Viral Inactivation with Emphasis on SARS-CoV-2 Using Physical and Chemical Disinfectants.

BACKGROUND: Recently, an outbreak of a novel human coronavirus SARS-CoV-2 has become a world health concern leading to severe respiratory tract infections in humans. Virus transmission occurs through person-to-person contact, respiratory droplets, and contaminated hands or surfaces. Accordingly, we aim at reviewing the literature on all information available about the persistence of coronaviruses, including human and animal coronaviruses, on inanimate surfaces and inactivation strategies with biocides employed for chemical and physical disinfection. METHOD: A comprehensive search was systematically conducted in main databases from 1998 to 2020 to identify various viral disinfectants associated with HCoV and methods for control and prevention of this newly emerged virus. RESULTS: The analysis of 62 studies shows that human coronaviruses such as severe acute respiratory syndrome (SARS) coronavirus, Middle East respiratory syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV), canine coronavirus (CCV), transmissible gastroenteritis virus (TGEV), and mouse hepatitis virus (MHV) can be efficiently inactivated by physical and chemical disinfectants at different concentrations (70, 80, 85, and 95%) of 2-propanol (70 and 80%) in less than or equal to 60 s and 0.5% hydrogen peroxide or 0.1% sodium hypochlorite within 1 minute. Additionally, glutaraldehyde (0.5-2%), formaldehyde (0.7-1%), and povidone-iodine (0.1-0.75%) could readily inactivate coronaviruses. Moreover, dry heat at 56°C, ultraviolet light dose of 0.2 to 140 J/cm2, and gamma irradiation could effectively inactivate coronavirus. The WHO recommends the use of 0.1% sodium hypochlorite solution or an ethanol-based disinfectant with an ethanol concentration between 62% and 71%. CONCLUSION: The results of the present study can help researchers, policymakers, health decision makers, and people perceive and take the correct measures to control and prevent further transmission of COVID-19. Prevention and decontamination will be the main ways to stop the ongoing outbreak of COVID-19.

Neutralisation of SARS-CoV-2 by anatomical embalming solutions.

Teaching and learning anatomy by using human cadaveric specimens has been a foundation of medical and biomedical teaching for hundreds of years. Therefore, the majority of institutions that teach topographical anatomy rely on body donation programmes to provide specimens for both undergraduate and postgraduate teaching of gross anatomy. The COVID-19 pandemic has posed an unprecedented challenge to anatomy teaching because of the suspension of donor acceptance at most institutions. This was largely due to concerns about the potential transmissibility of the SARS-CoV-2 virus and the absence of data about the ability of embalming solutions to neutralise the virus. Twenty embalming solutions commonly used in institutions in the United Kingdom and Ireland were tested for their ability to neutralise SARS-CoV-2, using an established cytotoxicity assay. All embalming solutions tested neutralised SARS-CoV-2, with the majority of solutions being effective at high-working dilutions. These results suggest that successful embalming with the tested solutions can neutralise the SARS-CoV-2 virus, thereby facilitating the safe resumption of body donation programmes and cadaveric anatomy teaching.

Can ketone bodies inactivate coronavirus spike protein? The potential of biocidal agents against SARS-CoV-2.

Biocidal agents such as formaldehyde and glutaraldehyde are able to inactivate several coronaviruses including SARS-CoV-2. In this article, an insight into one mechanism for the inactivation of these viruses by those two agents is presented, based on analysis of previous observations during electron microscopic examination of several members of the orthocoronavirinae subfamily, including the new virus SARS-CoV-2. This inactivation is proposed to occur through Schiff base reaction-induced conformational changes in the spike glycoprotein leading to its disruption or breakage, which can prevent binding of the virus to cellular receptors. Also, a new prophylactic and therapeutic measure against SARS-CoV-2 using acetoacetate is proposed, suggesting that it could similarly break the viral spike through Schiff base reaction with lysines of the spike protein. This measure needs to be confirmed experimentally before consideration. In addition, a new line of research is proposed to help find a broad-spectrum antivirus against several members of this subfamily.

Decontamination of filtering facepiece respirators using a low-temperature-steam-2%-formaldehyde sterilization process during a pandemic: a safe alternative for re-use.

BACKGROUND: The coronavirus disease 2019 pandemic has caused problems with respirator supplies. Re-use may minimize the impact of the shortage, but requires the availability of an efficient and safe decontamination method. AIM: To determine whether low-temperature-steam-2%-formaldehyde (LTSF) sterilization is effective, preserves the properties of filtering facepiece (FFP) respirators and allows safe re-use. METHODS: Fourteen unused FFP2, FFP3 and N95 respirator models were subjected to two cycles of decontamination cycles. After the second cycle, each model was inspected visually and accumulated residual formaldehyde levels were analysed according to EN 14180. After one and two decontamination cycles, the fit factor (FF) of each model was tested, and penetration tests with sodium chloride aerosols were performed on five models. FINDINGS: Decontamination physically altered three of the 14 models. All of the residual formaldehyde values were below the permissible threshold. Irregular decreases and increases in FF were observed after each decontamination cycle. In the sodium chloride aerosol penetration test, three models obtained equivalent or superior results to those of the FFP classification with which they were marketed, both at baseline and after one and two cycles of decontamination, and two models had lower filtering capacity. CONCLUSION: One and two decontamination cycles using LTSF did not alter the structure of most (11/14) respirators tested, and did not degrade the fit or filtration capacity of any of the analysed respirators. The residual formaldehyde levels complied with EN 14180. This reprocessing method could be used in times of shortage of personal protective equipment.