Airborne Viral Infections Research Articles

Dependence on relative humidity in the formation of reactive oxygen species in water droplets

Water microdroplets (7 to 11 µm average diameter, depending on flow rate) are sprayed in a closed chamber at ambient temperature, whose relative humidity (RH) is controlled. The resulting concentration of ROS (reactive oxygen species) formed in the microdroplets, measured by the amount of hydrogen peroxide (H2O2), is determined by nuclear magnetic resonance (NMR) and by spectrofluorimetric assays after the droplets are collected. The results are found to agree closely with one another. In addition, hydrated hydroxyl radical cations (•OH-H3O+) are recorded from the droplets using mass spectrometry and superoxide radical anions (•O2-) and hydroxyl radicals (•OH) by electron paramagnetic resonance spectroscopy. As the RH varies from 15 to 95%, the concentration of H2O2 shows a marked rise by a factor of about 3.5 in going from 15 to 50%, then levels off. By replacing the H2O of the sprayed water with deuterium oxide (D2O) but keeping the gas surrounding droplets with H2O, mass spectrometric analysis of the hydrated hydroxyl radical cations demonstrates that the water in the air plays a dominant role in producing H2O2 and other ROS, which accounts for the variation with RH. As RH increases, the droplet evaporation rate decreases. These two facts help us understand why viruses in droplets both survive better at low RH values, as found in indoor air in the wintertime, and are disinfected more effectively at higher RH values, as found in indoor air in the summertime, thus explaining the recognized seasonality of airborne viral infections.

Portable and Air Conditioner-Based Bio-Protection Devices to Prevent Airborne Infections in Acute and Long-Term Healthcare Facilities, Public Gathering Places, Public Transportation, and Similar Entities.

The nature in which the coronavirus disease 2019 (COVID-19) pandemic started and spread all over the world has surprised and shocked experts and the general population alike. This has brought out a worldwide desire and serious efforts to prevent, or at least reduce, the severity of another airborne viral infection and protect individuals gathering for various reasons. Toward this main purpose, a novel method to disinfect the air, using graded, predictable, safe, and reliable dosage of ultraviolet C (UVC), with specially designed devices, is described here. Individuals exclusively breathing this disinfected air can prevent infection, thus destroying the airborne virus or any other pathogens outside the human body to prevent acute and chronic damage to the organs and provide a sense of security to congregate, use public transport, and be protected in acute and long-term healthcare facilities. The study involved designing and testing a unit with one UVC chamber and another unit with six UVC chambers both enclosed in UVC-opaque housings that could be used to destroy airborne pathogens. Wild-type severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was used as a representative pathogen. The virus was fed into these units and in both units, the virus was destroyed to undetectable levels. Such disinfected air can be made available for individuals to breathe at an individual and a community level. The two units that were studied were able to destroy the SARS-CoV-2 virus completely in UVC-opaque housings, making them safe for human use. By employing the air to bring the virus to the UVC, the problem of the virus getting protected behind structures was avoided. The individuals get to breathe totally disinfected air through a mask or a ventilator. To protect individuals who are unable or unwilling to use these units meant for individual use, the same principle can be expanded for use with air conditioners to provide community protection. It is envisaged that this method can prevent airborne infections from turning into pandemics and is a clear example of advocating prevention, rather than treatment. These units are expandable and the UVC dosage to the pathogen can be adjusted and predictable, thereby making it a standard technique to study the dosage needed to inactivate different pathogens.

Venous Thrombosis in Airborne Viral Infections: Is Coronavirus Disease 2019 now Any Different from Influenza?

One of the hallmarks of coronavirus disease 2019 (COVID-19), particularly in complicated cases (i.e., requiring hospitalization or intensive care support), is persistent hemostasis activation, which may be associated with a vast array of thrombotic episodes involving both the arterial and venous systems. The renewed emphasis on the relationship between viral infections and venous thrombosis paves the way for determining whether a more common and often underestimated infection disease, such as influenza, may also be associated with a significant burden of venous thrombotic episodes, and how this eventual thrombotic risk compares to that seen in COVID-19, both in the past and with newer variants. Our review of studies comparing the burden of venous thromboembolism (VTE) in patients with COVID-19 or influenza revealed that the thrombotic risk appears to be significantly higher in patients with COVID-19 but remains certainly not meaningless in those with influenza, particularly in subjects infected by highly virulent strains (i.e., H1N1), in those who develop pneumonia and require intensive care support. In these specific clinical settings, the adoption of tailored thromboprophylaxis may be indicated though more studies are compellingly needed on this matter. As COVID-19 variants emerge, there is a possibility that the VTE burden of COVID-19 will decrease, and progress to that of other respiratory viruses.

Evaluation of Optimal Mechanical Ventilation Strategies for Schools for Reducing Risks of Airborne Viral Infection

Ventilation systems are one of the most effective strategies to reduce the risk of viral infection transmission in buildings. However, insufficient ventilation rates in crowded spaces, such as schools, would lead to high risks of infection transmission. On the other hand, excessive ventilation rates might significantly increase cooling energy consumption. Therefore, energy-efficient control methods, such as Demand Control Ventilation systems (DCV), are typically considered to maintain acceptable indoor air quality. However, it is unclear if the DCV-based controls can supply adequate ventilation rates to minimize the probability of infection (POI) in indoor spaces. This paper investigates the benefits of optimized ventilation strategies, including conventional mechanical systems (MV) and DCV, in reducing the POI and cooling energy consumption through a detailed sensitivity analysis. The study also evaluates the impact of the ventilation rate, social distancing, and number of infectors on the performance of the ventilation systems. A coupling approach of a calibrated energy model of a school building in Jeddah, KSA, with a validated Wells–Riley model is implemented. Based on the findings of this study, proper adjustment of the DCV set point is necessary to supply adequate ventilation rates and reduce POI levels. Moreover, optimal values of 2 ACH for ventilation rate and 2 m for social distance are recommended to deliver acceptable POI levels, cooling energy use, and indoor CO2 concentration for the school building. Finally, this study confirms that increasing the ventilation rate is more effective than increasing social distancing in reducing the POI levels. However, this POI reduction is achieved at the cost of a higher increase in the cooling energy.

Safety in Rats of a Novel Nasal Spray Formulation for the Prevention of Airborne Viral Infections.

Hexedra+® is a nasal spray containing hydroxypropyl methylcellulose, beta-cyclodextrin, and usnic acid. It has been developed with the aim of reducing the risk of transmission of airborne viral infections, with particular reference to influenza and COVID-19. As part of the preclinical development of the product, we carried out a study on thirty male Wistar rats divided into three study groups and treated with Hexedra+, an alternative formulation containing a double concentration of usnic acid (0.015% instead of 0.0075%) or saline solution. Products were administered at the dose of 30 μL into each nostril, three times a day for seven consecutive days by means of a micropipette. By the end of the treatment period, no significant changes were observed in body weight. Histological examination of nasal mucosa and soft organs did not show any significant difference in the three study groups. Serum transaminase level remained in the normal limit in all the animals treated. The serum level of usnic acid was measured in order to assess the absorption of the molecule through the nasal mucosa. By the end of the study period, the usnic acid serum level was negligible in all the animals treated. In conclusion, the safety profile of Hexedra+ appears favorable in the animal model studied.

Nirmatrelvir-ritonavir treatment of COVID-19 in a high-risk patient population: A retrospective observational study.

Coronavirus disease 2019 (COVID-19) is a highly contagious, airborne viral infection that can infect anyone. Those with certain underlying conditions may be at higher risk for infection to develop into a severe disease requiring hospitalization. This report summarizes use of nirmatrelvir-ritonavir for the treatment of COVID-19 in high-risk patients at a single academic medical center through a pharmacist delegation protocol and demonstrates real-world efficacy and safety of treatment. This retrospective, single-center, observational study analyzed all patients who received nirmatrelvir-ritonavir ordered by a clinical pharmacist for treatment of COVID-19 infection. The primary outcomes were safety and efficacy of nirmatrelvir-ritonavir. Safety was evaluated by analyzing drug interaction management and adverse events. Efficacy was evaluated through hospitalization and death within 28 days of nirmatrelvir-ritonavir use. Sixty patients were eligible for inclusion. No patients were hospitalized or died within 28 days after initiation of nirmatrelvir-ritonavir. Pharmacists identified 101 drug interactions with 60% considered clinically significant, requiring modification of home medications. Adverse outcomes associated with the use of nirmatrelvir-ritonavir were reported in 13 patients (21.7%). A comprehensive program to mitigate drug interactions and prescribe nirmatrelvir-ritonavir ensured timely access to COVID-19 therapy, which may be associated with the prevention of hospitalization and death.

Remdesivir in Solid Organ Recipients for COVID-19 Pneumonia

Solid organ transplant (SOT) recipients represent a vulnerable patient population and are of high risk for airborne viral infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). Treatment of COVID-19 is still challenging, as no proven therapeutic regimen is available for immunocompromised patients. Our aim was to evaluate the efficacy and safety of remdesivir (RDV) therapy in infected hospitalized SOT patients. All transplanted recipients (N=25; lung: 19; kidney: 3, liver: 2, heart: 1) who needed hospital care were reviewed in the time period between September 2020 and May 2021 out of the 945 patients treated at the Department. Case control matched patients receiving RDV (all in need of supplementary oxygen) and standard of care (SOC) were included as controls. Among the 25 SOT patients (female:male=11:14; average age=53.2 ± 12.7 years), 15 received RDV medication (RDV-TX), and in 10 cases SOC treatment was used (SOC-TX). Significantly worse clinical score was noted in RDV patients compared with RDV-TX; however, transfer to a higher intensity care unit as well as 60-day survival of RDV-TX patients were significantly worse. All SOT fatalities within 60 days of follow-up were lung transplant recipients (6 out of 19 lung transplant patients). No adverse events were noted related to RDV therapy. In SOT patients, especially lung transplant recipients, with severe COVID-19 needing supplementary oxygen, RDV treatment was safe; however, outcome was significantly worse as compared with nontransplanted individuals with initially worse clinical parameters.

Nebulized fusion inhibitory peptide protects cynomolgus macaques from measles virus infection

Measles is the most contagious airborne viral infection and the leading cause of child death among vaccine-preventable diseases. We show here that aerosolized lipopeptide fusion inhibitor, derived from heptad-repeat regions of the measles virus (MeV) fusion protein, blocks respiratory MeV infection in a non-human primate model, the cynomolgus macaque. We use a custom-designed mesh nebulizer to ensure efficient aerosol delivery of peptide to the respiratory tract and demonstrate the absence of adverse effects and lung pathology in macaques. The nebulized peptide efficiently prevents MeV infection, resulting in the complete absence of MeV RNA, MeV-infected cells, and MeV-specific humoral responses in treated animals. This strategy provides an additional means to fight against respiratory infection in non-vaccinated people, that can be readily translated to human trials. It presents a proof-of-concept for the aerosol delivery of fusion inhibitory peptides to protect against measles and other airborne viruses, including SARS-CoV-2, in case of high-risk exposure.

Negative Electrization of Air as a Means of Counteracting Airborne Viral Infections

Geneticists and genetic engineers, who constantly introduce nucleic acids into target cells, have experimentally proven that positive electrization of the external environment of cells increases the permeability of cell membranes to nucleic acids. Moreover, they experimentally found that those nucleic acids that are part of positively charged complexes, mostquickly penetrate into cells. Thus, the practical experience of geneticists and genetic engineers convincingly proves that the positive electrization of both the cellular environment and the objects present in it, increases the permeability of cytoplasmic membranes for the latter. Accordingly, all this suggests that the positive electrization of the internal environment of the human body promotes the penetration of foreign nucleic acids, especially viral, into its cells. Moreover, given the function of extracellular protons in creating a proton motive force that directs glucose into cells, it can be argued that the positive electrization of the external environment of human cells contributes to the reproduction of viruses in them. Accordingly, it can be expected that the negative electrization of the human internal environment should prevent both the penetration of viral nucleic acids into cells, and the reproduction of viruses there. Naturally, all this allows us to offer negative electrization of the air as the most affordable means to combat airborne viral infections. Offering such a means, we expect that the negative electrization of the air that a person inhales will lead to the same electrization of his internal environment, first of all – his respiratory tracts, which are the first to come into contact with viruses contained in the air. The validity of this offer is discussed here.

Influence of Ventilation in Healthcare Facilities Prevention of Infection COVID-19: Systematic Review Study

Currently, (2019-2020) COVID-19 global pandemic is caused by a member of the Coronaviridae group. Some human viruses are spread from human to human by way of droplets or aerosols, but fewer viruses are persistently airborne in transmission, and the healthcare-associated epidemic of airborne viral infection are restricted to very few surrogates. In addition, it is one of the most efficient tools (i.e., the second one) for preventing inside air pollution through ventilation. To our aim was to perform a rapid literature review to answer the following question: does ventilation in healthcare facilities prevention of infection COVID-19? This study is a systematic review by searching among published articles in Embase, PubMed/MEDLINE, Scopus, PubMed Central (PMC), Google Scholar databases as well as medRxiv by using the following keywords: ‘COVID-19’, ‘healthcare settings’, ‘prevention’, ‘ventilation’, ‘Hospital, ‘Infection’, and ‘Air changes per hour. After investigating the information and quality of articles, 52 articles were included in this study. The literature denotes that temperature, relative humidity, and ventilation and air conditioning systems have beneficial effects to prevent COVID-19 infection. The results of this study demonstrated that many parameters basic strategy of control COVID-19 include: hand hygiene, social distancing, screening and case finding, isolation and separating, decontamination and disinfection, and effective ventilation. Thus, based on recommendations of CDC, WHO, and other studies effective ventilation is the most important transmission of respiratory disease control strategy, specially COVID-19.

The role of ACE2 in the renin-angiotensin-system: Etiology and therapy of COVID-19 from a pharmaceutical perspective.

Angiotensin-2 converting enzyme (ACE2), a key element of the renin-angiotensin-system (RAS), is not only the direct target of infection by the human SARS-Cov-2 virus but is at the same the root for the complex pathogenetic events of COVID-19. From a pharmaceutical perspective, several established classes of medicines are involved in different phases of the disease. From their known mechanisms of action, a comprehensive understanding of COVID-19 will be hopefully soon delineated. A set of proven medicines is available to cope at least with some of the pathologies involved. To arrive back to normal life, vaccinations and broad consideration of hygienic measures are to be complemented by effective medicines to treat airborne viral infections. Therapeutic schemes based on a comprehensive understanding of the disease will include drug combinations made up from both established drugs as well as novel drugs presently under development.

Emerging Technologies for In Vitro Inhalation Toxicology.

Respiratory toxicology remains a major research area in the 21st century since current scenario of airborne viral infection transmission and pollutant inhalation is expected to raise the annual morbidity beyond 2 million. Clinical and epidemiological research connecting human exposure to air contaminants to understand adverse pulmonary health outcomes is, therefore, an immediate subject of human health assessment. Important observations in defining systemic effects of environmental contaminants on inhalation metabolic dysfunction, liver health, and gastrointestinal tract have been well explored with in vivo models. In this review, a framework is provided, a paradigm is established about inhalation toxicity testing in vitro, and a brief overview of breathing Lungs-on-Chip (LoC) as design concepts is given. The optimized bioengineering approaches and microfluidics with their fundamental pros, and cons are presented. There are different strategies that researchers apply to inhalation toxicity studies to assess a variety of inhalable substances and relevant LoC approaches. A case study from published literature and frame arguments about reproducibility as well as in vitro/in vivo correlations are discussed. Finally, the opportunities and challenges in soft robotics, systems inhalation toxicology approach integrating bioengineering, machine learning, and artificial intelligence to address a multitude model for future toxicology are discussed.

Dynamic assessment of the risk of airborne viral infection.

This paper applies the Rudnick and Milton method through the dynamic evaluation of the probability of airborne contagion, redefining all parameters and variables in discretized form. To adapt the calculation of the risk of contagion to real needs, scenarios are used to define the presence of people, infected subjects, the hourly production of the quanta of infection, and the calculation of the concentration of CO2 produced by exhalation in the air. Three case studies are discussed: a school, an office, a commercial activity. Complex scenarios include environmental sanitization, a variable number of people, and the possibility of simulating work shifts. The dynamic evaluation of the quanta of infection is also estimated, not foreseen by the Rudnick and Milton model, and involves updating the average values of the equivalent fraction of the indoor air with an improvement in the accuracy of the calculation due to the reduction of improper peaks of the stationary variables.

A REVIEW ON FIRST MEMBERS OF COVID-19 VACCINES IN PHASE 3 AROUND THE GLOBE

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), a member of the coronaviridae family is the cause of the pandemic which started in 2019 and the world is still fighting against it. In spite of the usage of drugs like remedesivir, flavinavir and hydroxycholoquine along with different approaches to increase the immunity or to treat the respiratory infection in humans, even now this viral infection is uncontrollable. According to the stats, till November 10, 2020 over 10 million people have lost their lives around the world, touching the mark of 37 mill ion plus patients around the world with epidemiology showing the most cases in USA followed by India, Russia, Brazil and Spain. After seeing the rapid spread and post disease effects of this air borne viral infection, an urgent need of the vaccine consider ed. This led to encourage researchers around the world to develop different types of vaccines, namely inactivated, live attenuated, nanoparticle based, viral vectored, recombinant type, DNA and RNA vaccines, among which few have already passed Phase 1 clinical trials and are under Phase 2 or 3 human trials. The vaccines which have the highest potential to be successful with minimal side effects proposed by different countries around the world with their type, mechanism of action and their effects along with the challenges and considerations regarded with these vaccines has been discussed in this paper.

Can ventilation in healthcare facilities prevention of infection COVID-19?

Currently, (2019-2020) COVID-19 global pandemic is caused by a member of the Coronaviridae group. Some human viruses are spread from human to human by way of droplets or aerosols, but fewer viruses are persistently airborne in transmission, and the healthcare-associated epidemic of airborne viral infection are restricted to very few surrogates. The prevention of air pollutants (i.e., biological, particles, chemicals, and smoke) at the resource has the highest efficiency to keep safe air. In addition, it is one of the most efficient tools (i.e. the second one) for preventing inside air pollution through ventilation. To our aim was to perform a rapid literature review to answer the following question: does ventilation in healthcare facilities prevention of infection COVID-19? We systematically searched Embase, PubMed/MEDLINE, Scopus, PubMed Central (PMC), Google Scholar databases as well as medRxiv by using the following key-words: ‘COVID-19’, ‘healthcare settings’, ‘prevention’, ‘ventilation’, ‘Hospital, ‘Infection’, and ‘Air changes per hour. A total of 26 eligible articles were identified. The literature denotes that temperature, relative humidity, and ventilation and air conditioning systems have beneficial effects to prevent COVID-19 infection. Thus, based on recommendations of CDC, WHO, and other studies effective ventilation is the most important transmission of respiratory disease control strategy, specially COVID-19.

Simulation-Based Rapid Development and Implementation of a Novel Barrier Enclosure for Use in COVID-19 Patients: The SplashGuard CG.

Background The current COVID-19 pandemic has resulted in over 54,800,000 SARS-CoV-2 infections worldwide with a mortality rate of around 2.5%. As observed in other airborne viral infections such as influenza and SARS-CoV-1, healthcare workers are at high risk for infection when performing aerosol-generating medical procedures (AGMP). Additionally, the threats of a global shortage of standard personal protective equipment (PPE) prompted many healthcare workers to explore alternative protective enclosures, such as the “aerosol box” invented by a Taiwanese anesthetist. Our study includes the design process of a protective barrier enclosure and its subsequent clinical implementation in the management of critically ill adults and children infected with SARS-CoV-2. Methods and Results The barrier enclosure was designed for use in our tertiary care facility and named “SplashGuard CG” (CG for Care Givers). The device has been adapted using a multi- and interdisciplinary approach, with collaboration between physicians, respiratory therapists, nurses, and biomechanical engineers. Computer-aided design and simulation sessions throughout the entire process facilitated the rapid and safe implementation of the SplashGuard CG in different settings (intensive care unit, emergency department, and the operating room) during AGMPs such as bag-valve-mask ventilation, nasopharyngeal suctioning, intubation and extubation, and noninvasive ventilation. Indications for use and anticipatory precautions were communicated to all healthcare workers using the SplashGuard CG. The entire process was completed within one month. Conclusion The rapid design, development, and clinical implementation of a new barrier enclosure, the “SplashGuard CG,” was feasible in this time of crisis thanks to close collaboration between medical and engineering teams and the use of recurring simulation sessions to test and improve the initial prototypes. Following this accelerated process, it is necessary to maintain team skills, monitor any undesirable effects, and evaluate and continuously improve this new device.

Infection Prevention and Control for ICU during COVID-19 Pandemic: Position Paper of the Indian Society of Critical Care Medicine.

Coronavirus disease-2019 (COVID-19) has very high rates of hospital-related transmission among healthcare workers (HCWs), mandating the need for careful intensive care unit (ICU) designing, optimization of staff resources, implementation of vigorous infection control practices, environmental disinfection, meticulous sample collection, and criteria for staff quarantine. Most of the ICUs are not designed to deal with airborne viral infections and require redesigning for the safety of HCWs and patients. Infection control practices related to the prevention of spread of COVD-19 are unique and are well described. The training of staff on infection control practices reduces the infection rate among HCWs significantly. Adequate staffing not only helps in infection control but also prevents burnout of the staff. In case of infection to HCW, the staff must be assessed systematically, and institute's infection control committee should guide for isolation period as well as return to work based upon standard recommendations. This article focuses on infection control and prevention measures required in ICU during the COVID-19 pandemic.How to cite this article: Sharma J, Nasa P, Reddy KS, Kuragayala SD, Sahi S, Gopal P, et al. Infection Prevention and Control for ICU during COVID-19 Pandemic: Position Paper of the Indian Society of Critical Care Medicine. Indian J Crit Care Med 2020;24(Suppl 5):S280–S289.

On respiratory droplets and face masks.

Face mask filters—textile, surgical, or respiratory—are widely used in an effort to limit the spread of airborne viral infections. Our understanding of the droplet dynamics around a face mask filter, including the droplet containment and leakage from and passing through the cover, is incomplete. We present a fluid dynamics study of the transmission of respiratory droplets through and around a face mask filter. By employing multiphase computational fluid dynamics in a fully coupled Eulerian–Lagrangian framework, we investigate the droplet dynamics induced by a mild coughing incident and examine the fluid dynamics phenomena affecting the mask efficiency. The model takes into account turbulent dispersion forces, droplet phase-change, evaporation, and breakup in addition to the droplet–droplet and droplet–air interactions. The model mimics real events by using data, which closely resemble cough experiments. The study shows that the criteria employed for assessing the face mask performance must be modified to take into account the penetration dynamics of airborne droplet transmission, the fluid dynamics leakage around the filter, and reduction of efficiency during cough cycles. A new criterion for calculating more accurately the mask efficiency by taking into account the penetration dynamics is proposed. We show that the use of masks will reduce the airborne droplet transmission and will also protect the wearer from the droplets expelled from other subjects. However, many droplets still spread around and away from the cover, cumulatively, during cough cycles. Therefore, the use of a mask does not provide complete protection, and social distancing remains important during a pandemic. The implications of the reduced mask efficiency and respiratory droplet transmission away from the mask are even more critical for healthcare workers. The results of this study provide evidence of droplet transmission prevention by face masks, which can guide their use and further improvement.

'TEK SAĞLIK' KAPSAMINDA CORONAVİRÜS COVID-19, SARS ve MERS ile DİĞER VİRAL ENFEKSİYONLAR KORUNMA ve KONTROL.

In late December 2019, the epidemic disease that occurred in Wuhan, China was named the new severe acute respiratory syndrome (SARS CoV-2) coronavirus disease 2019 (COVID-19) through the World Health Organization (WHO). The number of cases worldwide has exceeded 6 million and deaths have exceeded 370,000 at 01.06.2020. The main symptoms of coronavirus infection include fever, dry cough, dyspnoea, diarrhoea and sore throat, and progresses in severity ranging from multiple organ locations and death to asymptomatic infections in patients. COVID-19 belongs to a large family of viruses known as coronaviruses (CoVs), enveloped and positive polar RNA viruses. They cause zoonotic infections, have pandemic potential, and bats, rodents and poultry are natural reservoirs and vectors of the virus. They are characterized by an unusually large RNA genome and a unique multiplication strategy. While they cause enteritis and upper respiratory tract infections, which vary in severity and affect multiple organs in mammals, poultry, cattle and pigs, and they cause various diseases in humans, from upper respiratory tract diseases to infections that can have fatal potential. The transmission of viruses is by direct inhalation of small particles (10 nm) and airborne droplets, from contaminated surfaces (hands, wastes, etc.) and from the eye, nose, and throat and airway mucosa. Control of viral infections transmitted by air is more difficult. Various disinfectants are used to reduce contamination and should be odourless and economical without harming human and animal health and the environment, they should adapt to the surface, and do not cause abrasion and deterioration. An effective disinfectant; it should have a broad antimicrobial spectrum and should not be affected by organic substances and other chemicals used. Although the benefit of widespread use of face masks is limited, they are effective in preventing the spread of an infectious disease, especially in socialization and in common areas when used with disinfectants. Air cleaners use a variety of different designs and technologies to remove air passing through particles and sometimes odours. The purpose of this review is primarily to provide information on COVID-19 infection and other airborne viral infections, ways of protection from viral infections, disinfectants and air disinfection, in accordance with the concept of 'One Health', and to benefit from the protection and control of infections. 'Social Vaccine', which requires attention and restriction in social isolation and not to contact against COVID-19 infection, is currently the most effective and generally accepted prevention method.

Prevalence of Common Respiratory Viral Infections and Identification of Adenovirus in Hospitalized Adults in Harbin, China 2014 to 2017.

Background: Respiratory infections pose a great challenge in global health, and the prevalence of viral infection in adult patients has been poorly understood in northeast China. Harbin is one of the major cities in northeast China, and more than half of any given year in Harbin is occupied by winter. To reveal the viral etiology and seasonality in adult patients from Harbin, a 4-year consecutive survey was conducted in Harbin, China.Methods: From January 2014 to December 2017, specimens were obtained from adult patients admitted to the Second Affiliated Hospital of Harbin Medical University with lower respiratory tract infections. Sputum samples were examined by direct immunofluorescence assays to detect seven common respiratory viruses, including influenza virus (type A and B), parainfluenza virus (type 1 to 3), respiratory syncytial virus and adenovirus. Adenovirus positive samples were seeded onto A549 cells to isolate viral strains. Phylogenetic analysis was conducted on the highly variable region of adenoviral hexon gene.Results: A total of 1,300 hospitalized adult patients with lower respiratory tract infections were enrolled, in which 189 patients (14.5%) were detected as having at least one viral infection. The co-infection rate in this study was 25.9% (49/189). The dominant viral pathogen from 2014 to 2017 was parainfluenza virus, with a detection rate of 7.2%, followed by influenza virus, respiratory syncytial virus and adenovirus. Based on the climate seasons determined by daily average temperature, the highest overall viral detection rate was detected in spring (22.0%, 52/236), followed by winter (13.4%, 109/813), autumn (11.4%, 13/114) and summer (10.9%, 15/137). Adenovirus type 3 strains with slight variations were isolated from positive cases, which were closely related to the GB strain from the United States, as well as the Harbin04B strain isolated locally.Conclusion: This study demonstrated that common respiratory viruses were partially responsible for hospitalized lower respiratory tract infections in adult patients from Harbin, China, with parainfluenza virus as the dominant viral pathogen. Climate seasons could be rational indicators for the seasonality analysis of airborne viral infections. Future surveillance on viral mutations would be necessary to reveal the evolutionary history of respiratory viruses.