Eurosurveillance - Volume 30, Issue 15, 17 April 2025

The incidence of leptospirosis, a zoonotic infection transmitted mainly by rodents, has increased in humans over the past decade in the Netherlands. Previous studies, mostly from countries with tropical climates, suggest that temperature and rainfall influence leptospirosis incidence.

We aimed to identify factors that could explain the increasing leptospirosis incidence in the Netherlands, including temperature and precipitation.

Epidemiological data of leptospirosis cases notified from 2005 to 2023 to the national surveillance system were analysed to identify changes over the years. Negative binomial regression models were used to assess associations between weather variables and leptospirosis incidence.

From 2005 to 2023, 1,164 cases were notified. The annual number of cases increased 2.7-fold in the period of 2019–2023 compared with 2005–2009, and the number of autochthonous cases 4.1-fold. Data from 1,158 cases were included in the analyses, and 596 (51.5%) of these cases were autochthonous. Most cases were male (n = 927; 80.1%), needed hospital treatment (n = 861; 74.4%) and acquired the infection through contact with surface water and/or soil (n = 611, 72.6%). Higher mean winter (incidence rate ratio (IRR) = 1.27; 95% confidence interval (CI): 1.18–1.36) and summer (IRR = 1.38; 95% CI: 1.18–1.61) temperatures were significantly associated with increased leptospirosis incidence.

Leptospirosis incidence has increased over the past decades and may continue to increase due to climate change. Prevention should aim at advising the appropriate preventive measures to avoid exposure to Leptospira and increasing awareness about leptospirosis among clinicians to allow for timely diagnosis and treatment.

Regions of southern Europe are increasingly colonised by Aedes albopictus, with incidence of autochthonous dengue cases rising in recent years.

We describe and compare Aedes-borne disease (dengue, chikungunya and Zika) incidence from 2017 to 2023, and the surveillance systems and response measures operating in France, Italy and Portugal in 2023, to improve surveillance, prevention, preparedness and response in Europe.

We performed a benchmarking analysis to systematically capture the systems used in each country. We collected data from key-informant interviews, national guidelines, reports and scientific literature using a standardised questionnaire adapted from the European Centre for Disease Prevention and Control framework.

All three countries have an integrated surveillance system for Aedes-borne diseases and share similarities in surveillance type, geographic coverage and case definitions. Differences entail mainly event-based and active surveillance activities. Geographic coverage of vector surveillance is national in France and Portugal but regional in Italy. In response to autochthonous transmission, all countries implement/foresee active case-finding and blood safety protocols, while France and Italy strongly rely on vector control. Upon vector detection in non-colonised areas, the three countries implement ad hoc entomological surveillance and vector control.

Surveillance systems and response measures in France, Italy and Portugal are broadly similar, with variations reflecting differences in healthcare system organisation (centralised in Portugal and France, regionalised in Italy), Ae. albopictus distribution and local transmission of Aedes-borne diseases. Risk-based surveillance, considering the national and cross-border epidemiological and entomological situations, can strengthen preparedness and early warning for Aedes-borne diseases in Europe.

West Nile virus (WNV) is a growing public health concern in Europe. Greece is one of the most affected countries in Europe, with the highest annual incidences.

We aimed at assessing IgG antibodies to WNV in the Greek population and compared the results with a nationwide survey conducted in the period 2012–2013.

In a geographically stratified sampling, 4,416 serum samples were collected and analysed for WNV-specific IgG antibodies using ELISA. Samples positive for WNV IgG were further tested with a WNV serum neutralisation test to detect false positives.

The weighted seroprevalence, adjusted for age, sex and region, was 2.83% (95% confidence interval (CI): 2.32–3.44) in the 4,416 samples tested, significantly higher than in the 2012–2013 survey (1.55%; 95% CI: 1.17–2.04). The seropositivity increased with age with the highest seroprevalence in persons aged ≥ 80 years (6.04%; 95% CI: 3.28–10.88). No significant differences in seropositivity were observed between sexes or regions. We estimated that 312 (95% CI: 256–379) persons had a WNV infection per a case of West Nile neuroinvasive disease (WNND). A certain degree of discordance was observed between areas with increased seroprevalence and those with an increased incidence of WNND.

Our study reveals a wider geographical spread of WNV infections in Greece compared with previous investigations. The nearly twofold increase in seroprevalence highlights the need for ongoing monitoring and preventive measures to mitigate the impact of WNV on public health in Greece.

Post-acute care hospitals (PACH) may act as regional reservoirs for multidrug-resistant organisms.

We aimed to investigate the prevalence of carbapenem-resistant Acinetobacter baumannii (CRAB) carriers and identify risk factors for CRAB carriage in PACH.

We conducted a point prevalence survey in 18 PACH in Israel from June to December 2021. We screened patients in 55 wards of four types (mechanical ventilation, skilled nursing, sub-acute and rehabilitation) for CRAB carriage from skin, rectum and tracheostomy secretions (if applicable). We collected data on patient characteristics (including prior CRAB carriage) and ward and institution characteristics. We calculated the prevalence of CRAB carriers, the percentage of newly detected carriers, and assessed predictors of CRAB carriage using a mixed-effects logistic regression model.

We screened 1,725 patients, with 385 (22%) testing positive for CRAB. The median prevalence of CRAB carriers was 48% (interquartile range (IQR): 33–70) in ventilation wards, 28% (IQR: 18–46) in skilled nursing wards, 8% (IQR: 6–13) in sub-acute wards and 0% (IQR: 0–3) in rehabilitation wards. Only 31% (118/385) had a known history of CRAB carriage. Individual risk factors for CRAB positivity included known CRAB carriage, bedsores and presence of a feeding tube. Modifiable ward-level risk factors included poor availability of alcohol-based hand rub (adjusted odds ratio (aOR) = 3.22; 95% confidence interval (CI): 1.52–6.81) and suctioning in common areas (aOR = 2.23; 95% CI: 1.30–3.85).

The hidden reservoir of CRAB carriers in Israeli ventilation and skilled nursing wards is large. We identified modifiable risk factors at ward level, highlighting areas for targeted intervention.