Search Results (145)

Oropouche fever (OF), caused by Oropouche virus (OROV), has expanded beyond its Amazonian range into Minas Gerais (MG), Brazil, raising concern about transmission in extra-Amazonian Atlantic Forest landscapes. Critical gaps persist regarding Culicoides vector communities, anthropophily, and climate-sensitive transmission risk in these newly affected regions. We conducted targeted entomological surveys outbreak-driven by human OF cases, standardized across five MG communities using CDC light traps and Protected Human Attraction (PHA) to characterize Culicoides composition. Females of Culicoides underwent RT-qPCR for OROV (n = 819) and physiological assessment (n = 312). We developed an entomological alert framework that integrates blood-fed abundance, minimum infection rate (MIR) upper confidence bounds, and environmental drivers (i.e., mean temperature, relative humidity and precipitation) via generalized additive mixed models, which explained 68% of the variability in Culicoides abundance and the alert index across communities. We collected 1171 Culicoides individuals representing five species (C. leopoldoi, C. paraensis, C. pusillus, C. foxi, and C. limai). C. leopoldoi (79.1%) and C. paraensis (20.3%) were the predominant species; notably, C. paraensis is recognized as the primary vector of OROV in the Americas. C. paraensis was documented for the first time in all five outbreak areas and dominated PHA captures (90%), suggesting anthropophily. Although no specimens tested OROV-positive (consistent with expected field infection rates of 0.01–1%), MIR upper bounds reached 132/1000 in low-sample settings and humidity and temperature strongly modulated abundance. This operational baseline and alert index transform virologically negative, sparse surveillance data into prioritized targets for intensified sampling and vector control during early, low-prevalence phases, when containment of OROV’s extra-Amazonian spread is still achievable. Full article

Chagas disease remains a major public health concern in Latin America, with Bolivia reporting one of the highest burdens of infection. While congenital transmission has become the predominant route of new infections in several countries, vector-borne transmission persists in rural and peri-urban regions. Postrervalle, in the department of Santa Cruz, is officially classified as a low-infestation area; however, updated community-level data remain limited. We conducted a cross-sectional study in July 2023 involving 58 mothers and 104 of their children in Postrervalle. Participants underwent serological screening with three diagnostic assays, and epidemiological data were collected via structured maternal questionnaires. Logistic regression models were used to assess associations between child Trypanosoma cruzi seropositivity and maternal or household exposures during pregnancy. Seroprevalence was 15.5% among mothers and 3.8% among children. Notably, all seropositive children were born to mothers who tested seronegative, suggesting non-congenital transmission. In multivariable analysis, living in houses with mud walls during pregnancy was strongly associated with child seropositivity (adjusted OR = 38.566), while older child age also increased the odds of infection. Other maternal exposure variables showed elevated but imprecise associations. Despite its classification as a low-infestation area, Postrervalle shows serological patterns consistent with postnatal acquisition linked to domestic structural conditions that facilitate triatomine colonization. These findings overall highlight the need for integrated serological and entomological surveillance to better characterize and prevent Chagas transmission in rural communities. Full article

Weather radars enable the monitoring of airborne insects over spatial scales ranging from hundreds to thousands of kilometers. Quantitative information on migration intensity and spatial distribution can be obtained from weather radar observations. However, insect biological characteristics cannot be directly retrieved from weather radar, which limits species identification. Among the parameters associated with insect species, body length describes an important aspect of individual morphological characteristics. In this study, we propose a method for estimating the mean body length of airborne insect populations based on S-band polarimetric weather radar observations. A theoretical relationship is established between mean body length, insect number density, and the specific differential phase, which is defined as the range derivative of the phase difference between horizontally and vertically polarized radar signals. Electromagnetic simulations are conducted to analyze the relationship between specific differential phase and mean body length under known number density. Furthermore, the method is validated using joint observations from weather radar and entomological radar. The experimental results show that, for insects with body lengths ranging from 5 to 25 mm, the proposed method achieves a mean absolute percentage error (MAPE) of 10.75% in body length estimation, demonstrating its capability to accurately estimate the mean body length of insect populations. This study provides data support for species identification in current weather-radar-based insect monitoring and shows promise for applications in large-scale pest early warning, species classification, and ecological dynamics research. Full article

A new generation of insecticide-treated nets (ITNs) that incorporate the synergist piperonyl butoxide (PBO) has been shown to restore susceptibility to pyrethroids where P450 enzymes are the primary mechanism conferring the resistance. The present study evaluated the efficacy of YAHE 4.0, a PBO ITN, against wild free-flying Anopheles arabiensis in experimental huts in Lower Moshi, north-eastern Tanzania. It is the first evaluation of YAHE 4.0 in the country. Bio-efficacy evaluations, including susceptibility tests and cone bioassays, were conducted using the standard WHO guidelines. DuraNet Plus, a WHO-recommended PBO ITN, and Interceptor ITNs served as active and standard comparators, respectively. Unwashed and 20 times washed nets were subjected to experimental hut trials. Multiple logistic regression was employed to analyse experimental hut trial data. The results of the susceptibility testing showed that the An. arabiensis population of Lower Moshi was resistant to pyrethroids, but susceptible to organophosphates. Particularly, low mortality was recorded for cyhalothrin (2%) and alpha-cypermethrin (38%). Mortality rates to alpha-cypermethrin pirimiphos-methyl were 38% and 100%, respectively. The non-inferiority of YAHE 4.0 to DuraNet Plus ITN in terms of mortality and blood feeding was determined according to the WHO guidelines. The results for pooled unwashed and 20 times washed ITNs showed that YAHE 4.0 was superior to Interceptor ITN (adjusted odds ratio, AOR = 1.33; 95% CI = 1.04–1.69; non-inferiority margin, NIM = 0.68; p-value = 0.023) and non-inferior to DuraNet Plus (AOR = 1.02; 95% CI = 0.78–1.35; NIM = 0.72; p-value = 0.867) in terms of mortality. In terms of blood feeding inhibition for pooled unwashed and 20× washed ITNs, YAHE 4.0 was superior to both Interceptor ITN (AOR = 0.80; 95% CI = 0.64–1.00; NIM = 1.35; p-value = 0.049) and DuraNet Plus (AOR = 0.67; 95% CI = 0.52–0.86; NIM = 1.33; p-value = 0.002). Chemical analysis showed higher wash retention of active ingredients in YAHE 4.0 LLIN (88.9% for PBO and 94.9% for alpha-cypermethrin) compared to DuraNet Plus LLIN (89.2% for PBO and 90.5% for alphaypermethrin) before the hut trial. YAHE 4.0 LLIN demonstrated superior entomological efficacy and wash durability to DuraNet Plus and Interceptor LLINs, and fulfilled WHO non-inferiority criteria for mosquito mortality and blood-feeding inhibition. Therefore, YAHE 4.0 LLIN should be considered as an addition to the current list of pyrethroid-PBO nets used for control of pyrethroid-resistant vector populations with P450 enzymes as the main mechanism conferring resistance. Full article

Insects constitute a vital component of terrestrial ecosystems, yet their ongoing global decline underscores the urgency of identifying the factors that facilitate or hinder public engagement in their conservation. This study identifies the key psychological drivers of insect-related conservation behavior within a Romanian context, an understudied geographical and sociocultural setting. Using data collected from 346 adult respondents via an online questionnaire, the predictive performance of the Value–Belief–Norm (VBN) theory, the Theory of Planned Behavior (TPB), and an integrated VBN–TPB framework was examined through Partial Least Squares Structural Equation Modeling (PLS-SEM). The VBN model exhibited superior explanatory power relative to TPB, with biospheric values, ecological worldviews, and personal moral norms emerging as the most influential determinants of behavioral intention and self-reported action. Although participants demonstrated moderate levels of general entomological knowledge, awareness of specific insect-friendly practices was notably limited and frequently characterized by misconceptions. Perceived barriers, particularly informational deficits, time constraints, and financial considerations, exerted significant inhibitory effects on conservation engagement. The findings indicate that effective interventions must extend beyond knowledge transmission, incorporating strategies that activate moral norms, strengthen affective and identity-based motivations, and reduce structural barriers to action. Full article

Daytime biting malaria mosquitoes present a challenge for malaria elimination efforts in sub-Saharan Africa. Diurnal mosquito host-seeking activity times were assessed indoors and outdoors in two villages in the Manhiça district. Subsequently, sunrise and sunset data across longitudes and latitudes spanning the African continent were used to assess if current entomological surveillance approaches align with (seasonal changes in) local daylight cycles. The most abundant species was Anopheles tenebrosus, and daytime (defined as the period between 06:00 and 18:00) host-seeking was only observed in a single Anopheles ziemanni. However, sunset occurred at 17:06 on that day, which means this specimen (collected between 16:00 and 18:00) could have been collected during nighttime. Further analysis of sunrise and sunset times across several African countries show these can change by over 2 h throughout the year, depending on longitude and latitude. As changes in daylight cycles can affect mosquito and human behaviors (e.g., time spent indoors and sleeping), surveillance strategies need to be adjusted to match actual daylight cycles and/or important human behavioral components. This will allow us to collect more actionable data to inform malaria control and elimination programs. Full article

Determining the postmortem interval remains one of the most persistent and fragmented challenges in forensic science. Conventional approaches—thermal, biochemical, molecular, or entomological—capture only isolated fragments of a single physical reality: the irreversible drift of a once-living system toward equilibrium. This Perspective proposes a unifying paradigm in which death is understood as a progressive rise in entropy, encompassing the loss of biological order across thermal, chemical, structural, and ecological domains. Each measurable postmortem variable—temperature decay, metabolite diffusion, macromolecular breakdown, tissue disorganization, and microbial succession—represents a distinct expression of the same universal law. Within this framework, entropy becomes a dimensionless index of disorder that can be normalized and compared across scales, transforming scattered empirical data into a coherent continuum. A Bayesian formulation further integrates these entropic signals according to their temporal reliability, yielding a probabilistic, multidomain equation for PMI estimation. By merging thermodynamics, information theory, and biology, the concept of death as rising entropy offers a comprehensive physical description of the postmortem process and a theoretical foundation for future computational, imaging, and metabolomic models in forensic time analysis. Full article

West Nile virus (WNV) is a mosquito-borne pathogen of the Flaviviridae family that poses recurring public health threats in Tunisia, where Culex pipiens is recognized as the primary vector. Identification of circulating strains in different mosquito species is essential for targeted prevention and control. Between November 2021 and October 2022, mosquitoes were collected at four high-risk sites, and human samples were obtained through the national meningitis surveillance program. Human serum, cerebrospinal fluid (CSF), and urine samples were tested for WNV-specific IgM and IgG antibodies using ELISA, and molecular diagnosis was performed using Real-time RT-PCR (RRT-PCR). Positive samples underwent sequencing for phylogenetic characterization. Serological investigation on human serum revealed the presence of IgM and/or IgG antibodies reactive to WNV antigens, which may indicate exposure to WNV or related flaviviruses. RNA of WNV was detected in 21 mosquito pools (10.19%) belonging to Culex pipiens, Cx. perexiguus, Aedes caspius, and Ae. detritus, as well as in three human cases. Phylogenetic analysis of positive human and mosquito samples showed that all detected WNV strains belonged to sublineage 1a. The concurrent detection of WNV in vectors and humans confirms active circulation in Tunisia and underscores the role of Culex spp. Mosquitoes in transmission. Sustained multidisciplinary surveillance integrating entomological and clinical data is critical for early detection, guiding control measures, and preventing future outbreaks in humans and animals. Full article

In Brazil, public health programs have relied predominantly on chemical insecticides to control Aedes aegypti, Anopheles spp., Culex quinquefasciatus, triatomines, and phlebotomines. Rising vector-borne disease incidence and insecticide resistance (IR) call for a critical appraisal of historical and current control practices. This literature review compiles secondary data produced from 1901 to 2024 obtained from Medline/PubMed, Google Scholar, and governmental notes and reports. Brazil’s vector control progressed from organochlorines (e.g., DDT) to organophosphates, carbamates, pyrethroids, insect growth regulators, microbial larvicides (Bti and Lsp), spinosad, and recently formulations with dual active-ingredient. Ae. aegypti showed widespread resistance to temephos and pyrethroids, decreased susceptibility to pyriproxyfen, and no documented Bti resistance. Anopheles spp. exhibited low to moderate resistance to pyrethroids. Cx. quinquefasciatus resistance is likely influenced by collateral exposure from Aedes control and domestic use. Regarding triatomines and phlebotomines, there was a predominant reliance on pyrethroids; most studies indicate their susceptibility to these compounds. In short, Brazil’s century-long, insecticide-centric strategy has delivered episodic gains but fostered Aedes aegypti resistance. For other species, for which there is no dedicated program for a long period, data on resistance are scarce or nonexistent. Sustainable progress requires strengthened, nationwide IR surveillance and entomological mapping to coordinate cross-program actions. Full article

West Nile Virus (WNV) is a mosquito-borne zoonosis with recurrent equine and human cases in Romania. Horses, although dead-end hosts, act as sentinels for local viral circulation. Farm-level risk conditions remain under-characterized. This pilot, exploratory cross-sectional study assessed 42 equine facilities in western Romania (2024). A standardized 10-item checklist was applied and a Composite Environmental Risk Score (CERS) (0–10, unweighted) was computed per facility. Spatial analysis in QGIS included distances to nearby water bodies. No serological or entomological data were collected; these are recommended for future validation. Stagnant water occurred at 71.4% (30/42) of facilities, uncovered rain-collecting containers at 64.3% (27/42), and outdoor housing of horses at 81.0% (34/42). Insect screens were present at 21.4% (9/42) and chemical/biological control at 33.3% (14/42). By design, the CERS ranged from 0 to 10; in our sample the observed range was 0–8 because not all assessed risk conditions co-occurred across sites. Overall, 42.9% (18/42) were classified as high risk (≥6). Neurological signs were reported anecdotally by some managers but were not analyzed. Mosquito-favorable conditions are widespread in Romanian equine facilities. CERS shows promise as a low-cost, rapid tool for routine facility-level assessment of environmental conditions favoring mosquito presence and prioritization of preventive actions. Integrating environmental risk scoring with entomological and serological surveillance could strengthen One Health early-warning systems. Such integration would support prevention of WNV and other mosquito-borne zoonotic pathogens in endemic European settings. Full article

Background and Objectives: Climate change is modifying the ecological and climatic conditions that influence the distribution and activity of arthropod vectors. Rising temperatures and prolonged warm seasons have favored the establishment of Aedes albopictus in Mediterranean regions, increasing the risk of autochthonous Dengue transmission. Therefore, this study describes the evolution of Dengue surveillance in Sardinia between 2018 and 2024, integrating human and entomological data to assess trends, system performance, and implications for prevention and control. Materials and Methods: Data on human cases were retrieved from national notification systems (namely PREMAL, arbo.iss.it) and the New Health Information System. Entomological surveillance data were obtained from the Experimental Zooprophylactic Institute of Sardinia. Mosquitoes were collected using BG-Sentinel^® traps and ovitraps, covering major cities and points of entry. Descriptive analyses were conducted for both datasets. Results: Sixteen Dengue cases were reported during the study period, all imported and laboratory-confirmed in 81% of cases. Most patients were adults (mean age 38 years), and 77% required hospitalization. The most frequent travel origins were Southeast Asia, Africa, and Latin America. No autochthonous cases were identified. Entomological surveillance showed a progressive increase in Aedes albopictus captures from 2020 onwards, with seasonal peaks between September and October. Despite intensified sampling and expanded geographic coverage, no mosquito pools tested positive for the Dengue virus. Conclusions: Although no locally acquired Dengue infections have been detected, the widespread and increasing presence of Aedes albopictus indicates that Sardinia meets the ecological prerequisites for possible autochthonous transmission. Strengthening the timeliness and completeness of human surveillance, improving clinicians’ awareness of reporting requirements, promoting vaccination for travelers, and maintaining continuous entomological monitoring are essential to prevent and promptly manage future outbreaks. Full article

Oropouche virus (OROV), an emerging arbovirus of the Peribunyaviridae family, is responsible for acute febrile illness and, in some cases, neurological or hemorrhagic complications. Although traditionally confined to tropical areas of Central and South America, the 2024–2025 epidemic has signaled a major shift in its geographic and clinical profile, with sustained transmission in the Caribbean, over 15,000 confirmed cases, and the first imported infections reported in Europe and the United States. New clinical observations include fatalities in previously healthy adults, suspected vertical transmission with adverse fetal outcomes, and potential sexual transmission. Despite entomological data indicating low competence of European mosquito species and the absence of the main vector Culicoides paraensis, the increasing frequency of imported cases underscores the need for continued vigilance. Diagnostic limitations and clinical overlap with other arboviruses further complicate early detection. This review summarizes current knowledge on OROV’s epidemiology, transmission dynamics, and clinical features, and highlights the urgent need for integrated surveillance, diagnostic readiness, and coordinated research efforts. Emphasis is placed on Europe’s preparedness strategies, with Italy’s Jubilee 2025 offering a real-world case study for managing arboviral threats during mass gatherings. Full article

The spread of the invasive mosquitoes Aedes albopictus, Aedes aegypti, and Aedes japonicus in Spain represents an increasing public health risk due to their capacity to transmit arboviruses such as dengue, Zika, and chikungunya, among others. Traditional field entomological surveillance remains essential for tracking their spread, but it faces limitations in terms of cost, scalability, and labor intensity. Since 2014, the Mosquito Alert citizen-science project has enabled public participation in surveillance through the submission of geolocated images via a mobile app, which are identified using AI in combination with expert validation. While field surveillance provides high accuracy, citizen science offers low-cost, large-scale, real-time data collection aligned with open data management principles. It is particularly useful for detecting long-distance dispersal events and has contributed up to one-third of the municipal detections of invasive mosquito species since 2014. This study assesses the value of integrating both surveillance systems to capitalize on their complementary strengths while compensating for their weaknesses in the areas of taxonomic accuracy, scalability, spatial detection patterns, data curation and validation systems, geographic precision, interoperability, and real-time output. We present the listing of municipal detections of these species from 2004 to 2024, integrating data from both sources. Spain’s integrated approach demonstrates a pioneering model for cost-effective, scalable vector surveillance tailored to the dynamics of invasive species and emerging epidemiological threats. Full article

Progressive climate change has increased the emergence of bark beetle outbreaks, which justifies the need for in-depth research into their response to climatic factors in order to improve forest resource management strategies. A measure of the adaptation of species to changing conditions is provided by the determination of the breadth of their ecological niches. This study proposes a novel, minimally invasive method to estimate the niche breadth of Tomicus piniperda, a representative species in its taxonomic group. EntomologiJcal analyses were carried out on trap trees. The niche of T. piniperda was described by means of stepwise regression, and its niche breadth was found to depend significantly on the bark thickness and gallery density on stems (p < 0.001). The constructed models explained over 80% of the variation in T. piniperda niche breadth on the stems, and the differences between the observed and predicted mean niche breadth were not significant (p > 0.05), with the relative errors for individual trees generally not exceeding 13%. Data on the parameters of niches may be useful in evaluating the possible consequences of changes in climatic factors for organismal fitness, for example, or as a starting point for the construction of models of bark beetle population size. Full article

Malaria, caused by a protozoan parasite of the genus Plasmodium and transmitted by mosquitoes of the genus Anopheles, remains a significant vector-borne disease worldwide. In 2018, Paraguay became the first country in the Americas in 45 years to be certified malaria-free by the World Health Organization. Between 2016 and 2017, a period with no reported human malaria cases, the presence of Plasmodium spp. in Anopheles mosquitoes was investigated in the departments of Caaguazú and Alto Paraná. These studies found that the most prevalent Anopheles species in Paraguay, including Anopheles albitarsis (59.4%), Anopheles strodei (21.5%), and other Anopheles species in smaller proportions, were all negative to the parasite. The objective of this study was to re-evaluate these presence data and to define environmentally suitable areas for Anopheles spp. and their association with bioclimatic variables using DIVA-GIS/MaxEnt software for the entomological surveillance of malaria risk in Paraguay. Results showed that areas of bioclimatic suitability included the Humid Chaco, Cerrado, Paraná Atlantic Forest, and Southern Cone Mesopotamian savanna ecoregions. The most relevant climatic variables were the precipitation of the wettest month (contribution of 80.4%) and the precipitation of the driest month (contribution of 18.4%). Anopheles albitarsis, also reported as a vector of the Venezuelan equine encephalitis virus in neighbouring countries, was the most abundant mosquito species. Anopheles darlingi, the main vector of malaria in Paraguay, was not found. However, species richness indices (Chao/ACE) suggest that cryptic or sibling species may be present. Finally, the possible succession of Anopheles species and their geographical segregation are discussed in scenarios of entomological surveillance and epidemiological risk. Full article