Spread Of Respiratory Viruses Research Articles

Text-Guided Synthesis of Masked Face Images

The COVID-19 pandemic has made us all understand that wearing a face mask protects us from the spread of respiratory viruses. The face authentication systems, which are trained on the basis of facial key points such as the eyes, nose, and mouth, found it difficult to identify the person when the majority of the face is covered by the face mask. Removing the mask for authentication will cause the infection to spread. The possible solutions are: (a) to train the face recognition systems to identify the person with the upper face features (b) Reconstruct the complete face of the person with a generative model. (c) train the model with a dataset of the masked faces of the people. In this paper, we explore the scope of generative models for image synthesis. We used stable diffusion to generate masked face images of popular celebrities on various text prompts. A realistic dataset of 15K masked face images of 100 celebrities is generated and is called the Realistic Synthetic Masked Face Dataset (RSMFD). The model and the generated dataset will be made public so that researchers can augment the dataset. According to our knowledge, this is the largest masked face recognition dataset with realistic images. The generated images were tested on popular deep face recognition models and achieved significant results. The dataset is also trained and tested on some of the famous image classification models, and the results are competitive. The dataset is available on this link:- https://drive.google.com/drive/folders/1yetcgUOL1TOP4rod1geGsOkIrIJHtcEw?usp=sharing

The multi-dimensional challenges of controlling respiratory virus transmission in indoor spaces: Insights from the linkage of a microscopic pedestrian simulation and SARS-CoV-2 transmission model.

SARS-CoV-2 transmission in indoor spaces, where most infection events occur, depends on the types and duration of human interactions, among others. Understanding how these human behaviours interface with virus characteristics to drive pathogen transmission and dictate the outcomes of non-pharmaceutical interventions is important for the informed and safe use of indoor spaces. To better understand these complex interactions, we developed the Pedestrian Dynamics-Virus Spread model (PeDViS): an individual-based model that combines pedestrian behaviour models with virus spread models that incorporate direct and indirect transmission routes. We explored the relationships between virus exposure and the duration, distance, respiratory behaviour, and environment in which interactions between infected and uninfected individuals took place and compared this to benchmark 'at risk' interactions (1.5 metres for 15 minutes). When considering aerosol transmission, individuals adhering to distancing measures may be at risk due to build-up of airborne virus in the environment when infected individuals spend prolonged time indoors. In our restaurant case, guests seated at tables near infected individuals were at limited risk of infection but could, particularly in poorly ventilated places, experience risks that surpass that of benchmark interactions. Combining interventions that target different transmission routes can aid in accumulating impact, for instance by combining ventilation with face masks. The impact of such combined interventions depends on the relative importance of transmission routes, which is hard to disentangle and highly context dependent. This uncertainty should be considered when assessing transmission risks upon different types of human interactions in indoor spaces. We illustrated the multi-dimensionality of indoor SARS-CoV-2 transmission that emerges from the interplay of human behaviour and the spread of respiratory viruses. A modelling strategy that incorporates this in risk assessments can help inform policy makers and citizens on the safe use of indoor spaces with varying inter-human interactions.

Epidemiologic and Genomic Evidence for Zoonotic Transmission of SARS-CoV-2 among People and Animals on a Michigan Mink Farm, United States, 2020.

Farmed mink are one of few animals in which infection with SARS-CoV-2 has resulted in sustained transmission among a population and spillback from mink to people. In September 2020, mink on a Michigan farm exhibited increased morbidity and mortality rates due to confirmed SARS-CoV-2 infection. We conducted an epidemiologic investigation to identify the source of initial mink exposure, assess the degree of spread within the facility's overall mink population, and evaluate the risk of further viral spread on the farm and in surrounding wildlife habitats. Three farm employees reported symptoms consistent with COVID-19 the same day that increased mortality rates were observed among the mink herd. One of these individuals, and another asymptomatic employee, tested positive for SARS-CoV-2 by real-time reverse transcription PCR (RT-qPCR) 9 days later. All but one mink sampled on the farm were positive for SARS-CoV-2 based on nucleic acid detection from at least one oral, nasal, or rectal swab tested by RT-qPCR (99%). Sequence analysis showed high degrees of similarity between sequences from mink and the two positive farm employees. Epidemiologic and genomic data, including the presence of F486L and N501T mutations believed to arise through mink adaptation, support the hypothesis that the two employees with SARS-CoV-2 nucleic acid detection contracted COVID-19 from mink. However, the specific source of virus introduction onto the farm was not identified. Three companion animals living with mink farm employees and 31 wild animals of six species sampled in the surrounding area were negative for SARS-CoV-2 by RT-qPCR. Results from this investigation support the necessity of a One Health approach to manage the zoonotic spread of SARS-CoV-2 and underscores the critical need for multifaceted public health approaches to prevent the introduction and spread of respiratory viruses on mink farms.

Titanium dioxide nanostructures that reduce the infectivity of respiratory syncytial virus

The spread of respiratory diseases has gained significant attention since the detection and rapid global spread of COVID-19. Respiratory viruses are commonly transmitted when an infected person coughs or sneezes onto a surface, infecting persons who subsequently contact this surface. For this reason, developing surfaces with inherent antipathogenic properties is crucially needed for controlling the spread of deadly pathogens. Recent studies have established the antipathogenic potential of hydrothermally synthesised titanium dioxide (TiO2) nanostructured surfaces against bacteria strains (Gram-positive and negative) and several respiratory viruses, including SARS-CoV-2, HRV-16 and HCoV-NL63. This study investigates the antiviral behaviour of TiO2 nanostructured surfaces against Respiratory Syncytial Virus (RSV), a respiratory virus commonly contracted by children, to reduce viral transmission in high-traffic environments such as hospitals and childcare centers. Mimicking droplets produced when a person coughs or sneezes, RSV droplets were exposed to nanostructured surfaces to investigate their antiviral potential. Results show that nanostructured TiO2 reduced the RSV infectious viral load at all timepoints compared to control surfaces, showing 1.7, 2.6 and 3.2 log reductions after 2-, 5- and 7-hours exposure, respectively. Interestingly, virus exposed to nanostructured surfaces showed little to no infectivity after 5 h exposure while viable virus was still detected on control surfaces after 7 h exposure. These encouraging results establish TiO2 nanostructured surfaces as a potential method for reducing transmission and spread of respiratory viruses and bacterial strains.

Relaxing Mask Mandates in New Jersey

Photo by Mika Baumeister on Unsplash INTORDUCTION In March of 2022, New Jersey Governor Phil Murphy announced that the state would no longer mandate face masks for students, staff, and visitors at schools and childcare centers. Two-thirds of New Jersey residents already supported this decision.[1] Soon after, Princeton University led the way in learning to live with the virus by making the use of masks optional in most situations. At a time when vaccination rates were already high and Omicron hospitalization rates were falling, the decision to relax mask mandates was the right call.  Yet, Rutgers University has extended its mask mandate for the rest of the academic year, with no stated endpoint. In a university-wide email, Executive Vice President and Chief Operating Officer Antonio Calcado announced: The university has been clear that the science and data would guide our path forward with respect to the health and safety of our community… Use of appropriate face coverings will still be required in all teaching spaces (classrooms, lecture halls, seminar rooms, etc.), teaching labs, computer labs, buses, libraries, and clinical facilities.[2] Despite the university’s purported commitment to follow “the science and data,” there has been a noticeable lack of transparency regarding the scientific rationale and official endpoint for this extension of the mask mandate. Given the same set of scientific data available, these neighboring universities came to opposite conclusions on the need for continued mask mandates. Notably, the Rutgers mask mandate continues to require students to mask in libraries but not in crowded cafeterias. These discrepancies have led to understandable frustration among members of the Rutgers community. In response, the Rutgers student newspaper objects to “the sense of optics” and “the lack of clear communication,” resulting in “confusion,” arguing that the university administration “needs to be more transparent” and “must communicate and explain the policy changes more effectively.”[3] At a time when trust in public health institutions is at an all-time low, Ava Kamb warns that a lack of transparent messaging can reduce public trust even further.[4] Instead, Kamb argues that public health mandates should use the least restrictive means necessary in order to promote health and civil liberties at the same time. The ethical question is whether university mask mandates should be relaxed. I argue that the use of face masks by healthy individuals has uncertain benefits, which potential harms may outweigh, and should therefore be voluntary. ANALYSIS Rutgers intends “the science and data” to guide its path forward. As such, it is worth revisiting the controversial science behind mask mandates. From 2019 to 2020, systematic reviews by the World Health Organization (WHO) and Cochrane Acute Respiratory Infections concluded that the use of face masks by healthy individuals in the community lacks effectiveness in reducing viral transmission based on moderate-quality evidence.[5] Neither study concerned COVID-19 specifically. Since then, the only two randomized controlled trials of face masks published during the pandemic found little to no benefit.[6] Yet, the Centers for Disease Control and Prevention (CDC) cite many observational and modeling studies (based on empirical assumptions) which suggest that community masking is beneficial.[7] These studies support a larger benefit associated with masking, but they use less reliable research methods. Based on these non-randomized data and mechanistic plausibility, WHO’s current position is also supportive of community masking recommendations. But without high-quality evidence, it is difficult to justify a requirement rather than a recommendation. It may be useful to draw an ethical distinction between a recommendation and a mandate in public health. A public health recommendation does not generally undermine individual autonomy because individuals have the choice to follow the recommendation. I argue that recommendations may be justified by a lower standard of proof or a lesser expected benefit precisely because they do not violate individual autonomy. On the other hand, a public health mandate demands compliance using the threat of penalty. To ethically justify an infringement of autonomy, strong evidence that demonstrates a significant health benefit should support a public health mandate. While the recommendation to use masks in accordance with personal preference may be a reasonable precaution—particularly for vulnerable individuals—the higher standards of evidence and benefit that would ethically justify mask mandates have not been met. Notwithstanding, one might argue the precautionary principle justifies mask mandates. For example, Chinese CDC Director-General George Gao, medical researcher Trisha Greenhalgh, and others espouse such a view.[8] The precautionary principle holds that it is better to be safe than sorry. In the context of COVID-19, the principle has been used to advocate for public health measures which lack high-quality evidence. Accordingly, it might be thought that it is safer to implement potentially ineffective mask mandates than to risk forgoing a lifesaving benefit. Yet, the precautionary principle is an ill-defined concept that is philosophically problematic. Health economist Jay Bhattacharya and epidemiologist Sunetra Gupta argue that the precautionary principle cuts both ways because a public health mandate without high-quality evidence has both potential benefits and potential harms.[9] If the precautionary principle can justify implementing mask mandates due to the risk of forgoing possible benefit, then it might also be able to justify not implementing mask mandates due to the risk of potential harm caused by the intervention. It is commonly thought that there is little to lose from the use of face masks, but this is not necessarily true. According to WHO, CDC, and the European Centre for Disease Prevention and Control (ECDC), the harms of face masks may include headaches, difficulty breathing, skin lesions, difficulty communicating, a false sense of security, environmental pollution, impaired learning, delayed psychosocial development, and disadvantages for individuals with cognitive or mental disorders.[10] These include both potential and observed harms drawn from the scientific literature. Yet, the negative side effects of masks remain significantly under-investigated. For example, there is emerging mechanistic evidence that prolonged mask use or reuse increases both inhaled and environmental microplastics, the long-term effects of which are unknown.[11] The harms related to communication, learning, and psychosocial development are particularly problematic for educational institutions, whose mission is to promote these very things. It is, therefore, possible that masks have done more harm than good. While many observational studies and models support the potential benefits of masks, some interpret these studies to mean that masks clearly work. However, the limited body of randomized data paints a less optimistic picture and cannot be used to rule out an increase in infection from masks.[12] Other types of studies, less reliable research methods, do rule this out and support masking. Bhattacharya and Gupta would argue that it is safer to encourage voluntary, evidence-based interventions than to foist these potential harms upon individuals for the sake of uncertain benefits. It remains unclear whether and to what extent the use of face masks by healthy individuals in the community influenced COVID-19 mortality. However, it is clear to me that community masking does not meet the higher standard of evidence necessary to justify a mandate and that mask use is associated with potential harm. The already tenuous case for masks continues to weaken with a mixed body of evidence, the availability of effective pharmaceuticals, and widespread natural immunity to COVID-19. If public health should aim for the least restrictive means necessary to promote health while respecting civil liberties, then the extension of burdensome mask mandates which lack high-quality evidence is ethically problematic. CONCLUSION Given the current state of COVID-19, a university mask mandate for a low-risk population with high levels of immunity is not justified. In times of fear and uncertainty, higher education institutions ought to make reasoned policy decisions guided by “the science and data.” It would seem that, of the universities that mandated masks, Princeton has emerged as a national leader in mask policy while Rutgers lags behind. Schools across the nation should take note. - [1] Rutgers University Eagleton Institute of Politics. Two-thirds of New Jerseyans agree with lifting school mask mandate, most comfortable returning to normal; half think NJ has done “just right” on pandemic. Accessed May 14, 2022. https://eagletonpoll.rutgers.edu/wp-content/uploads/2022/03/Rutgers-Eagleton-Poll-COVID-March-7-2022.pdf [2] Calcado AM. Return to Campus Update – January 31, 2022. Accessed May 14, 2022. https://coronavirus.rutgers.edu/changes-related-to-covid-19-protocols [3] The Daily Targum. Rutgers’ new mask policies are more than confusing. Accessed May 14, 2022. https://dailytargum.com/article/2022/04/editorial-rutgers-new-mask-policies-are-more-than-confusing [4] Kamb A. The false choice between public health and civil liberties. Voices in Bioethics 2020;6. doi:10.7916/vib.v6i.6297. [5] World Health Organization Global Influenza Programme. Non-pharmaceutical public health measures for mitigating the risk and impact of epidemic and pandemic influenza. Geneva: World Health Organization; 2019; Jefferson T, Del Mar CB, Dooley L, et al. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database of Systematic Reviews 2020;11(CD006207). doi:10.1002/14651858.CD006207.pub5. [6] Abaluck J, Kwong LH, Styczynski A, et al. Impact of community masking on COVID-19: A cluster-randomized trial in Bangladesh. Science 2022;375(6577):eabi9069. doi:10.1126/science.abi9069. (intervention reduced symptomatic seroprevalence by 9.5%; 95% confidence interval = [0.82, 1.00].); Bundgaard H, Bundgaard JS, Raaschou-Pedersen DET, et al. Effectiveness of adding a mask recommendation to other public health measures to prevent SARS-CoV-2 infection in Danish mask wearers: A randomized controlled trial. Ann Intern Med 2021;174(3):335-343. doi:10.7326/M20-6817. (trial was conducted in a setting where mask wearing was uncommon and the findings were inconclusive; 95% confidence interval = [0.54, 1.23].) [7] U.S. Centers for Disease Control and Prevention. Science Brief: Community Use of Masks to Control the Spread of SARS-CoV-2. Accessed May 14, 2022. https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/masking-science-sars-cov2.html [8] Zimmerman A. The precautionary principle in mask-wearing: When waiting for explicit scientific evidence is unwise. Voices in Bioethics 2020;6. doi:10.7916/vib.v6i.5896. (supporting the use of masks early in the pandemic arguing that the harms of masking in the short term were unlikely to be severe or to outweigh the benefits.); Greenhalgh T, Schmid MB, Czypionka T, et al. Face masks for the public during the COVID-19 crisis. BMJ 2020;369:m1435. doi:10.1136/bmj.m1435. [9] Bhattacharya J. On the Catastrophic Misapplication of the Precautionary Principle. Accessed May 14, 2022. https://collateralglobal.org/article/misapplication-of-the-precautionary-principle; Gupta S. A Betrayal of the Precautionary Principle. Accessed May 14, 2022. https://collateralglobal.org/article/a-betrayal-of-the-precautionary-principle [10] World Health Organization. Mask use in the context of COVID-19: Interim guidance, 1 December 2020. Accessed May 14, 2022. https://apps.who.int/iris/handle/10665/337199; U.S. Centers for Disease Control and Prevention; European Centre for Disease Prevention and Control. Using face masks in the community: First update - Effectiveness in reducing transmission of COVID-19. Accessed May 14, 2022. https://www.ecdc.europa.eu/sites/default/files/documents/covid-19-face-masks-community-first-update.pdf [11] Li L, Zhao X, Li Z, et al. COVID-19: Performance study of microplastic inhalation risk posed by wearing masks. J Hazard Mater 2021;411:124955. doi:10.1016/j.jhazmat.2020.124955; Ma J, Chen F, Xu H, et al. Face masks as a source of nanoplastics and microplastics in the environment: Quantification, characterization, and potential for bioaccumulation. Environ Pollut 2021;288:117748. doi:10.1016/j.envpol.2021.117748; Chen X, Chen X, Liu Q, et al. Used disposable face masks are significant sources of microplastics to environment. Environ Pollut 2021;285:117485. doi:10.1016/j.envpol.2021.117485. [12] Bundgaard et al. (inconclusive with a 95% confidence interval = [0.54, 1.23]).

Outpatient Antibiotic Prescriptions in France: Patients and Providers Characteristics and Impact of the COVID-19 Pandemic.

In France, despite several successive plans to control antimicrobial resistance, antibiotic use remains high in the outpatient setting. This study aims to better understand outpatient antibiotic use and prescription in order to identify tailored targets for future public health actions. Using data from the French National Health Data System, we described and compared the individual characteristics of patients with and without an antibiotic prescription. The prescribed antibiotics (ATC-J01) were detailed and compared between 2019 and 2020. Antibiotic prescribing indicators that take prescriber activity into account were estimated and compared. Patients who were female, advanced age, and the presence of comorbidities were associated with antibiotic prescriptions. The overall prescription rate was estimated at 134 per 1000 consultations and 326 per 1000 patients seen in 2019. General practitioners (GPs), dentists and paediatricians were associated with 78.0%, 12.2% and 2.2% of antibiotic prescriptions, respectively, with high prescription rates (391, 447, and 313 p. 1000 patients seen, respectively). In comparison with 2019, this rate decreased in 2020 for paediatricians (−30.4%) and GPs (−17.9%) whereas it increased among dentists (+17.9%). The reduction was twice as high among the male prescribers than among their female counterparts (−26.6 and −12.0, respectively). The reduction in prescriptions observed in 2020 (−18.2%) was more marked in children (−35.8%) but less so among individuals ≥65 years (−13.1%) and those with comorbidities (−12.5%). The decrease in penicillin prescriptions represents 67.3% of the overall reduction observed in 2020. The heterogeneous decrease in prescriptions by age and antibiotic class could be explained by the impact of COVID-19 control measures on the spread of respiratory viruses; thus, a substantial proportion of the prescriptions avoided in 2020 is likely inappropriate, particularly among children. In order to keep the rate of prescriptions comparable to that observed in 2020, male prescribers, paediatricians and GPs should be encouraged to maintain that level, while a campaign to raise awareness of the appropriate use of antibiotics should be aimed at dentists in particular.

Very Low Incidence of SARS-CoV-2, Influenza and RSV but High Incidence of Rhino-, Adeno- and Endemic Coronaviruses in Children With Acute Respiratory Infection in Primary Care Pediatric Practices During the Second and Third Wave of the SARS-CoV-2 Pandemic.

Respiratory viruses were detected by multiplex-polymerase chain reaction from oropharyngeal swabs in 114/168 (67.9%) children with acute respiratory infection presenting to 5 pediatric practices in Germany between November 2020 and April 2021. In contrast to rhino- (48.8%), adeno- (14.3%) and endemic coronaviruses (14.9%), SARS-CoV-2 and influenza virus were detected only once; respiratory syncytial virus was not detected. This demonstrates differing impacts of pandemic infection control measures on the spread of respiratory viruses.

A solution scan of societal options to reduce transmission and spread of respiratory viruses: SARS-CoV-2 as a case study

Societal biosecurity – measures built into everyday society to minimize risks from pests and diseases – is an important aspect of managing epidemics and pandemics. We aimed to identify societal options for reducing the transmission and spread of respiratory viruses. We used SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) as a case study to meet the immediate need to manage the COVID-19 pandemic and eventually transition to more normal societal conditions, and to catalog options for managing similar pandemics in the future. We used a ‘solution scanning’ approach. We read the literature; consulted psychology, public health, medical, and solution scanning experts; crowd-sourced options using social media; and collated comments on a preprint. Here, we present a list of 519 possible measures to reduce SARS-CoV-2 transmission and spread. We provide a long list of options for policymakers and businesses to consider when designing biosecurity plans to combat SARS-CoV-2 and similar pathogens in the future. We also developed an online application to help with this process. We encourage testing of actions, documentation of outcomes, revisions to the current list, and the addition of further options.

Effectiveness of face masks for the population.

Health authorities and organizations consider non-medical face masks as an additional passive means to prevent virus diffusion. Communication strategies disseminate information among the population that such masks are essential for mitigating virus diffusion. However, scientific studies are not conclusive in showing the undisputed filtration efficiency of fabric/cloth facial masks (both commercial and homemade). This study examines scientific data about the effectiveness of face masks before and during the COVID-19 emergency. Present trends in the making of commercial and homemade fabric/cloth face masks are also examined. Statistical data of published studies are analyzed and compared. Main considerations and sugge-stions are also extracted and discussed. Current approaches are examined for assessing the characteristics and effectiveness of fabric/cloth commercial and homemade face masks intended for the population. Conflicting data exist as to whether non-medical masks have a protective effect from the spread of respiratory viruses. Both medical masks (MDs) and respiratory personal protection equipment (PPE) show a given effectiveness value. Concerning commercial and homemade fabric/cloth masks, giving general indications on the choice of materials and their assemblage is difficult as it is not possible to assess the effectiveness of the filter media with respect to the kind of multiphase fluid that may be emitted upon breathing, sneezing, or coughing under different environmental conditions. This is particularly important because airflow rate, temperature, humidity, and duration of use will affect the performance of filter media. Moreover, while a mask may have excellent filter media, droplets may leak into the face-piece unless there is an adequate facial seal. In the presence of leaks, any type of mask may actually offer less protection independently of its nominal filtering effìciency.

Life of a droplet: Buoyant vortex dynamics drives the fate of micro-particle expiratory ejecta.

We show that the dynamics of the expiratory cloud ejected during human respiratory events can be modeled by extending the theory of buoyant vortex rings with an initial momentum. We embed the integral conservation laws that govern the cloud’s motion into the model of an expanding vortex to determine the velocity field inside and outside the cloud. We then apply a Lagrangian particle-tracking model to calculate the trajectories of the mucosalivary droplets suspended within the cloud. Our results show very good agreement with the available experimental data. The vortex is shown to have a significant effect on suspending the droplets present in the cloud, increasing the time they remain airborne and extending their range further than predicted by the existing models. We also study the role that initial conditions have on the maximum streamwise range of the droplets, finding that decreasing the angle of projection can reduce the spread of the droplets by an order of meters. Finally, we discuss the importance of these findings in the context of informing public health policies and global information campaigns to slow down the spread of respiratory viruses.

Efficacy of face mask in preventing respiratory virus transmission: A systematic review and meta-analysis

BackgroundConflicting recommendations exist related to whether masks have a protective effect on the spread of respiratory viruses. MethodsThe Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement was consulted to report this systematic review. Relevant articles were retrieved from PubMed, Web of Science, ScienceDirect, Cochrane Library, and Chinese National Knowledge Infrastructure (CNKI), VIP (Chinese) database. ResultsA total of 21 studies met our inclusion criteria. Meta-analyses suggest that mask use provided a significant protective effect (OR = 0.35 and 95% CI = 0.24–0.51). Use of masks by healthcare workers (HCWs) and non-healthcare workers (Non-HCWs) can reduce the risk of respiratory virus infection by 80% (OR = 0.20, 95% CI = 0.11–0.37) and 47% (OR = 0.53, 95% CI = 0.36–0.79). The protective effect of wearing masks in Asia (OR = 0.31) appeared to be higher than that of Western countries (OR = 0.45). Masks had a protective effect against influenza viruses (OR = 0.55), SARS (OR = 0.26), and SARS-CoV-2 (OR = 0.04). In the subgroups based on different study designs, protective effects of wearing mask were significant in cluster randomized trials and observational studies. ConclusionsThis study adds additional evidence of the enhanced protective value of masks, we stress that the use masks serve as an adjunctive method regarding the COVID-19 outbreak.

Spread of Respiratory Viruses: Temperature and Physical Environment. Temperature Control May Exploit Virus Hypo-Thermolabity; A Possibile, Immediate Solution for COVID-19

surface cells work at a specific temperature range. At this range (37-38 C°) their response to viruses and bacteria tend to be optimal and mucus tends to have the specific grade of fluidity to contrast infections [1, 2]. With a decrease of 3-4 C° or more, these cells may be less protected, less active and not ready to fight infections. Most viruses may work (and replicate) only at lower temperatures (i.e. 34-35°C).

Can physical interventions help reduce the spread of respiratory viruses?

Can physical interventions help reduce the spread of respiratory viruses?

Type I Interferons as Regulators of Lung Inflammation.

Immune responses to lung infections must be tightly regulated in order to permit pathogen eradication while maintaining organ function. Exuberant or dysregulated inflammation can impair gas exchange and underlies many instances of lung disease. An important driver of inflammation in the lung is the interferon (IFN) response. Type I IFNs are antiviral cytokines that induce a large range of proteins that impair viral replication in infected cells. This cell-intrinsic action plays a crucial role in protecting the lungs from spread of respiratory viruses. However, type I IFNs have also recently been found to be central to the initiation of lung inflammatory responses, by inducing recruitment and activation of immune cells. This helps control virus burden but can cause detrimental immunopathology and contribute to disease severity. Furthermore, there is now increasing evidence that type I IFNs are not only induced after viral infections but also after infection with bacteria and fungi. The pro-inflammatory function of type I IFNs in the lung opens up the possibility of immune modulation directed against this antiviral cytokine family. In this review, the initiation and signaling of type I IFNs as well as their role in driving and maintaining lung inflammation will be discussed.

Hospital-associated infections in children: a prospective post-discharge follow-up survey in three different paediatric hospitals

Reported viral hospital-associated infection (HAI) frequencies have ranged from 1% to 24% between paediatric wards and hospitals. Reasons for this variation remain unclear. To evaluate the rate of viral HAIs and risk factors in three different paediatric hospitals. Data were collected prospectively for two years in one infectious disease ward and three general paediatric wards in Finland and Switzerland. Infections were recorded during the hospitalization and one week after discharge. Ward-specific risk factors for HAIs within each ward were searched by using multivariate logistic regression analysis. Altogether 5119 patients were hospitalized. Total HAI frequency was 12.2%, with 2.4% of the patients developing HAI in hospital, most often gastroenteritis, and 9.8% [95% confidence interval (CI): 8.9-10.8%] within 72 h of discharge. HAI rates varied from 5.8% to 17.1% between the wards, the highest rate being in a general paediatric ward where shared rooms were common and active cohorting according to viral aetiology was not done. Shared room (OR: 5.45; 95% CI: 2.44-12.2 in a general ward treating infants), longer hospitalization (OR: 1.42 per day; 95% CI: 1.20-1.67 in an infectious disease ward) and young age (OR: 0.71 per year; 95% CI: 0.51-0.98 in general paediatric ward for children aged >1 year) increased risk of HAI in hospital. Most viral HAIs in paediatric wards become evident after discharge. Single room bedding appears to be effective in preventing HAIs, especially the spread of respiratory viruses. It also appears that caring for patients with contagious diseases in a separate unit is advantageous.

Simple physical interventions such as hand washing and wearing masks can reduce spread of respiratory viruses

Commentary on: T Jefferson, MC Del, L Dooley, et al.. Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review. BMJ2009;339:b3675.

Swine flu, pandemics, and critical care

The recent discovery of a new strain of swine flu (officially known as Influenza A /H1N1/ Mexico City 2009) and the ensuing epidemic demonstrates the collective vulnerability of humankind to pandemic spread of respiratory viruses. We have been planning for pandemic influenza for decades and it is now upon us. This new strain is a hybrid virus with its major surface hemagglutinin antigen sequences derived from swine, human and avian flu sources. This new virus is highly communicable by human-to-human transmission; fortunately, at least thus far, it appears to have relatively low pathogenecity potential with an overall low mortality rate in the single digits. The enlarging pandemic is centered primarily in young, healthy, adolescent populations. This segment of the population is typically high mobile and exposed to crowded environments (schools, social gatherings, traveling) and is infrequently immunized with annual influenza vaccines. The degree of protection afforded by previous vaccination with prior Influenza A H1N1 strain antigens is currently the matter of some debate.