Maria Andrea Previtali

This quasi-experimental study evaluated a participatory vs. conventional strategy for dengue and leptospirosis prevention in vulnerable neighborhoods of Santa Fe, Argentina (2024–2025). Using a difference-in-differences design, biological and KAP indicators were monitored. Participatory interventions significantly reduced Aedes aegypti breeding sites (−54% in 2024, p = 0.001; −57.6% in 2025, p = 0.043), larval containers (−67%, p = 0.001; −56.8%, p = 0.017), adult mosquitoes (−57%, p = 0.046; −56.3%, p = 0.007), and rodent activity (−23%, p = 0.01; −33%, p = 0.001) vs. controls, while optimizing waste management and KAP profiles. Findings validate participatory approaches for public health policy.

Background/Objectives: Dengue is an emerging arboviral disease in temperate South America, where urban expansion, climate variability, and social vulnerability favor transmission. In Argentina, the endemic circulation of dengue was established in the late 1990s and outbreaks are reported every three or four years. Methods: This cross-sectional study assessed dengue virus (DENV) seropositivity and associated sociodemographic, environmental, and knowledge-attitudes-practices (KAPs) factors in three socioeconomically vulnerable peripheral neighborhoods of Santa Fe, Argentina, between December 2019 and March 2020. Results: A total of 188 adults were surveyed and tested for anti-DENV IgG using ELISA. KAPs questionnaires and direct peridomiciliary observations were used to characterize exposure contexts. Apparent seropositivity was 16.5%, with an adjusted estimate of 10.7% after accounting for test performance, indicating substantial unrecognized DENV circulation. Most seropositive individuals had no previous dengue diagnosis, highlighting underdetection likely related to asymptomatic infections, limited healthcare access, or surveillance gaps. Although dengue awareness was high (98.4%), knowledge was often incomplete and was weakly correlated with preventive practices, suggesting that awareness alone does not translate into effective risk reduction under structural constraints. In multivariate analysis, living farther from vacant lots was associated with higher odds of seropositivity, consistent with transmission concentrated in denser urban settings. Conclusions: Integrating serology with KAPs surveys provides critical insights into hidden transmission and supports targeted surveillance and public health interventions in vulnerable urban settings.

Predator–prey interactions are vital to ecosystem functioning but may be disrupted by climate change. We investigated a food‐web network involving three owl species over 24 years in a semi‐arid ecosystem at Bosque Fray Jorge National Park, Chile. We hypothesized that years of low precipitation cause resource scarcity, prompting dietary niche partitioning by owls via diet specialization or differential diversification. Because climate varies across multiple temporal scales (seasonal variability, medium‐scale changes influenced by El Niño–Southern Oscillation cycles, and long‐term shifts associated with climate change), we expected food‐web characteristics to exhibit matching multi‐scale temporal structure. Using 16 932 owl pellets collected over 229 monthly surveys between 1990 and 2015 and analyzed with an asymmetric eigenvector map framework, we assessed temporal patterns in niche partitioning, diet specialization, trophic niche breadth, and prey richness across time scales to evaluate climatic and biotic drivers. Owl trophic characteristics exhibited significant temporal structure at medium (3.4–9.4 years) and long (15–24 years) timescales, the former aligning with climatic oscillations and the latter with decadal shifts. Consistent with the prediction that resource scarcity promotes diet specialization, decreases in precipitation, small‐mammal abundance, and ecosystem productivity led to reduced niche overlap and narrower niche breadth at medium scales. At the larger scales, a major shift after 2003 coincided with declines in both precipitation and temperature. Detected changes were also consistent with niche theory but suggest more complex mechanisms at play at this timescale, since decreases in niche overlap were associated not only with diet specialization but also with increases in overall prey richness, indicating the incorporation of unused prey species. Temperature was the strongest driver of large‐scale structure in prey richness, exceeding resource‐based variables. Together, our results highlight the complex interplay between climatic factors and resource availability in shaping owl–prey networks, and underscore their fragility under ongoing climate change.

This study aimed to identify areas with the presence of pathogenic Leptospira in marginalized neighborhoods of Santa Fe, Argentina, through a participatory research approach. Additionally, we aimed to optimize a low-cost and sensitive detection method suitable for public sector laboratories in resource-limited settings. Three neighborhoods highly vulnerable to hydrological risks and leptospirosis outbreaks—Colastiné Sur, La Vuelta del Paraguayo, and Chalet—were selected. A series of meetings with local residents were conducted to discuss the risks of leptospirosis and to collaboratively map high-priority water sampling sites based on local knowledge and perceived exposure. Community members then participated actively in sample collection and documentation of environmental conditions. In parallel, we optimized a DNA extraction and qPCR protocol tailored for complex environmental matrices, enabling the sensitive detection of pathogenic Leptospira . Leptospira DNA was detected in 21.1% of the 33 water samples collected: 9.09% in La Vuelta del Paraguayo, 18.18% in Chalet, and 36.36% in Colastiné Sur. The results were subsequently shared and discussed with community members, fostering a dialogue between scientific findings and local knowledge. This study is the first of its kind in Santa Fe and highlights the dual value of community engagement in environmental health surveillance and the implementation of an affordable and robust molecular tool for leptospirosis monitoring. Our findings illustrate how integrating participatory mapping with environmental sampling can guide the molecular detection of Leptospira in urban water bodies—an approach that has rarely been documented—and underscore the potential of combining local knowledge and accessible molecular tools to strengthen public health responses in flood-prone settings.

Background Argentina has experienced several dengue outbreaks since its reemergence in 1998, but cases are underreported due to asymptomatic infections and inadequate access to the healthcare system, particularly in marginalized neighborhoods. Methods Between December 2019 and March 2020, we assessed seroprevalence of DENV in three neighborhoods in the periphery of the city of Santa Fe. Serum samples were obtained from one adult per household and analyzed by ELISA for DENV IgG antibodies. Multivariate logistic regression models were used to analyze seropositivity by demographic, socio-economic and environmental variables. Results From 184 participants,overall seroprevalence was 15.2% (95% CI: 10.7; 21.1%). Proximity to a vacant lot decreased the likelihood of seropositivity by 65% (OR: 0.35; 95% CI: 0.15; 0.80). This aligns with studies suggesting vegetation cover can reduce vector abundance and that DENV transmission is higher in densely populated urban areas. Surprisingly, knowledge of disease symptoms and transmission was not linked to lower seropositivity, echoing findings from other studies. Conclusions These findings contribute to building consensus on the factors that increase DENV infection and will be valuable in designing public health interventions in vulnerable neighborhoods during dengue outbreaks.

Leptospirosis and dengue are zoonotic diseases that share some risk factors, necessitating interdisciplinary approaches for a comprehensive understanding. Santa Fe City exhibits environmental and social conditions conducive to the transmission of both diseases. The objective of this study was to characterize the epidemiological, biological, and socio-cultural potential risk factors in Alto Verde. A survey of knowledge, attitudes, and practices (KAPs) was conducted alongside serological analysis for antibodies, and detection of vectors and reservoirs. Rodent sampling involved the placement of hair traps in four transects in December 2023, followed by live-trapping in February 2024 (totaling 88 trap-nights per sampling). Eight mosquito sampling points were established, each comprising 5 houses. Sampling involved recording the number of potential breeding sites, collecting and quantifying Aedes larvae and utilizing two Prokopack-type vacuums for collecting adults. A total of 126 neighbors responded the questionnaire and 102 serum samples were obtained. Dengue seroprevalence was determined by ELISA IgG test; 10% samples were positive; analysis of Leptospira seroprevalence is ongoing. Positive hair traps accounted for 49% of the tubes used and rodents captured were nine mice and two rats. Mosquito data showed great variation among sampling points in the number of breeding sites recorded (47-248), and in Aedes larvae (23-241) and adults (3-15) collected, indicating the presence of hotspots in the sampling area. High dengue antibody prevalence in the surveyed areas correlated with numerous potential breeding sites. Rodent infestation was substantial, and surveys indicated a lack of leptospirosis awareness among the population, contrasting with their knowledge of dengue

This study focuses on the prevention of dengue and leptospirosis in vulnerable populations in the riverside area of the city of Santa Fe, Argentina, comparing the effectiveness of vector and reservoir control strategies through participatory interventions with a community approach, compared to traditional vertical strategies in riverside areas of Santa Fe. In the face of the hegemonic sanitary and medical model, it is necessary to provide more knowledge on the effectiveness of other possible forms of prevention, based on critical, socio-ecological, participatory models and approaches, which occur at the local scale, in the territories inhabited by the community. The methodology of the study comprised a quali-quantitative, randomized, controlled community trial with local community action. Two representative zones were selected from riverside sectors of Santa Fe, which share similar socioeconomic indices. In one area, participatory interventions were applied based on participatory action research, Citizen Science, and SEPA (Sociabilization of Evidence for Action) approaches. Simultaneously, and as a control, vertical and centralized prevention mechanisms were applied in the other zone. In order to make comparisons of effectiveness, a characterization of the socio-environmental, sanitary, vector and reservoir conditions, and knowledge, attitudes and practices regarding these diseases was carried out in both zones, at pre- and post-intervention times.In exploratory analyses of the data collected, significant rates of change were found between both zones post-intervention, and a significant effect of the participatory interventions for response variables of health importance in dengue. Sampling for leptospirosis remains to be done

The objective of this study was to detect geographical areas of the city with the highest incidence for each disease, find and compare patterns of association between incidences of dengue and leptospirosis with socio-environmental descriptors related to social and health inclusion. Data from the National Health Surveillance System were georeferenced to determine the number of cases and incidences for each radio/census fraction using geographic information systems. Satellite images and socioeconomic and demographic databases were used to characterize the habitat and the degree of social exclusion. The indices considered were: unsatisfied basic needs, socioeconomic stratum, educational level, and health vulnerability. A positive correlation was found between the distribution of the incidence of leptospirosis with low socioeconomic status and health vulnerability. With respect to dengue there is a negative correlation, so the incidence increases in areas with less social vulnerability. In the present study we provide evidence in favor of dengue being a disease that affects broad sectors, mainly those with less social and health vulnerability, unlike leptospirosis. However, attention in public policies is greater for dengue and scarce for leptospirosis.