Eurosurveillance

Background: Within the VEBIS-EHR project, monthly vaccine effectiveness (VE) of COVID-19 vaccines is routinely estimated across EU/EEA countries. While VE quantifies direct protection, it does not capture the overall population benefit of vaccination campaigns in terms of severe outcomes prevented. Aim: To estimate the impact of the 2023 and 2024 autumn COVID-19 vaccination campaigns in adults aged [≥]65 years. Methods: We conducted a retrospective cohort study using electronic health records data from Belgium, Denmark, Italy, Navarre (Spain), Portugal, Norway and Sweden. Weekly numbers of averted COVID-19-related hospitalisations and deaths during the 12 months following each campaign were estimated using observed COVID-19-related events, vaccine coverage (VC) and interpolated weekly VE. Results: Across participating countries/regions, among adults aged [≥]65 years, the 2023 autumn vaccination campaign averted approximately 6,200 hospitalisations (prevented fraction [PF] 10%) compared with 2,200 (PF 12%) in 2024. Among those aged [≥]80 years, the number of averted COVID-19-related deaths was 811 (PF 13%) for the 2023 campaign and 156 (PF 12%) for the 2024 campaign. Impact varied across countries, reflecting differences in VC, vaccination timing and outcome occurrence. Conclusion: The 2023 and 2024 autumn vaccination campaigns resulted in substantially different numbers of averted COVID-19-related hospitalisations and deaths among older adults, with fewer events averted in 2024. These findings highlight that the impact of vaccination programmes depends not only on VC and VE but also on alignment between vaccination timing and periods of increased viral circulation.

Background: High national vaccination coverage may conceal age-specific and spatially concentrated measles susceptibility. Objective: To assess whether published age-specific seropositivity results can be converted into a time-updated susceptibility profile that corresponds with subsequent measles incidence, while distinguishing susceptibility from infectious introductions and transmission conditions. Methods: For Israel, published 2015 age-specific seropositivity estimates were mapped to monthly birth cohorts and projected to 1 March 2018, accounting for births, aging, maternal antibody, routine vaccination, vaccine effectiveness, and uncertainty in assay interpretation. The primary outcome was reported age-specific incidence during the 2018-2019 outbreak; national and Jerusalem District case burdens were secondary outcomes. Published evidence from the Netherlands, Czechia, and Australia was compared using a common framework covering age distribution, assay classification, vaccination, importation, spatial concentration, and transmission context. Results: The estimated number susceptible in Israel on 1 March 2018 ranged from approximately 0.55 million (6.3% of the modelled population) to 1.92 million (22.4%), with a central estimate of 1.22 million (14.2%). Children aged <1 year had the highest central susceptible proportion (75.7%) and the highest later incidence (196.0 per 100,000). Jerusalem District accounted for 2,202 of 4,311 reported national cases, consistent with susceptibility concentrated in communities with lower first-dose coverage. The external comparisons showed that clustering amplified Dutch outbreak risk, survey design affected Czech estimates, and importation dominated Australian activity. Conclusions: Published seropositivity can identify immunity gaps, but useful outbreak-risk assessment must also represent susceptible density and distribution, introduction pressure, and local transmission conditions. Although the model was not designed to compare alternative vaccination schedules directly, its identification of substantial susceptibility during early childhood provides epidemiological support for Israel's recent decision to advance the second routine MMRV dose from 6 years to 18 months of age, thereby shortening the period during which young children remain dependent on single-dose protection.

Antimicrobial resistance constitutes a major threat to global public health. Among emerging extensively drug-resistant bacteria (eXDR), carbapenemase-producing Enterobacteriaceae (CPE) expose hospitals to outbreaks through rapid dissemination, and to therapeutic limitations. Through a mixed epidemiological-qualitative methods study, we report the most extensive CPE carriage outbreak known to date in France, which occurred at Hopital Europeen Marseille (HEM) between January and June 2025. By the end of November 2024, the admission of an index patient returning from Senegal carrying an NDM-producing Escherichia coli led to an extensive transmission, despite adherence to national screen and isolate guidelines. More than 7,500 rectal screening tests evidenced 481 CPE carriers (including 343 NDM, 129 OXA-48-like and 9 other CPE), and 14 vancomycin-resistant Enterococcus faecium carriers. This major outbreak conducted to a phenomenal involvement of clinical, technical and administrative teams within the institution. It highlighted operational limitations in current screening, cohorting and biocleaning strategies in the context of hospital-wide outbreak. We describe the outbreak trajectory, the control measures implemented and provide a structured synthesis of lessons learned across organisational, scientific and policy domains.

Mass gathering events (MGEs) play a critical role for infectious disease dynamics on a population level as they provide opportunities for superspreading; however, underlying mechanisms remain insufficiently understood. We analyzed nationwide GPS-based, individual-level location data from mobile phone users in Germany between April and August 2024 with 16m spatial precision. Potentially infectious contacts were inferred from close co-location and linked to contact settings using OpenStreetMap data. Various MGEs, including EURO 2024 matches, major concerts, festivals, and fairs were compared using a common contact metric. Non-football events generated substantially more contacts than football events. While overall national contact numbers remained stable, MGEs produced so-called "small-world" contacts which gather people from distant locations into close proximity and could strongly enhance infectious disease dynamics. Crucially, most high-risk contacts occurred within two hours before the event, not at the event itself, and concentrated in public transport, leisure, and event-adjacent areas. Our work provides the first systematic and comparative evaluation of contact exposure across various types of MGEs and contact settings. Event-type-specific dynamics, particularly indirect and mobility-driven contacts, critically shape infection risk. These insights can inform accurate transmission modeling, targeted intervention and event-management strategies.

The global dissemination of antimicrobial resistance is increasingly driven by bacterial clones combining antimicrobial resistance with enhanced virulence and environmental adaptability. Escherichia coli sequence type 131 (ST131) has historically been regarded as a major disseminator of the extended-spectrum {beta}-lactamase (ESBL) blaCTX-M-15. However, the emergence of E. coli ST1193 carrying blaCTX-M-15 may represent an ongoing shift in the epidemiology of this resistance determinant. Here, we investigated the prevalence, genomic characteristics, virulence and antimicrobial resistance potential of ST1193 in comparison with ST131. A total of 1,136 E. coli isolates were recovered from touristic and non-touristic environments, hospital-associated samples, and aircraft toilets in Guadeloupe. Isolates were whole-genome sequenced and analysed for antimicrobial resistance and virulence determinants. Additionally, publicly available genomic data comprising 1,215 blaCTX-M-15-positive ST131 and ST1193 isolates were analysed to assess temporal and geographical trends. ST1193 was significantly associated with aircraft-associated samples and exhibited a higher antimicrobial resistance gene burden than ST131, while maintaining a comparable virulence factor content. Analysis of publicly available genomes revealed similar temporal emergence patterns for blaCTX-M-15-positive ST1193 and ST131, with ST1193 showing a more recent distribution and a higher number of deposited isolates in recent years, consistent with a potential ongoing clonal replacement. Comparative genomic analysis identified numerous virulence and adaptation-associated genes shared between both sequence types, while ST1193 additionally carried distinct determinants, including components of the transmissible locus of stress tolerance. Furthermore, quinolone resistance-associated mutations were strongly linked to blaCTX-M-15 carriage, particularly among ST1193 isolates. Together, these findings identify E. coli ST1193 as an emerging high-risk clone with substantial potential for blaCTX-M-15 dissemination. Its association with aircraft-associated samples further highlights the potential role of air travel in long-distance transmission and underscores the need to reconsider current surveillance strategies focused predominantly on ST131.

Background Severe acute respiratory infections (SARI) strain healthcare systems. Sentinel surveillance remains central to SARI monitoring, but routinely collected hospital discharge data offer a scalable, population-wide complement. In Finland, national registers now enable register-based surveillance, yet SARI case definitions remain unevaluated. Aim To evaluate whether routinely collected electronic health records can support register-based SARI surveillance and establish a national case definition. Methods We conducted a retrospective register-based study linking inpatient discharge data from the Finnish Care Register for Health Care (Hilmo) and laboratory-confirmed pathogen notifications from the National Infectious Diseases Register (NIDR). Admissions were aggregated into hospitalisation episodes using generic and pathogen-specific respiratory ICD-10 codes and linked to laboratory-confirmed respiratory pathogens within an admission-centred window. We assessed the impact of diagnostic coding position, laboratory linkage windows and alternative case definitions on age distribution, seasonality and epidemic trend detection. Results We included 145,435 respiratory hospitalisation episodes. Laboratory confirmations clustered around admission, and a -7-to-+3-day window was selected; 51,498 (35.4%) had a linked laboratory confirmation. Specific primary-position diagnoses preserved clear seasonality and age distributions consistent with SARI epidemiology, whereas secondary-position diagnoses showed attenuated seasonality. A combined case definition incorporating specific primary diagnoses and laboratory-supported syndromic episodes produced stable epidemic curves while improving sensitivity over laboratory confirmation alone. Conclusion National discharge and laboratory registers can support robust SARI surveillance in Finland when case definitions are carefully designed. A combined register-based definition balances specificity, sensitivity and feasibility, complementing sentinel surveillance and integrated respiratory monitoring. Keywords Severe acute respiratory infection (SARI); surveillance; electronic health records; ICD-10; case definition; Finland

Background: Mass gathering events (MGEs) are associated with several public health challenges and may cause a strain on healthcare services. Literature findings on the impact of MGEs on emergency departments (EDs) are heterogeneous. Objectives: To examine shifts in ED attendance characteristics during a major sporting tournament, namely the UEFA European Football Championship 2024 held in Germany. Methods: We conducted a retrospective observational study using ED data from the Emergency Department Data Registry. We compared baseline ED attendance characteristics between the tournament and the reference period, defined as two weeks before and two weeks after the tournament, and between Germany game days and non-Germany game days. Hourly attendance patterns were analysed for all Germany games using a reference range. Results: We included data from 41 EDs, totalling 253,493 attendances during the study period. A 1.57% increase in attendance was observed during the tournament compared to the reference period, with baseline characteristics remaining similar. The median daily attendance within all EDs was slightly lower on Germany game days (4066) compared to non-Germany game days (4128). Modest changes were observed in the hourly attendance on Germany game days, most notable during the last Germany game where a decrease in attendance below the reference range extended over three hours. Conclusions: The observed shifts in ED attendance were minimal, suggesting that no major changes of public health relevance occurred in ED attendance during the tournament. We highlight the utility of using ED data for monitoring and for enhancing the understanding of the public health risks and challenges associated with MGEs.

Tokyo experienced a measles outbreak (260 cases) in early 2026 despite elimination status. Adults aged 20-39 years were most affected, and 38% of cases were modified measles, increasing with prior vaccination. Although incidence rose until April, the effective reproduction number; R(t) fell below 1, consistent with outbreak control. Multiple clusters were identified, but many cases lacked epidemiological links, suggesting that modified measles is less likely to be considered in differential diagnosis. Intensive contact tracing and surveillance contributed to limiting transmission.

West Nile virus (WNV) has become an important public health concern in Europe. Italy is one of the most affected countries, yet our understanding of WNV epidemiology, genomics, and dispersal across hosts and geographic regions is incomplete. AIM: To reveal the history of WNV in Italy by integrating epidemiological, genomic, and environmental data into descriptive and quantitative assessments of its past spatio-temporal surveillance and expansion. We collated vertebrate and mosquito WNV records from national surveillance and the scientific literature spanning multiple decades. Historical serological and molecular data were summarized by host and region, climatic associations with case trends were assessed using regression models, and phylodynamic and phylogeographic analyses reconstructed viral introductions and dispersal within Italy.WNV circulation in Italy has changed markedly over time, with increasing human case reporting and expansion beyond historically affected northern regions. Climate-informed regression models explained recent reporting trends, supporting an environmental contribution to transmission. Phylodynamic analyses identified multiple independent introductions and sustained local transmission with increasing regional connectivity. Wavefront analyses revealed lineage-specific dispersal patterns associated with seasonal climatic gradients. Discrepancies between epidemiological records and genomic sampling highlighted uneven surveillance across regions and host species.WNV emergence in Italy reflects repeated viral introductions, local persistence, heterogeneous surveillance, and environmentally associated dispersal dynamics. Strengthening integrated surveillance combining epidemiological, environmental, and genomic data will improve early detection, the monitoring of transmission dynamics, and public health preparedness under ongoing environmental change.

Background Clinical trials demonstrated high efficacy of daily and event-driven oral pre-exposure prophylaxis (PrEP) in HIV prevention. Event-driven PrEP involves taking two tablets before and two times one tablet after sexual contact (2-1-1/on-demand). While both are implemented in Dutch clinical practice, evaluating real-world effectiveness requires large-scale data from routine clinical care. This study compared HIV incidence between daily and event-driven PrEP in the Netherlands. Methods We used surveillance data from the Dutch national PrEP program (August 1, 2019-December 31, 2025). Individuals [&ge;]16 years with [&ge;]1 follow-up consultation after PrEP initiation were included; PrEP regimen since last visit was recorded at each visit. Person-time was modeled as time-varying based on the regimen reported at each consultation. HIV incidence rates were calculated per 100 person-years and Cox proportional hazards models estimated hazard ratios between regimens for HIV acquisition, adjusted for sociodemographics, sexual behavior, and history of sexually transmissible infections. Findings 16,469 individuals (15,843 men who have sex with men, 579 transgender and gender diverse persons, 45 women and two men who have sex with women) initiated PrEP and had [&ge;]1 follow-up visit (median follow-up 2.0 years (IQR=0.8-4.0)). Median age was 33 years (IQR=27-44). 49 PrEP users were diagnosed with HIV over 41,092 person-years (IR=0.12/100 py;95%CI=0.09-0.16), of whom 42 event-driven users (IR=0.20/100 py;95%CI=0.15-0.27) and seven daily PrEP users (IR=0.04/100 py;95%CI=0.02-0.07). In multivariable Cox regression, event-driven PrEP use was associated with a higher hazard of HIV acquisition (aHR=7.0;95%CI=3.0-16.4). Interpretation Despite overall low HIV incidence, the incidence rate in the Dutch national PrEP program was seven-fold higher during event-driven PrEP use compared to daily, which may be due to lower adherence. These findings denotes that, in real-world settings, improved person-centered counseling is needed for individuals interested in, or using event-driven PrEP. Research should identify domains and preferred methods of support. Funding None for this study.

Background Using a population-based cohort from the Calgary Health Zone (CHZ), Canada, we integrated longitudinal antimicrobial susceptibility and prescribing data with the whole genome sequences of five major pathogens. We aimed to assess how antimicrobial resistance (AMR) responds to prescribing changes and determine which bacterial strains shape these dynamics. Methods We analysed antibiotic prescribing rates, clinical and genomic data from 7,271 Staphylococcus aureus, 1,609 Enterococcus faecalis, 801 Enterococcus faecium, 11,363 Escherichia coli, and 2,319 Klebsiella pneumoniae isolates, associated with bacteraemia episodes in the CHZ between 2006-2022. Genomic clusters (referred to as strains) were identified using StrainGST and assigned to known sequence types (STs) or clonal complexes (CCs). Strain-level incidence, stratified by community-onset (isolates collected [&le;]48h after admission) and hospital-onset (>48h after admission), AMR phenotypes, and prescribing rates were modelled using negative-binomial and binomial regression. Temporal trends were quantified using average annual percentage change (AAPC). Findings Between 2010-2022, fluoroquinolone prescribing declined in both community (AAPC=-6.8% [95% CI -8.1, -5.4]; p<0.0001) and hospital settings (AAPC=-5.1% [-6.5, -3.7]; p<0.0001). This was accompanied by a significant reduction in fluoroquinolone resistance among Gram-positive species. Specifically, S aureus bacteraemia resistant to clinically important antibiotics, cloxacillin, ciprofloxacin, erythromycin, and clindamycin, declined from 2006 to 2022, mostly in hospital-onset cases (AAPC=-16.0%, [-19.3%, -12.7%], p<0.0001). In E coli, ceftriaxone and ciprofloxacin resistance were clustered in ST131 and the emerging ST1193; the latter increased steadily, particularly in community-onset cases (AAPC=17.7%, [0.0%, 30.0%], p<0.0001). CTX-M-27-producing E coli ST131 strains increased (AAPC=23.8%, [17.4%, 30.5%], p<0.0001) between 20082022, while CTX-M-14-producing E coli ST131 declined (AAPC=-15.9%, [-21.3%, -10.2%], p<0.0001) between 2013-2022. These trends were paralleled by an increase in community cephalosporin prescribing (AAPC=7.3%, [4.2%, 10.5%], p<0.0001) between 2010-2022. For K pneumoniae, hypervirulent ST23 was most common (N=88) with an increasing trend in incidence (AAPC=3.0%, [-2.8%, 9.2%]) between 2006-2019. Conclusions The contrasting resistance trends between Gram-positive and Gram-negative species underscore the complexity of AMR control efforts. Effective strategies will require stewardship efforts targeting multiple drug classes, genomic surveillance for emerging resistant strains, and interventions extending beyond hospital settings.

COVID-19 vaccination helped change the course of the pandemic and remains critical for protecting high-risk groups. We analyzed data submitted to WHO to describe COVID-19 vaccination coverage during the emergency period from 2021-2023 and annual uptake in 2024, the first post-emergency calendar year after the Public Health Emergency of International Concern designation was lifted. By end-2023, global complete primary series coverage reached 65% in the total population, 82% among older adults, and 91% among health and care workers (HCWs), across reporting countries. Booster coverage was lower, at 33%, 60%, and 69%, respectively. Across indicators, disparities by country income group and region emerged early and persisted through 2024. In 2024, vaccination of older adults and HCWs was limited and heterogeneous. These findings underscore the need for stronger, sustainably financed adult immunization platforms and associated monitoring systems to enhance life-course vaccination benefits and to support future outbreak, epidemic, and pandemic responses.

Carbapenem-resistant Escherichia coli (CR-E. coli) is an emerging One Health threat, but recent shifts in predominant lineages and genomic links between clinical and food reservoirs in Hong Kong remain poorly defined. We analyzed 271 CR-E. coli isolates from four hospitals (2022-2026) and 585 isolates recovered from 4,917 retail food samples (2022-2025). Isolates underwent antimicrobial susceptibility testing, whole-genome sequencing, multilocus sequence typing, resistance-gene and plasmid profiling, core-genome SNP phylogenetics, and comparative genomics. Food isolates were mainly from raw pork (268/585, 45.8%) and raw chicken (231/585, 39.5%). blaNDM-5 was detected in 527/585 (90.1%) food and 241/271 (88.9%) clinical isolates. ST69 was the most frequent defined sequence type in both collections, representing 44/585 (7.5%) food and 36/271 (13.3%) clinical isolates, in contrast to the heterogeneous lineages and carbapenemases previously reported in Hong Kong. Applying a predefined [&le;]50-pairwise-SNP threshold for close genomic relatedness, core-genome phylogeny of 80 ST69 isolates identified two major mixed-source clusters collectively comprising 28 clinical and 27 food isolates. Clustered isolates showed similar antimicrobial resistance profiles, carried blaNDM-5 and blaTEM-1, and were associated with IncI1 MLST | ST136 plasmids. Comparative analyses showed >99.85% average nucleotide identity and broad conservation of the blaNDM-5-associated plasmid backbone across sources. These findings indicate the emergence of blaNDM-5-carrying ST69 as a prominent CR-E. coli lineage in Hong Kong and demonstrate close genomic relatedness between selected clinical and retail food isolates. Although transmission direction have not been inferred yet, the findings support integrated One Health surveillance and source-tracing across clinical, food, animal, and environmental sectors.

Background: Travellers visiting friends and relatives (VFRs) experience a disproportionate burden of travel-associated infectious diseases, yet little is known about the complexity of pre-travel consultations required to support their care. We compared enquiries relating to VFR travellers and tourists received by the UK National Travel Health Network and Centre (NaTHNaC) specialist Advice Line to identify differences in traveller characteristics, destinations and clinical complexity. Methods: We conducted a retrospective observational study of enquiries to the NaTHNaC Advice Line between 1 January 2019 and 31 December 2025. Enquiries relating to VFR travellers and tourists were compared using descriptive statistics and appropriate statistical tests. Traveller demographics, travel characteristics, destinations and enquiry management were analysed. Results: Of 16,367 enquiries relating to specific travellers, 3,090 (18.9%) concerned VFR travellers and 7,237 (44.2%) concerned tourists. Compared with tourists, VFR travellers were younger (median age 24 vs 52 years, P<0.001), more likely to undertake long-stay (8.4% vs 1.8%, P<0.001) and last-minute travel (5.0% vs 1.1%, P<0.001), and more frequently travelled to the WHO African Region (56.6% vs 29.2%, P<0.001) and Eastern Mediterranean Region (12.7% vs 2.8%, P<0.001). Pregnancy was substantially more common among VFR travellers (11.6% vs 4.3%, P<0.001). Enquiries concerning VFR travellers were more likely to require a call-back (16.1% vs 13.8%, P=0.012) and escalation to a specialist doctor (13.1% vs 10.5%, P<0.001), indicating greater consultation complexity. General practice generated a higher proportion of VFR-related enquiries than tourist enquiries (69.5% vs 63.9%, P<0.001). Conclusions: VFR travellers generate disproportionately complex pre-travel consultations characterised by higher rates of specialist escalation, distinct travel patterns and travel to destinations associated with the greatest burden of imported infectious diseases. These findings highlight the importance of specialist travel medicine support for healthcare professionals managing VFR travellers and reinforce the need for equitable access to timely, high-quality pre-travel healthcare for this high-risk population.

During the 2026 Bundibugyo virus disease outbreak in the Democratic Republic of the Congo and Uganda, we projected potential airline-mediated importation risk using contemporary airline network and an externally calibrated Ebola importation hazard. Effective-distance analyses identified major international hub countries, including Belgium, France, South Africa, Kenya, and the United Arab Emirates, as higher-probability gateways within 30 days. These early projections provide a reproducible framework for real-time international situational awareness, while emphasizing that importation risk does not imply local transmission risk.

Objectives: To examine changes in seasonal influenza vaccine uptake among clinical risk groups over periods of differing age-based eligibility. Design: Retrospective cohort study. Setting: Individuals in England registered in the Clinical Practice Research Datalink Aurum. Participants: Between 1,239,802 (2019/20) and 1,289,330 (2023/24) individuals aged 40-69 years in clinical risk groups. Interventions: Natural experiment involving temporary expansion of age-based eligibility for influenza vaccination to include 50-64-year-olds from 2020/21 to 2022/23. Main outcome measures: Influenza vaccine uptake from 1st September to 28th February, incidence rate ratio (IRR) of vaccine uptake across consecutive seasons within age groups, and the ratio of IRRs between age groups. Results: Influenza vaccine uptake increased in all age groups in 2020/21 relative to 2019/20. The increase was larger in individuals aged 50-64 years (13.3%; IRR 1.50, 95% CI 1.50-1.51) compared with those aged 40-49 years (8.3%; IRR 1.35, 95% CI 1.34-1.35) and 65-69 years (6.8%; IRR 1.34, 95% CI 1.33-1.35). From 2020/21 to 2022/23, vaccine uptake decreased, with a more pronounced decline among those aged 40-49 years (-5.4%) compared with age-eligible groups (50-64 years: -3.0%; 65-69 years: -3.1%). The reversion of age eligibility in 2023/24 was associated with a larger decrease in uptake among those aged 50-64 years (-9.6% vs 2022/23; IRR 0.79, 95% CI: 0.79-0.79) compared with those aged 40-49 years (-4.9%; IRR 0.87, 95% CI: 0.87-0.88) and 65-69 years (-3.3%; IRR 0.97, 95% CI: 0.96-0.97). Patterns were broadly consistent across clinical risk groups. Conclusions: The COVID-19 pandemic saw a general increase in seasonal influenza vaccine uptake in clinical risk groups. This increase was larger and more sustained in 50-64 year-olds who had also become eligible based on age. Our findings highlight the potential gains in vaccine coverage among clinical risk groups based on expanded age-based eligibility.

A parvovirus recently associated with an outbreak in Dutch pigs was found in Denmark in symptomatic pigs and in fox (Vulpes vulpes) feces and spleens. Pig viruses were more closely related to each other than to viruses found in the respective local wildlife, suggesting a link between the farm outbreaks.

Background: A maternal vaccine (MV) and a long-lasting monoclonal antibody (la-mAB) have been licensed to protect children against RSV. Given the swift waning of their protection, we evaluated the added benefit of seasonal la-mAB administration for children born to vaccinated mothers shortly after the RSV season in Germany. Methods: We fitted an age- and birth season-structured catalytic model to cross-sectional seroprevalence data of RSV antibodies using a Bayesian framework to estimate the timing of RSV infections in children <5. We then estimated the incidence of severe outcomes in the absence of immunisation in children <1. Finally, we estimated the impact of the MV and of additional la-mAB administration, accounting for the waning of protection. Results: We estimate that children would, on average, be 7 months old (mo) at their first infection, those born in the autumn being the youngest at first infection (4 mo). Together with the children born in the winter, they account for 46% of all RSV hospitalisations and 62% of RSV ICU admissions in unimmunised <1 yo. MV would prevent a total of 776 (473-1,122) hospitalisations per 100,000 vaccinees and 73 (51-94) ICU admissions per 100,000 vaccinees, predominantly among autumn-born children. The summer birth cohort would benefit most from additional la-mAB administration, preventing an additional 46% (10-63) of ICU admissions compared to MV alone, corresponding to an additional 25 (4-45) ICU admissions prevented per 100,000 immunised children. Conclusion: Compared to MV alone, the impact of MV+la-mAB on RSV hospitalisations and ICU admissions would likely be modest.

Objectives: To estimate early growth rate, back-calculate transmission onset, and characterise the case-fatality trajectory of the 2026 Bundibugyo virus disease (BDBV) outbreak in the Democratic Republic of the Congo, the largest recorded BDBV outbreak to date. Design or methods: We analysed a corrected daily surveillance series (65 observations, 14 May to 27 July 2026) using non-linear least-squares regression and a Bayesian Poisson growth model fitted by Markov chain Monte Carlo, with five sensitivity analyses. Results: Early confirmed cases grew at 0.1261 per day (95% CI 0.0885-0.1636), a doubling time of 5.50 days (4.24-7.83), three-fold faster than previous BDBV outbreaks (15-18 days). Bayesian back-calculation placed transmission onset on 19 April 2026 (95% highest-density interval 9-27 April), 16 days before the WHO alert and 25 days before laboratory confirmation. Confirmed case-fatality ratio rose from 12.1% to 44.3%; a higher ratio among suspected than confirmed cases on 21 May (23.6% vs 10.8%; p=0.0080) supported progressive reclassification rather than increasing virulence. Conclusions: Rapid BDBV growth leaves little time for outbreak-triggered mobilisation. Sentinel alerts based on unexplained healthcare-worker death clusters, together with pre-positioned surveillance, diagnostic, and response capacity, could reduce avoidable amplification before confirmation.

Filoviruses, including the likely bat-borne Ebola virus (EBOV) and Marburg virus (MARV), cause severe hemorrhagic fevers in humans. The 2013-2016 EBOV outbreak caused >11,000 human fatalities in Guinea, Liberia, and Sierra Leone. Nearby countries, including Ghana, have been under sampled for filoviruses relative to West African countries where large outbreaks have occurred. While there have been no reported EBOV disease cases in Ghana, there were two fatal MARV disease cases in 2022, suggesting that at least one filovirus is circulating in the country. In this study, we investigated filovirus circulation in fruit bats and humans in Ghana. We leveraged an extensive serological dataset collected from multiple fruit bat species (n = 6,874) and humans (n = 1,300) across a decade in Ghana (2010-2020), including both rural and urban regions. We observed evidence of MARV circulation in Rousettus aegyptiacus bats, a presumed reservoir, as well as occasional seropositivity in sympatric bat species, suggesting that these other bats are incidental, dead-end hosts. Multivariate analyses suggested that multiple, partially cross-reactive filoviruses are circulating among fruit bats in Ghana. Finally, people who reported spending time in caves and hunting bats had higher serological reactivity against EBOV and MARV relative to individuals with no direct bat exposure, indicating possible undetected filovirus spillover at the bat-human interface in Ghana.