Autochthonous transmission of dengue in southern Europe has emerged as a growing public health concern, especially in regions such as Spain, due to the expansion of mosquito vector species, such as Aedes albopictus and Aedes aegypti, introduced into these regions. This article presents an overview of the situation based on the analysis of the different reports published by international and national health agencies, together with key scientific studies on autochthonous transmission of dengue in Europe and Spain. Through this work, the factors considered to be contributing or hypothesized drivers of the spread of the virus on the European continent, such as climate change, human mobility, and the proliferation of mosquito vectors, are described. It explores the cases of autochthonous transmission documented in several European countries and Spain. In addition, the surveillance protocols implemented by Spanish health authorities and the health responses to outbreaks in Spain are also examined. Finally, the risk of future transmission in Spain is assessed, and strategies are proposed to strengthen epidemiological surveillance, improve preparedness for possible outbreaks, and optimize vector-control policies in the context of global change.

Sexually transmitted infections (STIs) are common among people living with human immunodeficiency virus (HIV) (PLWH). This nationwide register study linked HIV and STI registries to examine STI trends before and after HIV diagnosis in Finland 1995–2019 among all PLWH residing in the country. Analysed STIs were chlamydia, gonorrhoea, syphilis, and hepatitis B and C. An extended Cox model assessed factors associated with STI events. Among 3,775 PLWH (mean follow-up 17.9 person-years), 71% had no STIs, 17% had one, and 12% had two or more. Overall, 10.7% had an STI before HIV diagnosis and 18.1% after. STI incidence was 32 per 1,000 person-years and increased over time, although chlamydia and gonorrhoea declined. STI risk was highest among men who have sex with men (MSM) and lowest among people who inject drugs; it remained stable or declined after HIV diagnosis. STIs before HIV diagnosis offer opportunities for HIV testing and pre-exposure prophylaxis promotion. As most had no STIs other than HIV, HIV testing should not be limited to STI screening but also performed in other indicator conditions. After HIV diagnosis, accessible low-threshold STI testing, particularly for MSM, and consideration of doxycycline prophylaxis may benefit those at highest risk.

International travel is thought to be a major risk factor for developing gastrointestinal illness in England. Transmission is thought to be more likely in countries which have lower food hygiene standards, poorer sanitation, and lack of access to clean water. However, many studies are conducted within travel clinic settings which may bias findings. Here, we present a case–control study undertaken in returning English travellers in the community conducted with cases of gastrointestinal illness notified to UKHSA.

All Cryptosporidiosis, Giardiasis, non-typhoidal Salmonellosis, and Shigellosis cases notified to the UK Health Security Agency (UKHSA) between 01 July 2023 and 15 October 2023 were asked to complete an anonymous electronic questionnaire if travelling during their incubation period. Asymptomatic travellers were recruited as controls via a market research panel and asked to complete the same questionnaire. A destination water, hygiene, and sanitation score were derived from the WHO ‘Attributable fraction of diarrhoea to inadequate WASH’ dataset. Demographics, travel details, and exposures while travelling were compared by Pearson’s chi-squared test, and pathogen and destination specific multivariable analyses were performed using a forward stepwise approach.

A total of 653 cases and 483 controls were included. The odds of being a case were significantly higher when travelling to countries outside of the EU (OR:4.6, 95%CI:3.5–6.0; p = <0.001) and to countries with high-risk WASH score (OR 6.6, 95%CI:4.9–9.1; p = <0.001), particularly Egypt, Mexico, Tunisia, and Turkey. For those travelling to a low-risk destination, eating undercooked meat or fish and swallowing water from environmental water sources were significantly associated with higher odds of illness by multivariable analysis (p < 0.05). At high-risk destinations, eating foods consumed on excursions, swallowing water from environmental sources, and eating foods from hotel buffets were significantly associated with higher odds of being a case.

Travel to popular tourist destinations is a potentially under-recognized risk factor for acquiring gastrointestinal infections. Exposures at low-risk destinations were broadly similar to risk factors in the UK. Exposures in high-risk destinations highlighted potential risks associated with catered hotels and tourist excursions which should be explored further.

A global increase in severe group A Streptococcus (GAS) infections has been reported following the COVID-19 pandemic, but data from Asia remain limited. We examined epidemiology and clinical characteristics of severe paediatric GAS infections across 86 Japanese hospitals, focusing on patients under 18 years of age, hospitalized between 1 January 2019 and 31 March 2024. Severe GAS infection was defined by the isolation of GAS from sterile sites, or from non-sterile sites under specific conditions, such as streptococcal toxic shock syndrome (STSS). A total of 83 cases were analysed. Cases increased from the summer of 2023, exceeding pre-pandemic levels. The median age was 4 (interquartile range: 1–8) years, with the highest number among 1-year-olds. No cases were reported in Hokkaido, northern Japan. Only 6% (5/83) of the cases had preceding GAS pharyngitis. Pneumonia was the most prevalent diagnosis (25%), with 76% of these cases being complicated by empyema, often necessitating intensive care or surgical intervention. Only 17% (14/83) of cases were reported as STSS in Japan’s national surveillance system. This study represents the first multicentre nationwide hospital-based investigation of severe paediatric GAS infections in Japan, identifying the recent increase in cases, thereby highlighting limitations of current STSS-based surveillance.

This study analyses 18 years of weekly reported dengue cases (January 2002–December 2020; 988 weeks) from Costa Rica’s Central Valley to examine seasonal and multi-year patterns. To model the spatio-temporal dynamics of dengue, we employ three statistical approaches for case counts: the spatial hurdle integer-valued generalized autoregressive conditional heteroskedasticity (INGARCH) model, the spatial zero-inflated generalized Poisson (ZIGP)-INGARCH model, and the endemic–epidemic (EE) model. Covariates include rainfall and maximum temperature or alternatively seasonal Fourier terms to represent annual seasonality. Using a Bayesian framework, we fit the spatial INGARCH-family models to weekly dengue cases. The EE model and the ZIGP-INGARCH model, both with Fourier seasonal terms, show the best predictive accuracy and provide estimates of seasonal intensity and peak timing relevant for dengue surveillance. Incorporating annual seasonality improves modelling of multivariate weekly dengue cases in Costa Rica’s Central Valley, underscoring the importance of cyclical patterns for strengthening early warning systems and guiding targeted vector control.

The COVID-19 pandemic and associated non-pharmaceutical interventions (NPIs) reduced transmission of other infections. We quantified changes in hospital admission rates for respiratory and gastrointestinal infections among young children in England during and after implementation of NPIs, compared to pre-pandemic, and variations by sociodemographic and clinical characteristics. Children aged <5 years at any time between 1 January 2017 and 31 January 2022 were followed from birth or 1 January 2017, until their 5th birthday, death, or 31 January 2022, within a birth cohort based on Hospital Episode Statistics data. Quarterly emergency admission rates for respiratory and gastrointestinal infections from April-June 2020 onwards were compared to corresponding quarters in 2017–2019 using Poisson regression, with and without interaction terms for time period and sociodemographic/clinical characteristics. Admission rates for respiratory and gastrointestinal infections were lower in April–June 2020 compared to this quarter pre-pandemic (incidence rate ratio (99% CI) 0.17 (0.17–0.18) for respiratory; 0.29 (0.28–0.31) for gastrointestinal). Rates remained below pre-pandemic levels until April–June 2021 (respiratory infections) and July–September 2021 (gastrointestinal infections), subsequently increasing above the corresponding pre-pandemic quarters. Changes in rates did not differ by sociodemographic/clinical characteristics. These results can inform planning for future pandemics and their aftermath.

In this nationwide cohort study, we assessed the long-term risk of major cardiovascular events following intensive care unit (ICU) treatment for community-acquired sepsis and septic shock, compared to the general population. We included 20313 adults admitted to Swedish ICUs between 2008 and 2019, identified through national healthcare registries, and matched each case to 20 randomly selected population controls. Entropy balancing adjusted for baseline co-morbidities, healthcare utilization, and socio-demographics. The association between sepsis and subsequent cardiovascular events (hospitalizations or deaths due to myocardial infarction, heart failure, or cerebral infarction) was analysed using Cox proportional hazards models. Sepsis was associated with increased cardiovascular risk, particularly during the first year (days 0–30 adjusted hazard ratio [aHR] 6.1 (95% CI 4.7–7.9); days 31–90; aHR 2.4 (95% CI 1.8–3.2); days 91–365 aHR 1.4 (95% CI 1.2–1.6)), with risk persisting through years 2–5 (aHRs 1.1–1.3). Heart failure risk remained elevated across all intervals, while risks of myocardial and cerebral infarction were mainly short term. The highest relative risks were observed in patients without prior heart disease or with low baseline cardiovascular risk. These findings suggest that sepsis might be an independent and under-recognized driver of long-term cardiovascular disease, highlighting the need for preventive strategies.

This study examines spatiotemporal patterns of tetracycline- and trimethoprim–sulfamethoxazole (TMP–SMX)–resistant Staphylococcus aureus (S. aureus) among United States (US) Veterans Health Administration (VHA) outpatients. Prevalence of tetracycline and TMP–SMX resistance in methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) was calculated for 2010–2023. MRSA cases from 2018 to 2022 were aggregated to commuting zones (CZs) in the eastern US, and CZ-specific relative risks and temporal trends were estimated using a hierarchical Bayesian Poisson model with a spatiotemporal interaction term. Results indicated that resistance in MRSA increased by 16.4% for tetracycline and 9.3% for TMP–SMX, while MSSA resistance remained stable. High-risk CZs were limited (3% for tetracycline, 4% for TMP–SMX) and distributed across the eastern US, with notable within-state variation in risk and trend. Most CZs exhibited stationary trends, although distinct patterns in the rate and timing of changes in resistance were observed in CZ-specific plots. These evolving and geographically variable patterns of antimicrobial resistance at finer spatial scales highlight the need for local surveillance and outpatient antibiotic stewardship strategies that consider place-based sociodemographic, ecologic, and clinical factors.

After the Zero COVID policy ended on December 7, 2022, ~90% of mainland Chinese were infected in a COVID-19 wave. This systematic review synthesized research estimating excess mortality during that wave in mainland China. We searched seven databases in May 2024 and updated our search in July–August 2025. Peer-reviewed research (Chinese or English), published since January 1, 2023, estimating excess deaths in the COVID-19 wave post-Zero-COVID was included. Risk of bias was assessed using a modified Newcastle-Ottawa Scale. Two authors independently conducted abstract screening, full-text review, data extraction, and risk-of-bias assessment. Seven articles were included. Two studies analysed the death records of a town and a district in Shanghai, estimating the excess mortality rates of 153.6% and 174.3%, respectively. Using indirect methods, four studies estimated national excess mortality (range: 0.71–1.87 million). Another study estimated excess mortality in Taiyuan. Studies used diverse methods to estimate excess deaths, resulting in widely varying and uncertain estimates. Choice of reference period, seasonality, and other factors affect expected mortality estimates.

This study aimed to analyse the patterns, trends, genomic characteristics, and key determinants of dengue virus (DENV) infections and associated deaths in South Asia from 2000 to 2023. We collected data from the World Health Organization dengue surveillance dashboard and the health ministries of respective countries, and publicly available data from eight South Asian (SA) countries. Descriptive measures, data visualization techniques, and time series analysis were used to identify key patterns and trends of DENV. A time-scaled phylogenetic analysis was carried out to explore the genomic epidemiology and evolution of DENV. A generalized linear model (GLM) was fitted to identify climatic, demographic, and socioeconomic factors. Between 2000 and 2023, SA countries showed a sharp increase in dengue cases and deaths, contributing to 6.5% of cases and 11.07% of deaths caused by DENV globally. The total cases in the region are projected to grow by approximately 40%, and total deaths by 61% by 2033. The predominant genotypes were DENV2/II, DENV3/I, and DENV3/III. GLM underscores climatic, demographic, and socioeconomic factors associated with DENV infection and deaths. The findings urge intensified public health measures emphasising the need for comprehensive interventions, including vector control, climate adaptation, and strengthened healthcare systems to de-escalate the situation.

Cytomegalovirus (CMV) is a ubiquitous virus with significant public health implications, including severe morbidity and mortality in neonates and immunosuppressed individuals. Substantial variation in CMV prevalence has been reported globally, and local epidemiological data are important to inform public health interventions. In this study, we estimated CMV seroprevalence and seroconversion rates among blood donors to provide baseline data on CMV epidemiology in Ireland. Seroprevalence was estimated in 74,821 donors, and seroconversion rates were calculated among returning donors, with associations assessed by demographic and geographical factors. Overall CMV seroprevalence in 2020 was 26.0% [95%CI: 25.7–26.3]. Female donors had higher odds of seropositivity than males (adjusted OR: 1.38, [95%CI: 1.34–1.43]). Among first-time donors, CMV seroprevalence was 23.82% [95% CI; 22.79–24.86], whereas within Sample Only New Donors (SOND), who are first-time donors born outside of Ireland and the UK, the seroprevalence was significantly higher, at 46.49% [95% CI; 40.41–52.98, p < 0.001]. The estimated annual seroconversion rate was 0.76% [95% CI: 0.68–0.85], with CMV DNA detected in 6.5% of seroconverters. These findings highlight a low CMV seroprevalence in Ireland, suggesting increased susceptibility to primary infection. Analysis of blood donor CMV data is a useful epidemiological tool to assess population-level risk.

This study aims to assess whether there was any excess mortality among the Aboriginal and non-Aboriginal populations in the Northern Territory (NT), Australia, during the COVID-19 pandemic. A time-series analysis using death data (1997–2023) was applied separately to the monthly and yearly death counts to develop an excess mortality surveillance model (using Auto-Regressive Integrated Moving Average (ARIMA)) for the NT population. Excess mortality was calculated by comparing expected deaths with actual deaths. In 2022, there was a statistically significant excess mortality of 193 (p < 0.01), compared with 82 recorded COVID-19 deaths. Excess mortality was significant for both the Aboriginal (N = 91) and non-Aboriginal (N = 102) populations in 2022. Even though some months had significant excess mortality among both Aboriginal and non-Aboriginal populations, the recorded COVID-19 deaths were not high in these months. This was associated with the peak of COVID-19 fatalities. The ARIMA model demonstrates deviations from expected deaths and helps understand the pandemic’s impact on the NT. Excess deaths occurred in 2022; however, no large spikes in most of the months suggest public health success in the NT.

Since the first report of erythromycin-resistant Bordetella pertussis (B. pertussis) in Arizona in 1994, macrolide-resistant strains have emerged worldwide, threatening pertussis control. This systematic review and meta-analysis aimed to quantify the prevalence and temporal trends of this resistance. Four databases (PubMed, Embase, Cochrane Library, Web of Science) were searched for studies on B. pertussis antimicrobial susceptibility through December 2024. Among 57 included studies (1994–2024), pooled resistance rates (breakpoint ≥32 mg/L) were: erythromycin 21% (95% CI 11–32%), azithromycin 25% (95% CI 12–40%), clarithromycin 15% (95% CI 4–30%), and clindamycin 49% (95% CI 28–70%). Subgroup analyses by country, year, and test method are presented. No trimethoprim/sulfamethoxazole (STX) resistance was reported. Six Japanese isolates showed high-level nalidixic acid resistance (MIC >256 mg/L). Seventy-seven studies contributed to MIC90 data for carbapenems, tetracyclines, aminoglycosides, quinolones, macrolides, cephalosporins, and others. Selected penicillins and intravenous third-generation cephalosporins demonstrated strong in vitro activity, suggesting alternative treatment options. Macrolide-resistant B. pertussis has increased significantly over the past decade. Due to the high burden of antibiotic resistance in China, enhanced surveillance is warranted, while continued monitoring in other countries also remains necessary.

Acute gastrointestinal infections (AGIs) can lead to significant morbidity and mortality. In diagnosing AGI, culture-independent diagnostic tests offer advantages over traditional methods and increase the chance of detecting multiple pathogens (co-detection). A retrospective analysis of data from a tertiary pediatric hospital was conducted to characterize occurrence of AGI co-detections and compare outcomes with patients who had only one AGI pathogen detected. Medical records were obtained for patients with stool samples tested using BioFire FilmArray GI Panel between 1 January 2016 and 31 December 2020. Data were described using descriptive statistics, correlation analysis, and logistic regression to identify risk factors and estimate co-detection rates. During the study period, 12,753 patients had a total of 17,159 stool samples tested. Of these, 8,212(47.9%) tested positive, with 6,040(73.6%) being single detections and 2,172(26.4%) being co-detections. Patients with single detection experienced higher hospitalization rates than patients with co-detection. Patients 1–4 years old exhibited the highest co-detection rate relative to other age groups, while Hispanic/Latino individuals were 1.75 times more likely to have co-detection than other races. This study emphasizes the significance of understanding pathogen interactions concerning clinical characteristics and epidemiology of AGI, and the necessity for effective diagnostic strategies and optimal healthcare resource allocation.

Carbapenem-resistant Enterobacterales were isolated from the outlet of a wastewater treatment plant in Kristianstad in southern Sweden, during spring and summer of the year 2024. MALDI-ToF MS identification and subsequent whole-genome sequencing identified eight Klebsiella pneumoniae strains belonging to ST437 and ST873 and 10 Escherichia coli strains belonging to ST167, ST648, ST1284, and ST8346. All strains, except K. pneumoniae ST873, were NDM-5 positive. K. pneumaniae ST437 and E. coli ST8346 carried two carbapenemase genes, blaNDM-5 and blaOXA-181, as well as the extended-spectrum-β-lactamases (ESBL) gene blaCTX-M-15. These two multi-drug-resistant ST variants that are widespread globally, that have previously not been detected in clinical settings in Sweden, are now detected in treated wastewater in a Swedish middle-sized town.

COVID-19 led to a pandemic in 2020, which officially arrived in Colombia on 6 March 2020. As in other parts of the world, the spread of the virus was underestimated due to the lack of diagnostic tests and follow-up protocols. The present study estimates the number of daily cases of COVID-19 infection compatible with theoretical knowledge of the disease, seroprevalence studies, and records of daily deaths due to the disease. To this end, the REMEDID (Retrospective Methodology to Estimate Daily Infections from Deaths) algorithm was applied in nine Colombian cities. On average, official records detected only around 13% of the maximum number of infected persons in the first wave, which they dated with a delay of 25 days. In addition, there was an average delay of 30 days in detecting the first cases. In particular, in Bogotá, the city with the highest number of infections in Colombia, it was observed that (1) the first infected person arrived on 26 January 2020, 40 days before the official registration; (2) the maximum peak of infections was around 6 times higher than that recorded in the official statistics; and (3) this peak was reached on 08 July 2020, 39 days before the official registration date.

Powassan virus (POWV), a tick-borne flavivirus, is an emerging public health threat in the United States. In New York State (NYS), incidence of human POWV infection has increased in recent years. We describe the epidemiology of confirmed and probable POWV infection cases reported in NYS from 2013 to 2023. A total of 44 human cases were reported over the study period, with the highest incidence rates in Columbia and Putnam counties. Most cases occurred in White, non-Hispanic males over age 50. Hospitalization was reported in 91% of cases, and 11% were fatal. Human case data and tick surveillance results were analysed to assess spatiotemporal patterns of disease emergence. Spatial analysis revealed clustering of human cases in the Capital and Metropolitan regions of NYS. The prevalence of POWV in adult tick populations increased significantly statewide, and entomological risk was positively but modestly correlated to disease incidence at the ZIP code level. These findings suggest that POWV infection is emerging in geographically concentrated areas of NYS, highlighting the need for enhanced surveillance and targeted prevention efforts in high-risk regions.

We developed a dynamic COVID-19 Vaccination Barrier Index (CVBI) at the census-tract level in Clark County, Nevada and assessed its geographic disparities and relationship with COVID-19 vaccination rates over time. Using monthly census-tract data from December 2020 to June 2022, the CVBI integrated demographic, socioeconomic, environmental, housing, and transportation variables, alongside surrogates for vaccination accessibility and vaccine hesitancy. Lagged weighted quantile sum regression was applied to construct monthly indices, while a Besag-York-Mollié model assessed associations with vaccination rates. The results revealed consistent vaccination barriers such as living in group quarters, housing inadequacy, and population density across all vaccination statuses (partial, full, booster). Rural and northern Clark County, especially northeastern Las Vegas, exhibited higher CVBI scores that correlated negatively with vaccination rates. Booster vaccination patterns differed, displaying fewer significantly vulnerable tracts. The dynamic nature of barriers is evident, highlighting temporal shifts in the significance of variables like driving distance to vaccine sites. This study emphasizes the importance of dynamic, localized assessments in identifying vaccination barriers, guiding public health interventions, and informing resource allocation to enhance vaccine accessibility during pandemics.

West Nile virus (WNV) is a zoonotic mosquito-borne Flavivirus, with bird populations reservoirs. Although often asymptomatic, infection in humans can cause febrile symptoms and, more rarely, severe neurological symptoms. Previous studies assessed environmental drivers of WNV infections, but most overlooked areas with potential WNV circulation despite no reported human case, and mixed mechanisms affecting hosts vs. vectors. Our objective was to generate a WNV Bird Risk Index (BRI) mapping the potential of WNV circulation in bird communities across Europe. We first used a bird traits-based model to estimate WNV seroprevalence in European wild bird species and identify eco-ethological characteristics associated with it. This allowed us to build a map of the WNV BRI that showed a strong spatial heterogeneity across Europe. To validate this metric, using a Besag-York-Mollie 2 spatial model in a Bayesian framework, we showed a positive association between the BRI and the number of years with notified WNV human cases between 2016 and 2023, at the NUTS administrative region scale. To conclude, we provide a map quantifying the suitability for WNV to circulate in the bird reservoir. This allows to target surveillance efforts in areas at risk for WNV zoonotic infections in the future.

In France, HIV prevention measures including HIV testing, treatment, and uptake of pre-exposure prophylaxis (PrEP), have increased throughout the last decade. To analyse their impact, we performed a time series analysis of monthly HIV diagnoses reported via the national HIV surveillance database. In addition, we compared the timing of HIV promotional campaigns with monthly trends in HIV testing and PrEP initiation. From January 2012 to December 2022, new HIV diagnoses steadily decreased among men who have sex with men (MSM) born in France and heterosexuals born in France, whereas HIV diagnoses increased among MSM born abroad. HIV testing activity and PrEP use in France both steadily increased from 2014 to 2020, during which multiple campaigns targeting HIV testing and prevention occurred. The decline in HIV diagnoses among MSM born in France preceded the introduction of PrEP in 2016 and continued post-2016 without any acceleration in the rate of decline. Increased awareness of, access to and uptake of HIV prevention measures remain essential to progress towards HIV elimination in France, especially among MSM born abroad.