such as wheelchairs between patient use. It .pdf). Visitors can be asked to wear a mask and provide a record of recent test results and/or a vaccination certificate. Lateral Flow (rapid antigen) kits can be stored on wards for immediate testing of individuals if required.

In order to protect elective surgical patients accessing outpatient clinics, it is advisable to create an elective pathway that minimises the risk of hospital-acquired COVID-19. This would comprise a separate entrance to outpatient and pre-admission/screening clinics, if geography permits, as well as temperature checks at presentation; managed waiting areas; masks; hand hygiene; and restricted entry, etc. Patients should attend alone unless a companion is required for vulnerability or mobility issues. To reduce the risk from overcrowding, patients may be asked to wait outside or in cars before their appointment slot. Low priority patients may be assessed by video call or telephone so that only those needing immediate care are required to attend the outpatient department. Point-of-care testing facilities can be set up in the clinic so that patients do not have to traverse the main hospital. These could also include preoperative screening, such as blood tests, ECG and certain radiological investigations, along with allocation of trained and administrative personnel assigned to outpatients. COVID-19 screening can be included if surgery is imminent or scheduled before a later admission date. Any patient requiring investigation in specialist departments, such as MRI scanning, should be invited to attend during periods designated solely for outpatients, subject to prior COVID-19 screening if possible.

It is important to nominate operating theatres for patients with a recent negative COVID-19 test, as opposed to patients with unknown COVID-19 status requiring emergency surgery. 18 Elective, day patients and in-patients can be tested in a timely fashion before planned surgery in order to minimise transmission risk in the theatre suite. Surgery should only be performed in a known positive patient if the benefits outweigh the risks from the higher mortality and pulmonary complications of COVID-19 alongside the usual surgical and anaesthetic risks. While all theatres should be subjected to routine ventilation monitoring and maintenance, those used for patients of unknown status should receive priority for regular review and upgrade if necessary. In particular, the requirement for filter testing and replacement have achieved much greater significance during the COVID-19 pandemic. 19 This is because SARS-CoV-2 has been isolated from air conditioning filters in the healthcare environment. There should also be an agreed time interval between each procedure in order to allow sufficient time for one complete air change in the entire operating theatre suite as well as targeted cleaning before the next operation. Equipment used for patients of unknown COVID-19 status may require additional cleaning attention, particularly items used for intubation and mechanical ventilation.

Day patients should be allocated their own waiting areas, theatre and recovery ward if possible, with independent access. 18 Keeping day surgery staff apart from those that care for in-patients is advised since day patients arriving from the community are more likely to have come into contact with the virus. This may be alleviated to some extent by testing within a 72-hour period before surgery but the risk of carriage is still greater than that from in-patients under constant review. All theatre, anaesthetic and allied portering staff should submit regular COVID-19 tests and change into their own clothes in designated changing facilities on completion of a shift. No one should return home in theatre scrubs or footwear. are not available to help clear potentially infectious particles. Initial studies suggest that HEPA units can be used to remove airborne contaminants in these areas. 23 The units should not replace appropriate PPE or N95 masks when aerosol-generating procedures are performed but, as an additional infection control intervention, they can decrease inhalation risk by reducing overall particle concentrations in small clinical rooms. There are other technologies, notably ceiling or upper room fixtures emitting ultra-violet (UV) light at wave lengths able to inactivate SARS-CoV-2. These products are marketed as non-toxic to humans in constant proximity. 24 As with HEPA units, however, UV fittings currently lack sufficient study and may be expensive to install and maintain.

The remainder of the hospital would also benefit from enhanced ingress of fresh air 25 Hesitant staff most frequently cite lack of information as the main factor in vaccine delay, which could be ameliorated by advertising and educational strategies managed by occupational health teams.

Ventilation aside, there are other relatively simple measures to ally COVID-19 risk in hospitals. Fitting lids to toilets is one example, but even the creation of a socially distanced waiting area, along with unidirectional pathway in an outpatient department provides a useful gesture towards risk reduction. Obviously, the presence of an on-site laboratory aids screening programmes as well as rapid identification of an infected individual in the hospital whether symptomatic or not. Managing staff and patient movement around the hospital should also be prioritised, since just one person could shed contaminated aerosol everywhere they go. High rates of patient boarding might be the single biggest risk for hospital transmission after inadequate ventilation.

Most of the cost-neutral recommendations suggested in this article could reduce the risk of further COVID-19 clusters, without compromising staff well-being or initiating concern. Such practices are not solely COVID-19 themed, however; they represent another layer of infection prevention that might also have an impact on other airborne pathogens such as influenza; respiratory viruses; norovirus; and Clostridiodes difficile (since the latter produces airborne spores which take 48 hours to settle). 22 MRSA, VRE and coliforms are also present in the air, and anything to improve indoor ventilation might conceivably help reduce the infection risks from these for everyone in healthcare environments.

The role of ventilation in indoor transmission of viruses has been on neglected for years. It has taken a pandemic to focus attention on airborne pathogens but now that it has, we should embrace the opportunity and explore all possibilities for better indoor quality air. 3, 7 Practice Points 

Hospital-acquired SARS-CoV-2 infection in the UK's first COVID-19 pandemic wave

Viable SARS-CoV-2 in the air of a hospital room with COVID-19 patients

How can airborne transmission of COVID-19 indoors be minimised?

Aerosol and surface contamination of SARS-CoV-2 observed in quarantine and isolation care

Dismantling myths on the airborne transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)

Applying prospective genomic surveillance to support investigation of hospital-onset COVID-19

Covid-19 has redefined airborne transmission

Epic3: national evidence-based guidelines for preventing healthcare-associated infections in NHS hospitals in England

Clinical utility of a rapid 'on-demand' laboratorybased SARS-CoV-2 diagnostic testing service in an acute hospital setting admitting COVID-19 patients

A Cross-Sectional Study on Knowledge, Attitude, and Practices of Donning and Doffing of Personal Protective Equipment: An Institutional Survey of Health-Care Staff during the COVID-19 Pandemic

A novel cohorting and isolation strategy for suspected COVID-19 cases during a pandemic

Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents

Effect of vaccination on transmission of COVID-19: an observational study in healthcare workers and their households

SARS-CoV-2 infection among health care workers despite the use of surgical masks and physical distancing-the role of airborne transmission

What is the risk of acquiring SARS-CoV-2 from the use of public toilets?

A Rosetta Stone for Understanding Infectious Drops and Aerosols

Fast-track ventilation strategy to cater for pandemic patient isolation surges

General surgery and COVID-19: review of practical recommendations in the first pandemic phase

Use of HEPA filters to reduce the risk of nosocomial spread of SARS-CoV-2 via operating theatre ventilation systems

Estimation of airborne viral emission: Quanta emission rate of SARS-CoV-2 for infection risk assessment

Outbreak of COVID-19 in a nursing home associated with aerosol transmission as a result of inadequate ventilation

Roles of sunlight and natural ventilation for controlling infection: historical and current perspectives

Evaluating and Contextualizing the Efficacy of Portable HEPA Filtration Units in Small Exam Rooms

Bare-bulb Upper-Room Germicidal Ultraviolet-C (GUV) Indoor Air Disinfection for COVID-19 †

Patient commentary: Protect patients like me-make covid vaccines mandatory for all eligible staff in care settings

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