Infection risk factor measurement based on spatial and temporal distribution of COVID-19 nucleic acid test sites: an example from Shenzhen.

COVID-19 has profoundly impacted global daily life, emphasizing the need for effective virus suppression strategies. In response, China has established numerous nucleic acid testing sites to facilitate rapid testing and curb outbreaks. However, these sites often experience congestion, increasing transmission risks and reducing testing efficiency. This study focuses on the spatial-temporal analysis of testing site distribution and associated infection risks in Shenzhen, China. Data from all Shenzhen testing sites were analyzed for the week of October 24-30, 2022, noting the percentage of busy hours per site and incorporating a population size factor by district to assess regional infection risks. Findings indicate three daily peak testing times-primarily in the evening-with the highest risk of transmission in Longgang District, followed by Yantian and Luohu, and the lowest in Futian. The risk coefficient varied from 0.040 to 0.349, with most areas showing stable risk levels between 0.06 and 0.20. This research underlines the necessity for policymakers to alleviate congestion at testing sites and suggests increasing site availability in Longgang District to mitigate COVID-19 spread, offering methodological guidance for managing infection risks in other major Chinese cities.

A Regional-Scale Assessment-Based SARS-CoV-2 Variants Control Modeling with Implications for Infection Risk Characterization.

Background: The emergence and progression of highly divergent SARS-CoV-2 variants have posed increased risks to global public health, triggering the significant impacts on countermeasures since 2020. However, in addition to vaccination, the effectiveness of non-pharmaceutical interventions, such as social distancing, masking, or hand washing, on different variants of concern (VOC) remains largely unknown. Objective: This study provides a mechanistic approach by implementing a control measure model and a risk assessment framework to quantify the impacts of control measure combinations on the transmissions of five VOC (Alpha, Beta, Delta, Gamma, and Omicron), along with a different perspective of risk assessment application. Materials and Methods: We applied uncontrollable ratios as an indicator by adopting basic reproduction number (R 0) data collected from a regional-scale survey. A risk assessment strategy was established by constructing VOC-specific dose-response profiles to implicate practical uses in risk characterization when exposure data are available. Results: We found that social distancing alone was ineffective without vaccination in almost all countries and VOC when the median R 0 was greater than two. Our results indicated that Omicron could not be contained, even when all control measure combinations were applied, due to its low threshold of infectivity (~3×10-4 plague-forming unit (PFU) mL-1). Conclusion: To facilitate better decision-making in future interventions, we provide a comprehensive evaluation of how combined control measures impact on different countries and various VOC. Our findings indicate the potential application of threshold estimates of infectivity in the context of risk communication and policymaking for controlling future emerging SARS-CoV-2 variant infections.

Wind velocity and dispersion/advection-diffusion of artificial droplets and droplet nuclei in a domed all-weather multi-purpose stadium.

To evaluate the COVID-19 infection risk and the effectiveness of countermeasures at mass-gathering events, we measured the dispersion and advective diffusion of artificial droplets and artificial droplet nuclei at the Tokyo Dome, Japan (capacity 55,000 people). We also measured and evaluated the effectiveness of wearing masks and increasing the space between seating areas. If people were seated facing forward, artificial droplets did not reach the mouths of surrounding people, suggesting low risk of droplet transmission. For an artificially generated cough or sneeze, the volume of droplets deposited on the hair, back of the neck, and back of the human in front, and the backs of the seats in front, decreased by two to three orders of magnitude when a mask was worn, regardless of the type of mask. However, when the mask was worn with the nose out, the amount deposited on the back of the seat in front was reduced by only 17%. Even in seats with the highest particle concentration in the vicinity of the source, only 0.097%-0.24% of the generated droplet nuclei (1.0-3.0 µm) from the source were inhaled. Our results suggest that the infection risk at the Tokyo Dome via droplet and airborne transmission was low.

Echinococcus granulosus complex infection in wild boar hunters and auxiliary hunting dogs.

Cystic echinococcosis (CE) caused by Echinococcus granulosus sensu lato (s.l.) is a zoonotic neglected tropical disease endemic in Italy, which perpetuates in several intermediate hosts, including wild boars, and dogs as definitive hosts. People living in rural and livestock-raising areas are exposed to E. granulosus s.l. infection, as well as people leading outdoor activities in endemic regions. Therefore, this study was designed to assess the exposure to Echinococcus spp. in wild boar hunters, the role of their hunting dogs as parasite reservoirs, along with hunter's knowledge on the infection risk. From December 2022 to May 2023, wild boar hunters (n = 122) from southern Italy were recruited on volunteer basis for blood and serum sampling and a questionnaire enquiring socio-demographic, anamnestic data and knowledge on CE was also filled out. Sera were tested for Echinococcus spp. IgG by a commercial enzyme-linked immunosorbent assay (Euroimmun ELISA®, Germany). In addition, faecal samples from their hunting dogs (n = 208) were screened for Taeniidae eggs by parasitological and molecular approaches. Overall, six (4.9 %) hunters scored either positive or borderline for IgG anti-Echinococcus spp., of which one presented a calcified hepatic cyst at abdominal ultrasonography. In addition, 6.3 % Taeniidae prevalence was recorded in faecal samples (13/208) of hunting dogs, and E. granulosus sensu stricto (s.s.) was molecularly identified in two samples. The statistical analysis revealed the risk factors (odds ratio > 1, p < 0.05) associated with parasitic exposure, including the hunter geographical provenience, and the presence of animals around or in the house. The E. granulosus s.l. exposure of hunters herein detected, coupled with the parasite molecular positivity of their hunting dogs and the limited awareness on Echinococcus spp. life cycle/infection risk, highlight the relevance to promote health surveillance and educational programs within the hunting category, for minimizing the cestode circulation in the wildlife-urban premises.

Model-based estimates of age-structured SARS-CoV-2 epidemiology in households.

BACKGROUND: Understanding how infectious disease transmission varies from person to person, including associations with age and contact behavior, can help design effective control strategies. Within households, transmission may be highly variable because of differing transmission risks by age, household size, and individual contagiousness. Our aim was to disentangle those factors by fitting mathematical models to SARS-CoV-2 household survey and serologic data. METHODS: We surveyed members of 3,381 Utah households from January-April 2021 and performed SARS-CoV-2 antibody testing on all available members. We paired these data with a probabilistic model of household importation and transmission composed of a novel combination of transmission variability and age- and size-structured heterogeneity. We calculated maximum likelihood estimates of mean and variability of household transmission probability between household members in different age groups and different household sizes, simultaneously with importation probability and probabilities of false negative and false positive test results. RESULTS: 12.8% of individual participants, residing in 17.4% of the participating households, showed serologic evidence of prior infection or reported a prior positive test on the survey. Serologically positive individuals in younger age groups were less likely than older adults to have tested positive during their infection according to our survey results. Our model results suggested that adolescents and young adults (ages 13-24) acquired SARS-CoV-2 infection outside the household at a rate substantially higher than younger children and older adults. Our estimate of the household secondary attack rate (HSAR) among adults aged 45 and older exceeded HSARs to and/or from younger age groups at a given household size. We found lower HSAR in households with more members, independent of age differences. The age-specific HSAR patterns we found could not be explained by age-dependent biological susceptibility and transmissibility alone, suggesting that age groups contacted each other at different rates within households. CONCLUSIONS: We disentangled several factors contributing to age-specific infection risk, including non-household exposure, within-household exposure to specific age groups, and household size. Within-household contact rate differences played a significant role in driving household transmission epidemiology. These findings provide nuanced insights for understanding community outbreak patterns and mechanisms of differential infection risk.

Incidence and Recurrence of Urinary Tract Infections Caused by Uropathogenic Escherichia coli: A Retrospective Cohort Study.

Purpose: Urinary tract infections (UTIs) are among the most common bacterial infections, with uropathogenic Escherichia coli (UPEC) as the main etiologic agent of uncomplicated UTIs (uUTIs). The prevalence of uUTis caused by organisms with antimicrobial resistance (AMR) is increasing worldwide, complexifying the disease management and increasing the risk of complications. In efforts to develop new strategies for uUTI prevention, it is imperative to understand factors associated with the occurrence of new episodes. Patients and Methods: This retrospective cohort study aimed to assess the incidence of uUTIs caused by UPEC (UPEC-uUTIs) or unknown etiology (untested uUTIs) in adults aged ≥18 years receiving care in a San Francisco healthcare system. Results: During 2014-2019, 1087 UPEC-uUTI and 4106 untested uUTI cases were documented, of which 324 (29.8%; 95% confidence interval: 27.1%-32.6%) and 1030 (25.1%; 95% confidence interval: 23.8%-26.4%) were followed by ≥1 new episode of uUTI within 12 months. In the UPEC-uUTI cohort, male gender, diagnosis of diabetes mellitus, and prior uUTI were risk factors for new episodes of uUTI. At the time of first UPEC-uUTI diagnosis, antimicrobial prescriptions were retrieved for 41.1% of cases. When tested, AMR was most frequently reported for trimethoprim/sulfamethoxazole or trimethoprim/sulfamethoxazole prescribed with other antimicrobials. Conclusion: Our study provides important information on the incidence and risk of repeated episodes of uUTIs, as well as on AMR related to them.

Surveillance data from 2011-2020 indicate a lower risk of Lyme disease in the USA in even-numbered years.

From 2011-2020 the number of reported cases of Lyme disease in the USA was lower in each even-numbered year compared with the preceding odd-numbered year. This observation suggests that fewer nymphal stage Ixodes scapularis ticks infected with Borrelia burgdorferi were present during even-numbered years in locations where people spend time.

Microbial growth on temporary pacemaker leads post-TAVR: pathogen spectrum and clinical implications.

BACKGROUND AND OBJECTIVE: Transcatheter aortic valve replacement (TAVR) is an established treatment option for patients with symptomatic severe aortic stenosis across all stages of surgical risk. Rapid pacing during the procedure and the risk for the occurrence of conduction disturbances after TAVR requires the pre-interventional insertion of a temporary pacemaker (TP). However, this approach poses risks, including the risk of infection. For this reason, the following study aimed to investigate microbial growth on temporary pacemaker leads and its association with outcome post-TAVR and to identify associated pathogens and related risk factors. METHODS: A prospective study was conducted including 344 patients undergoing TAVR at the Heart Centre Bonn. Of these, 97 patients did not require TP leads as they already had permanent pacemakers; this group was considered as comparison group. The TP leads of the remaining 247 patients were removed, sonicated, and cultured to investigate bacterial growth over a period of 14 days. Finally, we compared patients without microbial growth (n = 184) and patients with microbial growth (n = 63). The primary endpoint of the study was 30-day all-cause mortality, secondary endpoints were periprocedural infections, the length of the postprocedural hospital stay, 30-day major vascular complications and the 30-day stroke rate. RESULTS: The majority of cases (74.5%) showed no bacterial growth. In the remaining cases (25.5%), diverse microorganisms were identified, mostly non-pathogenic bacteria. The statistical analysis revealed no significant differences between groups according to microbial growth in terms of 30-day mortality (p = 0.446), postprocedural hospital stay (p = 0.401), periprocedural infections (p = 0.434), 30-day major vascular complications (p = 1.0), and 30-day stroke rate (p = 1.0). Notably, the timing of sheath insertion was significantly associated with microbial growth; sheath placement more than 2 days prior to the procedure was associated with a significantly higher risk of microbial growth (OR: 2.1; 95% CI 1.1-4.3) (p = 0.030). CONCLUSIONS: The presence of temporary leads does not significantly impact clinical outcomes, irrespective of bacterial growth on the lead. However, the timing and duration of sheath placement plays a crucial role in contamination incidence. Thus, temporary leads/sheaths should be placed shortly before the procedure and removed promptly to reduce the risk of contamination/infection.

The Spread of Mycobacterium chimaera from Heater-Cooler Units and Infection Risk in Heart Surgery: Lessons from the Global Outbreak?

Mycobacterium chimaera (MC), a member of the Mycobacterium avium complex, can cause infections in patients after open-heart surgery due to contaminated heater-cooler units (HCUs). The transmission route of HCU-related MC infection is non-inhalational, and infection can occur in patients without previously known immune deficiency. Patients may develop endocarditis of the prosthetic valve, infection of the vascular graft, and/or manifestations of disseminated mycobacterial infection (splenomegaly, arthritis, hepatitis, nephritis, myocarditis, etc.). MC infections have serious outcomes (30-50% recurrence rate, 20-67% mortality rate). In 2015, an international outbreak of M. chimaera infections among patients undergoing cardiothoracic surgeries was associated with exposure to contaminated LivaNova 3T HCUs (formerly Stöckert 3T heater-cooler system, London, United Kingdom). In response to the global outbreak, many international agencies have issued directives and recommendations in order to reduce the risk of MC infection in cardiac surgery. Whole-genome sequencing (WGS) technology can be used to describe the global spread and dynamics of MC infections, to characterize local outbreaks, and also to identify sources of infection in hospital settings. In order to minimize the risk of contamination of HCUs and reduce the risk of patient infection, it is imperative that healthcare facilities establish a program of regular cleaning and disinfection maintenance procedures as well as monitoring of the water used and the air in the operating room, in accordance with the manufacturer's procedure.

Hypogammaglobulinemia and infection risk in myotonic dystrophy type 1.

INTRODUCTION/AIMS: Hypogammaglobulinemia is a common yet under-recognized feature of myotonic dystrophy type 1 (DM1). The aims of our study were to determine the frequency of immunoglobulin G (IgG) deficiency in our cohort, to examine the association between immunoglobulin levels and cytosine-thymine-guanine (CTG) repeat length in the DMPK gene, and to assess whether IgG levels are associated with an increased risk of infection in DM1 patients. METHODS: We conducted a single-center, retrospective cross-sectional study of 65 adult patients with DM1 who presented to the Neuromuscular Clinic at Concord Repatriation General Hospital, Sydney, Australia, between January 2002 and January 2022. We systematically collected and analyzed clinical, laboratory, and genetic data for all patients with available serum electrophoresis and/or IgG level results. RESULTS: Forty-one percent of DM1 patients had IgG deficiency despite normal lymphocyte counts, IgA, IgM, and albumin levels. There was an association between CTG repeat expansion size and the degree of IgG deficiency (F = 6.3, p = .02). There was no association between IgG deficiency and frequency of infection in this group (p = .428). DISCUSSION: IgG deficiency is a frequent occurrence in DM1 patients and is associated with CTG repeat expansion size. Whether hypogammaglobulinemia is associated with increased infection risk in DM1 is unclear. A prospective multicenter cohort study is needed to evaluate this.

Effects of long-term corticosteroid use on susceptibility to respiratory viruses: a narrative review.

BACKGROUND: Synthetic glucocorticoids are among the most commonly administered drugs due to their potent immunomodulatory properties. However, they may put patients at risk for infections. Their effect on the incidence of respiratory viral infections (RVIs) remains unclear. OBJECTIVES: The aim of this review is to provide an insightful overview of the most up-to-date evidence regarding the extent to which the use of corticosteroids (CSs) influences the risk of RVIs. SOURCES: The PubMed database was searched for studies on the association between CSs and RVIs from inception until 15 December 2023. CONTENT: CSs have differing impacts on the risk of RVIs in asthma and chronic obstructive pulmonary disease, influenced by both the specific virus and the type and dose of CSs. Furthermore, current data demonstrate that CSs may increase the risk of RVIs in patients with systemic lupus erythematosus, rheumatoid arthritis, vasculitis, solid tumours, haematological malignancies, and among transplant recipients. IMPLICATIONS: Large-scale studies are imperative to inform a more accurate and personalized risk stratification for RVIs. This, in turn, will point towards new strategies for RVI prevention and associated morbidity and mortality in high-risk populations.

Effects of Physical Exercise on the Microbiota in Irritable Bowel Syndrome.

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder characterized by abdominal pain, bloating, diarrhea, and constipation. Recent studies have underscored the significant role of the gut microbiota in the pathogenesis of IBS. Physical exercise, as a non-pharmacological intervention, has been proposed to alleviate IBS symptoms by modulating the gut microbiota. Aerobic exercise, such as running, swimming, and cycling, has been shown to enhance the diversity and abundance of beneficial gut bacteria, including Lactobacillus and Bifidobacterium. These bacteria produce short-chain fatty acids that possess anti-inflammatory properties and support gut barrier integrity. Studies involving IBS patients participating in structured aerobic exercise programs have reported significant improvements in their gut microbiota's composition and diversity, alongside an alleviation of symptoms like abdominal pain and bloating. Additionally, exercise positively influences mental health by reducing stress and improving mood, which can further relieve IBS symptoms via the gut-brain axis. Long-term exercise interventions provide sustained benefits, maintaining the gut microbiota's diversity and stability, supporting immune functions, and reducing systemic inflammation. However, exercise programs must be tailored to individual needs to avoid exacerbating IBS symptoms. Personalized exercise plans starting with low-to-moderate intensity and gradually increasing in intensity can maximize the benefits and minimize risks. This review examines the impact of various types and intensities of physical exercise on the gut microbiota in IBS patients, highlighting the need for further studies to explore optimal exercise protocols. Future research should include larger sample sizes, longer follow-up periods, and examine the synergistic effects of exercise and other lifestyle modifications. Integrating physical exercise into comprehensive IBS management plans can enhance symptom control and improve patients' quality of life.

Relative Health Risk Reduction from an Advanced Multi-Modal Air Purification System: Evaluation in a Post-Surgical Healthcare Setting.

Advanced air treatment systems have the potential to reduce airborne infection risk, improve indoor air quality (IAQ) and reduce energy consumption, but few studies reported practical implementation and performance. PlasmaShield®, an advanced multi-modal HVAC-integrated system, was directly compared with a standard MERV-13 system in a post-surgical paediatric healthcare setting. The evaluation entailed monitoring of multi-size airborne particles, bioaerosols and key IAQ parameters. Measurements were taken for outside air, supply air and air in the occupied space for 3 days prior to, and after, the installation of the PlasmaShield system. Compared with the existing arrangement, very significant reductions in particle number concentrations were observed in the occupied space, especially with virus-like submicron particles. Significant reductions in airborne culturable bacteria and fungi were observed in the supply air, with more modest reductions in the occupied space. In the case of virus-like particles, there was an eight-fold improvement in equivalent clean air, suggesting a five-fold infection risk reduction for long-range exposure. The data suggest multiple benefits of airborne particle and bioaerosol reduction, with applications beyond healthcare. Long-term studies are recommended to confirm the combined IAQ, health and energy benefits.

Analysis of the effects of postoperative cluster nursing care on the incidence rate of postoperative complications and nutritional indicators in patients with primary laryngeal cancer.

OBJECTIVE: In this study, we investigated the effects of cluster nursing care on postoperative infection risk and nutritional indicators in patients with primary laryngeal cancer. METHODS: This study comprised 50 patients with primary laryngeal cancer diagnosed between March 2020 and December 2022. They were randomly divided into the test and control groups, with each group comprising 25 patients. The test group received cluster nursing care, while the control group received standard nursing care. Indicators for quantitative scoring, such as Patient Generated Subjective Global Assessment (PG-SGA), Zubrod Performance Status (ZPS), Karnofsky score, and Nutrition Risk Screening 2002 (NRS-2002), measurement indicators such as body mass index (BMI), body mass, hip circumference, calf circumference, grip strength, weight loss, and laboratory indicators, such as hemoglobin, albumin, and transaminase levels, were used to analyze change. RESULTS: Improvements were observed in the scores of PG-SGA, ZPS, and NRS-2002 in the test group following the implementation of nursing care for the test and control groups for 1 week, which were statistically significantly different from those at baseline (P < 0.05), and compared to the control group (P < 0.05). No statistically significant differences were observed in other indicators (P > 0.05). There was a statistically significant difference (P < 0.05) between the incidence rate of infections and complications in the test and control groups, which were 20.00% and 48.00%. CONCLUSION: The postoperative nutritional status of patients with primary laryngeal cancer improved in phases through specialized nursing care. It is also a factor closely related to postoperative complications.

[Clinical Analysis of Epstein-Barr Virus Infection after Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To analyze the risk factors of Epstein-Barr virus (EBV) infection after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and its impact on survival. METHODS: The clinical data of 347 patients who underwent their first allo-HSCT in our hospital from January 2014 to June 2021 were retrospectively analyzed. Patients were divided into EBV (n =114) and Non-EBV (n =233) groups according to whether they were infected with EBV. The incidence of EBV infection after allo-HSCT was calculated, and the risk factors of EBV infection were analyzed. RESULTS: A total of 114(32.8%) patients presented EBV infection (all peripheral blood EBV-DNA were positive). EBV infection occurred in 88 patients within 100 days after transplantation, which accounted for 77.2% of all patients with EBV infection. 5 cases (1.44%) were confirmed as post-transplant lymphoproliferative disorder (PTLD). The median onset time of patients was 57(7-486) days after transplantation. Multivariate analysis showed that the use of ATG/ATG-F, occurrence of CMV viremia, and grade III-IV aGVHD were risk factors for EBV infection. Furthermore, compared to BUCY, the use of intensified preconditioning regimens containing FA/CA was significantly increased the risk of EBV infection. CONCLUSION: EBV infection is a common complication after allo-HSCT. Intensified preconditioning regimens, use of ATG/ATG-F, CMV viremia and grade III to IV aGVHD increase the risk of EBV infection after allo-HSCT.

Is Full Scrubbing Necessary Before Short Endourological Procedures to Reduce the Risk of Post-Operative Infection? A Retrospective Cross-Sectional Study.

Background: Endoscopic surgery is now increasingly taking the place of open surgery in urology. Traditionally, endourological procedures are classified as clean-contaminated because the genitourinary tract is colonized by micro-flora, even in the case of sterile urine. The aim of this study was to determine whether a difference occurs in the infection rate after short endourological procedures using standard scrubbing and partial scrubbing techniques before the operations. Patients and Methods: This was a retrospective analysis of 397 patients who underwent a short endourological procedure, with all procedure durations lasting <30 min. Patients were divided into a first group who underwent operations using a full-scrub technique and a second group who underwent operations using a partial-scrub technique. All patients were followed up for the occurrence of urinary tract infections (UTIs). Both groups were compared for age, gender, and post-operative development of UTIs. Values of p < 0.05 were considered statistically significant. Results: Of the 397 patients, 200 and 197 underwent their procedures using the full-scrub and partial-scrub techniques, respectively. Females and males accounted for 142 (35.8%) and 255 (64.2%) patients, respectively. Only 18 (4.5%) patients developed documented UTIs and antibiotics were prescribed. Of the 18 patients diagnosed with post-operative UTIs, 10 (55.5%) had undergone partial-scrub operations and 8 (45.5%) had undergone full-scrub operations (p = 0.638). Conclusion: Our findings did not indicate any significant relationship between the risk of developing UTI after a short endourological procedure and the scrub technique used before the operation (partial or full scrub).

Influence of non-pharmaceutical interventions during the COVID-19 pandemic on respiratory viral infections - a prospective population-based cohort study.

Non-pharmaceutical interventions (NPI) have been proven successful in a population-based approach to protect from SARS-CoV-2 transmission during the COVID-19 pandemic. As a consequential-effect, a reduction in the spread of all respiratory viruses has been observed, but the primary factors behind this phenomenon have yet to be identified. We conducted a subgroup analysis of participants from the ELISA study, a prospective longitudinal cohort study on SARS-CoV-2 transmission, at four timepoints from November 2020 - September 2022. The aim was to provide a detailed overview of the circulation of respiratory viruses over 2 years and to identify potential personal risk factors of virus distribution. All participants were screened using qPCR for respiratory viral infections from nasopharyngeal swabs and answered a questionnaire regarding behavioral factors. Several categories of risk factors for the transmission of respiratory viruses were evaluated using a scoring system. In total, 1,124 participants were included in the study, showing high adherence to governmental-introduced NPI. The overall number of respiratory virus infections was low (0-4.9% of participants), with adenovirus (1.7%), rhino-/enterovirus (3.2%) and SARS-CoV-2 (1.2%) being the most abundant. We detected an inverse correlation between the number and intensity of NPI and the number of detected respiratory viruses. More precisely, the attendance of social events and household size was associated with rhino-/enterovirus infection while social contacts were associated with being positive for any virus. NPI introduced during the COVID-19 pandemic reduced the occurrence of seasonal respiratory viruses in our study, showing different risk-factors for enhanced transmission between viruses. Trial registration: DRKS.de, German Clinical Trials Register (DRKS), Identifier: DRKS00023418, Registered on 28 October 2020.

Polarization and health-related behaviours and outcomes during the COVID-19 pandemic: a systematic review protocol.

Introduction: The COVID-19 pandemic affected people's health behaviours and health outcomes. Political or affective polarization could be associated with health behaviours such as mask-wearing or vaccine uptake and with health outcomes, e.g., infection or mortality rate. Political polarization relates to divergence or spread of ideological beliefs and affective polarization is about dislike between people of different political groups, such as ideologies or parties. The objectives of this study are to investigate and synthesize evidence about associations between both forms of polarization and COVID-19 health behaviours and outcomes. Methods: In this systematic review, we will include quantitative studies that assess the relationship between political or affective polarization and COVID-19-related behaviours and outcomes, including adherence to mask mandates, vaccine uptake, infection and mortality rate. We will use a predetermined strategy to search EMBASE, Medline (Ovid), Cochrane Library, Cochrane COVID-19 Study Register, Global Health (Ovid), PsycInfo (Ovid), Web of Science, CINAHL, EconLit (EBSCOhost), WHO COVID-19 Database, iSearch COVID-19 Portfolio (NIH) and Google Scholar from 2019 to September 8 2023. One reviewer will screen unique records according to eligibility criteria. A second reviewer will verify the selection. Data extraction, using pre-piloted electronic forms, will follow a similar process. The risk of bias of the included studies will be assessed using the JBI checklist for analytical cross sectional studies. We will summarise the included studies descriptively and examine the heterogeneity between studies. Quantitative data pooling might not be feasible due to variations in measurement methods used to evaluate exposure, affective and political polarization. If there are enough relevant studies for statistical data synthesis, we will conduct a meta-analysis. Discussion: This review will help to better understand the concept of polarization in the context of the COVID-19 pandemic and might inform decision making for future pandemics. Protocol registration: PROSPERO ID: CRD42023475828.

Impact of machine perfusion on transplant infectious diseases: New challenges and opportunities.

Preservation techniques that maintain the viability of an organ graft between retrieval from the donor and implantation into the recipient remain a critical aspect of solid organ transplantation. While traditionally preservation is accomplished with static cold storage, advances in ex vivo dynamic machine perfusion, both hypothermic and normothermic, have allowed for prolongation of organ viability and recovery of marginal organs effectively increasing the usable donor pool. However, the use of these novel machine perfusion technologies likely exposes the recipient to additional infectious risk either through clonal expansion of pathogens derived during organ recovery or de novo exogenous acquisition of pathogens while the organ remains on the machine perfusion circuit. There is a paucity of high-quality studies that have attempted to quantify infection risk, although it appears that prolonging the time on the machine perfusion circuit and normothermic parameters increases the risk of infection. Conversely, the use of ex vivo machine perfusion unlocks new opportunities to detect and treat donor-derived infections before implantation into the recipient. This review seeks to reveal how the use of ex vivo machine perfusion strategies may augment the risk of infection in the organ recipient as well as outline ways that this technology could be leveraged to enhance our ability to manage donor-derived infections.

On modelling airborne infection risk.

Airborne infection risk analysis is usually performed for enclosed spaces where susceptible individuals are exposed to infectious airborne respiratory droplets by inhalation. It is usually based on exponential, dose-response models of which a widely used variant is the Wells-Riley (WR) model. We revisit this infection-risk estimate and extend it to the population level. We use an epidemiological model where the mode of pathogen transmission, airborne or contact, is explicitly considered. We illustrate the link between epidemiological models and the WR and the Gammaitoni and Nucci models. We argue that airborne infection quanta are, up to an overall density, airborne infectious respiratory droplets modified by a parameter that depends on biological properties of the pathogen, physical properties of the droplet and behavioural properties of the individual. We calculate the time-dependent risk of being infected for two scenarios. We show how the epidemic infection risk depends on the viral latent period and the event time, the time infection occurs. Infection risk follows the dynamics of the infected population. As the latent period decreases, infection risk increases. The longer a susceptible is present in the epidemic, the higher its risk of infection for equal exposure time to the pathogen is.