A comprehensive health effects assessment of the use of sanitizers and disinfectants during COVID-19 pandemic: a global survey.

COVID-19 has affected all aspects of human life so far. From the outset of the pandemic, preventing the spread of COVID-19 through the observance of health protocols, especially the use of sanitizers and disinfectants was given more attention. Despite the effectiveness of disinfection chemicals in controlling and preventing COVID-19, there are critical concerns about their adverse effects on human health. This study aims to assess the health effects of sanitizers and disinfectants on a global scale. A total of 91,056 participants from 154 countries participated in this cross-sectional study. Information on the use of sanitizers and disinfectants and health was collected using an electronic questionnaire, which was translated into 26 languages via web-based platforms. The findings of this study suggest that detergents, alcohol-based substances, and chlorinated compounds emerged as the most prevalent chemical agents compared to other sanitizers and disinfectants examined. Most frequently reported health issues include skin effects and respiratory effects. The Chi-square test showed a significant association between chlorinated compounds (sodium hypochlorite and per-chlorine) with all possible health effects under investigation (p-value <0.001). Examination of risk factors based on multivariate logistic regression analysis showed that alcohols and alcohols-based materials were associated with skin effects (OR, 1.98; 95%CI, 1.87-2.09), per-chlorine was associated with eye effects (OR, 1.83; 95%CI, 1.74-1.93), and highly likely with itching and throat irritation (OR, 2.00; 95%CI, 1.90-2.11). Furthermore, formaldehyde was associated with a higher prevalence of neurological effects (OR, 2.17; 95%CI, 1.92-2.44). Furthermore, formaldehyde was associated with a higher prevalence of neurological effects (OR, 2.17; 95%CI, 1.92-2.44). The use of sodium hypochlorite and per-chlorine also had a high chance of having respiratory effects. The findings of the current study suggest that health authorities need to implement more awareness programs about the side effects of using sanitizers and disinfectants during viral epidemics especially when they are used or overused.

Quaternary ammonium disinfectants and antiseptics: tolerance, resistance and potential impact on antibiotic resistance.

BACKGROUND: Due to the substantial increase in the use of disinfectants containing quaternary ammonion compounds (QACs) in healthcare and community settings during the COVID-19 pandemic, there is increased concern that heavy use might cause bacteria to develop resistance to QACs or contribute to antibiotic resistance. The purpose of this review is to briefly discuss the mechanisms of QAC tolerance and resistance, laboratory-based evidence of tolerance and resistance, their occurrence in healthcare and other real-world settings, and the possible impact of QAC use on antibiotic resistance. METHODS: A literature search was conducted using the PubMed database. The search was limited to English language articles dealing with tolerance or resistance to QACs present in disinfectants or antiseptics, and potential impact on antibiotic resistance. The review covered the period from 2000 to mid-Jan 2023. RESULTS: Mechanisms of QAC tolerance or resistance include innate bacterial cell wall structure, changes in cell membrane structure and function, efflux pumps, biofilm formation, and QAC degradation. In vitro studies have helped elucidate how bacteria can develop tolerance or resistance to QACs and antibiotics. While relatively uncommon, multiple episodes of contaminated in-use disinfectants and antiseptics, which are often due to inappropriate use of products, have caused outbreaks of healthcare-associated infections. Several studies have identified a correlation between benzalkonium chloride (BAC) tolerance and clinically-defined antibiotic resistance. The occurrence of mobile genetic determinants carrying multiple genes that encode for QAC or antibiotic tolerance raises the concern that widespread QAC use might facilitate the emergence of antibiotic resistance. Despite some evidence from laboratory-based studies, there is insufficient evidence in real-world settings to conclude that frequent use of QAC disinfectants and antiseptics has promoted widespread emergence of antibiotic resistance. CONCLUSIONS: Laboratory studies have identified multiple mechanisms by which bacteria can develop tolerance or resistance to QACs and antibiotics. De novo development of tolerance or resistance in real-world settings is uncommon. Increased attention to proper use of disinfectants is needed to prevent contamination of QAC disinfectants. Additional research is needed to answer many questions and concerns related to use of QAC disinfectants and their potential impact on antibiotic resistance.

Bleach Emissions Interact Substantially with Surgical and KN95 Mask Surfaces.

Mask wearing and bleach disinfectants became commonplace during the COVID-19 pandemic. Bleach generates toxic species including hypochlorous acid (HOCl), chlorine (Cl2), and chloramines. Their reaction with organic species can generate additional toxic compounds. To understand interactions between masks and bleach disinfection, bleach was injected into a ventilated chamber containing a manikin with a breathing system and wearing a surgical or KN95 mask. Concentrations inside the chamber and behind the mask were measured by a chemical ionization mass spectrometer (CIMS) and a Vocus proton transfer reaction mass spectrometer (Vocus PTRMS). HOCl, Cl2, and chloramines were observed during disinfection and concentrations inside the chamber are 2-20 times greater than those behind the mask, driven by losses to the mask surface. After bleach injection, many species decay more slowly behind the mask by a factor of 0.5-0.7 as they desorb or form on the mask. Mass transfer modeling confirms the transition of the mask from a sink during disinfection to a source persisting >4 h after disinfection. Humidifying the mask increases reactive formation of chloramines, likely related to uptake of ammonia and HOCl. These experiments indicate that masks are a source of chemical exposure after cleaning events occur.

Resolving the "health vs environment" dilemma with sustainable disinfection during the COVID-19 pandemic.

The overuse of disinfection during the COVID-19 pandemic leads to an emerging "health versus environment" dilemma that humans have to face. Irresponsible and unnecessary disinfection should be avoided, while comprehensive evaluation of the health and environmental impacts of different disinfectants is urgently needed. From this discussion, we reach a tentative conclusion that hydrogen peroxide is a green disinfectant. Its on-demand production enables a circular economy model to solve the storage issues. Water, oxygen, and electrons are the only feedstock to generate H2O2. Upon completion of disinfection, H2O2 is rapidly converted back into water and oxygen. This model adopts several principles of green chemistry to ensure overall sustainability along the three stages of its whole life cycle, i.e., production, disinfection, and decomposition. Physical methods, particularly UV irradiation, also provide sustainable disinfection with minimal health and environmental impacts.

Formation of Larger Molecular Weight Disinfection Byproducts from Acetaminophen in Chlorine Disinfection.

Acetaminophen is widely used to treat mild to moderate pain and to reduce fever. Under the worldwide COVID-19 pandemic, this over-the-counter pain reliever and fever reducer has been drastically consumed, which makes it even more abundant than ever in municipal wastewater and drinking water sources. Chlorine is the most widely used oxidant in drinking water disinfection, and chlorination generally causes the degradation of organic compounds, including acetaminophen. In this study, a new reaction pathway in the chlorination of acetaminophen, i.e., oxidative coupling reactions via acetaminophen radicals, was investigated both experimentally and computationally. Using an ultraperformance liquid chromatograph coupled to an electrospray ionization-triple quadrupole mass spectrometer, we detected over 20 polymeric products in chlorinated acetaminophen samples, some of which have structures similar to the legacy pollutants "polychlorinated biphenyls". Both C-C and C-O bonding products were found, and the corresponding bonding processes and kinetics were revealed by quantum chemical calculations. Based on the product confirmation and intrinsic reaction coordinate computations, a pathway for the formation of the polymeric products in the chlorination of acetaminophen was proposed. This study suggests that chlorination may cause not only degradation but also upgradation of a phenolic compound or contaminant.

Cationic Surfactants as Disinfectants against SARS-CoV-2.

The virucidal activity of a series of cationic surfactants differing in the length and number of hydrophobic tails (at the same hydrophilic head) and the structure of the hydrophilic head (at the same length of the hydrophobic n-alkyl tail) was compared. It was shown that an increase in the length and number of hydrophobic tails, as well as the presence of a benzene ring in the surfactant molecule, enhance the virucidal activity of the surfactant against SARS-CoV-2. This may be due to the more pronounced ability of such surfactants to penetrate and destroy the phospholipid membrane of the virus. Among the cationic surfactants studied, didodecyldimethylammonium bromide was shown to be the most efficient as a disinfectant, its 50% effective concentration (EC50) being equal to 0.016 mM. Two surfactants (didodecyldimethylammonium bromide and benzalkonium chloride) can deactivate SARS-CoV-2 in as little as 5 s.

One-pot fabrication of Ag @Ag2O core-shell nanostructures for biosafe antimicrobial and antibiofilm applications.

Microbial contamination is one of the major dreadful problems that raises hospitalization, morbidity and mortality rates globally, which subsequently obstructs socio-economic progress. The continuous misuse and overutilization of antibiotics participate mainly in the emergence of microbial resistance. To circumvent such a multidrug-resistance phenomenon, well-defined nanocomposite structures have recently been employed. In the current study, a facile, novel and cost-effective approach was applied to synthesize Ag@Ag2O core-shell nanocomposites (NCs) via chemical method. Several techniques were used to determine the structural, morphological, and optical characteristics of the as-prepared NCs. XRD, Raman, FTIR, XPS and SAED analysis revealed a crystalline hybrid structure of Ag core and Ag2O shell. Besides, SEM and HRTEM micrographs depicted spherical nanoparticles with size range of 19-60 nm. Additionally, zeta potential and fluorescence spectra illustrated aggregated nature of Ag@Ag2O NCs by - 5.34 mV with fluorescence emission peak at 498 nm. Ag@Ag2O NCs exhibited higher antimicrobial, antibiofilm, and algicidal activity in dose-dependent behavior. Interestingly, a remarkable mycocidal potency by 50 µg of Ag@Ag2O NCs against Candida albican; implying promising activity against COVID-19 white fungal post-infections. Through assessing cytotoxicity, Ag@Ag2O NCs exhibited higher safety against Vero cells than bulk silver nitrate by more than 100-fold.

Pt-, Rh-, Ru-, and Cu-Single-Wall Carbon Nanotubes Are Exceptional Candidates for Design of Anti-Viral Surfaces: A Theoretical Study.

As SARS-CoV-2 is spreading rapidly around the globe, adopting proper actions for confronting and protecting against this virus is an essential and unmet task. Reactive oxygen species (ROS) promoting molecules such as peroxides are detrimental to many viruses, including coronaviruses. In this paper, metal decorated single-wall carbon nanotubes (SWCNTs) were evaluated for hydrogen peroxide (H2O2) adsorption for potential use for designing viral inactivation surfaces. We employed first-principles methods based on the density functional theory (DFT) to investigate the capture of an individual H2O2 molecule on pristine and metal (Pt, Pd, Ni, Cu, Rh, or Ru) decorated SWCNTs. Although the single H2O2 molecule is weakly physisorbed on pristine SWCNT, a significant improvement on its adsorption energy was found by utilizing metal functionalized SWCNT as the adsorbent. It was revealed that Rh-SWCNT and Ru-SWCNT systems demonstrate outstanding performance for H2O2 adsorption. Furthermore, we discovered through calculations that Pt- and Cu-decorated SWNCT-H2O2 systems show high potential for filters for virus removal and inactivation with a very long shelf-life (2.2 × 1012 and 1.9 × 108 years, respectively). The strong adsorption of metal decorated SWCNTs and the long shelf-life of these nanomaterials suggest they are exceptional candidates for designing personal protection equipment against viruses.

Quaternary Ammonium Compounds (QACs) and Ionic Liquids (ILs) as Biocides: From Simple Antiseptics to Tunable Antimicrobials.

Quaternary ammonium compounds (QACs) belong to a well-known class of cationic biocides with a broad spectrum of antimicrobial activity. They are used as essential components in surfactants, personal hygiene products, cosmetics, softeners, dyes, biological dyes, antiseptics, and disinfectants. Simple but varied in their structure, QACs are divided into several subclasses: Mono-, bis-, multi-, and poly-derivatives. Since the beginning of the 20th century, a significant amount of work has been dedicated to the advancement of this class of biocides. Thus, more than 700 articles on QACs were published only in 2020, according to the modern literature. The structural variability and diverse biological activity of ionic liquids (ILs) make them highly prospective for developing new types of biocides. QACs and ILs bear a common key element in the molecular structure-quaternary positively charged nitrogen atoms within a cyclic or acyclic structural framework. The state-of-the-art research level and paramount demand in modern society recall the rapid development of a new generation of tunable antimicrobials. This review focuses on the main QACs exhibiting antimicrobial and antifungal properties, commercial products based on QACs, and the latest discoveries in QACs and ILs connected with biocide development.

High concentrations of hypochlorous acid-based disinfectant in the environment reduced the load of SARS-CoV-2 in nucleic acid amplification testing.

During the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic, chlorine-containing disinfectants have been widely used in nucleic acid amplification testing laboratories. Whether the use of disinfectants affect the results of viral nucleic acid amplification is unknown. We examined the impact of different hypochlorous acid (HOCl) concentrations on the quantitative results of SARS-CoV-2 by real-time reverse-transcription polymerase chain reaction (RT-PCR). We also explored the mechanisms and models of action of chlorine-containing disinfectants that affected the detection of SARS-CoV-2. The results showed that different HOCl concentrations and different action times had an impact on the SARS-CoV-2 results. High concentrations of ambient HOCl have a greater impact than low concentrations, and this effect will increase with the extension of the action time and with the increase in ambient humidity. Compared with the enzymes or the extracted RNA required for RT-PCR, the impact of HOCl on the SARS-CoV-2 detection is more likely to be caused by damage to primers and probes in the PCR system. The false negative result still existed after changing the ambient disinfectant to ethanol but not peracetic acid. The use of HOCl in the environment will have an unpredictable impact on the nucleic acid test results of SARS-CoV-2. In order to reduce the possibility of false negative of SARS-CoV-2 nucleic acid test and prevent the spread of epidemic disease, environmental disinfectants should be used at the beginning and end of the experiment rather than during the experimental operation.

Virucidal efficacy of different formulations for hand and surface disinfection targeting SARS CoV-2.

In the ongoing SARS CoV-2 pandemic, effective disinfection measures are needed, and guidance based on the methodological framework of the European Committee for Standardization (CEN) may enable the choice of effective disinfectants on an immediate basis. This study aimed to elucidate whether disinfectants claiming 'virucidal activity against enveloped viruses' as specified in the European Standard EN 14476 as well as in the German Association for the Control of Viral Diseases/Robert Koch Institute (DVV/RKI) guideline are effectively inactivating SARS-CoV-2. Two commercially available formulations for surface disinfection and one formulation for hand disinfection were studied regarding their virucidal activity. Based on the data of this study the enveloped SARS-CoV-2 is at least equally susceptible compared to the standard test virus vaccinia used in the EN 14476 and DVV/RKI guidelines. Thus, chemical disinfectants claiming 'virucidal activity against enveloped viruses' based on the EN 14476 and DVV/RKI guidelines will be an effective choice to target enveloped SARS-CoV-2 as a preventive measure.

Olanexidine gluconate formulations as environmental disinfectants for enveloped viruses infection control.

This study investigated the potential of olanexidine gluconate as environmental disinfectant against enveloped viruses in the suspension test and three non-porous surface tests. In the suspension test, olanexidine gluconate showed immediate virucidal activity. In addition, non-porous surface tests demonstrated that, although the immediate effect of aqueous formulations was weak, the final virucidal efficacy outcompeted that of ethanol for disinfection. Furthermore, the effectiveness of olanexidine gluconate persisted even after drying on environmental surfaces. This study demonstrated the potential usage of olanexidine gluconate formulations as an environmental disinfectant in the infection control of enveloped viruses.

Preparation of cellulose-based wipes treated with antimicrobial and antiviral silver nanoparticles as novel effective high-performance coronavirus fighter.

Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV). We succeeded in preparing disinfectant cellulose-based wipes treated with antimicrobial and antiviral silver nanoparticles to be used for prevention of contamination and transmission of several pathogenic viruses and microbes to human in critical areas such as hospitals and healthcare centers especially coronavirus. In this work, the antimicrobial and antiviral activities of silver nanoparticles (AgNPs) prepared with four different techniques were investigated for the utilization as a disinfectant for cellulose-based wipes. These four methods are namely; 1) trisodium citrate with cotton yarn as a reducing agent, 2) preparing AgNP's using aqueous solution of PVA in the presence of glucose, 3) trisodium citrate with cotton fabric as a reducing agent, and 4) photochemical reaction of polyacrylic acid and silver nitrate solution. Polyester/viscose blended spunlace nonwoven fabrics as cellulose based fabrics were treated with the prepared silver nanoparticles to be used as surfaces disinfection wipes. The properties of the nonwoven fabrics were examined including thickness, tensile strength in dry and wet conditions in both machine direction (MD) and cross-machine direction (CMD), bursting strength, air permeability, water permeability and surface wettability. Characterization of the AgNPs was carried out in terms of UV-VIS spectroscopy, TEM, SEM, and Zeta potential analysis. The assessment of AgNPs active solutions for antimicrobial and antiviral activities was evaluated. The results obtained from the analyses of the AgNPs samples prepared with different techniques showed good uniformity and stability of the particles, as well uniform coating of the AgNPs on the fibers. Additionally, there is a significant effect of the AgNPs preparation method on their disinfectant performance that proved its effectiveness against coronavirus (MERS-CoV), S. aureus and B. subtilis as Gram-positive bacteria, E. coli and P. mirabilis as Gram-negative bacteria, A. niger and C. albicans fungi.

Promotion of Surgical Masks Antimicrobial Activity by Disinfection and Impregnation with Disinfectant Silver Nanoparticles.

BACKGROUND: The COVID-19 pandemic is requesting highly effective protective personnel equipment, mainly for healthcare professionals. However, the current demand has exceeded the supply chain and, consequently, shortage of essential medical materials, such as surgical masks. Due to these alarming limitations, it is crucial to develop effective means of disinfection, reusing, and thereby applying antimicrobial shielding protection to the clinical supplies. PURPOSE: Therefore, in this work, we developed a novel, economical, and straightforward approach to promote antimicrobial activity to surgical masks by impregnating silver nanoparticles (AgNPs). METHODS: Our strategy consisted of fabricating a new alcohol disinfectant formulation combining special surfactants and AgNPs, which is demonstrated to be extensively effective against a broad number of microbial surrogates of SARS-CoV-2. RESULTS: The present nano-formula reported a superior microbial reduction of 99.999% against a wide number of microorganisms. Furthermore, the enveloped H5N1 virus was wholly inactivated after 15 min of disinfection. Far more attractive, the current method for reusing surgical masks did not show outcomes of detrimental amendments, suggesting that the protocol does not alter the filtration effectiveness. CONCLUSION: The nano-disinfectant provides a valuable strategy for effective decontamination, reuse, and even antimicrobial promotion to surgical masks for frontline clinical personnel.

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.

Novel boronium salt exhibits substantial antibacterial activity when compared to a commercial quaternary ammonium disinfectant.

Commercial disinfectants are routinely used to decontaminate surfaces where microbes are expected and unwelcome. Several disinfectants contain quaternary ammonium salts, or "quats", all being derived from ammonium. Quaternary alkyl dimethyl benzyl ammonium chloride or bromide disinfectants are widely available. These compounds are effective in reducing or eliminating bacteria on contaminated nonporous surfaces. A unique benzyl derived boronium salt with strong detergent action has been developed. It demonstrated 4-8X greater antibacterial activity against 3 different bacteria when compared to an equal concentration of a commercial quant disinfectant solution containing alkyl dimethyl benzyl ammonium chloride and alkyl dimethyl ethylbenzyl ammonium chloride. Antibacterial effectiveness of each agent was determined by the minimum inhibitory concentration (MIC) method.

In vitro inactivation of SARS-CoV-2 by commonly used disinfection products and methods.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is currently a global pandemic, and there are limited laboratory studies targeting pathogen resistance. This study aimed to investigate the effect of selected disinfection products and methods on the inactivation of SARS-CoV-2 in the laboratory. We used quantitative suspension testing to evaluate the effectiveness of the disinfectant/method. Available chlorine of 250 mg/L, 500 mg/L, and 1000 mg/L required 20 min, 5 min, and 0.5 min to inactivate SARS-CoV-2, respectively. A 600-fold dilution of 17% concentration of di-N-decyl dimethyl ammonium bromide (283 mg/L) and the same concentration of di-N-decyl dimethyl ammonium chloride required only 0.5 min to inactivate the virus efficiently. At 30% concentration for 1 min and 40% and above for 0.5 min, ethanol could efficiently inactivate SARS-CoV-2. Heat takes approximately 30 min at 56 °C, 10 min above 70 °C, or 5 min above 90 °C to inactivate the virus. The chlorinated disinfectants, Di-N-decyl dimethyl ammonium bromide/chloride, ethanol, and heat could effectively inactivate SARS-CoV-2 in the laboratory test. The response of SARS-CoV-2 to disinfectants is very similar to that of SARS-CoV.

Alcohol-free hand sanitizer and other quaternary ammonium disinfectants quickly and effectively inactivate SARS-CoV-2.

BACKGROUND: SARS-CoV-2 is the virus responsible for the current global pandemic, COVID-19. Because this virus is novel, little is known about its sensitivity to disinfection. METHODS: We performed suspension tests against SARS-CoV-2 using three commercially available quaternary ammonium compound (Quat) disinfectants and one laboratory-made 0.2% benzalkonium chloride solution. FINDINGS: Three of the four formulations completely inactivated the virus within 15 s of contact, even in the presence of a soil load or when diluted in hard water. CONCLUSION: Quats rapidly inactivate SARS-CoV-2, making them potentially useful for controlling SARS-CoV-2 spread in hospitals and the community.

How Alcoholic Disinfectants Affect Coronavirus Model Membranes: Membrane Fluidity, Permeability, and Disintegration.

Atomistic molecular dynamics simulations have been carried out with a view to investigating the stability of the SARS-CoV-2 exterior membrane with respect to two common disinfectants, namely, aqueous solutions of ethanol and n-propanol. We used dipalmitoylphosphatidylcholine (DPPC) as a model membrane material and did simulations on both gel and liquid crystalline phases of membrane surrounded by aqueous solutions of varying alcohol concentrations (up to 17.5 mol %). While a moderate effect of alcohol on the gel phase of membrane is observed, its liquid crystalline phase is shown to be influenced dramatically by either alcohol. Our results show that aqueous solutions of only 5 and 10 mol % alcohol already have significant weakening effects on the membrane. The effects of n-propanol are always stronger than those of ethanol. The membrane changes its structure, when exposed to disinfectant solutions; uptake of alcohol causes it to swell laterally but to shrink vertically. At the same time, the orientational order of lipid tails decreases significantly. Metadynamics and grand-canonical ensemble simulations were done to calculate the free-energy profiles for permeation of alcohol and alcohol/water solubility in the DPPC. We found that the free-energy barrier to permeation of the DPPC liquid crystalline phase by all permeants is significantly lowered by alcohol uptake. At a disinfectant concentration of 10 mol %, it becomes insignificant enough to allow almost free passage of the disinfectant to the inside of the virus to cause damage there. It should be noted that the disinfectant also causes the barrier for water permeation to drop. Furthermore, the shrinking of the membrane thickness shortens the gap needed to be crossed by penetrants from outside the virus into its core. The lateral swelling also increases the average distance between head groups, which is a secondary barrier to membrane penetration, and hence further increases the penetration by disinfectants. At alcohol concentrations in the disinfectant solution above 15 mol %, we reliably observe disintegration of the DPPC membrane in its liquid crystalline phase.

Increased microbial loading in aerosols produced by non-contact air-puff tonometer and relative suggestions for the prevention of coronavirus disease 2019 (COVID-19).

OBJECTIVE: To evaluate the microbial loading in aerosols produced after air-puff by non-contact tonometer (NCT) as well as the effect of alcohol disinfection on the inhibition of microbes and thus to provide suggestions for the prevention and control of COVID-19 in ophthalmic departments of hospitals or clinics during the great pandemics. METHODS: A cross-sectional study was carried out in this study. A NIDEK NCT was used for intraocular pressure (IOP) measurement for patients who visited Department of Ophthalmology in Qilu Hospital of Shandong University during March 18-25 2020. After ultra-violate (UV) light disinfection, the room air was sampled for 5 minutes. Before and after alcohol disinfection, the air samples and nozzle surface samples were respectively collected by plate exposure method and sterile moist cotton swab technique after predetermined times of NCT air-puff. Microbial colony counts were calculated after incubation for 48 hours. Finally, mass spectrometry was performed for the accurate identification of microbial species. RESULTS: Increased microbial colonies were detected from air samples close to NCT nozzle after air-puff compared with air samples at a distance of 1 meter from the nozzle (p = 0.001). Interestingly, none microbes were detected on the surface of NCT nozzle. Importantly, after 75% alcohol disinfection less microbes were detected in the air beside the nozzle (p = 0.003). Microbial species identification showed more than ten strains of microbes, all of which were non-pathogenic. CONCLUSION: Aerosols containing microbes were produced by NCT air-puff in the ophthalmic consultation room, which may be a possible virus transmission route in the department of ophthalmology during the COVID-19 pandemic. Alcohol disinfection for the nozzle and the surrounding air was efficient at decreasing the microbes contained in the aerosols and theoretically this prevention measure could also inhibit the virus. This will give guidance for the prevention of virus transmission and protection of hospital staff and patients.