Stability of SARS-CoV-2 on inanimate surfaces: A review.

The stability of SARS-CoV-2 for varying periods on a wide range of inanimate surfaces has raised concerns about surface transmission; however, there is still no evidence to confirm this route. In the present review, three variables affecting virus stability, namely temperature, relative humidity (RH), and initial virus titer, were considered from different experimental studies. The stability of SARS-CoV-2 on the surfaces of six different contact materials, namely plastic, metal, glass, protective equipment, paper, and fabric, and the factors affecting half-life period was systematically reviewed. The results showed that the half-life of SARS-CoV-2 on different contact materials was generally 2-10 h, up to 5 d, and as short as 30 min at 22 °C, whereas the half-life of SARS-CoV-2 on non-porous surfaces was generally 5-9 h d, up to 3 d, and as short as 4 min at 22 â„ƒ. The half-life on porous surfaces was generally 1-5 h, up to 2 d, and as short as 13 min at 22 °C. Therefore, the half-life period of SARS-CoV-2 on non-porous surfaces is longer than that on porous surfaces, and thehalf-life of the virus decreases with increasing temperature, whereas RH produces a stable negative inhibitory effect only in a specific humidity range. Various disinfection precautions can be implemented in daily life depending on the stability of SARS-CoV-2 on different surfaces to interrupt virus transmission, prevent COVID-19 infections, and avoid over-disinfection. Owing to the more stringent control of conditions in laboratory studies and the lack of evidence of transmission through surfaces in the real world, it is difficult to provide strong evidence for the efficiency of transmission of the contaminant from the surface to the human body. Therefore, we suggest that future research should focus on exploring the systematic study of the entire transmission process of the virus, which will provide a theoretical basis for optimizing global outbreak prevention and control measures.

Real-life lack of evidence of viable SARS-CoV-2 transmission via inanimate surfaces: The SURFACE study.

INTRODUCTION: Although the potential role of inanimate surfaces in SARS-CoV-2 transmission has yet to be adequately assessed, it is still routine practice to apply deep and expensive environmental disinfection protocols. The aim of this study was to verify the presence of viable virus on different surfaces exposed to droplets released by coughing in SARS-CoV-2 RNA positive patients. METHODS: Patients admitted to hospital with a positive SARS-CoV-2 real-time (RT)-PCR swab were asked to cough on steel, cardboard, plastic and their hands. Surfaces were tested at baseline (T0) and at different timepoints thereafter using swabs dipped in medium, and quickly seeded on VERO E6 cells that were checked every other day for cytopathic effect (CPE). Laboratory-propagated SARS-CoV-2 strains were examined at the same time points and on identical materials. RESULTS: Ten RNA-positive patients were enrolled into the study. The median cycle threshold value was 20.7 (range 13-28.3). Nasopharyngeal swabs from 3 of the patients yielded viable virus 2-10 days post-inoculation. However, in none of the patients was it possible to isolate viable SARS-CoV-2 from sputum under identical experimental conditions. A CPE was instead already visible using laboratory-propagated SARS-CoV-2 strains at 20', 60', 180' while an effect at 24 h required a 6-day incubation. CONCLUSION: The evidence emerging from this real-life study suggests that droplets delivered by SARS-CoV-2 infected patients on common inanimate surfaces did not contain viable virus. In contrast, and in line with several laboratory-based experiments, in vitro adapted viruses could survive and grow on the same fomites.

Inanimate Surfaces as a Source of Hospital Infections Caused by Fungi, Bacteria and Viruses with Particular Emphasis on SARS-CoV-2.

The carriers of nosocomial infections are the hands of medical personnel and inanimate surfaces. Both hands and surfaces may be contaminated as a result of contact with the patient, their body fluids, and touching contaminated surfaces in the patient's surroundings. Visually clean inanimate surfaces are an important source of pathogens. Microorganisms have properties thanks to which they can survive in unfavorable conditions, from a few days to several months. Bacteria, viruses and fungi are able to transmit from inanimate surfaces to the skin of the patient and the medical staff. These pathogens include SARS-CoV-2, which can survive on various types of inanimate surfaces, being a potential source of infection. By following the recommendations related to washing and disinfecting hands and surfaces, and using appropriate washing and disinfecting agents with a broad biocidal spectrum, high material compatibility and the shortest duration of action, we contribute to breaking the chain of nosocomial infections.

Environmental testing for SARS-CoV-2 in three tertiary-care hospitals during the peak of the third COVID-19 wave.

Contamination of surfaces has been implicated in transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We tested by real-time PCR for SARS-CoV-2 contamination environmental samples from three hospitals during the peak of the third pandemic wave. Overall, 19 of 463 (4.1%) samples tested positive: 12 of 173 (6.9%) samples from a COVID-19 hospital, 3 of 177 (1.7%) samples from a non-COVID-19 hospital, and 4 of 113 (3.5%) samples from a pediatric hospital with dedicated COVID-19 clinics. Most positive samples originated from emergency departments (EDs) (47.3%) and the intensive care units (ICUs) (26.3%) of the COVID-19 hospital. Positive samples belonged almost exclusively (18/19) to the highly transmissible B.1.1.7 cluster, that might explain environmental contamination at this stage of the pandemic. The frequency and efficiency of disinfection in high-risk patient areas, such as EDs and ICUs, should be reinforced, especially during this period where highly transmissible variants of concern are widespread.

A systematic review of human coronaviruses survival on environmental surfaces.

The current pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has led people to implement preventive measures, including surface disinfection and use of alcohol-based hand gel, in order to avoid viral transmission via fomites. However, the role of surface transmission is still debated. The present systematic review aims to summarize all the evidence on surface survival of coronaviruses infecting humans. The analysis of 18 studies showed the longest coronavirus survival time is 28 days at room temperature (RT) on different surfaces: polymer banknotes, vinyl, steel, glass, and paper banknotes. Concerning SARS-CoV-2 human infection from contaminated surfaces, dangerous viral load on surfaces for up to 21 days was determined on polymer banknotes, steel, glass and paper banknotes. For viruses other than SARS-CoV-2, the longest period of survival was 14 days, recorded on glass. Environmental conditions can affect virus survival, and indeed, low temperatures and low humidity support prolonged survival of viruses on contaminated surfaces independently of surface type. Furthermore, it has been shown that exposure to sunlight significantly reduces the risk of surface transmission. Although studies are increasingly investigating the topic of coronavirus survival, it is difficult to compare them, given the methodology differences. For this reason, it is advisable to define a reference working protocol for virus survival trials, but, as an immediate measure, there is also a need for further investigations of coronavirus survival on surfaces.

Contamination of inert surfaces by SARS-CoV-2: Persistence, stability and infectivity. A review.

Undoubtedly, there is a tremendous concern regarding the new viral strain "Severe Acute Respiratory Syndrome Coronavirus-2" (SARS-CoV-2) and its related disease known as COVID-19. The World Health Organization has stated that SARS-CoV-2 is mainly transmitted from person-to-person close contact, as well as by small aerosol respiratory droplets. Moreover, the results of some recent studies about the role of air pollution on the spread and lethality of the novel coronavirus suggest that air contaminants could be also a transmission pathway of the virus. On the other hand, indirect transmission of the virus cannot be discarded. Among many sources of indirect transmission, there is the contamination of inert/inanimate surfaces. This manuscript was aimed at reviewing the scientific literature currently available in PubMed and Scopus. The results of the reviewed studies point out that SARS-CoV-2 can last on different surfaces from hours to a few days. However, rapid SARS-CoV-2 inactivation is possible by applying commonly available chemicals and biocides on inanimate surfaces. Consequently, although the presence of SARS-CoV-2 on inanimate surfaces can represent a potential route of transmission, appropriate disinfection measures should reduce the possibilities of coronavirus transmission, and hence, significantly decrease the risks of COVID-19.

Stability of SARS-CoV-2 and other coronaviruses in the environment and on common touch surfaces and the influence of climatic conditions: A review.

Although the unprecedented efforts the world has been taking to control the spread of the human coronavirus disease (COVID-19) and its causative aetiology [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)], the number of confirmed cases has been increasing drastically. Therefore, there is an urgent need for devising more efficient preventive measures, to limit the spread of the infection until an effective treatment or vaccine is available. The preventive measures depend mainly on the understanding of the transmission routes of this virus, its environmental stability, and its persistence on common touch surfaces. Due to the very limited knowledge about SARS-CoV-2, we can speculate its stability in the light of previous studies conducted on other human and animal coronaviruses. In this review, we present the available data on the stability of coronaviruses (CoVs), including SARS-CoV-2, from previous reports to help understand its environmental survival. According to available data, possible airborne transmission of SARS-CoV-2 has been suggested. SARS-CoV-2 and other human and animal CoVs have remarkably short persistence on copper, latex and surfaces with low porosity as compared to other surfaces like stainless steel, plastics, glass and highly porous fabrics. It has also been reported that SARS-CoV-2 is associated with diarrhoea and that it is shed in the faeces of COVID-19 patients. Some CoVs show persistence in human excrement, sewage and waters for a few days. These findings suggest a possible risk of faecal-oral, foodborne and waterborne transmission of SARS-CoV-2 in developing countries that often use sewage-polluted waters in irrigation and have poor water treatment systems. CoVs survive longer in the environment at lower temperatures and lower relative humidity. It has been suggested that large numbers of COVID-19 cases are associated with cold and dry climates in temperate regions of the world and that seasonality of the virus spread is suspected.

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

Currently, the emergence of a novel human coronavirus, SARS-CoV-2, has become a global health concern causing severe respiratory tract infections in humans. Human-to-human transmissions have been described with incubation times between 2-10 days, facilitating its spread via droplets, contaminated hands or surfaces. We therefore reviewed the literature on all available information about the persistence of human and veterinary coronaviruses on inanimate surfaces as well as inactivation strategies with biocidal agents used for chemical disinfection, e.g. in healthcare facilities. The analysis of 22 studies reveals that human coronaviruses such as Severe Acute Respiratory Syndrome (SARS) coronavirus, Middle East Respiratory Syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV) can persist on inanimate surfaces like metal, glass or plastic for up to 9 days, but can be efficiently inactivated by surface disinfection procedures with 62-71% ethanol, 0.5% hydrogen peroxide or 0.1% sodium hypochlorite within 1 minute. Other biocidal agents such as 0.05-0.2% benzalkonium chloride or 0.02% chlorhexidine digluconate are less effective. As no specific therapies are available for SARS-CoV-2, early containment and prevention of further spread will be crucial to stop the ongoing outbreak and to control this novel infectious thread.

Potential role of inanimate surfaces for the spread of coronaviruses and their inactivation with disinfectant agents.

The novel human coronavirus SARS-CoV-2 has become a global health concern causing severe respiratory tract infections in humans. Human-to-human transmissions have been described, probably via droplets but possibly also via contaminated hands or surfaces. In a recent review on the persistence of human and veterinary coronaviruses on inanimate surfaces it was shown that human coronaviruses such as Severe Acute Respiratory Syndrome (SARS) coronavirus, Middle East Respiratory Syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV) can persist on inanimate surfaces like metal, glass or plastic for up to 9 days. Some disinfectant agents effectively reduce coronavirus infectivity within 1 minute such 62%-71% ethanol, 0.5% hydrogen peroxide or 0.1% sodium hypochlorite. Other compounds such as 0.05%-0.2% benzalkonium chloride or 0.02% chlorhexidine digluconate are less effective. An effective surface disinfection may help to ensure an early containment and prevention of further viral spread.