Search Results (674)

Dengue, Zika, yellow fever, chikungunya, and Mayaro arboviruses represent an increasing threat to public health because of the serious infections they cause annually in many countries. Serological diagnosis of these viruses is challenging, making the development of new diagnostic strategies imperative. In this study, we investigated the effectiveness of gold nanorods (GNRs) functionalized with specific anti-dengue and anti-orthoflavivirus antibodies in detecting viral particles. GNRs were created with a length-to-width ratio of up to 5.5, a size of 71.4 ± 6.5 nm, and a light absorption peak at 927 nm, and they were treated with 4 mM polyethyleneimine. These GNRs were attached to a small amount of monoclonal antibodies that target flaviviruses, and the viral particles were detected by measuring the localized surface plasmon resonance using an UV-Vis/NIR spectrometer. The tests found Orthoflavivirus dengue and Orthoflavivirus zikaense in diluted human serum and ground-up mosquitoes, with the lowest detectable amount being 100 PFU/mL. The GNRs described in this study can be used to enhance flavivirus diagnostic tests or to develop new, faster, and more accurate diagnostic techniques. Additionally, the functionalized GNRs presented here are promising for supporting virological surveillance studies in mosquitoes. Our findings highlight a fast and highly sensitive method for detecting Orthoflavivirus in both human and mosquito samples, with a detection limit as low as 100 PFU/mL. Full article

Background: Arthropod-borne diseases primarily affect tropical and subtropical regions, exhibiting seasonal patterns that peak during hot and rainy months when conditions favor mosquito vector proliferation. Factors such as high temperatures, elevated humidity, rainfall, urbanization, and the abundance of natural and artificial breeding sites influence Aedes vector dynamics. In this context, arboviruses pose significant public health challenges, likely worsened by global warming. In Brazil, Aedes (Stegomyia) aegypti (Linnaeus, 1762) is the primary vector for yellow fever, dengue, chikungunya, and Zika. Aedes (Stegomyia) albopictus (Skuse, 1894) is an important global arbovirus vector and is considered a potential vector in Brazil. Entomological surveillance of these species often uses oviposition traps targeting immature stages. Evaluating studies that use ovitraps to collect Ae. aegypti and Ae. albopictus egg is essential for improving mosquito surveillance strategies. This study systematically reviewed peer-reviewed articles on ovitrap-based surveillance of Aedes mosquitoes in Brazil, published in Portuguese and English from 2012 to 2022. The findings suggest that ovitraps are an effective method for detecting the presence or absence of Ae. aegypti and Ae. albopictus, serving as a reliable proxy for estimating mosquito abundance in Brazilian contexts. Full article

The mosquito Aedes aegypti is the vector responsible for the transmission of important arboviruses such as dengue fever, Chikungunya, Zika virus, and yellow fever. These diseases affect millions of people and exert impacts on healthcare systems throughout the world. Given the increasing resistance to synthetic insecticides, essential oils from plants constitute an ecologically viable alternative for the control of this vector. The aim of the present study was to investigate the larvicidal activity of the essential oil (EO), aqueous extract, rutin, and hydrolate from the leaves of Myrciaria floribunda against Aedes aegypti larvae in the initial L4 stage. The yield of EO was 0.47%. Thirty-seven chemical constituents were identified and quantified using chromatographic methods. The major constituents were (E)-caryophyllene (27.35%), 1,8-cineole (11.25%), β-selinene (4.92%), and α-muurolene (4.92%). In the larvicidal tests, the lethal concentration (LC₅₀) was 201.73 ppm for the essential oil, 15.85% for the aqueous extract, and 22.46 ppm for rutin. The hydrolate had no larvicidal activity. The compounds that exhibited larvicidal activity against Aedes aegypti constitute a promising option for the development of natural formulations to diminish the propagation of this vector. Full article

Background and Objectives: The relationship between ABO or Rh blood groups and susceptibility to Chikungunya virus (CHIKV) infection remains unclear. This systematic review and meta-analysis aimed to synthesize available evidence on this association. Materials and Methods: Studies reporting ABO and/or Rh blood groups and CHIKV infection were searched through PubMed, Scopus, EMBASE, MEDLINE, Ovid, ProQuest, and Google Scholar up to 8 July 2025. A random-effects meta-analysis was conducted to calculate pooled odds ratios (Ors) with 95% CIs. Heterogeneity was assessed using I² statistics. Subgroup analyses were performed based on study design and study quality. Sensitivity analysis was conducted using a leave-one-out method. Publication bias was evaluated via funnel plots and Egger’s test. Results: Seven studies, including 24,828 participants, were included. No significant associations were observed between blood groups A, B, AB, or Rh(D) and CHIKV infection. However, blood group O was significantly associated with an increased risk of CHIKV infection (OR: 1.52, 95% CI: 1.01–2.29, p = 0.043, I² = 95.38%) compared to non-O blood groups. Subgroup analyses showed stable results. Nevertheless, the sensitivity analysis indicated that certain studies had a greater influence on the overall results. In addition, significant publication bias was also detected. Conclusions: Current evidence indicates that blood group O is significantly associated with an increased susceptibility to CHIKV infection. In contrast, no consistent associations were observed for other ABO or Rh blood groups. Due to substantial heterogeneity and methodological limitations, these findings should be interpreted with caution. Further well-designed, large-scale studies with standardized diagnostics are needed to clarify these associations and underlying mechanisms. Full article

Chikungunya virus (CHIKV), a mosquito-borne alphavirus, has re-emerged, causing widespread outbreaks and a significant clinical burden. Despite advances in virology, the molecular mechanisms governing CHIKV’s interaction with host cells remain poorly understood. In this study, we aimed to identify novel host protein interactors of the CHIKV nonstructural protein 3 (nsP3), a critical component of the viral replication complex, using mass spectrometry-based proteomic profiling in liver-derived Huh7 cells. Co-immunoprecipitation followed by LC-MS/MS identified a wide array of host proteins associated with nsP3, revealing 52 proteins classified as high-confidence (FDR of 1%, and unique peptides > 2) CHIKV-specific interactors. A bioinformatic analysis using STRING and Cytoscape uncovered interaction networks enriched in metabolic processes, RNA processing, translation regulation, cellular detoxification, stress responses, and immune signaling pathways. A subcellular localization analysis showed that many interactors reside in the cytosol, while others localize to the nucleus, nucleolus, and mitochondria. Selected novel host protein interactions were validated through co-immunoprecipitation and immunofluorescence assays. Our findings provide new insights into the host cellular pathways hijacked by CHIKV and highlight potential targets for therapeutic intervention. This is the first report mapping direct nsP3–host protein interactions in Huh7 cells during CHIKV infection. Full article

Early biomarkers are needed to predict the long-term persistence of rheumatical symptoms in patients infected with Chikungunya virus (CHIKV). This nested case-control study aimed to assess immunological factors during the early phases of CHIKV infection to predict the risk of post-CHIK chronic rheumatism (pCHIK-CR) in adult patients of two prospective cohorts. We evaluated 46 febrile patients (median age: 33.5 years; IQR: 19 years; women: 50.0%) with CHIKV infection confirmed during the 2014–2015 outbreak in Santander, Colombia. The participants were classified by a rheumatologist as either cases (pCHIK-CR) or controls (WoRM, without rheumatical manifestations). We quantified serum levels of IL-4, IL-6, IL-8/CXCL-8, IL-27, CCL-2, CXCL-9, CXCL-10, and IgG using Luminex and ELISA assays during the acute and subacute phases of infection. Then, we evaluated the association of these immune factors with the case-control status using piecewise logistic regression adjusted for age and sex. There were non-linear associations between IL-8/CXCL-8, CXCL-9, and CXCL-10 with pCHIK-CR. Increases in the levels of IL-8/CXCL-8 (<35.7 pg/mL), CXCL-9 (≥6000 pg/mL), and CXCL-10 (≥36,800 pg/mL) were significantly associated with a reduced risk of pCHIK-CR (adjusted ORs: 0.85, 0.96, and 0.94, respectively). These results suggest that increases in IL-8/CXCL-8, CXCL-9, and CXCL-10 levels, measured in the early stages of CHIKV infection, may predict a chronic disease risk. This suggests the possibility that an early and strong immune response could contribute to enhancing CHIKV control and potentially reduce the risk of persistent joint symptoms. Given their expression patterns and timing, these three immune factors may be considered promising biomarker candidates for assessing the risk of chronic rheumatologic disease. These findings should be considered as exploratory and validated in additional cohort studies. Full article

The Chikungunya virus (CHIKV) continues to pose a significant global health challenge due to the absence of effective antiviral treatments and limited vaccine availability. This study employed a comprehensive in silico workflow, incorporating high-throughput virtual screening, binding free-energy calculations, ADMET (absorption, distribution, metabolism, excretion, and toxicity) analysis, and 200 ns molecular dynamics (MD) simulations, to identify new inhibitors targeting the E1–E2 glycoprotein complex, crucial for CHIKV entry and membrane fusion. Four promising candidates were identified from a library of 20,000 compounds, with CID 136801451 showing the most potent binding (docking score: −10.227; ΔG_bind: −51.53 kcal/mol). The top four compounds exhibited favorable ADMET profiles, meeting nearly all criteria. MD simulations confirmed stable binding and strong interactions between CID 136801451 and the E1–E2 complex, evidenced by consistently low RMSD values. These findings highlight CID 136801451 as a promising CHIKV entry inhibitor, warranting further in vitro and in vivo evaluation to advance the development of effective anti-CHIKV therapeutics. Full article

Evaluating the development process of mosquito species under the influence of temperature is essential for understanding their ecology and geographical distribution, as well as assessing their potential as vectors of pathogens. Aedes (Protomacleaya) terrens, a species recognized for its susceptibility and competence in transmitting the chikungunya virus, serves as a relevant model for research in this context. This study aimed to analyze the influence of temperature on egg hatching and the development cycle of this species to expand knowledge on its biology and implications for public health. During the experiment, 800 eggs were used, collected through 10 ovitraps in a forest remnant located in Uruaçu, Goiás, Brazil. The total number of eggs was divided into four groups, exposed to constant temperatures of 15 ± 2 °C, 20 ± 2 °C, 25 ± 2 °C, and 30 ± 2 °C. After hatching, first-instar larvae were individually separated and monitored daily under controlled conditions until adult emergence. The highest hatching rate occurred at 25 °C, showing an optimal point around 27 °C. Throughout development, temperature significantly reduced the duration of each stage, with the fastest complete cycle at 30 °C, a difference of approximately 10–12 days when compared to 20 °C and approximately 47 days when compared to 25 °C. These results offer valuable insights into the temperature sensitivity of Ae. terrens across its developmental stages, suggesting that each stage has its own optimal temperature. Thus, small variations in responses to environmental conditions and differentiation between sexes may become more pronounced throughout development. In this sense, temperature can affect not only the development and survival of dipterans but also the capacity for virus transmission, as the pathogen influences the reproduction rate and longevity of the vectors. Full article

Arboviruses, including but not limited to dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV), pose a significant global threat to human health. The transmission of DENV, ZIKV, and CHIKV is facilitated by mosquitoes belonging to the genus Aedes, which are prevalent in both urban and rural regions of Vietnam. In 2023 an investigation into the population of mosquitoes was conducted in a number of provinces located within the central region of Vietnam. A total of 12,546 mosquitoes were collected during the study. The mosquitoes collected comprised the genera Culex spp., Aedes spp., Anopheles spp., and Armigeres spp. The Aedes spp. mosquitoes were predominant, being collected in 908 pools. These were then examined by RT-qPCR for the detection of DENV, ZIKV, and CHIKV. DENV viral RNA was detected in 92 mosquito pools, ZIKV was detected in 1 mosquito pool, and CHIKV was not detected. The typing of samples containing DENV RNA was carried out. It is evident from the results of the typing process that three distinct types of DENV have been identified. The three main dengue virus types are DENV-1, DENV-2, and DENV-4. Full article

Mosquitoes of the Aedes and Culex genera are primary vectors of arboviruses such as the dengue, Zika, chikungunya (CHIKV), Oropouche, and West Nile viruses, causing millions of infections annually. Standard virus detection in mosquitoes requires capturing, transporting, and processing samples with a cold chain to preserve RNA, which is challenging in resource-limited areas. FTA cards preserve viral RNA at room temperature and have been used to collect mosquito saliva, a key sample for assessing transmission. However, most FTA-based traps require electricity or CO₂, limiting use in low-resource settings. This study adapted and evaluated the BR-ArboTrap, a low-cost trap derived from an oviposition trap, integrating a sugar-based attractant with FTA cards to collect mosquito saliva, without electricity or refrigeration. Aedes aegypti exposed to CHIKV were used in three experiments to evaluate: (i) RNA preservation under different conditions, (ii) the minimum number of positive mosquitoes for detection, and (iii) RNA amounts on FTA versus blood. RT-qPCR detected CHIKV RNA in 90% of FTA cards and 96% of exposed mosquitoes. RNA remained stable under varying conditions, with no significant difference compared to blood. BR-ArboTrap is an effective, affordable, and field-ready tool to enhance arbovirus surveillance in remote and low-resource areas. Full article

The rapid global expansion of Aedes aegypti-borne diseases such as dengue, chikungunya, and Zika has positioned this mosquito as a key target for vector control programs. These programs rely heavily on insecticide use, leading to the widespread emergence of insecticide resistance. Understanding the molecular basis of resistance is essential for developing effective management strategies. In this study, we employed a whole-transcriptome (RNA-seq) approach to analyze gene expression in three Ae. aegypti populations from Mexico that underwent four generations of laboratory selection with deltamethrin. Several cytochrome P450 genes (CYP6AG4, CYP6M5, CYP307A1) and a chitin-binding peritrophin-like gene (Ae-Aper50) were significantly overexpressed following selection, supporting roles for both detoxification and midgut protection. We also observed a consistent downregulation of cuticular protein genes in deltamethrin-selected groups relative to the baseline populations, suggesting their involvement in baseline tolerance rather than induced resistance. Additionally, the overexpression of immune- and stress-related genes, including the RNA helicase MOV-10, indicates that insecticide selection may trigger broader physiological responses. These findings highlight complex, multi-pathway transcriptomic changes associated with resistance development in Ae. aegypti. Full article

The Aedes aegypti mosquito is a vector for several arboviral diseases, posing a significant threat to human populations and exacerbating health disparities. Puerto Rico is a subtropical region where A. aegypti mosquitoes circulate all the year promoting the transmission of arboviruses. A cross-sectional study in the municipality of Ponce, Puerto Rico was conducted to determine the prevalence of arbovirus in A. aegypti mosquitoes and community members, and the impact that sociodemographic and environmental factors on the presence of arbovirus in the community. Our results indicate that more than a third of the population has long-term antibodies (IgG) against chikungunya and the Mayaro virus (56% and 17%, respectively). In addition, more than two-thirds of the population have long-term antibodies (IgG) against dengue and Zika virus (96.0% and 77%, respectively). Dengue virus 1 (DENV-1) was only detected in mosquitoes from urban areas. The practice of storing water in containers uncovered and living near a river increased the odds of having arbovirus in the community (OR = 3.5, 95% CI = 1.8–10.6) (p < 0.05) and (OR = 1.6, 95% CI = 1.2–3.7). Furthermore, lower income was a social determinant associated with being at risk of arboviral disease in the communities (OR = 2.9, 95% CI = 1.4–8.5) (p < 0.05). It is recommended that public health activities be implemented, including education workshops on prevention and health promotion and health services such as vector control, to prevent arboviral diseases in communities. Full article

Background/Objectives: This overview provides a comprehensive safety evaluation of the approved live-attenuated vaccine VLA1553 (IXCHIQ^®) for active immunization for the prevention of disease caused by chikungunya virus (CHIKV) in clinical trials. Methods: Protocol-defined solicited systemic events (i.e., fever, arthralgia, myalgia, fatigue, and headache) and other unsolicited arthralgia-related events were evaluated. Additionally, during a regulatory review, a broader definition of adverse events of special interest (broad-definition AESIs) (fever and ≥1 AESI symptom within 30 days post-vaccination) was evaluated post hoc. Results: The most frequently reported solicited systemic events post-VLA1553 included fever (13.5%), arthralgia (17.2%), myalgia (23.9%), fatigue (28.5%), and headache (31.6%), with very few prolonged symptoms. The incidence of unsolicited arthralgia-related events (arthritis, osteoarthritis, musculoskeletal stiffness, joint stiffness, and joint swelling) was comparable between VLA1553 and placebo groups. Broad-definition AESIs were observed in 11.7% (361/3082) participants (VLA1553) and 0.6% (6/1033) participants (placebo), with a duration of 1–182 days (median: 4 days; prolonged broad-definition AESI [≥1 symptom lasting ≥ 30 days] occurred in 0.5% of participants) (VLA1553) and 4–27 days (median: 8 days) (placebo). Most symptoms contributing to broad-definition AESIs were solicited. In the VLA1553 group, the most common of these symptoms, in addition to fever, were headache (9.1% of participants), fatigue (8.6%), myalgia (7.0%), and arthralgia (5.2%). There were few severe cases (1.6% of participants in the VLA1553 group). Conclusions: In clinical trials, VLA1553 showed an acceptable safety profile that was consistent with other live-attenuated vaccines. The incidence of broad-definition AESIs was mainly limited to the immediate post-vaccination period, and broad-definition AESI symptoms were mostly solicited systemic adverse events. Full article

Aedes aegypti (Linnaeus, 1762) is Brazil’s primary vector of epidemiologically significant arboviruses such as yellow fever, dengue, Zika, and chikungunya. Despite using conventional chemical control measures, this species has developed resistance to standard chemical insecticides, prompting the search for natural larvicidal compounds. Plant protease inhibitors offer an insecticidal alternative as the primary digestive enzymes in the midgut of Ae. aegypti are proteases (trypsin and chymotrypsin). Ae. aegypti larvae fed with ILTI, a Kunitz-type trypsin inhibitor derived from Inga laurina seeds, at concentrations between 0.03 mg of protein per mL (mgP/mL) and 0.12 mgP/mL, exhibited delayed larval development, with a lethal concentration (LC₅₀) of 0.095 mgP mL⁻¹ of ILTI for 50% of fourth-instar larvae (L₄). The ex vivo assay indicated that ILTI effectively inhibited the activity of larval trypsin, which remained susceptible to the inhibitor. Additionally, molecular modelling and docking studies were conducted to predict the three-dimensional ILTI/enzyme molecular complexes at the atomic level. Therefore, the results demonstrate that ILTI functions as a protease inhibitor in this species, presenting itself as a promising larvicidal tool in the control of Ae. aegypti. Full article