Search Results (207)

The COVID-19 pandemic highlighted the need for a scientific framework that enables quantitative assessment and control of airborne infection risks in indoor environments. This study identifies limitations in the traditional Wells–Riley model—specifically its assumptions of perfect mixing and steady-state conditions—and addresses these shortcomings by adopting the REHVA (Federation of European Heating, Ventilation and Air Conditioning Associations) infection risk assessment model. We propose a five-tier risk classification system (Monitor, Caution, Alert, High Risk, Critical) based on two key metrics: the probability of infection (Pₙ) and the event reproduction number (R_event). Unlike the classical model, our approach integrates airborne virus removal mechanisms—such as natural decay, gravitational settling, and filtration—with occupant dynamics to reflect realistic contagion scenarios. Simulations were conducted across 10 representative indoor settings—such as classrooms, hospital waiting rooms, public transit, and restaurants—considering ventilation rates and activity-specific viral emission patterns. The results quantify how environmental variables (ventilation, occupancy, time) impact each setting’s infection risk level. Our findings indicate that static mitigation measures such as mask-wearing or physical distancing are insufficient without dynamic, model-based risk evaluation. We emphasize the importance of incorporating real-time crowd density, occupancy duration, and movement trajectories into risk scoring. To support this, we propose integrating computer vision (CCTV-based crowd detection) and entry/exit counting sensors within a live airborne risk assessment framework. This integrated system would enable proactive, science-driven epidemic control strategies, supporting real-time adaptive interventions in indoor spaces. The proposed platform could serve as a practical tool for early warning and management during future airborne disease outbreaks. Full article

Arboviruses are a growing concern in many nations. Several reports of arboviral outbreaks have been recorded globally in the past decade alone. Repeated arboviral outbreaks in developing countries have consistently highlighted vulnerabilities in disease surveillance and response systems, exposing critical gaps in early detection, contact tracing, and resource allocation. The 2024 Dengue fever outbreak in Ghana, which recorded 205 confirmed cases out of 1410 suspected cases, underscored the urgent need to evaluate the country’s preparedness for arboviral outbreaks, given the detection of competent vectors in the country. A retrospective analysis of Ghana’s 2009–2013 pandemic influenza response plan revealed significant deficiencies in emergency preparedness, raising concerns about the country’s ability to manage emerging arboviral threats. This review assessed Ghana’s current arboviral outbreak response and preparedness by examining (a) the effectiveness of vector control measures, (b) the role of early warning systems in mitigating outbreaks, (c) laboratory support and diagnostic capabilities, and (d) community engagement strategies. It highlights the successes made in previous outbreaks and sheds light on several gaps in Ghana’s outbreak response efforts. This review also provides recommendations that can be implemented in many countries across Africa as they brace themselves for any arboviral outbreak. Full article

Background: During the COVID-19 pandemic, the emergence of multidrug-resistant (MDR) pathogens, driven by heightened antibiotic usage and device-associated infections, has posed significant challenges to healthcare. This study reports an outbreak of Proteus mirabilis producing NDM-5 and CTX-M-15 β-lactamases in a hospital in Buenos Aires, Argentina, from October 2020 to April 2021. To our knowledge, this represents the first documented outbreak of NDM-5-producing P. mirabilis in the country. Methods: A total of 82 isolates were recovered from 40 patients, with 41.5% from blood cultures and 18.3% from respiratory and urinary samples, among others. Antimicrobial susceptibility testing, PCR-based methods, and MALDI-TOF MS cluster analysis were conducted. Whole genome sequencing (WGS) was performed to characterize the MLST, resistome and plasmid content. Biofilm formation assays and in vitro rifampicin susceptibility tests were also conducted. Result: Most isolates exhibited resistance to carbapenems, cephalosporins, aminoglycosides, and fluoroquinolones, while retaining susceptibility to aztreonam. Genetic analysis confirmed the co-presence of the bla_NDM-5 and bla_CTX-M-15 genes. Clonal relationships was supported by PCR-based typing and MALDI-TOF MS cluster analysis. WGS revealed a resistome comprising 25 resistance genes, including rmtB and both β-lactamases, as well as the presence of an incomplete IncQ1 replicon associated with multiple resistance determinants. MLST classified this clone as belonging to ST135. Despite the biofilm-forming capacity observed across strains, rifampicin demonstrated potential for disrupting established biofilms at concentrations ≥32 µg/mL in vitro. The MDR profile of the outbreak strain significantly limited therapeutic options. Conclusions: This study highlights the growing threat of NDM-producing P. mirabilis in Argentina. The absence of surveillance cultures from the index case limits insights into the outbreak’s origin. These findings underscore the importance of integrating genomic surveillance into infection control protocols to mitigate the spread of MDR pathogens. Full article

Pseudorabies virus (PRV) is a highly contagious pathogen in swine that can cross species barriers and infect other mammals, including humans. Given the potential for interspecies transmission and its threat to public health, understanding the molecular biology of PRV strains is essential for developing effective control measures and preparing for future pandemics. In this study, a novel PRV strain, PRV-HL-2021, was isolated from an outbreak in Heilongjiang Province, China. The viral genome was used to establish a reverse genetics system based on a fosmid library of the PRV-HL-2021 genome. This system facilitated the creation of recombinant PRV, including one expressing EGFP and another with deletions in the US9, gI, and gE genes. PRV-HL-2021 was found to be highly lethal to mice in vivo. The recombinant PRV strains, such as rPRV-US9-EGFP and rPRV-delgI/gE/US9, exhibited growth characteristics similar to the parental PRV-HL-2021 strain. The isolation and characterization of PRV-HL-2021 contribute to a better understanding of the genetic diversity of PRV strains. The developed reverse genetics system provides valuable tools for investigating viral functions, creating genetically modified PRV strains, and advancing the development of safer vaccines. These findings will enhance strategies for controlling PRV outbreaks and mitigating its impact on both animal and public health. Full article

Background: The COVID-19 pandemic highlighted the crucial role of community preventive behaviors in controlling the virus’ spread. Studies show that people’s risk perceptions and awareness significantly contribute to the containment and prevention of infections by motivating adoption of desired actions and behaviors. This study aimed at assessing the role of risk communication and factors that influenced responses during the COVID-19 pandemic in rural communities in Western Kenya. Methods: A descriptive cross-sectional study was conducted using a quantitative research approach, collecting data from 806 individuals across Kisumu, Vihiga, and Kakamega counties. Descriptive statistics were used to detail the demographic characteristics of the study population, while logistic regression analysis estimated the associations between risk communication and demographic characteristics on COVID-19 vaccine acceptance, compliance with mitigation behaviors, perceived severity, and perceived susceptibility. Results: The results showed that 55% of participants were male and 45% were female, with an average moderate compliance with safety measures (mean = 5.15). A significant portion of participants wore face masks (85.3%), practiced hand hygiene (78.9%), and avoided close contact behaviors (66.6%). Most respondents received information through mass media (86.1%) and health workers (72.9%). Compliance with COVID-19 mitigation measures was highest among those who trusted information from official institutions, health professionals, and mass media, compared to social media, with increased odds of 2.7 times and 2.5 times, respectively. Higher risk perception was significantly associated with older age groups (above 50 years), being male, and working in the private sector. Effective risk communication significantly influenced risk perception, compliance with COVID-19 measures, and vaccination acceptance. Conclusions: The findings suggest that effective risk communication strategies are critical during public health emergencies and hence implications for future public health crises. The results underscore the importance of targeted communication and tailored interventions to improve compliance and vaccine acceptance among different demographic groups, ensuring a more robust public health response during outbreaks and pandemics. Full article

Background: Respiratory droplets are the main way in which the COVID-19 pandemic’s causal agent, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), spreads. Angiotensin-converting enzyme 2 (ACE2) receptors, especially in lung cells, allow the virus to enter host cells. However, ACE2 expression in intestinal cells has sparked worries about possible fecal transfer, particularly in poor-sanitation areas like India. Methods: Between July 2021 and July 2024, clinical (nasopharyngeal, saliva, and stool samples) and sewage samples were collected from outpatient departments and sewage treatment plants (STPs), respectively, from the high-population-density area under study in order to investigate SARS-CoV-2 transmission. Results: This proof-of-concept study analyzed clinical samples from n = 60 COVID-19-positive patients at a central Indian tertiary care hospital and n = 156 samples from hospital STPs. Variants of SARS-CoV-2 were found using qRT-PCR and Next-Generation Sequencing (NGS). Of the n = 37 qRT-PCR-positive patients who gave their assent, 30% had stool samples that tested positive for viral RNA. In 70% of positive NP and 65% of positive saliva samples, along with two stool samples from immunocompromised patients, the live virus was identified using Vero E6 cell lines. Although 18% of the tests reported qRT-PCR-positive results, no live virus was detected in sewage samples despite NGS validation. The detection of SARS-CoV-2 in the absence of confirmed clinical cases may indicate the silent circulation of the virus within the community, suggesting that sewage surveillance can serve as an early warning system before an outbreak occurs. Conclusions: These findings provide critical insights into the importance of continuous environmental surveillance, silent virus circulation, changes in viral epidemiology throughout the years, and strategies to mitigate coronavirus outbreaks. Full article

Seasonal outbreaks and occasional pandemics triggered by influenza viruses annually impose considerable burdens on public health and finances. The continual evolution of viral strains with drug resistance emphasizes the urgency of discovering novel agents for influenza viruses. This study investigated a set of innovative substances derived from Morinda officinalis with antiviral potential against influenza virus strains. The top candidate, anthraquinone-2-carboxylic acid (A2CA), presented antiviral activity against diverse influenza virus strains, including those resistant to oseltamivir. In an influenza mouse model, the pre-administration of A2CA dose-dependently ameliorated influenza A virus (IAV)-mediated weight loss as well as protected mice from a lethal IAV infection. In addition, lung injury and cytokine dysregulation were mitigated. Further investigation revealed that IAV-induced activation of the RIG-I/STAT1 signaling pathway did not occur after A2CA treatment. A time-of-addition assay revealed that A2CA targeted the final phase of intracellular replication, which was further determined by molecular docking between A2CA and the IAV RdRp protein. Finally, transcriptome analysis revealed that the TP53TG3C, CFAP57 and SNX30-DT genes may be involved in the antiviral effects of A2CA. These results play a part in achieving a thorough comprehension of the capacity of A2CA to inhibit influenza virus infection. Full article

The implementation of COVID-19 policy and the rapid development of SARS-CoV-2 vaccines in the early pandemic significantly contained numerous outbreaks and reduced the severity and mortality of COVID-19. However, the population immunity induced by existing vaccines was insufficient to prevent SARS-CoV-2 outbreaks. The host immunity induced by the wide spread of Omicron variants and its influence on emerging SARS-CoV-2 variants are attracting broad attention. In this study, a clinical data analysis of the patients indicated that pre-vaccination reduced inflammatory responses and mitigated the severity of COVID-19 cases caused by natural infection with Omicron BA.5.2. The analysis of adaptive immune responses indicated that natural infection with BA.5.2 induced robust and broad immune responses, including both humoral and T cell-mediated immune responses (IFN-γ) against highly conserved viral antigens, and provided cross-reactive neutralization against various viral variants. Collectively, we report that the natural infection with Omicron BA.5.2 induced broad cross-reactive immunity against SARS-CoV-2 variants, which suggests that the development of a live attenuated SARS-CoV-2 vaccine with desired safety, high efficacy, broad spectrum, and long-term immune persistence is feasible. Therefore, we suggest that herd immunity, achieved through vaccination with attenuated vaccines, combined with booster doses of existing vaccines and antiviral therapy for people with high viral loads, may contribute to the eradication of this virus. Full article

Background: Pregnant people in Canada during the pandemic faced complex decision-making related to COVID-19 exposure risks and the safety of mitigation measures, including vaccines. To help inform future infectious disease–health promotion, we assessed pandemic pregnancy experiences and COVID-19 risk mitigation strategies. Methods: Respondents, pregnant at any time after January 2020 in Canada, completed an online, cross-sectional, descriptive survey from September 2021 to February 2022. Logistic regression was used to identify predictive factors associated with COVID-19 vaccine uptake and history of infection. Results: A purposive sample of predominantly non-racialized, high socioeconomic status women (n = 564), 58.2% primigravid during the pandemic, reported high COVID-19 vaccine uptake (87.4%). Educational attainment beyond high school predicted COVID-19 vaccination (college AOR: 2.72, CI: 1.24–5.94, p < 0.001; university AOR 4.01, CI: 1.91–8.40, p < 0.001; post-graduate university AOR: 7.31, CI: 2.84–18.81, p < 0.001). Immigrant status reduced the likelihood of COVID-19 vaccination (AOR: 0.20; CI: 0.09–0.49, p < 0.001). Racialized participants were 2.78-fold more likely to report infection (CI:1.19–6.50, p = 0.018). Conclusions: COVID-19 vaccination uptake was very high; however, vaccine hesitancy was evident among immigrants, with racialized participants more likely to report a history of COVID-19 infection. Tailored public health messaging using a health equity lens may yield more robust vaccine uptake for future infectious respiratory disease outbreaks. Full article

Bordetella pertussis is the causative agent of pertussis or whooping cough, an acute and highly contagious respiratory infection that can have serious and fatal complications such as pneumonia, encephalopathy, and seizures, especially for newborns. The disease is endemic not only in the European Union (EU)/European Economic Area (EEA) but also globally. Larger outbreaks are anticipated every three to five years, even in countries where vaccination rates are high. Despite the high pertussis vaccination coverage in developed countries and a low rate of pertussis incidence for many years, especially during the COVID-19 pandemic, the incidence of pertussis has been on the rise again, with outbreaks in some places, which is referred to as “re-emergence of pertussis”. The aim of this review is to underscore the critical importance of achieving high vaccination coverage, particularly among pregnant women, to safeguard vulnerable neonates from pertussis during their early months, before they are eligible for vaccination. This aligns with the need to address diagnostic challenges, mitigate disease severity, and strengthen public health strategies in light of the ongoing 2024 Bordetella pertussis resurgence. Full article

Background/Objectives:Ralstonia spp., opportunistic Gram-negative bacilli, pose increasing risks for nosocomial infections, particularly in neonatal intensive care units (NICUs). This study investigates an outbreak caused by Ralstonia mannitolilytica in an NICU during the COVID-19 pandemic, examining colonization and infection risk factors, clinical outcomes, and antibiotic resistance. Methods: A retrospective analysis was conducted on neonates hospitalized in a tertiary NICU from 2020 to 2021. Colonization and infection were identified via microbiological testing of clinical samples. Risk factors, such as mechanical ventilation, vascular access, mode of feeding, and antibiotic use, were recorded. Environmental sampling identified potential contamination sources. Antibiotic susceptibility was determined using EUCAST PK/PD breakpoints. Results: Among 36 neonates affected, 31 were colonized, and 5 developed infections, including bloodstream infection, pneumonia, surgical site infection, and urinary tract infection. Environmental investigations revealed contaminated water heaters as the primary sources. All isolates showed resistance to carbapenems and aminoglycosides but retained susceptibility to trimethoprim-sulfamethoxazole. The vast majority were susceptible to fluoroquinolones. Conclusions: This outbreak underscores the role of environmental water reservoirs, invasive procedures, and broad-spectrum antibiotics in R. mannitolilytica colonization and infection. Biofilm formation and antibiotic resistance complicate eradication and treatment. Heightened surveillance, rigorous infection control, and antimicrobial stewardship are crucial for mitigating risks in NICU settings. Full article

Background and Objectives: The coronavirus disease 2019 pandemic presented unprecedented challenges in balancing infection control measures with the timely management of ST-segment elevation myocardial infarction (STEMI), a time-sensitive condition. This study investigates the pandemic’s effects on STEMI management times and outcomes at a high-volume medical center in Taiwan. Materials and Methods: A retrospective analysis of 1309 STEMI patients was conducted at Chang Gung Memorial Hospital between 2017 and 2022. Patients were divided into pre-pandemic and pandemic groups. Measurement outcomes include in-hospital mortality rate, management times (e.g., door-to-balloon time), the rates of intra-aortic balloon pump (IABP) and/or veno-arterial extracorporeal membrane oxygenation (VA-ECMO) usage, mechanical ventilation, inotropic support, and the length of intensive care unit (ICU) and hospital stay. Kaplan–Meier survival analysis and statistical comparisons were performed to assess temporal trends and prognostic outcomes. Results: No significant difference in in-hospital mortality was observed between pre-pandemic (5.85%) and pandemic (7.03%) groups (p = 0.45). The pandemic group experienced longer management times, including door-to-cath arrival (p = 0.0335) and door-to-balloon time (p = 0.014), although all times remained below the 90 min threshold. Quality improvements during the first outbreak allowed the institution to handle higher case volumes during subsequent waves without further delays. Ninety-day survival analysis showed no significant disparity between groups (p = 0.3655). Conclusions: Pandemic-related delays in STEMI management were effectively mitigated through workflow optimization, preventing significant increases in mortality rates. This study highlights the adaptability of healthcare systems in responding to crises while maintaining quality care for time-sensitive emergencies. Future multicenter studies could provide broader insights into global STEMI management strategies under pandemic conditions. Full article

The COVID-19 pandemic has increased the interest in the use of wastewater-based surveillance (WBS) strategy for infectious disease monitoring, especially when clinical cases are underreported. The excretion of monkey virus (MPXV) in the feces of both symptomatic and preclinical individuals has further driven the interest in WBS applicability to MPXV monitoring in wastewater to support its mitigation efforts. We performed a systematic review with meta-analysis, using six databases to assess MPXV detection in wastewater. We performed a random-effects model meta-analysis to calculate the pooled prevalence at a 95% confidence interval (95% CI). Also, we carried out a subgroup analysis according to the country regions and a sensitivity analysis excluding studies classified as having a high risk of bias. The overall MPXV positivity rate in wastewater was estimated at 22% (95% CI: 14−30%; I² = 94.8%), with more detection rate in North America (26%, 95% CI: 8–43%) compared to Europe and Asia (22%, 95% CI: 12–31%). The MPXV detection rate was significantly higher in 2022 studies (22%, 95% CI: 13–31%) compared to 2023 (19%, 95% CI: 14–25%). The real-time PCR platform significantly detected more MPXV (24%, 95% CI: 14–34%) than the digital droplet PCR-based studies (17%, 95% CI: 4–31%), which was used less frequently. Viral concentration with centrifugation procedure indicated higher detection rates (21%, 95% CI: 10–33%) than other known sample concentration protocols. Generally, MPXV detection rates in wastewater samples strongly correlate with incidence cases of mpox (range of R = 0.78–0.94; p < 0.05). Findings from this study suggest that WBS of MPXV could be employed as an epidemiological early warning tool for disease monitoring and mpox outbreak prediction similar to the clinical case-based surveillance strategies. Full article

To identify measures that mitigate the impact of influenza in Latin America and the Caribbean, we compared the burden and detection capacity in humans and animals after the 2009 pandemic. The incidence rate in people was higher in Chile (23.72 per 100,000 people), but the impact was greater for Guatemala (503.78 disability-adjusted life years per 100,000 people). Brazil, Peru, Argentina, and Mexico built better medical testing, with typing being less frequent in Chile and Argentina, where costs for medical care were higher. The positivity rate among avian and nonhuman mammals was 5.8%, with more cases in Mexico, but constant testing in Chile. H5N1, H5N2, and H7N6 are deadly to poultry, whereas H1N1 is common in swine, and H3N8 in equines. By June 2023, H5N1 had caused severe influenza in two persons and killed millions of birds and hundreds of mammals with aquatic lifestyles. An analysis of the efforts in response to this outbreak revealed that handling of outbreaks in animals needs homogeneity and reinforcement of vaccination. Surveillance in exposed individuals requires articulation of medical and animal health authorities, and the region also demands decentralized typing and networks for genomic characterization. Full article

Background: During the COVID-19 pandemic, we continuously monitored the epidemiology of influenza virus among pediatric patients from January 2021 to December 2023 in Hainan Island, China. Methods: In this study, we collected 54,974 nasopharyngeal swab samples for influenza A Virus (IAV) testing and 53,151 samples for influenza B Virus (IBV) testing from pediatric outpatients. Additionally, we also collected 19,687 nasopharyngeal swab samples from pediatric inpatients for IAV and IBV testing. Outpatient samples were screened for influenza viruses (IVs) infection by the colloidal gold method. Targeted Next-Generation Sequencing (tNGS) was used to detect influenza virus infections in inpatients. Influenza virus types were identified by analyzing the HA/NA partial regions. Results: The findings revealed a significant decrease in the infection rate of IBV over the specified period, while the infection rate of IAV exhibited a rising trend. Additionally, B/Victoria lineage was the dominant epidemic strain in 2021, while the epidemic strains in 2022 and 2023 underwent a dynamic transformation from A/H3N2 to A/H1N1. Phylogenetic analysis revealed close relationships among the circulating strains. Nonetheless, because the sample size is limited, additional research is required. Conclusions: Our findings suggest that the predominant types of influenza viruses in the pediatric population are undergoing dynamic changes, influenced by the implementation and relaxation of non-pharmaceutical intervention measures. These findings highlight the need for adaptive influenza vaccination and containment strategies, particularly in tropical regions like Hainan, where climate and public health policies significantly impact viral transmission patterns. The insights gained from this study could inform more effective public health strategies in similar regions to mitigate the impact of influenza outbreaks in the future. Full article