Single-Use and Reusable Flexible Bronchoscopes in Pulmonary and Critical Care Medicine

Flexible bronchoscopy plays a critical role in both diagnostic and therapeutic management of a variety of pulmonary disorders in the bronchoscopy suite and the intensive care unit. In the set-ting of the ongoing viral pandemic, single-use flexible bronchoscopes (SUFB) have garnered attention as various professional pulmonary societies have released guidelines regarding uses for SUFB given the concern for risk of viral transmission when using reusable flexible bronchoscopes (RFB). In addition to offering sterility, SUFBs are portable, easily accessible, and may be more cost-effective than RFB when considering the potential costs of treating bronchoscopy-related infections. Furthermore, since SUFBs are one time use, they do not require reprocessing after use, and therefore may translate to reduced cleaning and storage costs. Despite these advantages, RFBs are still routinely used to perform advanced diagnostic and therapeutic bronchoscopic procedures given the need for optimal maneuverability, handling, angle of deflection, image quality, and larger channel size for passing of ancillary instruments. Here, we review the published evidence on the applications of single-use and reusable bronchoscopes in bronchoscopy suites and intensive care units. Specifically, we will discuss the advantages and disadvantages of these devices as pertinent to fundamental, advanced, and therapeutic bronchoscopic interventions.

Mudanças Climáticas e seu Impacto na Incidência de Arboviroses: Uma Revisão Sistemática de Estudos Recentes

Estudos indicam que as mudanças climáticas poderão afetar a distribuição global de arboviroses, influenciando fatores como sobrevivência de vetores, patógenos e transmissão viral. Assim, buscou-se nesse estudo realizar uma revisão sistemática dos artigos mais recentes – publicados entre 2015 e 2020 - relativos a essa temática. Após a aplicação de critérios de elegibilidade, 28 artigos foram selecionados para análise. A partir da revisão, verificou-se que as mudanças climáticas poderão afetar a aptidão das regiões para transmissão viral e a distribuição geográfica de mosquitos do gênero Aedes. Contudo, o efeito das mudanças climáticas varia em diferentes regiões, podendo causar expansão ou contração das áreas aptas para a ocorrência de arboviroses. Em geral, verifica-se um potencial crescimento das áreas aptas em regiões temperadas, sobretudo para o A. albopictus. Em regiões tropicais, por outro lado, o aumento da temperatura poderá limitar as áreas, atualmente, consideradas aptas. Embora não seja intuitivo, alguns estudos previram que a mitigação parcial das mudanças climáticas pode ocasionar maior risco de transmissão viral do que nenhuma mitigação. Assim, é possível verificar que a relação entre as mudanças climáticas e a transmissão de arboviroses não é direta e pode variar em diferentes cenários e locais. Climate Change and its Impact on the Incidence of Arboviruses: A Systematic Review of Recent Studies A B S T R A C TStudies indicate that climate change may affect the global distribution of arboviruses, influencing factors such as vector survival, pathogens, and viral transmission. Thus, this study aimed to conduct a systematic review of the most recent articles - published between 2015 and 2020 - related to this theme. After applying eligibility criteria, 28 papers were selected for analysis. From the review, it was found that climate change may affect the suitability of regions for viral transmission and the geographical distribution of mosquitoes of the genus Aedes. However, the effect of climate change varies in different regions, which may cause expansion or contraction of areas suitable for the occurrence of arboviruses. In general, there is a potential for growth in suitable areas within temperate regions, especially for A. albopictus. In tropical regions, on the other hand, the increase in temperature may limit the areas currently considered suitable. Although not intuitive, some studies have predicted that partial mitigation of climate change may lead to a higher risk of viral transmission than no mitigation. Thus, it is possible to verify that the relationship between climate change and the transmission of arboviruses is not direct and may vary in different scenarios and locations.Keywords: Climate; Projection; Aedes; Arboviruses.

HIV-1 trans-Infection Mediated by DCs: The Tip of the Iceberg of Cell-to-Cell Viral Transmission

HIV-1 cell-to-cell transmission is key for an effective viral replication that evades immunity. This highly infectious mechanism is orchestrated by different cellular targets that utilize a wide variety of processes to efficiently transfer HIV-1 particles. Dendritic cells (DCs) are the most potent antigen presenting cells that initiate antiviral immune responses, but are also the cells with highest capacity to transfer HIV-1. This mechanism, known as trans-infection, relies on the capacity of DCs to capture HIV-1 particles via lectin receptors such as the sialic acid-binding I-type lectin Siglec-1/CD169. The discovery of the molecular interaction of Siglec-1 with sialylated lipids exposed on HIV-1 membranes has enlightened how this receptor can bind to several enveloped viruses. The outcome of these interactions can either mount effective immune responses, boost the productive infection of DCs and favour innate sensing, or fuel viral transmission via trans-infection. Here we review these scenarios focusing on HIV-1 and other enveloped viruses such as Ebola virus or SARS-CoV-2.

Virucidal Activity of Different Mouthwashes Using a Novel Biochemical Assay

Background: Saliva of patients with COVID-19 has a high SARS-CoV-2 viral load. The risk of spreading the virus is not insignificant, and procedures for reducing viral loads in the oral cavity have been proposed. Little research to date has been performed on the effect of mouthwashes on the SARS-CoV-2 virus, and some of their mechanisms of action remain unknown. Methods: SARS-CoV-2 positive nasopharyngeal swabs measured by RT-PCR were used for virucidal activity in a 1:1 ratio, with an incubation time of 1 min. The solutions used in this study were: iodopovidone (8 mg); * D-limonene, a terpene extracted from citrus peels (0.3%); † cetylpyridinium chloride (0.1%) (CPC); ‡ chlorhexidine gluconate (10%) (CHX); § a CPC (0.12%) and CHX (0.05%) containing formula; ** a formula containing essential oils; †† a CPC containing formula (0.07%); ‡‡ a D-limonene (0.2%) and CPC (0.05%) containing formula; §§ a solution containing sodium fluoride (0.05%) and CPC (0.075%); *** a solution containing CHX (0.12%) and; ††† a CHX (0.2%) containing formula. ‡‡‡ As a control reaction, saline solution or excipient solution (water, glycerin, citric acid, colorant, sodium citrate) was used. Conclusion: Within the limitations of this study, we can conclude that a mouthwash containing both D-limonene and CPC reduced the virucidal activity in about 6 logs (>99.999% reduction). Hence, establishing a clinical protocol for dentists is suggested, where all patients to be treated rinse pre-operatively with a mouthwash containing both D-limonene and CPC to reduce the likelihood of infection with SARS-CoV-2 for dentists. This is a relatively inexpensive way to reduce viral transmission of SARS-CoV-2 from infected individuals within the community. It is also a simple way to decrease infections from asymptomatic and pre-symptomatic patients.

Is the increased transmissibility of SARS-CoV-2 variants driven by within or outside-host processes?

Understanding the factors that increase the transmissibility of the recently emerging variants of SARS-CoV-2 can aid in mitigating the COVID-19 pandemic. The enhanced transmissibility could be attributed to enhanced within-host processes, such as contagiousness (viral shedding by an infected individual) and infectivity (the probability of a susceptible individual to get infected), or outside-host processes, such as viral stability on surfaces and in the air. We utilized a mathematical model in order to theoretically analyze the specific mechanisms of virus transfer between an infected and susceptible individual. This allowed us to examine how the within-host or outside-host processes affect the overall viral transmission. Our analysis is based the available data on the Alpha, Epsilon and Delta variants as well as the currently emerging Omicron variant. We found that the higher transmissibility of the SARS-CoV-2 variants can be attributed only to within-host processes. Specifically, enhanced contagiousness drives the Delta variant transmissibility, while the Alpha, Epsilon and Omicron are characterized by an enhanced infectivity. Since outside-host processes have little contribution to the observed increase in the transmissibility, leading stricter hygienic and behavioral measures than those that were already applied are not expected to achieve a pronounced mitigating effect.

Enoxaparin and Pentosan Polysulfate Bind to the SARS-CoV-2 Spike Protein and Human ACE2 Receptor, Inhibiting Vero Cell Infection

As with many other pathogens, SARS-CoV-2 cell infection is strongly dependent on the interaction of the virus-surface Spike protein with the glycosaminoglycans of target cells. The SARS-CoV-2 Spike glycoprotein was previously shown to interact with cell-surface-exposed heparan sulfate and heparin in vitro. With the aim of using Enoxaparin as a treatment for COVID-19 patients and as prophylaxis to prevent interpersonal viral transmission, we investigated GAG binding to the Spike full-length protein, as well as to its receptor binding domain (RBD) in solution by isothermal fluorescence titration. We found that Enoxaparin bound to both protein variants with similar affinities, compared to the natural GAG ligand heparan sulfate (with Kd-values in the range of 600–680 nM). Using size-defined Enoxaparin fragments, we discovered the optimum binding for dp6 or dp8 for the full-length Spike protein, whereas the RBD did not exhibit a significant chain-length-dependent affinity for heparin oligosaccharides. The soluble ACE2 receptor was found to interact with unfractionated GAGs in the low µM Kd range, but with size-defined heparins with clearly sub-µM Kd-values. Interestingly, the structural heparin analogue, pentosan polysulfate (PPS), exhibited high binding affinities to both Spike variants as well as to the ACE2 receptor. In viral infection experiments, Enoxaparin and PPS both showed a strong inhibition of infection in a concentration range of 50–500 µg/mL. Both compounds were found to retain their inhibitory effects at 500 µg/mL in a natural biomatrix-like human sputum. Our data suggest the early topical treatment of SARS-CoV-2 infections with inhaled Enoxaparin; some clinical studies in this direction are already ongoing, and they further imply an oral or nasal prophylactic inactivation of the virus by Enoxaparin or PPS for the prevention of inter-personal viral transmission.

Impact of the Coronavirus (COVID-19) Pandemic on the Care of Pediatric Acute Appendicitis

Background Appendicitis is the most common abdominal surgical emergency in children. With the rise of the Coronavirus-19 pandemic, quarantine measures have been enforced to limit the viral transmission of this disease. The purpose of this study was to identify differences in the clinical presentation and outcomes of pediatric acute appendicitis during the Coronavirus-19 pandemic. Methods A single-institution retrospective assessment of all pediatric patients (<18 years old) with acute appendicitis from December 2019 to June 2020 was performed at a tertiary care children’s hospital. Patients were divided into two groups: (1) the Pre-COVID group presented on or before March 15, 2020, and (2) the COVID group presented after March 15, 2020. Demographic, preoperative, and clinical outcomes data were analyzed. Results 45 patients were included with a median age of 13 years [IQR 9.9 - 16.2] and 35 males (78%). 28 patients were in the Pre-COVID group (62%) and 17 in the COVID group (38%). There were no differences in demographics or use of diagnostic imaging. The COVID group did have a significantly delayed presentation from symptom onset (36 vs 24 hours, P < .05), higher Pediatric Appendicitis Scores (8 vs 6, P = .003), and longer hospital stays (2.2 vs 1.3 days, P = .04). There were no significant differences for rates of re-admission, re-operation, surgical site infection, perforation, or abscess formation. Conclusion During the Coronavirus-19 pandemic, the incidence of pediatric acute appendicitis was approximately 40% lower. These children presented in a delayed fashion with longer hospital stays. No differences were noted for postoperative complications.