Search Results (725)

Arboviruses such as dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) remain major global health threats, especially in tropical regions, with no effective antiviral treatments available. Recent research highlights progress in identifying antiviral compounds from natural sources against arboviruses belonging to the flavivirus genus, such as DENV and ZIKV. These compounds, derived from plants, marine organisms, and microorganisms, fall into several key chemical classes: quinones, flavonoids, phenolics, terpenoids, and alkaloids. Quinones inhibit viral entry and replication by targeting envelope proteins and proteases. Flavonoids disrupt RNA synthesis and show virucidal activity. Phenolic compounds reduce expression of non-structural proteins and inhibit enzyme function. Terpenoids demonstrate broad-spectrum activity against multiple arboviruses, while alkaloids interfere with early infection stages or viral enzymes. To support the reviewed literature, we performed molecular docking analyses of selected natural compounds and some arboviral proteins included as illustrative examples. These analyses support the structure–activity relationships reported for some natural compounds and highlight their potential interactions with essential viral targets such as the NS2B-NS3 protease and NS5 polymerase. Together, these literature and computational insights highlight the potential of natural products as scaffolds for antiviral drug development. Full article

Multiplexed detection of arboviruses using a 4 × 4 Si-based electrolyte-gated transistor (EGT) array functionalized with specific aptamers has been investigated. The Si-based EGTs were fabricated using conventional Si microfabrication processes. The EGTs showed excellent intrinsic electrical characteristics, including a low threshold voltage of 0.8 V, a sub-threshold swing of 75 mV/dec, and a gate leakage of <10 pA, ensuring uniform device performance with low device-to-device variation. Aptamers specific to the yellow fever virus nonstructural protein 1 (YF), dengue virus nonstructural protein 1 (DN), and chikungunya virus envelope protein 2 (CHK) were functionalized on EGT arrays to evaluate individual and multiplexed detection. In individual-target detections, concentration-dependent negative shifts in threshold voltage were observed, and relevant limits of detection (LOD) as low as 38.6 pg/mL, 95.2 pg/mL, and 1.6 ng/mL were extracted for YF, DN, and CHK, respectively. In multiplexed detections, sensitivities decreased and variations increased relative to the individual responses, resulting in higher LODs. The extracted LODs were 0.2 ng/mL, 0.6 ng/mL, and 2.8 ng/mL for YF, DN, and CHK, respectively, which are lower than those reported for other methods. These results suggest that Si-based EGT arrays are promising as a scalable, low-cost, and highly sensitive biosensing platform for multiplexed arbovirus detection and point-of-care diagnostics. Full article

Zika virus (ZIKV) was first identified in Africa in the mid-20th century and circulated for decades with limited and often unnoticed human cases. This situation changed with the emergence of the Asian lineage, responsible for large outbreaks in the Pacific and the Americas and for severe complications such as Guillain–Barré syndrome and Congenital Zika Syndrome (CZS). In contrast, the African lineage, although frequently more efficient in replication, cytopathogenicity, and mosquito transmission in experimental systems, has not been linked to comparable epidemics or congenital disease clusters. This review summarizes current knowledge on the differences between African and Asian lineages at the molecular, cellular, and epidemiological levels. It highlights how genetic variation interacts with host immunity, ecological factors, and human activity to shape epidemic potential. Understanding these interactions is essential for anticipating future outbreaks and for improving strategies to mitigate the impact of emerging arboviruses. Full article

Background: Molecular mimicry contributes to the development of unwanted responses to self-antigens. Autoimmune phenomena have been observed in diseases caused by Aedes aegypti-transmitted arboviruses, but the occurrence of mimicry between salivary and human proteins has been unexplored. Methods: We used bioinformatic tools to determine if peptides from Aedes aegypti salivary proteins were present in the human proteome. We further characterized the potential of shared sequences to induce immunity by analyzing their predicted binding to MHC molecules and their occurrence in peptides from the Immune Epitope Database (IEDB). Results: We analyzed 9513 octapeptides from 29 Aedes aegypti salivary proteins against the human proteome and found 47 peptides identical to sequences from 52 human proteins, ranging in length from 8 to 18 amino acids. We found 302 matches of peptides predicted to bind with high affinity to MHC-I and MHC-II alleles associated with autoimmune diseases, and 14 human peptides containing shared sequences with Aedes aegypti salivary proteins validated as immunogenic in the IEDB. Conclusions: These results support the existence of molecular mimicry between Aedes aegypti salivary proteins and human antigens and provide a framework for studies to determine its contribution to responses directed to self-antigens in the context of arboviral infections. Full article

Mosquito-borne viruses like West Nile virus (WNV) and Usutu virus (USUV) present growing public health concerns, especially with climate change and expanding vector ranges. This study describes the development and validation of a duplex Real-Time RT-PCR assay targeting β-actin (ACTB) mRNA as an endogenous control and a conserved 92 bp region shared by WNV and USUV genomes. Degenerate primers for ACTB ensure RNA extraction quality and PCR performance while enabling simultaneous detection of both viruses. A total of 1002 mosquito pools collected in Piedmont, Italy, during the 2024 vector season under the National Surveillance Plan for Arboviruses (PNA), were tested. The assay showed 100% accuracy—ACTB mRNA was detected in all pools, and six pools tested positive for WNV or USUV (three each). Diagnostic specificity was confirmed on 40 horse and bovine serum samples. Sanger sequencing confirmed ACTB identity across multiple mosquito species. The assay also demonstrated reproducibility across different operators and thermocyclers. The limit of detection (LOD) evaluation showed that the assay is capable of detecting viral RNA at very low concentrations, confirming its high analytical sensitivity. The duplex RT-PCR here developed is a reliable, sensitive, and specific tool for arbovirus surveillance, combining pathogen detection with internal quality control of RNA extraction and amplification, thus improving early warning and rapid response to mosquito-borne disease threats. Full article

Control of Aedes aegypti, the primary vector of arboviruses such as dengue, Zika, and chikungunya, is increasingly difficult due to resistance to synthetic insecticides and environmental concerns. Plant essential oils offer sustainable alternatives with multi-target modes of action and rapid biodegradation. This study evaluated the insecticidal potential of the essential oil of Aniba canelilla (EOANIB), its major constituent 1-Nitro-2-phenylethane (NFTANE), and the derivative 1-Nitro-2-phenylethene (NFTENE) against larvae and adults of A. aegypti. Acetylcholinesterase (AChE) inhibition was quantified using enzymes from Electrophorus electricus, Aedes aegypti and Drosophila melanogaster. Pluronic^® F127 (5% w/v) nanoformulations loaded with EOANIB, NFTANE, or NFTENE at 1.5% or 0.34% (w/v) improved efficacy and stability. Formulations remained stable for 120 to 190 days at 25 to 60 °C. Larvicidal assay at 24 h yielded LC₅₀ values of 86.9 (CI 78.2–94.7) ppm for EOANIB, 84.8 ppm (CI 75.6–92.4) for NFTANE and 10.9 (CI 8.0–14.0) ppm for NFTENE. Against adults, EOANIB achieved an LC₅₀ of 33.9 ppm at 1.5 h. Nanoformulation reduced the EOANIB LC₅₀ by 22.2% after 24 h and 40.1% after 48 h. Toxicity assays evaluated selectivity with Artemia salina (EOANIB LC₅₀: 77.2 ppm) and no mortality in D. melanogaster at 100 ppm. The convergence of efficacy, formulation-enhanced performance, and demonstrated storage stability positions Aniba canelilla as a promising source of bioinsecticide candidates for Aedes aegypti control and supports further development of micellar delivery systems for integrated vector management. Full article

This study presents a technique for categorizing Aedes aegypti mosquitoes infected with the Zika virus under laboratory conditions. Our approach involves the utilization of the near-infrared spectroscopy technique and machine learning algorithms. The model developed utilizes the absorption of light from 350 to 1000 nm. It integrates Linear Discriminant Analysis (LDA) of the signal’s windowed version to exploit non-linearities, along with Support Vector Machine (SVM) for classification purposes. Our proposed methodology can identify the presence of the Zika virus in intact mosquitoes with a balanced accuracy of 96% (row C2HT, average of columns TPR (%) and SPC (%)) when heads/thoraces of mosquitoes are scanned at 4, 7, and 10 days post virus infection. The model was 97.1% (10 DPI, row C2AB, column ACC (%)) accurate for mosquitoes that were used to test it, i.e., mosquitoes scanned 10-days post-infection and mosquitoes whose abdomens were scanned. Notable benefits include its cost-effectiveness and the capability for real-time predictions. This work also demonstrates the role played by different spectral wavelengths in predicting an infection in mosquitoes. 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

Acute respiratory infections and other infectious diseases causing acute febrile syndrome are major public health concerns in Colombia, particularly among vulnerable populations such as the Wayuu Indigenous community in Manaure, La Guajira. To investigate their viral etiology, 55 nasopharyngeal swabs and 58 serum samples were collected from febrile Wayuu individuals in Manaure. RT-qPCR screening identified Coronavirus, Enteroviruses, Adenovirus, and Influenza A/B in respiratory samples, while no arboviruses were detected in serum. Sixteen representative samples underwent metatranscriptomic next-generation sequencing (mtNGS) using the Chan-Zuckerberg ID (CZ-ID) platform. This analysis confirmed RT-qPCR findings and additionally revealed six viral contigs related to Orthopicobirnavirus hominis. Sequencing coverage enabled the reconstruction of a consensus RdRp segment, which was phylogenetically compared with sequences from diverse hosts. The virus clustered within genogroup 1, alongside Colombian isolates linked to severe acute respiratory infection. The absence of strict host-specific clustering suggests possible interspecies transmission. These findings underscore the complementary roles of targeted and unbiased approaches: RT-qPCR detected common respiratory viruses, whereas mtNGS uncovered a virus previously unreported in this community. Overall, mtNGS emerges as a powerful tool to support viral surveillance and provide baseline evidence in indigenous populations, emphasizing the need to decentralize advanced molecular diagnostics and strengthen public health capacity in Colombia. Full article

The Orthobunyavirus Oropouche (OROV) has become an urgent public health threat in Central and South America, as well as in other countries worldwide. Since its initial identification, there have been over 30 outbreaks, with the largest reported in late 2024 in Brazil. This outbreak prompted an epidemiological alert due to a significant increase in OF cases in non-Amazonian states in the Americas region, as well as in European countries, where 44 imported cases were identified. Humans become infected predominantly through the bite of the Culicoides paraensis midge, and the symptoms could be misinterpreted due to their similarity to those of other arboviral infections. Due to the lack of a point-of-care test, RT-qPCR is currently the key diagnostic test during the acute phase of the disease. This review focuses primarily on the available molecular and serological diagnostic methods. The latter could indeed be used as a confirmation test to monitor the patient’s immunological status and better distinguish between cross-reacting arboviruses. In addition, this review explains also the existing sequencing methods required to enforce the surveillance system for OROV reassortant species that could cause a new worldwide outbreak. The information gathered could provide a valuable basis for implementing additional surveillance systems in those countries lacking up-to-date data. Full article

Cacipacoré virus (CPCV) is an understudied orthoflavivirus with significant gaps in research that hinders our understanding of its ecology, host range, and potential public health impact. A notable barrier to filling this gap is the absence of standardized methodologies for viral quantification, such as plaque-forming and focus-forming assays. This short communication outlines the development of optimized protocols for CPCV titration in two cell lines, Vero CCL-81 and BHK CCL-10, using several overlay and time point conditions. These methodologies address the need for robust quantitative tools to advance research on CPCV and its implications for human and animal health, fostering progress in the surveillance and understanding of this underexplored arbovirus. Full article

Rickettsia rickettsii is the most virulent agent of the genus Rickettsia that causes one of the most relevant vector-borne diseases in the Americas (RRSF). RRSF manifests with many non-specific acute clinical symptoms complicating its diagnosis and can lead to death if not treated appropriately. RRSF has been reported in Canada, the United States of America, Mexico, Costa Rica, Panama, Colombia, Brazil, and Argentina. In addition to R. rickettsii, mild and severe spotted fever group rickettsioses (SFGR) have been reported in the Americas; however, the true prevalence of these diseases is unknown. In Panama, RRSF have been reported in four of 14 provinces during two outbreak periods: five cases including two fatalities were identified in 1950–1951, and 23 cases including 17 fatalities between 2004 and 2025. This paper presents the clinical characterization of a fatal case of RRSF in Coclé province and a severe case of SFGR in a mountainous area of the Gnäbe Buglé Indigenous Comarca (GBIC). Laboratory confirmation was performed by molecular analysis of tissues obtained from necropsies in the case of RRSF and by immunofluorescence assay (IFA) in the case of SFGR. Furthermore, this paper identifies existing gaps in the initial clinical suspicion and pertinent to SFGR in Panama, which may be applicable to other countries in the region. In the last 21 years, cases have occurred upon contact with ticks in rural areas (13), urban and suburban locations (7), rural woodlands (2), and forests (1). Provinces with more cases are Panamá (7 of 23, 6 died), Coclé (5 of 23, 5 died), Colón (3 of 23, 1 died), Panamá Oeste (1 of 23, 1 died), and GBIC (7 of 23, 4 died), including a cluster of seven cases in 2019. Therefore, Coclé province is considered one of the endemic areas for RRSF in Panama, while the latest cases from the GBIC since 2019 indicate that mountainous areas are an eco-epidemiological scenario to include in the transmission of these diseases. Although this disease has a low prevalence, patients who present symptoms commonly associated with more common diseases such as dengue, other arboviruses, malaria, and leptospirosis, among others, should be included in the diagnostic suspicion. Without diagnostic suspicion and adequate treatment, the patient can die. Full article

Rift Valley fever (RVF) is a re-emerging vector-borne zoonotic disease that causes outbreaks in humans and animals across Africa. To better understand RVF at human–animal interfaces, a prospective longitudinal survey of people, livestock, and mosquitoes was conducted from 2016 to 2018, in two regions of Tanzania, with distinct climatic zones (Iringa and Morogoro). Molecular and serological tools for testing (RT-qPCR and IgM/IgG ELISA) for RVF virus (RVFV) were used to assess infection and exposure in people and animals. Mosquitoes were collected quarterly from 10 sentinel locations. In total, 1385 acutely febrile humans, 4449 livestock, and 3463 mosquito pools were tested. In humans, IgM seroprevalence was 3.75% (n = 52/1385), and overall seroprevalence (IgM and/or IgG positive) was 8.30% (n = 115/1385). People from Iringa had a higher exposure risk than those from Morogoro (aOR 2.63), and livestock owners had an increased risk compared to non-owners (aOR 2.51). In livestock, IgM seroprevalence was 1.09%, while overall seroprevalence was 10.11%. A total of 68.4% of herds had at least one seropositive animal. Sentinel animal follow-up revealed that the probability of seroconversion was significantly higher in Morogoro. Low-level RVFV RNA was detected in 8 human and 22 mosquito pools. These findings indicate active transmission among vectors, livestock, and people during the study period, highlighting the need for One Health surveillance approaches for RVFV and other arboviruses. Full article

A May 2025 symposium convened leading virology experts across Latin America and the Caribbean (LAC) to advance regional research and collaborative efforts. Sessions explored cutting-edge developments in arbovirology, pressing challenges in viral surveillance, and the complexities of vector biology. Integrated networking opportunities and hands-on workshops offered mentorship and training, focused on the next generation of virologists, and strengthened scientific communication within the region. The morning session included reports from the LAC Global Virus Network (GVN) Centers of Excellence. A roundtable dialogue tackled the present challenges faced in arbovirus research. The Abbott Pandemic Defense Coalition reported on its collaborative progress. Trainees from the University at Buffalo, the State University of New York, and the University of the West Indies Global Infectious Diseases Research Training program showcased their current research projects. A session concentrated on health landscapes and the capacity for viral vaccinations within the region. A mentoring workshop focused on immune evasion methodologies and obstacles associated with arboviruses. One Health perspectives on viral zoonotic diseases addressed developments in the surveillance of vector-borne viruses in the Caribbean. Studies of mosquitoes and ticks as vectors of viruses included discussion on the neurovirulence of arboviruses and symptoms occurring after viral infections. Pediatric infectious diseases were highlighted in their environmental health context. An additional mentoring workshop centered on viruses and the microbiome. The relationship between viruses and cancer was discussed in the South American context and included recent advancements in the field of vaccinology. The Jamaica Regional GVN meeting promoted collaboration, facilitated the exchange of knowledge, and advanced research efforts throughout the region. Full article

Dengue and malaria are common vector-borne tropical diseases and are associated with high morbidity and mortality. Co-infection of dengue and malaria is underestimated due to parsimonious diagnostic approaches once the diagnosis of either is made, particularly using point-of-care assays, such as rapid diagnostic tests (RDTs). We present a case of dengue and Plasmodium vivax co-infection in a returned traveler from an endemic region, in whom the epidemiology and clinical course are highly suggestive of dengue triggering a P. vivax relapse. The literature on the co-occurrence of dengue and malaria in travelers is reviewed, as is the state of knowledge surrounding dengue as a precipitant to relapsing malaria. Full article