Search Results (54)

Oropouche virus (OROV) is an emerging zoonotic arthropod-borne virus of public health importance. The host range of OROV is largely unknown, but antibody evidence suggests that wildlife and livestock species could be susceptible hosts. To identify potential North American mammalian reservoir hosts, OROV replication curves were generated using eight cell lines derived from livestock, wildlife, and domestic animal species (cow, sheep, bison, white-tailed deer, elk, pig, horse, and dog). The virus replicated in all cell lines by 48 h post infection, except for the horse cells. OROV replication success was greatest in the bison cells followed by pig and dog cells. Moderate replication was achieved in the deer, elk, sheep, and cow cells. These results indicate that numerous animal species may be susceptible hosts for OROV, including important agricultural and wildlife species, but pathogenesis studies are required to confirm this finding. Identifying the reservoir hosts for OROV will allow livestock producers, veterinarians, and public health officials to prepare appropriate vector and disease control measures should the virus initiate an outbreak in the United States. Full article

Oropouche virus (OROV) is an emerging arthropod-borne virus in the Americas that has evolved from a pathogen historically restricted to forest environments into an increasingly important regional and international public health concern. Despite decades of documented circulation, the true burden of OROV infection remains substantially underestimated, largely because of frequent misdiagnosis and the high proportion of asymptomatic or subclinical infections. This review synthesizes current evidence on the historical emergence, epidemiology, transmission dynamics, and clinical features of OROV, with a particular focus on populations at increased risk due to biological susceptibility, environmental exposure, and limited access to healthcare. Drawing on seroepidemiological data, we demonstrate that OROV transmission is far more widespread than routine surveillance suggests and examine how factors such as age, pregnancy, immune status, underlying health conditions, occupational exposure, and healthcare accessibility interact to influence disease risk and detection. Although multiple vaccine platforms have shown promise in preclinical studies, progress toward clinical development remains constrained by limited immunological evidence, shortcomings of available animal models, diagnostic uncertainty, and structural barriers in endemic regions. We propose that future OROV vaccine development prioritize population-specific needs rather than focusing solely on technological platforms, and that effective prevention will require integrating vaccination with strengthened surveillance, improved diagnostics, and equitable delivery systems. Full article

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

Oropouche virus (OROV) has emerged as a significant arboviral pathogen in South America, responsible for recurrent outbreaks of febrile illness. In the Loreto region of Peru, more than 600 cases were reported in 2024, markedly exceeding expected incidence rates. We conducted a retrospective observational study using clinical–epidemiological records of all RT-qPCR-confirmed cases of Oropouche fever from the Regional Health Directorate of Loreto between October 2024 and March 2025. A total of 100 confirmed cases were identified. The most frequent symptoms were fever (88%), headache (78%), and myalgia (72%). No atypical or neurological presentations were reported. No severe cases or deaths occurred. Eight patients required hospitalization, mainly due to severe abdominal pain, persistent vomiting, arthralgia, and pregnancy. Six pregnant women were identified; three experienced pregnancy complications, though no fetal malformations or miscarriages were observed. This outbreak represents a new OROV epidemic in the region, with fewer cases than in 2024 and predominantly mild clinical courses. Although outcomes were generally favorable, the occurrence of complications in pregnant women underscores the importance of continued molecular surveillance and targeted public health interventions. Full article

Oropouche virus (OROV) is an emerging and underreported arbovirus with dengue-like symptoms confounding diagnosis. OROV is also neuroinvasive, with a small number of cases presenting severe neurological symptoms. There have been recently reported deaths from confirmed cases of OROV and reported instances of vertical transmission from mother to foetus, with confirmed cases in Brazil and a congenital anomaly, reportedly as a consequence of OROV infection in Cuba, with further cases under investigation. Whilst cases of OROV infection occur mainly in South America, many cases have been imported elsewhere, including the United States and Europe. Despite the emerging threat to public health, animal modelling to study OROV pathogenicity and immunity and to evaluate therapeutic candidates remains limited. For this review, we carried out a literature search through major research databases (PubMed and Scopus) up to September 2025 to capture the extent of in vivo model development for this pathogen. We identified only 17 relevant primary research articles within these criteria which detailed hamster, mouse and non-human primate (NHP) models. Here, we discuss the extent of in vivo model development for OROV. In summary, small and large animal models need to be assessed with recent clinical isolates and reassortants, asymptomatic disease presentation in the NHP model requires further study and the hamster model shows potential for use in pathogenicity and vaccine or antiviral efficacy studies. We also compile relevant metadata and discuss the need for an animal model that more closely resembles human disease. Full article

Arthropod-borne viruses (arboviruses) are an increasingly significant threat to public health in tropical regions. In this study, we investigated the seroprevalence of various arboviruses in two species of sloth (Choloepus hoffmanni and Bradypus variegatus) in rural and peri-urban areas of Western Panama province. Between 2013 and 2018, blood samples from 60 sloths were tested for neutralizing antibodies against ten arboviruses. Significant variation in seroprevalence of different arboviruses was observed: 6.7% of sloths were seropositive for Madariaga virus, 6.7% for Venezuelan equine encephalitis virus, and 4.8% for Oropouche virus, while none were seropositive for dengue type 2, Zika, chikungunya, Una, Mayaro, or Punta Toro viruses. Notably, two Changuinola virus (CGLV) strains, which were previously isolated from Panamanian sloths in the 1970s, showed high seroprevalence: Pansloth 149 (23.3%) and D50 (53.3%). Given the high seroprevalence detected in our study and the lack of genomic characterization of the historical Pansloth 149 isolate, we performed next-generation sequencing of its complete genome using Illumina technology to understand its genetic diversity and evolutionary relationship with other CGLV strains. Full article

Oropouche virus (OROV), an emerging orthobunyavirus of increasing public health concern in the Americas, currently lacks approved antiviral therapies. In this study, we employed a structure-based in silico approach to identify natural antiviral scaffolds capable of targeting the Gc glycoprotein, a class II fusion protein essential for host membrane fusion and viral entry. A library of 537 plant-derived compounds was screened against the Gc head domain (PDB ID: 6H3X) through molecular docking and redocking, followed by 100-nanosecond molecular dynamics simulations, MM-PBSA free energy calculations, and ADMET profiling. Curcumin and Berberine emerged as standout candidates. Curcumin demonstrated a balanced profile, with stable binding (−38.14 kcal/mol), low backbone RMSD (1.82 Å), and consistent radius of gyration (Rg ~ 18.8 Å), suggesting strong conformational stability and compactness of the protein–ligand complex. Berberine exhibited the most favorable binding energy (−13.10 kcal/mol) and retained dynamic stability (RMSD 1.86 Å; Rg ~ 19.0 Å), though accompanied by predicted cytotoxicity that may require structural refinement. Both compounds induced reduced residue-level fluctuations (RMSF < 2.5 Å) in functionally critical regions of the Gc protein, consistent with a mechanism of action that involves stabilization of the prefusion conformation and interference with the structural transitions required for viral entry. These findings identify curcumin and berberine as promising scaffolds for anti-OROV drug development and offer a rational foundation for future experimental validation targeting viral fusion mechanisms. Full article

Oropouche virus (OROV) is an emerging arbovirus responsible for Oropouche fever, also known as sloth fever, a febrile illness that can lead to recurrent outbreaks in affected regions. Endemic to parts of South and Central America, OROV is primarily transmitted by biting midges (Culicoides paraensis), although mounting evidence implicates mosquitoes, particularly the Culex and Aedes species, as additional vectors. Recent ecological disturbances—such as deforestation, urbanization, and climate change—have driven significant shifts in vector population dynamics, contributing to the expanded geographic range and increased transmission of OROV. Notably, recent reports of OROV infections among American and European travelers to Cuba highlight the virus’s growing potential for international dissemination and underscore its significance as a global health concern. OROV is an enveloped orthobunyavirus within the Peribunyaviridae family, possessing a tripartite, single-stranded, negative-sense RNA genome composed of the S (small), M (medium), and L (large) segments. These segments encode the nucleocapsid (N) protein, glycoproteins (Gn and Gc), and RNA-dependent RNA polymerase, respectively. Despite increasing incidence and potential for global spread, no licensed vaccines or antiviral therapies currently exist, and effective diagnostic tools remain limited. Furthermore, although human-to-human transmission has not been observed, the absence of robust surveillance systems complicates timely outbreak detection and response. In this study, we present a comprehensive molecular characterization of OROV’s major structural proteins, with an emphasis on structural modeling and epitope prediction. By integrating bioinformatics approaches with available structural data, we identify key antigenic regions that could serve as targets for the development of serological diagnostics and vaccine candidates. Our findings contribute critical insights into the molecular virology of OROV and provide a foundational framework for future efforts aimed at the prevention, diagnosis, and control of this neglected tropical pathogen. These advancements are essential for mitigating the impact of OROV in endemic regions and reducing the risk of global emergence. 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 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

The simultaneous circulation of multiple arboviruses, often driven by (re)emergence events, poses challenges to public health systems. In Brazil, the co-circulation of Dengue virus (DENV), Zika virus (ZIKV), Chikungunya virus (CHIKV), and Oropouche virus (OROV), together with the potential urban emergence of Mayaro virus (MAYV), underscores the importance of understanding interactions among these pathogens within their vectors. This study investigated the effects of CHIKV and MAYV coinfection and superinfection on replication dynamics in Aedes aegypti. Mosquitoes were experimentally exposed to CHIKV and MAYV through artificial blood meals under coinfection and superinfection conditions. Infection (IR), dissemination (DR), and transmission (TR) rates, as well as viral loads, were quantified by quantitative reverse transcription PCR (qRT-PCR). To confirm viral replication and assess cytopathic effects, positive saliva samples were inoculated in Vero cells, followed by serial passages and plaque assays for viral titration. The results showed that Ae. aegypti is capable of transmitting both CHIKV and MAYV concurrently during coinfection. However, in superinfection scenarios, prior infection with either virus significantly reduced the transmission efficiency of the subsequently acquired virus, indicating viral interference at the replication level. These findings underscore the complexity of arboviral interactions within vectors and highlight their potential implications for transmission dynamics. Continuous entomo-virological surveillance and targeted research are essential for anticipating and mitigating the impact of arboviral co-circulation in endemic regions. Full article

Background/Objective: Oropouche virus (OROV—Orthobunyvirus oropoucheense) is a neglected arbovirus endemic to parts of Latin America, particularly the Brazilian Amazon. Despite its increasing epidemiological relevance, little is known about healthcare professionals’ awareness and preparedness regarding the virus. Methods: A cross-sectional, questionnaire-based study was conducted between February 2024 and March 2025 with 760 healthcare professionals across 21 Brazilian states. Participants represented various professional categories, including nursing, medicine, pharmacy, and biomedical sciences. The survey assessed knowledge on OROV epidemiology, clinical recognition, diagnostic practices, and compulsory notification. Results: Among participants, 37.4% had never heard of OROV, and 38.0% had heard of it but knew little about it. Most professionals first learned about the virus within the past year (31.8%). The majority (86.1%) reported not having received information about OROV during undergraduate education. Only 21.9% knew which diagnostic test to request, and 64.7% were aware that OROV is subject to mandatory notification. Notably, 71.2% were unaware of the virus’s potential neurological complications. Conclusions: These findings reveal a significant gap in the education and training of healthcare professionals regarding OROV, even in endemic areas. The results underscore the need for curricular reform, expanded continuing education, and stronger integration of OROV into national epidemiological surveillance efforts. Full article

The Oropouche virus (OROV) has been circulating in the Amazon region since the 1960s, with a progressive increase in outbreaks and human cases reported in Brazil and neighboring countries. In the Rio de Janeiro state, there has been a significant rise in suspected cases of arboviruses, with only 30% of laboratory tests confirming infections with dengue, Zika, or chikungunya viruses. The investigation of OROV virus circulation in the Rio de Janeiro state was initiated and confirmed in April 2024. Our study aimed to retrospectively investigate OROV infections in dengue-suspected cases with inconclusive diagnosis in order to better understand the temporal and geographic introduction of OROV in the Rio de Janeiro state. Municipalities from Rio de Janeiro with arbovirus-like fever cases but a low percentage of dengue-positive RT-PCR test confirmations were identified in the laboratory database. Samples were selected for testing OROV infections using real-time RT-PCR as recommended by the Brazilian Ministry of Health. Municipalities in the Middle Paraíba region of the state showed 93% negative tests results for dengue, Zika, and chikungunya starting in September 2023. A total of 118 positive cases of Oropouche were recorded in the state of Rio de Janeiro between March and July 2024. Moreover, by genome sequencing of eight strains, it was shown that OROV circulating in Rio de Janeiro belongs to recently emergent M₁L₂S₂ lineage. Our findings retrospectively revealed a concentration of cases in the Middle Paraíba region and an outbreak in the rural village of Cacaria, located in the municipality of Piraí. According to our data, this region is the first area with sustained transmission in the Rio de Janeiro state. Full article

Background/Objectives: This study aimed to examine the effects of a Fucoidan-rich extract from Saccharina latissima (SLE-F) on differential gut microbiota composition, intestinal inflammation status, and microbial functional gene expression in participants infected with Dengue or Oropouche virus at the Hermanos Ameijeiras Hospital in Havana, Cuba. Methods: Fecal samples were collected at baseline, day 28, and day 90 from 90 healthy adults, some of whom contracted the virus during the study period. Functional gene analysis was conducted using two approaches—the Kruskal–Wallis H test and linear discriminant analysis effect size—applied to ortholog-level data normalized by read count and gene copy number. Results: Infected participants exhibited significantly lower Lachnospiraceae-to-Enterobacteriaceae (LE) ratios, indicating increased intestinal inflammation. High-dose SLE-F treatment led to a significant reduction in the LE ratio (p = 0.006), suggesting a strong anti-inflammatory effect. Microbiome analysis revealed a shift from dysbiosis to a more balanced composition by the end of the study, characterized by increased abundances of Akkermansia muciniphila, Bifidobacterium adolescentis, and B. longum, along with decreased pro-inflammatory taxa such as Fusobacterium. Conclusions: Genetic analysis provided distinct yet complementary insights into the microbiome’s functional responses to infection and therapeutic modulation by Fucoidan. These findings highlight the therapeutic potential of high-dose Fucoidan in reducing gut inflammation and promoting microbiome recovery following viral infections. Full article