Influenza and Other Respiratory Viruses

BackgroundWe previously reported that nasal SARS-CoV-2 viral loads (VL) peaked around the fourth day of symptoms in highly immune adults sampled April 2022 - April 2023, while influenza A VL peaked soon after symptom onset. We hypothesized that SARS-CoV-2 kinetics may have changed due to reduced COVID-19 incidence and altered vaccination patterns. Understanding how viral kinetics evolve over time is essential to inform testing strategies. MethodsParticipants with symptomatic upper respiratory i...

This study shows that the quality of the morbidity data is sufficient to allow for meaningful analyses of spatiotemporal dynamics and provides a significant contribution to understanding the 1918-1920 influenza pandemic in Switzerland by complementing existing mortality- focused research with a morbidity perspective. Previous studies have examined the spatial patterns of mortality during the 1918-1920 influenza pandemic and associated explanatory factors. However, while mortality reflects the se...

BackgroundRespiratory syncytial virus (RSV) is a leading cause of severe acute respiratory infection in infants, young children and vulnerable adults. Despite implications for designing interventions, our understanding of RSV infection/reinfection patterns during community outbreaks is incomplete. MethodsTo characterize respiratory virus infections regardless of symptom status, we performed a prospective cohort surveillance in coastal Kenya from August 2023 to August 2024. Nasopharyngeal/oropha...

Since the cessation of real-time monitoring of COVID-19 hospitalizations in early 2024, the burden of and vaccine effectiveness (VE) against severe COVID-19 in the Netherlands was largely unknown. Recently, hospitalization data from 2024 were made available for the purpose of monitoring and evaluating the COVID-19 vaccination campaigns. These data were linked to the population registry, vaccination registry and healthcare use data (for classification into medical risk groups). We analyzed the n...

ObjectivesTo determine associations of common infections with self-reported sleep and explore whether these links differ by race in a diverse cohort. MethodsWe studied 602 participants from the Baltimore Epidemiologic Catchment Area Study (mean age 59.0{+/-}12.8 years; 36.9% male; 35.6% minoritized adults) with data on common infections (IgG antibodies to herpes simplex virus type 1, cytomegalovirus, varicella zoster virus, Epstein-Barr virus, and Toxoplasma gondii) and self-reported symptoms o...

ObjectiveTo estimate dengue virus (DENV) seroprevalence and assess parental vaccine perceptions among children in the US Virgin Islands (USVI). MethodsA cross-sectional serosurvey was conducted during April-May 2022 among 372 children aged 8-16 years from 15 schools across USVI. Past DENV infection was determined using a dengue IgG rapid diagnostic test. Data on demographics, dengue knowledge, and vaccine acceptance were collected from parents. Catalytic models estimated annual DENV force of in...

BackgroundHealthcare-associated carbapenemase-producing Enterobacterales (CPE) outbreaks are a major healthcare challenge. Epidemiological studies have identified patient-level risk factors for CPE transmission, and genomic studies have highlighted high-risk lineages or mobile genetic elements (MGEs); however, a unified dissemination risk-prediction framework is lacking. ObjectivesTo synthesise available data on epidemiological, microbiological and genomic risk factors to quantify healthcare-as...

ObjectivesDespite the availability of effective vaccines, achieving the seroprevalence thresholds recommended by the World Health Organization (WHO) for eliminating measles, rubella, and mumps remains a public health challenge. MethodsA retrospective, cross-sectional serological survey was conducted, including 9,587 serum samples collected from 31 of the 32 federal entities of Mexico between September and December 2024. IgG antibody levels against measles, rubella, and mumps were quantified usi...

BackgroundRespiratory viruses are major contributors to population mortality, but cause-of-death coding undercounts their impact. Ecological regression models linking viral circulation to mortality fluctuations can address this limitation. AimTo estimate the population attributable fraction (PAF) of mortality associated with influenza A and B, respiratory syncytial virus (RSV), and SARS-CoV-2 in Ontario, Canada (1993-2024). MethodsWe analysed monthly all-cause mortality data with laboratory su...

Background and objectiveRespiratory Syncytial Virus (RSV) can cause severe illness in adults, leading to respiratory and non-respiratory complications, functional decline, hospitalisation, and death. This study describes French patients aged [≥]50 years hospitalised with RSV (2015-2022) and their care pathways, including hospitalisation and outpatient healthcare use and costs. MethodsData were extracted from the French National Health Data System (SNDS). Patients were classified into four ri...

In the three years since Omicron emergence, SARS-CoV-2 dynamics have exhibited persistent twice-yearly waves in the United States, peaking in late summer and winter, with heterogeneity in timing and intensity across states. This semiannual pattern sharply contrasts with typical annual respiratory pathogen dynamics in the US, yet their underlying mechanisms and whether this pattern will persist remain poorly understood. Here, we tested several hypothesized mechanisms and found that a combination ...

BackgroundSerotype 3 (S3) has remained a major cause of invasive pneumococcal disease (IPD) despite its inclusion in 13-valent pneumococcal conjugate vaccine (PCV). In October 2023, a 15-valent PCV (PCV15) including S3 was introduced into the Catalan universal childhood immunization program. MethodsWe conducted a retrospective pre-post surveillance study to compare pediatric IPD incidence in Catalonia during a pre-PCV15 period (October 1, 2022-September 30, 2023) and two post-PCV15 periods (Oct...

BackgroundNorovirus causes substantial burden to healthcare systems. England experienced high activity in recent seasons alongside a shift in the dominant genotype from GII.4 to GII.17. It remains unclear whether this increased burden reflects changes in severity or other transmission mechanisms associated with the strain replacement. MethodsIndividual-level testing and mortality data in England from 2022/23-2024/25 seasons were linked from national surveillance systems. Piece-wise exponential ...

ObjectivesPeriodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is the most common autoinflammatory disorder of childhood, characterized by recurrent febrile episodes driven by dysregulated innate immune activation. Although genetic susceptibility contributes to disease risk, environmental modifiers remain poorly defined. Vaccinations may induce long-lasting modulation of innate immune responses and influence PFAPA incidence. We aimed to assess whether childhoo...

SARS-CoV-2 mutations play a key role in viral evolution, in immune escape, and potentially in disease severity. However, the clinical impact of most mutations remains poorly understood, particularly across different variants. A historical observational study was conducted using SARS-CoV-2 whole-genome sequencing data linked to clinical metadata from 175,503 COVID-19 cases in Israel. The dataset was stratified into four variant-specific periods: B.1.1.7, B.1.617.2, BA.1, and BA.2. Logistic regres...

Dengue virus (DENV), comprising four distinct serotypes (DENV-1 to DENV-4), poses a major public health challenge in tropical regions. Infection with one serotype confers long-term immunity to that serotype alone, while subsequent heterologous infections are associated with increased risk of severe disease, necessitating vaccines that induce durable, balanced immunity across all serotypes. However, achieving such balance immunity remains a central challenge for dengue vaccine development. Using ...

BackgroundObstructive sleep apnea (OSA), as measured by the Apnea Hypopnea Index (AHI), is associated with adverse outcomes. Measures that characterize the temporal variability in events may provide information over and beyond a simple summary of event frequency as measured by the AHI. Research QuestionTo assess whether temporal variability in the occurrence of obstructive apnea/hypopneas during the night is associated with all-cause mortality or incident cardiovascular disease (CVD). Study De...

BackgroundNontyphoidal Salmonella enterica (NTS) is a major public-health threat in the United States of America (U.S.). Evaluating associations between serovars, exposure sources, and settings in multistate outbreaks can reveal the drivers of NTS transmission and guide prioritization of targeted prevention and control strategies. MethodsWe analyzed multistate animal-contact NTS outbreaks reported to the CDC National Outbreak Reporting System during 2009-2022. We calculated incidence rates per ...

Influenza forecasting in (sub-)tropical regions remains understudied due to year-round, irregular transmission patterns. Further, the variation in seasonality and transmission characteristic of influenza in post-COVID-19 pandemic could be attributed to various drivers to quantify for better understanding. To address this issue, this study introduced an ensemble forecasting approach that incorporates varied dataset lengths to forecast influenza activity in Hong Kong, integrating multi-stream surv...

BackgroundTwo RSV immunisations products: a maternal vaccine, Abrysvo, and a long-acting monoclonal antibody, nirsevimab, both designed to prevent RSV illness in infants, have recently become available. Modelling evidence is required to inform how to optimally use these products in immunisation programs to reduce the burden of RSV in young children. MethodsWe extend a dynamic transmission model calibrated to RSV-hospitalisation data of children aged < 5 years in temperate Western Australia (WA)...