Infection control

Clostridioides difficile infection (CDI) is the main healthcare acquired infection (HCAI) in the US. It is responsible for 14,000 deaths and an attributable cost of $4.8 billion in excess healthcare facilities. CDI is easily spread as even a very low infectious dose can transmit the infection. Disposable personal protective equipment (PPE) are recommended for use with CDI patients to prevent transmission in healthcare centres.

Aerosol generating procedures associated with C. difficile, such as toilet flushing, bedpan washing and other housekeeping activities, may result in cross-contamination. The article examines air sampling equipment in their effectiveness of testing for airborne C. difficile spores.

A major way to reduce aerosol generation of C. difficile spores is to follow best practice guidelines in human waste management. This may include individual patient toileting facilities and effective linen washing. Bedpan management systems should also minimise aerosol generation. One-way systems reduce the risk of steam generation of C. difficile spores because bedpans are immediately eliminated in a secured, enclosed appliance. 

Further Reading

Cooper, Casey et al., “Comparison and Evaluation of a High Volume Air Sampling System for the collection of Clostridioides difficile Endospore Aerosol in Healthcare Environments” American Journal of Infection Control. April 22, 2020. https://doi.org/10.1016/j.ajic.2020.04.014.

The Amoy Gardens SARS outbreak is an important lesson in our current response to COVID-19. SARS-CoV was the first identified severe acute respiratory syndrome coronavirus and is therefore important in understanding the current coronavirus (SARS-CoV-2). Amoy Gardens is a high-rise, densely populated housing estate in Hong Kong that became a site of the second major outbreak of the SARS virus (the first being at the Prince of Wales Hospital). A man infected with SARS and presenting with diarrhoea symptoms is believed to be the source of the outbreak in Amoy Gardens. Rapid spread to other residents is believed to have happened through defective plumbing and sewage systems which released aerosols infected with the SARS virus around the complex through ventilation systems in the building. 73% of Amoy Gardens patients presented with diarrhoea, compared to 20% in the Prince of Wales Hospital. The mortality rate for Amoy Gardens patients was also significantly higher at 13%, compared to 3% in the Prince of Wales Hospital.

So, what does this mean in the current struggle COVID-19 pandemic?

Clinical studies have found positive SARS-CoV-2 RNA in stool in up to 53.42% of patients and has continued to test positive for up to 33 days after negative respiratory samples (Gastroenterology, The Lancet). Many studies have therefore warned of a fecal-oral transmission route of SARS-CoV-19.

Aerosolization of contaminated faeces was a major reason for spread of SARS in Amoy Gardens. Studies have shown a bedpan washer-disinfector failure rate of up to 33%, and the release of steam when washing could present a serious infection control risk if contaminated with the virus. This puts care homes and hospitals at a particularly high-risk of disease spread. Even if patients are not presenting respiratory symptoms, or there are effective measures in place to prevent respiratory spread, fecal aerosolization could spread the virus as happened with SARS in Amoy Gardens.

How can we prevent spread of COVID-19 through aerosols from bedpan washer-disinfectors?

Best-practice guidelines released by the WHO advocate the use of single-use devices with COVID-19 patients. Hospitals and care homes should therefore exclusively use single-use, or one-way, processes with COVID-19 patients to reduce risk of transmission.

References

Wu, Yongjian; Guo, Cheng; Tang, Lantian; Hong, Zhongsi; Zhou, Jianhui; Dong, Xin. “Prolonged presence of SARS-CoV-2 viral RNA in faecal samples”, The Lancet, March 19, 2020. https://doi.org/10.1016/S2468-1253(20)30083-2.

Xiao F, Tang M, Zheng X, Liu Y, Li X, Shan H. “Evidence for Gastrointestinal Infection of SARS-CoV-2”. Gastroenterology. 2020;S0016-5085(20)30282-1. doi:10.1053/j.gastro.2020.02.055

Jessica Hamzelou. “How long does coronavirus stay on surfaces and can they infect you?” New Scientist. 25 March 2020. https://www.newscientist.com/article/2238494-how-long-does-coronavirus-stay-on-surfaces-and-can-they-infect-you/

“Severe Acute Respiratory Syndrome (SARS) - multi-country outbreak - Update 33” World Health Organisation. 18 April 2003. https://www.who.int/csr/don/2003_04_18/en/

S S C Chim, S K W Tsui, K C A Chan et al. “Genomic characterisation of the severe acute respiratory syndrome coronavirus of Amoy Gardens outbreak in Hong Kong” The Lancet 362, 939

What kind of PPE do you wear in ICU?

It depends what we are doing and on the patient. In the ICU ward, we have ‘clean’ zones and ‘dirty’ zones. The clean zone is the nurse’s station and areas over two metres from patients’ beds. In this area we wear surgical face masks, plastic aprons, and gloves.

What do you wear in the ‘dirty’ zones in ICU?

Full PPE is required when seeing patients in ‘dirty’ zones of the ICU. This includes: surgical gowns, an FFP3 respirator, eye protection, two layers of gloves and arm gauntlets. Donning and doffing are carried out according to Public Health England guidelines and is carried out in designated areas.

What do you do with used PPE?

All ‘clean’ zone PPE is single-use and directly disposed of in infectious waste bins. When doffing full PPE from the ‘dirty’ zone, the gloves, respirator and gauntlets is also disposed of in infectious waste bins. Surgical gowns are placed in an alginate bag (a bag for infectious laundry) and then inside a laundry bag in a box by the patient’s bed. Eye protection (goggles or glasses) are directly placed in disinfectant, and are cleaned before re-use

Are there any ways you feel you could reduce infection pathway risks related to PPE?

Public Health England recommend using long gloves (up to elbow level), however due to shortages we are currently using surgical gloves and gauntlets. Using long gloves would remove a stage in our donning and doffing process and therefore secure an infection pathway.

Where possible, our trust sources single-use PPE as it is easier, safer and more reliable than disinfecting reusables.

How have you been affected by PPE shortages?

Fortunately, our hospital does not have the shortage problems that are reported in others in the country – we have sufficient PPE to safely provide treatment. There is more careful distribution of PPE than before the outbreak of COVID-19, but this is mainly to ensure reliable access to equipment.

National guidelines advise that patients with suspected or confirmed COVID-19 should be isolated from others where possible to reduce the transmission of the virus. Health authorities have advocated that single-use personal protective equipment (PPE) be disposed of immediately after use. PPE comes into contact with high-risk droplets, therefore it is safer and easier to dispose of rather than attempt to clean.

The WHO has advocated that a one-way process should be applied to medical devices such as stethoscopes, blood pressure cuffs and thermometers. This means that they should be single use where possible and disposed of after contact with a patient. As medical devices, bedpans should also be disposed of after use.

For centres which usually wash bedpans between patients, single-use alternatives could be used in the interim. These could be disposed after use, but this can cause problems such as smells, overfilling and infection control risks in the event of breakages. Bedpan macerators are available as rental options for short-medium term use, and are a good option for care homes wishing to provide best-practice infection control in their centres.

We have been informed by Haigh Engineering that they have availability of rental and purchase options for care homes.

References

World Health Organisation. Interim Guidance: “Infection prevention and control during health care when COVID-19 is suspected”. 19 March 2020.

Gov UK Guidance, “Transmission characteristics and principles of infection prevention and control”, updated 6 April 2020. https://www.gov.uk/government/publications/wuhan-novel-coronavirus-infection-prevention-and-control/transmission-characteristics-and-principles-of-infection-prevention-and-control#survival-in-the-environment