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Introduction: Dengue is one of the most widespread arboviruses in Latin America and is now affecting areas previously free of transmission. The COVID-19 pandemic and climatic variations appear to have affected the incidence of the disease, abundance of vectors and health programs related to dengue in some countries. Objective: To analyze the epidemiology of dengue in Paltas, Ecuador (2016–2022), compare the periods before and during the COVID-19 pandemic, examine entomological reports and discuss the possible implications of the COVID-19 pandemic and climatic variations. Methodology: In this observational, retrospective study, cases of dengue registered in the SIVE-Alert epidemiological surveillance system and the available larval indices were examined. Results: No autochthonous cases were reported before 2016. Between 2016 and 2022, 182 cases without warning signs were reported, mostly in women (51.1%), people ≥ 20 years (68.7%) and people living in urban areas (78.6%). During the COVID-19 pandemic, there was a significant decline in cases in urban areas, with displacement toward rural areas (p < 0.001). A clear pattern of dengue incidence was observed throughout the year, with a predominance (84.6%) in epidemiological weeks 16–39 (April–September), which coincided with the dry season in the region. In 2016 and 2018, larval rates were high in urban areas but decreased in 2019. Postpandemic incidence rates increased in urban and rural areas, even in areas without transmission of the disease. Conclusions: There is a clear pattern of incidence of dengue in the dry season in the region. After the 2016 outbreak, larval cases and rates decreased, suggesting the effectiveness of vector control before the COVID-19 pandemic. However, during the pandemic there was a resurgence in dengue with expansion in rural and urban areas. The increase in larval rates during the COVID-19 pandemic, even in dengue-free areas, is worrisome. A critical challenge in the control of mosquito breeding sites is climatic variations, which increase the need to reserve water for domestic use. [ABSTRACT FROM AUTHOR]

Introduction: Powassan virus (POWV), a vector-borne pathogen transmitted by Ixodes ticks in North America, is the causative agent of Powassan encephalitis. As obligate hematophagous organisms, ticks transmit pathogens like POWV at the tick bite site, specifically during the initial stages of feeding. Tick feeding and salivary factors modulate the host's immunological responses, facilitating blood feeding and pathogen transmission. However, the mechanisms of immunomodulation during POWV transmission remain inadequately understood. In this study, we investigated the global cutaneous transcriptomic changes associated with tick bites during POWV transmission. Methods: We collected skin biopsies from the tick attachment sites at 1, 3, and 6 h after feeding by POWV-infected and uninfected ticks, followed by RNA sequencing of these samples. Differentially expressed genes were analyzed for pathway enrichment using gene ontology and pathway enrichment analyses. Results: Our findings reveal that tick feeding alone significantly impacts the skin transcriptome within the first 1 to 3 h of tick attachment. Although early POWV transmission induces minimal changes in the local environment, a pronounced shift toward a proinflammatory state is observed 6 h after tick attachment, characterized by neutrophil recruitment and interleukin signaling. Discussion: These transcriptomic data elucidate the dynamic changes at the tick bite site, transitioning from changes that assist blood meal acquisition to a proinflammatory phase that may facilitate viral dissemination. [ABSTRACT FROM AUTHOR]

Background: Human activities, such as urbanization and climate change, have facilitated the spread of arbovirus-carrying vectors, disproportionately affecting vulnerable traditional Indigenous communities. Objective: To explore the relationships between subclinical myocardial dysfunction, assessed by global longitudinal strain (GLS), and comprehensive arbovirus serology in an Indigenous population, while also describing the serological and epidemiological profile of dengue, chikungunya, and Zika viruses. Methods: This ancillary study is part of the first phase (2016–2017) of the Project of Atherosclerosis among Indigenous Populations (PAI), a cross-sectional study involving participants from two Indigenous communities with different degrees of urbanization and a highly urbanized city in Northeast Brazil. We assessed the seroprevalence of dengue, chikungunya, and Zika viruses in the Fulni-ô Indigenous community, the less urbanized and most traditional group. Additionally, we explored the relationship between these viruses and subclinical heart disease, assessed by speckle-tracking echocardiography-derived GLS. Results: One hundred seventy-four participants were included, with a median age of 45.0 years (interquartile range 38.0–55.0). The majority were female (58.6%; n = 102). The prevalence of anti-ZIKV IgG was 95.3%; anti-DENV IgG was 85.8%, and anti-CHIKV IgG was 70.9%. GLS abnormalities were detected in nearly half (48.3%) of the cohort. However, no significant association was found between arbovirus serology and GLS. Conclusions: The findings reveal a high prevalence of positive serology for arboviruses and a significant rate of subclinical cardiac dysfunction. There was no significant association between reduced left ventricular longitudinal strain and positive arbovirus serology, likely due to the limited number of participants with indications of acute contact with the viruses studied. However, the unprecedented and relevant results of this study are noteworthy, as they address critical public health issues, particularly in vulnerable populations. Further research is needed to explore these findings in more depth. [ABSTRACT FROM AUTHOR]

Rapid urbanization and migration in Latin America have intensified exposure to insect-borne diseases. Malaria, Chagas disease, yellow fever, and leishmaniasis have historically afflicted the region, while dengue, chikungunya, and Zika have been described and expanded more recently. The increased presence of synanthropic vector species and spread into previously unaffected areas due to urbanization and climate warming have intensified pathogen transmission risks. This review examines recent outbreaks and reemergence of insect-borne diseases through five case studies: (i) malaria transmission linked to political instability and large-scale migration through the Amazon jungle; (ii) the expansion of triatomine bug habitats into overcrowded, substandard urban settlements, increasing Chagas disease incidence; (iii) the influence of movement and ecotourism in the Amazonia on yellow fever transmission in peri-urban areas; (iv) the spread of visceral leishmaniasis driven by deforestation and human–canine movement; and (v) dengue outbreaks in rural Amazon regions, spurred by urbanization and rural development. The findings underscore the complex interactions among vectors, pathogens, and shifting environmental and social conditions, complicating predictability and control. Addressing the social, economic, and political determinants of health is crucial to reducing disease transmission. Key measures include scaling vaccine coverage, especially for dengue and yellow fever; developing vaccines and treatments for neglected diseases; improving housing and sanitation; strengthening vector surveillance and control; fostering community engagement; enhancing data-driven interventions. [ABSTRACT FROM AUTHOR]

Mosquito-borne flaviviruses represent a public health challenge due to the high-rate endemic infections, severe clinical outcomes, and the potential risk of emerging global outbreaks. Flavivirus disease pathogenesis converges on cellular factors from vectors and hosts, and their interactions are still unclear. Exosomes and microparticles are extracellular vesicles released from cells that mediate the intercellular communication necessary for maintaining homeostasis; however, they have been shown to be involved in disease establishment and progression. This review focuses on the roles of extracellular vesicles in the pathogenesis of mosquito-borne flavivirus diseases: how they contribute to viral cycle completion, cell-to-cell transmission, and cellular responses such as inflammation, immune suppression, and evasion, as well as their potential use as biomarkers or therapeutics (antiviral or vaccines). We highlight the current findings concerning the functionality of extracellular vesicles in different models of dengue virus, Zika virus, yellow fever virus, Japanese encephalitis virus, and West Nile virus infections and diseases. The available evidence suggests that extracellular vesicles mediate diverse functions between hosts, constituting novel effectors for understanding the pathogenic mechanisms of flaviviral diseases. [ABSTRACT FROM AUTHOR]

Oropouche virus (OROV) is an orthobunyavirus endemic in the Brazilian Amazon that has caused numerous outbreaks of febrile disease since its discovery in 1955. During 2024, Oropouche fever spread from the endemic regions of Brazil into non-endemic areas and other Latin American and Caribbean countries, resulting in 13,014 confirmed infections. Similarly to other orthobunyaviruses, OROV can undergo genetic reassortment events with itself as well as other viruses. This occurred during this current outbreak, resulting in novel strains with increased pathogenicity and levels of transmission. For the first time, pregnant women with Oropouche fever have sustained poor perinatal outcomes, including miscarriage, fetal demise, stillbirths and malformation syndromes including microcephaly. In July 2024, PAHO issued an Epidemiological Alert warning of the association of OROV with vertical transmission. OROV has now been identified in the fetal blood, cerebrospinal fluid, placenta and umbilical cords, and fetal somatic organs including the liver, kidneys, brain, spleen, heart, and lungs using nucleic acid and antigen testing. Perinatal autopsy pathology has confirmed central nervous system infection from OROV in infants with congenital infection including microcephaly, ventriculomegaly, agenesis of corpus callosum, and neuronal necrosis. The latest data from Brazil show 3 confirmed cases of OROV vertical transmission; 2 cases of fetal death; 1 case of congenital malformation; and ongoing investigations into the role of OROV in 15 cases of fetal death, 3 cases of congenital malformations and 5 spontaneous miscarriages. This Commentary discusses the mechanisms and significance of development of novel reassortant strains of OROV during the current outbreak and their recent recognition as causing vertical infection and adverse perinatal outcomes among pregnant women with Oropouche fever. [ABSTRACT FROM AUTHOR]

Current arbovirus surveillance strategies in Australia involve mosquito collection, species identification, and virus detection. These processes are labour-intensive, expensive, and time-consuming and can lead to delays in reporting. Mosquito excreta has been proposed as an alternative sample type to whole mosquito collection, with potential to streamline the virus surveillance pipeline. In this study, we investigated the feasibility of Aedes aegypti excreta as a sample type in the detection of Dengue virus serotype 2 (DENV2). DENV2 could be detected from as little as one DENV2-infected mosquito excreta spot, with virus levels in individual excreta spots varying within and between mosquitoes and depending highly on mosquito viral load. Detectability was improved by pooling up to 20 DENV2-infected mosquitoes and collecting excreta into liquid substrate, followed by virus concentration using magnetic nanoparticles. Virus concentration improves quantification accuracy in comparison to unconcentrated samples and increases the amount of material available for detection, expanding detection capabilities to techniques with higher limits of detection. Mosquito excreta as a sample type, coupled with magnetic virus concentration, expands the current detection toolbox for DENV2 and has the potential to improve arbovirus surveillance strategies in Australia. [ABSTRACT FROM AUTHOR]

Background: The risk of mosquito-borne disease transmission is increasing in temperate climates with the colonization and proliferation of the Asian tiger mosquito vector Aedes albopictus and the rapid mass transport of passengers returning from tropical regions where viruses are endemic. The prevention of major Aedes-borne viruses heavily relies on the use of insecticides for vector control, mainly pyrethroids. In Europe, only deltamethrin is authorized. Methods: High-throughput molecular assays can provide a cost-effective surrogate to phenotypic insecticide resistance assays when mutations have been previously linked to a resistance phenotype. Here, we screened for the spatial distribution of knockdown resistance (kdr) mutations at a large scale using a two-step approach based on multiplexed amplicon sequencing and an unprecedented collection of field-derived mosquitoes from 95 sites in 61 municipalities, alongside a west-to-east transect in the south of France, from June to September 2021. Results: We identified the presence of the V1016G allele in 14 sites. The V1016G allele was predominantly found in southeast France close to the Italian border, with two additional isolated sites close to Bordeaux and Marmande. All mosquitoes were heterozygous for this mutation and should not be phenotypically resistant to pyrethroid insecticide. Four other mutations were identified in our targeted genomic sequence: I1532T, M1006L, M1586L, M995L. Sequencing a section of maternally inherited mitochondrial genome confirmed that the spread of Ae. albopictus in France originated from founders within haplogroup A1. Conclusions: These findings contribute to the broader understanding of resistance dynamics in Europe and can inform targeted approaches to mitigate the impact of resistance on vector control. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Aim Methods Results Conclusions West Nile virus (WNV) is the most widely distributed mosquito‐borne flavivirus. Over the past decade, its spread across Europe has raised significant concerns for both public and animal health. Although WNV exposure has been evidenced in various wild mammal species in Spain, no seroepidemiological studies have been conducted on this flavivirus in wild lagomorphs so far.This study aimed to assess WNV exposure in European wild rabbit (Oryctolagus cuniculus) and Iberian hare (Lepus granatensis) populations inhabiting Spanish Mediterranean ecosystems.Sera from 540 wild lagomorphs (399 European wild rabbit and 141 Iberian hares), from 106 hunting grounds distributed throughout Andalusia (southern Spain), were collected between the 2018/2019 and 2022/2023 hunting seasons.Antibodies against flavivirus were detected by blocking enzyme‐linked immunosorbent assay (bELISA) in 5.0% (27/540; 95% CI: 3.2–6.8) of the wild lagomorphs. Exposure to WNV was confirmed in 4.8% (19/394; 95% CI: 2.7–6.9) of wild rabbits and 0.7% (1/141; 95% CI: 0.0–2.1) of Iberian hares by virus microneutralisation test. Anti‐WNV antibodies were found in wild lagomorphs sampled from three (2.8%) hunting grounds located in western Andalusia during the seasons 2020–2021 and 2021–2022. Remarkably, this spatiotemporal distribution overlaps with the largest outbreak of WNV in Spain. Antibodies against Usutu virus and Bagaza virus were not detected in the wild lagomorph populations analysed.This study constitutes the first report of WNV exposure in wild rabbit in Spain and in Iberian hare worldwide. While these species seem not play a primary role in the epidemiology of the virus, they could serve as sentinel for monitoring WNV in Iberian Mediterranean ecosystems. [ABSTRACT FROM AUTHOR]

Crimean‐Congo hemorrhagic fever virus (CCHFV) causes a serious human tick‐borne disease. In animals, CCHFV infections are mainly subclinical. The circulation of the virus has received little attention in areas where the main vector (Hyalomma spp.) is not considered to be present or established (e.g., the Northern Iberian Peninsula). The presence of antibodies against CCHFV was evaluated in sera collected from 1190 wild boars, 36 red deer, and 36 roe deer in the Basque Country (Northern Iberian Peninsula) in 2014–2019. Antibodies were found in the three wild ungulate species with an overall prevalence of 2.5%. The highest seroprevalence was found in red deer (22.2%) and in the southwest province: Araba (8.6%). The presence of antibodies against CCHFV in wild ungulates reported in this study could be due to an underestimated presence of Hyalomma ticks, the sporadic exposure to infected Hyalomma ticks transported by animals (e.g., migratory birds), or the role of other tick species in the virus's circulation. The detection of exposed animals since 2014 suggests that the circulation of the virus beyond the southwestern regions of the Iberian Peninsula could have been more widespread than previously thought. [ABSTRACT FROM AUTHOR]

Arthropod-borne (arbo) viruses cause emerging diseases that affect the livelihoods of people around the world. They are linked to disease outbreaks resulting in high morbidity, mortality, and economic loss. In sub-Saharan Africa, numerous arbovirus outbreaks have been documented, but the circulation and magnitude of illness caused by these viruses during inter-epidemic periods remains unknown in many regions. In Rwanda, there is limited knowledge on the presence and distribution of arboviruses. This study aimed at determining the occurrence and distribution of selected arboviruses, i.e., chikungunya virus (CHIKV), o'nyong-nyong virus (ONNV), dengue virus (DENV), West Nile virus (WNV), Zika virus (ZIKV), Rift Valley fever virus (RVFV) and Crimean-Congo haemorrhagic fever virus (CCHFV), among febrile patients visiting health centres in Rwanda. A total of 2294 dry blood spots (DBS) were collected on filter papers during August 2019 – December 2020. Reverse-transcription polymerase chain reaction (RT-PCR) was performed on samples in pools of ten, using both quantitative (DENV, ZIKV, RVFV) and conventional PCR (CHIKV, ONNV, WNV, CCHFV) with virus specific primers, followed by sequencing. Demographic data and clinical manifestations of illness were analysed. ONNV infection was detected in 12 of 230 pools (5.2%) and ZIKV in three pools (1.3%). The other arboviruses were not detected. All ONNV cases were found in the Rwaniro health centre, while ZIKV infection was found among patients visiting the Kirinda and Zaza health centres. There was temporal variability in ONNV infections with most cases being recorded during the long dry season, while ZIKV infection occurred during both dry and wet seasons. Patients with ONNV were older and more were females. In conclusion, ONNV and ZIKV infection were detected in acute patients and can explain some of the feverish diseases in Rwanda. [ABSTRACT FROM AUTHOR]

Although the highlands of East Africa lack the geo-ecological landmarks of Rift Valley fever (RVF) disease hotspots to participate in cyclic RVF epidemics, they have recently reported growing numbers of small RVF clusters. Here, we investigated whether RVF cycling occurred among livestock and humans in the central highlands of Kenya during inter-epidemic periods. A 2-year prospective hospital-based study among febrile patients (March 2022–February 2024) in Murang'a County of Kenya was followed by a cross-sectional human–animal survey. A total of 1468 febrile patients were enrolled at two clinics and sera tested for RVF virus RNA and antiviral antibodies. In the cross-sectional study, humans (n = 282) and livestock (n = 706) from randomly selected households were tested and questionnaire data were used to investigate sociodemographic and environmental risk factors by multivariate logistic regression. No human (n = 1750) or livestock (n = 706) sera tested positive for RVFV RNA. However, 4.4% livestock and 2.0% humans tested positive for anti-RVFV IgG, including 0.27% febrile patients who showed four-fold IgG increase and 2.4% young livestock (<12 months old), indicating recent virus exposure. Among humans, the odds of RVF exposure increased significantly (p < 0.05, 95% CI) in males (aOR: 4.77, 2.08–12.4), those consuming raw milk (aOR: 5.24, 1.13–17.9), milkers (aOR: 2.69, 1.23–6.36), and participants residing near quarries (aOR: 2.4, 1.08–5.72). In livestock, sheep and goats were less likely to be seropositive (aOR: 0.27, 0.12–0.60) than cattle. The increase in RVF disease activities in the highlands represents a widening geographic dispersal of the virus, and a greater risk of more widespread RVF epidemics in the future. [ABSTRACT FROM AUTHOR]

The West Nile virus (WNV) has recently become more widespread, posing a threat to both human and animal health. In Western Europe, most outbreaks have been caused by WNV lineage 1, while in Eastern Europe, WNV lineage 2 has led to human and bird mortality. The ability to appropriately manage this threat is dependent on integrated surveillance and early detection. This study aimed to quantify the prevalence of WNV infection in mosquitoes and to identify the circulating viral lineage in eastern Croatia. Mosquito traps were set up in rural and urban areas during the 2021–2023 seasons, and the collected specimens were identified morphologically. Mosquito species Culex pipiens and Aedes albopictus were tested for Flaviviruses using conventional PCR in a heminested system. The positive samples were then subjected to a specific real-time PCR designed to detect WNV. A total of 385 mosquito pools were tested, and positive pools were found in samples from Osijek-Baranja and Vukovar-Srijem, both of which contained Cx. pipiens mosquitoes. Sequencing of amplicons revealed WNV lineage 2 partial NS5 gene sequences. Phylogenetic analysis suggests the Hungarian origin of strain, which complements birds' migratory routes. These findings indicate the first detection of WNV in mosquitoes in Croatia. This suggests that human cases in this region are likely due to infections with lineage 2 transmitted by local Culex mosquitoes. [ABSTRACT FROM AUTHOR]

We used the model output to explore relationships between EEEV occurrence and environmental factors, as well as generated risk maps for each season. We also introduced a normalized difference risk index to identify locations with high risk during both seasons. LULC variables were better predictors of EEEV than bioclimatic or topographic variables. Summer cases occurred in locations that were in or near rural lands at high elevations that were near woody wetlands and coniferous forests, while winter cases occurred primarily in areas with large proportions of evergreen forests and rural land. Because EEEV is often fatal to both horses and humans, the goal was to provide more accurate EEEV risk maps for each season to guide disease management and vector control efforts. [ABSTRACT FROM AUTHOR]

We report a fatal case of Crimean-Congo hemorrhagic fever in Portugal. An 83-year-old man, initially suspected of having Mediterranean spotted fever, was later confirmed to have Crimean-Congo hemorrhagic fever by the detection of viral genome in the patient's serum and the presence of specific IgM antibodies.

We used the model output to explore relationships between EEEV occurrence and environmental factors, as well as generated risk maps for each season. We also introduced a normalized difference risk index to identify locations with high risk during both seasons. LULC variables were better predictors of EEEV than bioclimatic or topographic variables. Summer cases occurred in locations that were in or near rural lands at high elevations that were near woody wetlands and coniferous forests, while winter cases occurred primarily in areas with large proportions of evergreen forests and rural land. Because EEEV is often fatal to both horses and humans, the goal was to provide more accurate EEEV risk maps for each season to guide disease management and vector control efforts.

The epidemiologic effects of Zika virus (ZIKV) sexual transmission in virus-endemic countries remain unclear. We conducted a 2-level, linear mixed-effects logistic regression analysis by using a recently acquired population-based ZIKV and chikungunya virus (CHIKV) serologic dataset obtained from persons residing in Northeast Brazil (n = 2,070 participants). We adjusted mathematical models for housing type and age of participants; the models indicated a significantly higher likelihood of ZIKV seropositivity among persons engaged in a sexual relationship within the same household (odds ratio 1.25 [95% CI 1.00–1.55]; p = 0.047), regardless of their partner’s ZIKV serostatus, and among participants with a ZIKV-seropositive sex partner within the same household (odds ratio 1.54 [95% CI 1.18–2.01]; p = 0.002). CHIKV was also modeled as a control; no sex-associated effects were observed for CHIKV serology. Inclusion of ZIKV sexual transmission in prevention and control strategies is urgently needed, particularly in ZIKV-endemic regions.

Introduction Dengue disease represents a large and growing global threat to public health, accounting for a significant burden to health systems of endemic countries. The World Health Organization’s (WHO) Strategic Advisory Group of Experts (SAGE) and the European Medicines Agency (EMA) currently recommend the use of TAK-003 dengue vaccine in high dengue burden and transmission settings for countries considering vaccination as part of their integrated management strategy for prevention and control of Dengue.Areas covered This paper describes the main conclusions of a workshop held by the Arbovirus Committee of the Latin American Society of Pediatric Infectious Diseases (SLIPE) in November 2023, to generate consensus recommendations on the introduction of this new vaccine in the region. Considerations were made regarding the molecular epidemiology of dengue infection in the Americas and the need for more precise phylogenetic classification and correlation with clinical outcome and disease severity.Expert opinion Introduction of dengue vaccine should be considered as an strategy for health entities in the region, with participation of social sectors, scientific societies, and ministries of health that could be able to create a successful vaccination program.

Abstract Background At the end of 2021, an epidemic of reproductive abnormalities in cows occurred in Jilin Province, China, posing an urgent need for a rapid diagnosis. Results To identify the cause of the disease, a total of 172 samples were collected from 21 dead calves and 45 aborting or pregnant cows in 10 farms across the province. Routine PCR or RT-PCR detection did not find any common abortion-related agents. We then employed the viromics-based precision diagnosis method to analyze these samples, and the read-based annotation showed signals of an Akabane disease virus (AKAV) in some libraries. To further identify the virus, nested RT-PCR detection revealed that 52.3% (11/21) of dead calves and 26.6% (12/45) of cows were positive for the virus. Phylogenetic analysis of the partial fragments showed that the S segment of the virus was 100% identical to the Chinese strain TJ2016, but its M and L segments shared 94.3% and 96.5% identities with an Israeli strain. Conclusions The viromic and molecular results suggested that these animals were infected with a reassortant AKAV. Coupled with the clinical signs, the virus should be responsible for the epizootic, highlighting that molecular and serological surveys of the virus in cows during early pregnancy, as well as ecological investigation in its arthropod vectors, are necessary.

Objetivos. Evaluar la frecuencia de los síntomas en pacientes con oropouche y compararlos con los observados en el dengue y otras arbovirosis. Métodos. Se realizó una revisión sistemática basada en MOOSE y PRISMA; se incluyeron estudios sobre manifestaciones clínicas agudas en pacientes con oropouche. La búsqueda incluyó las bases de datos PubMed, Biblioteca Virtual en Salud, Cochrane Library y Google Scholar hasta septiembre de 2024. Se compararon los síntomas del oropouche con los del dengue y otras arbovirosis, y se valoró la certeza con el enfoque GRADE. Resultados. Se incluyeron 23 estudios con 3 648 pacientes con oropouche. Los síntomas más frecuentes en pacientes con oropouche fueron fiebre (97%) y cefaleas (86%). No hubo diferencias en la frecuencia de fiebre ni cefaleas entre pacientes con oropouche y dengue. Sin embargo, la odinofagia (28%) y el dolor abdominal (15%) fueron más frecuentes en el oropouche que en el dengue (OR 3,20 y 2,50, respectivamente). Las mialgias (69%) y las artralgias (57%) fueron menos frecuentes en los pacientes con oropouche en comparación con el dengue. Conclusiones. La fiebre y las cefaleas son frecuentes en la fiebre de Oropouche, pero no ayudan a diferenciarlo del dengue. En cambio, la odinofagia y el dolor abdominal son más frecuentes en los pacientes con oropouche, mientras que las mialgias, las artralgias y el exantema prevalecen más en el dengue. Estos hallazgos pueden ayudar en el diagnóstico diferencial en áreas de cocirculación arboviral. Se requieren estudios adicionales sobre la recurrencia y la duración de los síntomas para mejorar las estrategias diagnósticas.

【Objective】The zoonotic infectious diseases caused by arbovirus of family Flavivirus have a severe impact on China's animal husbandry and public health. Due to the wide types and similar infection symptoms of arbovirus, as well as its heavy clinical surveillance, the study aims to establish a fast and high-throughput detection technology for four serious Flavivirus arbovirus to provide technical support for clinical diagnosis and epidemiological monitoring of arbovirus.【Method】Based on Luminex xTAG technology, four pairs of specific primers were designed for 5' UTR of Japanese encephalitis virus (JEV), 5' UTR and part of C gene of West Nile virus (WNV), 5' UTR of yellow fever virus (YFV), NS5 gene of Zika virus (ZIKV), and were modified with TAG sequence and Biotin. Multiplex PCR amplification was carried out with standard virus strains as model. Then, PCR products were hybridized with magnetic beads with complementary TAG sequences and streptavidin-phycoerythrin, and the fluorescence signals of magnetic beads and phycoerythrin were detected by Luminex 200 instrument to indicate the classification and quantification of the pathogens of the arbovirus samples.【Result】The Luminex xTAG method applied to detect JEV, WNV, YFV and ZIKV was established, and the optimal primer working concentration was 0.5, 0.5, 0.75, 0.5 µmol/L; the established hybridization system and reaction conditions were: 20 μL of magnetic bead working solution, 5 μL of PCR amplification product, and 75 μL of SAPE working buffer solution; the hybridization temperature, hybridization time and pH value were 37 ℃, 30 min, and 8.0, respectively. The quadruple Luminex xTAG method could detect JEV, WNV, YFV and ZIKV simultaneously, and there was no cross reaction with dengue virus. The duplicate test results indicated that, the coefficient of variation of the intra-assay for quadruple Luminex xTAG method was 2.50%-5.63% and inter-assay was 3.61%-12.50%. The detection limits of JEV and ZIKV were 1×104 copies/μL, and those of WNV and YFV were 1×103 copies/μL, respectively. The sensitivity for WNV, YFV and ZIKV was 10 to 100 times that of conventional PCR. A total of 209 clinical samples and simulated samples were detected by Luminex xTAG and RT-qPCR methods, with the coincidence rate of JEV, MNV, YFV and ZIKV of 100%.【Conclusion】The established quadruple Luminex xTAG method has high throughput, high specificity and sensitivity as well as high cost-effectiveness, providing a high-throughput technology method for clinical diagnosis and epidemiological monitoring of arboviruses.

Fort Sherman virus (FSV) was isolated in Panama in 1985 from a US soldier. We report a case of human FSV infection in a febrile patient from northern coastal Peru in 2020. FSV infections spanning ≈35 years and a distance of 2,000 km warrant diagnostics, genomic surveillance, and investigation of transmission cycles.

Objetivo. Identificar e sintetizar evidências sobre efetividade e custo-efetividade da metodologia Aedes com Wolbachia para redução dos casos de arboviroses. Método. Revisão sistemática rápida, com busca realizada em fevereiro de 2022 em cinco portais de busca e bases de dados bibliográficas online. As etapas de seleção foram conduzidas por dois revisores, com resolução de conflitos por um terceiro. A extração dos dados foi feita por um revisor e conferida posteriormente por outro. Os critérios de inclusão foram estudos com descrição de custo-efetividade e efetividade da metodologia Aedes com Wolbachia, a partir de intervenções em campo, publicados nos idiomas português, inglês e espanhol, sem restrição de data de publicação. Resultados. Foram incluídos quatro estudos, sendo um ensaio randomizado em cluster, dois quase- experimental e um antes-depois, publicados entre 2019 e 2021 em quatro países. Os estudos encontrados tiveram resultados efetivos em alguns dos desfechos avaliados, como na diminuição da incidência de casos de dengue, Zika e chikungunya. Apesar de não terem sido identificados estudos experimentais abordando custo-efetividade da estratégia Aedes com Wolbachia, alguns estudos de modelagem demonstraram um potencial custo-benefício desta estratégia. Conclusão. Considerando os resultados apresentados, conclui-se que a Wolbachia apresenta potencial para ser uma estratégia economicamente efetiva e que leva à redução da incidência de casos de dengue, Zika e chikungunya. Apesar disso, não é possível, todavia, recomendar a estratégia como política pública, pois ainda são necessários mais estudos de grande porte e de alta qualidade metodológica para subsidiar a tomada de decisão política.

Abstract Vector‐borne diseases caused by arthropod‐borne viruses (arboviruses) are a considerable challenge to public health globally. Mosquito‐borne arboviruses, such as Chikungunya, Dengue, and Zika viruses, cause a range of human illnesses and may be fatal. Currently, efforts to control these diseases still face challenges due to growing vector resistance towards insecticides, urbanization, and limited effective antiviral treatments and vaccines. Animal models are crucial in antiviral research on mosquito‐borne arboviruses, playing a role in understanding disease mechanisms, vaccine development, and toxicity testing, but the application of animal models still faces the challenges of ethical considerations and animal‐to‐human translational success. Genetically engineered mouse models, hamster models and non‐human primate (NHP) are currently used in arbovirus research, but new models such as tree shrews and novel humanized mice are emerging. In the context of Malaysian research, the use of long‐tailed macaques as potential NHP models for arbovirus research is possible; however, it faces the ethical dilemma of using an endangered species for scientific purposes. Overall, animal models play a crucial role in advancing infectious disease research, but a balance between medical research and species conservation must be upheld.

Western equine encephalitis virus (WEEV) is a mosquitoborne virus that reemerged in December 2023 in Argentina and Uruguay, causing a major outbreak. We investigated the outbreak using epidemiologic, entomological, and genomic analyses, focusing on WEEV circulation near the Argentina‒Uruguay border in Rio Grande do Sul state, Brazil. During November 2023‒April 2024, the outbreak in Argentina and Uruguay resulted in 217 human cases, 12 of which were fatal, and 2,548 equine cases. We determined cases on the basis of laboratory and clinical epidemiologic criteria. We characterized 3 fatal equine cases caused by a novel WEEV lineage identified through a nearly complete coding sequence analysis, which we propose as lineage C. Our findings highlight the importance of continued surveillance and equine vaccination to control future WEEV outbreaks in South America.

Background: At the end of 2021, an epidemic of reproductive abnormalities in cows occurred in Jilin Province, China, posing an urgent need for a rapid diagnosis. Results: To identify the cause of the disease, a total of 172 samples were collected from 21 dead calves and 45 aborting or pregnant cows in 10 farms across the province. Routine PCR or RT-PCR detection did not find any common abortion-related agents. We then employed the viromics-based precision diagnosis method to analyze these samples, and the read-based annotation showed signals of an Akabane disease virus (AKAV) in some libraries. To further identify the virus, nested RT-PCR detection revealed that 52.3% (11/21) of dead calves and 26.6% (12/45) of cows were positive for the virus. Phylogenetic analysis of the partial fragments showed that the S segment of the virus was 100% identical to the Chinese strain TJ2016, but its M and L segments shared 94.3% and 96.5% identities with an Israeli strain. Conclusions: The viromic and molecular results suggested that these animals were infected with a reassortant AKAV. Coupled with the clinical signs, the virus should be responsible for the epizootic, highlighting that molecular and serological surveys of the virus in cows during early pregnancy, as well as ecological investigation in its arthropod vectors, are necessary. [ABSTRACT FROM AUTHOR]

There is an increasing global burden from chikungunya virus (CHIKV). Bangladesh reported a major epidemic in 2017, but it was unclear whether there had been prior widespread transmission. We conducted a nationally representative seroprevalence survey in 70 randomly selected communities immediately before the epidemic. We found that 69 of 2938 sampled individuals (2.4%) were seropositive to CHIKV. Seropositivity to dengue virus (adjusted odds ratio, 3.13 [95% confidence interval, 1.86–5.27]), male sex (0.59 [.36–.99]), and community presence of Aedes aegypti mosquitoes (1.80 [1.05–3.0]7) were significantly associated with CHIKV seropositivity. Using a spatial prediction model, we estimated that across the country, 4.99 (95% confidence interval, 4.89–5.08) million people had been previously infected. These findings highlight high population susceptibility before the major outbreak and that previous outbreaks must have been spatially isolated. [ABSTRACT FROM AUTHOR]

The incidence of arbovirus infections has increased in recent decades. Other than dengue, chikungunya, and West Nile viruses, the data on arbovirus in solid organ transplant (SOT) are limited to case reports, and infections in renal transplant recipients account for most of the reported cases. Dengue and West Nile infections seem to be more severe with higher mortality in SOT patients than in the general population. Acute kidney injury is more frequent in patients with dengue and chikungunya although persistent arthralgia with the latter is less frequent. There is no clear relationship between arboviral infection and acute cellular rejection. Pre-transplant screening of donors should be implemented during increased arboviral activity but, despite donor screening and negative donor nucleic acid amplification test (NAT), donor derived infection can occur. NAT may be transiently positive. IgM tests lack specificity, and neutralizing antibody assays are more specific but not readily available. Other tests, such as immunohistochemistry, antigen tests, PCR, metagenomic assays, and viral culture, can also be performed. There are a few vaccines available against some arboviruses, but live vaccines should be avoided. Treatment is largely supportive. More data on arboviral infection in SOT are needed to understand its epidemiology and clinical course. [ABSTRACT FROM AUTHOR]

Vesicular stomatitis virus (VSV), comprising vesicular stomatitis New Jersey virus (VSNJV) and vesicular stomatitis Indiana virus (VSIV), emerges from its focus of endemic transmission in Southern Mexico to cause sporadic livestock epizootics in the Western United States. A dearth of information on the role of potential arthropod vectors in the endemic region hampers efforts to identify factors that enable endemicity and predict outbreaks. In a two-year, longitudinal study at five cattle ranches in Chiapas, Mexico, insect taxa implicated as VSV vectors (blackflies, sandflies, biting midges, and mosquitoes) were collected and screened for VSV RNA, livestock vesicular stomatitis (VS) cases were monitored, and serum samples were screened for neutralizing antibodies. VS cases were reported during the rainy (n = 20) and post-rainy (n = 2) seasons. Seroprevalence against VSNJV in adult cattle was very high (75–100% per ranch) compared with VSIV (0.6%, all ranches). All four potential vector taxa were sampled, and VSNJV RNA was detected in each of them (11% VSNJV-positive of 874 total pools), while VSIV RNA was only detected in four pools of mosquitoes. Our findings indicate that VSNJV is the dominant serotype across our sampling sites with a variety of potential insect vectors involved in its transmission throughout the year. Although no livestock cases were reported in Chiapas during the dry season, VSNJV was detected in insects during this period, suggesting that mechanisms other than transmission from livestock support VSV endemicity. [ABSTRACT FROM AUTHOR]

Aim of Study: The study aims to assess the growing public health threat posed by Oropouche virus (OROV), focusing on its epidemiology, transmission patterns, and the challenges in diagnosis and control. By analyzing the recent spread of OROV to new regions, including Cuba and Colombia, the study seeks to highlight the need for improved surveillance, enhanced diagnostic capabilities, and research into potential treatments and vaccines. Additionally, the study investigates the clinical similarities between Oropouche fever and other arboviruses, which often lead to diagnostic difficulties and mismanagement in affected regions. Results: The virus has caused over 500,000 cases in Brazil alone, with recent outbreaks reporting fatalities, suspected vertical transmission, and potential associations with microcephaly in newborns. Underreporting and limited surveillance have likely led to the underestimation of the true burden of Oropouche fever. Current diagnostic methods, such as serology and RT-PCR, are often inaccessible in low-resource settings, further complicating efforts to control the spread of the virus. The study highlights the importance of improving diagnostic capacity, enhancing surveillance, and conducting further research into vector control, antiviral treatments, and vaccine development. Conclusion: This study emphasizes the urgent need for coordinated international efforts to address the rising threat of Oropouche virus. Considering its rapid spread and potential for global transmission, comprehensive public health measures are necessary to protect vulnerable populations and mitigate the impact of this emerging disease. Enhanced surveillance and the development of accessible diagnostics, vaccines, and treatment options are critical to containing OROV and preventing further outbreaks. [ABSTRACT FROM AUTHOR]

West Nile Virus, an arthropod-borne RNA virus, may result in severe neurological disease. West Nile neuroinvasive disease is characterized by meningitis, encephalitis, and possible acute flaccid paralysis. Here, we report a case of neuroinvasive WNV in a 65-year-old woman hospitalized for hyperpyrexia, chills, intense asthenia, and continuous vomiting. Within days, her clinical condition worsened with the onset of severe neurological symptoms, leading to her death within 10 days despite supportive therapies being administered. The diagnosis of West Nile disease was made through nucleic acid amplification testing (NAAT) on blood and cerebrospinal fluid. However, in the final stages of the illness, cerebrospinal fluid collection was not possible due to the patient's critical condition, and a nasopharyngeal swab was used instead. The nasopharyngeal swab facilitated the collection of a sample, which was subsequently analyzed for the presence of the virus and allowed for sequencing, showing that it was a strain that had been circulating in Sardinia for some time and had demonstrated its pathogenicity by causing the death of a hawk in 2021. This case report highlights the rapid progression and severity of WNV infection, particularly in vulnerable individuals, and suggests the potential utility of nasopharyngeal swabs as a less invasive option for sample collection. It also underscores the potential for the zoonotic transmission of the virus from birds to humans through vectors, emphasizing the importance of monitoring and controlling WNV outbreaks, especially in regions where such circulation is observed. [ABSTRACT FROM AUTHOR]

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Panama is a country with endemic Dengue virus (DENV) transmission since its reintroduction in 1993. The four serotypes have circulated in the country and the region of the Americas, however, DENV-4 confirmed autochthonous cases have not been identified since 2000, despite its circulation in neighboring countries. Here, we report DENV-4 detection in Panama in the last four-month period of 2023 with cocirculation of the other serotypes, this was associated with a peak of dengue cases during the dry season even thoughmost dengue outbreaks are described in the rainy season. Complete genomes of DENV-4 allowed us to determine that cases were caused by DENV-4 genotype IIb, the same genotype as 23 years ago, with high similarity to DENV-4 sequences circulating in Nicaragua and El Salvador during 2023. This report shows the importance ofmaintaining serotype and genotype surveillance for early detection of new variants circulating in the country. [ABSTRACT FROM AUTHOR]

Background Over the past 20 years, over 5 million cases of chikungunya, a mosquito-transmitted viral disease, have been reported in over 110 countries. Until recently, preventative strategies for chikungunya were largely ineffective, relying on vector control and individual avoidance of mosquito bites. Methods This review outlines the preclinical and clinical efficacy and safety data that led to the approval of VLA1553 (IXCHIQ®), a live-attenuated vaccine against chikungunya disease. It also describes the innovative development pathway of VLA1553, based on an immunological surrogate of protection, and discusses ongoing and future post-licensure studies. Results In mice and non-human primate models, VLA1553 elicited high titres of neutralizing antibodies, conferred protection against wild-type chikungunya virus challenge and raised no safety concerns. A Phase 1 clinical trial of VLA1553 demonstrated 100% seroconversion among 120 healthy participants, with sustained neutralizing antibody titres after 12 months. These results and determination of a surrogate marker of protection led to advancement of VLA1553 directly into Phase 3 clinical development, as agreed with the US Food and Drug Administration (FDA) and the European Medicines Agency. The pivotal Phase 3 trial met its primary immunogenicity endpoint, achieving seroprotective levels based on immuno-bridging in baseline seronegative participants 28 days post-vaccination. These findings enabled submission of a Biologics Licence Application to the FDA for accelerated approval of VLA1553 in the US for adults aged ≥18 years. Ongoing and planned studies will confirm the clinical efficacy/effectiveness and safety of VLA1553 in adults and younger individuals, and will generate data in chikungunya endemic countries that have the highest unmet need. Conclusion VLA1553 is the first vaccine approved for the prevention of chikungunya disease in adults, following accelerated development based on a serological surrogate marker of protection. VLA1553 adds to strategies to reduce the spread and burden of chikungunya in endemic populations and travellers. [ABSTRACT FROM AUTHOR]