Ultraviolet-C Irradiation, Heat, and Storage as Potential Methods of Inactivating SARS-CoV-2 and Bacterial Pathogens on Filtering Facepiece Respirators

End-user acceptability of personal protective equipment disinfection for potential reuse: a survey of health-care workers in Aotearoa New Zealand

BACKGROUND

The COVID-19 pandemic has highlighted personal protective equipment (PPE) supply, distribution, and disposal issues worldwide. Calls to conserve PPE stocks and increase supply resulted in the rapid development of potential disinfection methods, with the possibility of improvements in medical waste reduction. However, how receptive health-care workers are to PPE reuse remains unknown. We aimed to examine the views of health-care workers who used PPE during the first COVID-19 wave in Aotearoa New Zealand, in relation to acceptability of PPE disinfection and reuse.

METHODS

In this multi-methods survey, health-care workers in New Zealand, were invited via a multimodal recruitment strategy to complete a survey regarding use of PPE during the first COVID-19 wave. Gender question options were male, female, gender diverse, or prefer not to say. Demographic differences in self-reported PPE reuse and acceptability were examined. The survey included closed (single-response, multi-response, ranking, and Likert-scale questions) and open-text questions. Any open-text comments were analysed with thematic analysis. The survey was built and deployed using Qualtrics software.

FINDINGS

1411 health-care workers completed the survey between Oct 7 and Nov 30, 2020. 1397 participants had gender data available (1140 [82%] female and 257 [18%] male) and 995 (74%) of 1347 were of New Zealand European ethnicity. PPE reuse was common and reported by 628 (45%) of the 1411 participants, with 396 (63%) of the 628 reporting reusing PPE multiple times in 1 day. Acceptability of the concept of PPE disinfection for potential reuse was high overall (1196 [85%] of 1411) but varied depending on the type of PPE. Thematic analysis confirmed that PPE reuse was already occurring and respondents recognised the potential benefits of reduced medical wastage and increased PPE supply. Important caveats for consideration included the availability of scientific evidence, level of negotiated risk, and trust in the organisation undertaking PPE disinfection, with clear communication about decontamination processes being crucial to acceptability.

INTERPRETATION

PPE reuse occurred frequently during the first wave of COVID-19 in New Zealand. Although support for the disinfection of PPE for reuse was high, the success of any future programmes to reuse PPE will require meaningful engagement and clear communication with health-care workers. Further research into PPE disinfection safety and logistics is warranted, alongside the development of standard operating procedures and clearly communicated policies for the end user, should this more sustainable health-care practice be planned for adoption in certain settings.

FUNDING

New Zealand Ministry of Business, Innovation and Employment (COVID-19 Innovation Acceleration Fund) and the Medical Assurance Society Foundation.

Efficacy of Dry Heat Treatment against Clostridioides difficile Spores and Mycobacterium tuberculosis on Filtering Facepiece Respirators

The COVID-19 pandemic has required novel solutions, including heat disinfection of personal protective equipment (PPE) for potential reuse to ensure availability for healthcare and other frontline workers. Understanding the efficacy of such methods on pathogens other than SARS-CoV-2 that may be present on PPE in healthcare settings is key to worker safety, as some pathogenic bacteria are more heat resistant than SARS-CoV-2. We assessed the efficacy of dry heat treatment against Clostridioides difficile spores and Mycobacterium tuberculosis (M. tb) on filtering facepiece respirator (FFR) coupons in two inoculums. Soil load (mimicking respiratory secretions) and deionized water was used for C. difficile, whereas, soil load and PBS and Tween mixture was used for M. tb. Dry heat treatment at 85 °C for 240 min resulted in a reduction equivalent to 6.0-log10 CFU and 7.3-log10 CFU in C. difficile spores inoculated in soil load and deionized water, respectively. Conversely, treatment at 75 °C for 240 min led to 4.6-log10 CFU reductions in both soil load and deionized water. C. difficile inactivation was higher by >1.5-log10 CFU in deionized water as compared to soil load (p < 0.0001), indicating the latter has a protective effect on bacterial spore inactivation at 85 °C. For M. tb, heat treatment at 75 °C for 90 min and 85 °C for 30 min led to 8-log10 reduction with or without soil load. Heat treatment near the estimated maximal operating temperatures of FFR materials (which would readily eliminate SARS-CoV-2) did not achieve complete inactivation of C. difficile spores but was successful against M. tb. The clinical relevance of surviving C. difficile spores when subjected to heat treatment remains unclear. Given this, any disinfection method of PPE for potential reuse must ensure the discarding of any PPE, potentially contaminated with C. difficile spores, to ensure the safety of healthcare workers.

COVID-19 Pandemic: New Prevention and Protection Measures

As of the end of February 2021, more than 420,000,000 confirmed cases of COVID-19 have been reported worldwide, with 5,856,224 deaths. Transmission of the different genetically engineered variants of SARS-CoV-2, which have been isolated since the beginning of the pandemic, occurs from one infected person to another by the same means: the airborne route, indirect contact, and occasionally the fecal–oral route. Infection is asymptomatic or may present with flulike symptoms such as fever, cough, and mild to moderate and severe respiratory distress, requiring hospitalization and assisted ventilation support. To control the spread of COVID-19, the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) have indicated that the appropriate use of personal protective equipment (PPE), as well as the adoption of effective hygiene systems, is one of the primary prevention measures for the entire population. Companies and institutions around the world are therefore trying to find the best ways to reorganize their operations, minimizing the risk of infection among their employees, in order to protect their health and prevent internal outbreaks of SARS-CoV-2, including through the development of new technologies that could also be an innovative and driving factor for the relaunch of companies in a more sustainable, ethically correct, and safe for the health of employees perspective. On the basis of the above premises, in view of the coexistence with SARS-CoV-2 that will most likely accompany us in the coming years, and in view of the vaccination campaign adopted worldwide, the purpose of our narrative review is to update the previous operational protocols with the latest scientific knowledge to be adopted in the workplace even when the emergency crisis is over.