Chikungunya, Dengue, and Zika viruses are endemic to Brazil, with a high annual incidence rate. It is a serious public health issue and is responsible for outbreaks and epidemics worldwide. As COVID-19 emerged as a pandemic, the diagnosis of arboviruses was underestimated. Hence, this study aimed to characterize the sociodemographic and clinical aspects of arboviruses in the con-text of the COVID-19 pandemic in the state of Maranhão, Brazil. Sociodemographic and clinical data were obtained by applying questionnaires to 179 patients treated at health units in São José de Ribamar, Paço do Lumiar, Raposa, Santa Inês, and Vargem Grande municipalities. Serologi-cal and polymerase chain reaction analyses were performed do detect Chikungunya, Zika, Den-gue, and COVID-19 infections. The Maranhão state registered 706 probable cases of Chikungunya from 2019 to 2020. In 2020, the cases were reduced by 74.8% compared to those reported in 2019. The test results were analyzed separately. Here, 46.3% of the Chikungunya virus test results were negative, and 36.8% were positive. For the Zika virus tests, most (79.9%) were positive, as well as the DENV1, DENV2, DENV3, and DENV4 tests (88.3%, 88.3%, 89.4%, and 65.9%, respectively). For the COVID-19 tests, of the 146 individuals tested, 52.7% were reactive when considering the anti-S test, and 17.8% were positive when considering the anti-N test. Fever and myalgia were the symptoms most frequently reported by patients. Our results emphasize the importance of contin-uous epidemiological surveillance of arboviruses in northeastern Brazil, and simultaneous test-ing for Chikungunya, Dengue, and Zika viruses among suspected patients.

Orthobunyaviruses (order Bunyavirales, family Peribunyaviridae) in the Simbu serogroup have been responsible for widespread epidemics of congenital disease in ruminants. Australia has a national program to monitor arboviruses of veterinary importance. While monitoring for Akabane virus, a novel orthobunyavirus was detected. To inform the priority that should be given to this detection, a scoping review was undertaken to 1) Characterise the associated disease presentations and establish which of the Simbu group viruses are of veterinary importance; 2) Examine the diagnostic assays that have undergone development and validation for this group of viruses, and 3) Describe the methods used to monitor the distribution of these viruses. Two search strategies identified 224 peer-reviewed publications for 33 viruses in the serogroup. Viruses in this group may cause severe animal health impacts, but only those phylogenetically arranged in clade B are associated with animal disease. Six viruses (Akabane, Schmallenberg, Aino, Shuni, Peaton, and Shamonda) were associated with congenital malformations, neurological signs, and reproductive disease. Diagnostic test interpretation is complicated by cross-reactivity, the timing of foetal immunocompetence and sample type. Serological testing in surveys remains a mainstay of the methods used to monitor the distribution of SGVs. Due to significant differences in survey designs, only broad mean seroprevalence estimates could be provided. Further research is required to characterise the SGV detected and determine the disease risk posed by novel orthobunyaviruses and how they could challenge current diagnostic and surveillance capabilities.

Arboviruses represents a real public health problem globally and in the Central African subregion in particular that represents a high risk zone for the emergence and re-emergence of arboviruses outbreaks. Furthermore, an updated review on the current arboviruses burden and associated mosquito vectors is lacking for this region. To contribute in filling this knowledge gap, the current study was designed with following objectives: (i) to systematically review data on the occurrence and distribution of arboviruses and mosquito fauna and (ii) to identify potential spillover mosquito species in Central African region in the last 30 years. Web search enabled the documentation of 2454 articles from different online databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and The Quality of Reporting of Meta-analyses (QUORUM) steps for a systematic review enabled the selection of 164 articles that fulfilled our selection criteria. Of the six arboviruses (Dengue Virus (DENV), Chikungunya Virus (CHIKV), Yellow Fever Virus (YFV), Zika Virus (ZIKV), Rift Valley Fever Virus (RVFV), and West Nile Virus (WNV)) of public health concern studied, the most frequently reported were Chikungunya and Dengue. The entomological records showed >248 species of mosquitoes and regrouped under 15 genera with Anopheles (n= 100 species), Culex (n= 56 species) and Aedes (n=52 species) having high species diversity. Three genera were rarely represented with only one species and included: Orthopodomyia, Lutzia, and Verrallina, but individuals of the genera Toxorhinchites and Finlayas were not identified upto the species level. We found that two Aedes species (Ae. aegypti and Ae. albopictus) colonised the same microhabitat and were involved in major epidemics of the six medically important arboviruses and other less frequently identified mosquito-genera consisted of competent species and were associated with outbreaks of medical and zoonotic arboviruses. The present study reveals high species richness of competent mosquito-vectors that could lead to the spillover of medically important arboviruses in the region. Although epidemiological studies were found, they were not regularly documented and this also applies to vector competence and transmission studies. Future studies will consider unpublished information in dissertations, technical reports from different countries to enable it more consistent. A regional project entitled: Ecology of Arboviruses (EcoVir) is underway in three countries (Gabon, Benin and Cote d’Ivoire) to generate a more comprehensive epidemiological and entomological data on this topic.

Dengue virus (DENV) is a member of the Flaviviridae family and is responsible for the most common mosquito-borne human disease. Currently, there are no available antiviral drugs to treat DENV infections. However, certain flavonoids, including baicalein and baicalin, have demon-strated significant anti-DENV effects in vitro. This study aimed to assess the bioavailability of baicalein and its metabolite, baicalin, in the blood serum of Albino Wistar rats using the LC/MS/MS method. The in vitro activity of sera obtained from rats administered baicalein was evaluated for its anti-DENV properties using quantitative RT-PCR and the Foci Forming Reduction Assay (FFRA). The results obtained through LC/MS/MS analysis indicated that the bioavailability of baicalin in rat blood serum reached 44.20 µg/ml one hour after oral administration of baicalein. Furthermore, the sera collected from rats given baicalein exhibited a significant 78.26% inhibition of DENV-2 replication when tested against Dengue-2 using both quantitative RT-PCR and FFRA. These findings suggest that baicalein and baicalin hold promise as potential therapeutic candidates for further investigation in the development of treatments against DENV infections.

We hypothesize the possible route of introduction of the cosmopolitan DENV-2 genotype into Brazil through the border with Peru. The five sequences presented in this study create a geographical link with the three others sequences of this genotype already recorded on the continent.

Arboviruses such as yellow fever virus (YFV), dengue virus (DENV), and chikungunya virus (CHIKV) presenting wide global dissemination and the pathogenic profile developed in infected individuals, which develop from nonspecific clinical conditions to severe forms, characterized by the promotion of significant lesions in different organs of the harborer, culminating in multiple organ dysfunction. To characterize, quantify, and compare the patterns of histopathological alterations in human liver samples from patients with yellow fever (YF), dengue fever (DF), and chikungunya fever (CF). Analytical cross-sectional study by histopathological analysis with 70 samples of liver patients, collected from 2000 to 2017, with confirmed laboratory diagnosis who died due to infection and complications by the YF, DF, and CF. Of the histopathological findings in human liver samples there was a significant difference between the control and infection groups, with a predominance of alterations in the midzonal area of the three cases analyzed, among the arboviruses studied, the hepatic involvement in cases of YF showed greater intensity of histopathological changes. Among the alterations evaluated, cell swelling, microvesicular steatosis and apoptosis were classified as degree of tissue damage from severe to very severe. The pathological abnormalities associated with infection by YFV, DENV, and CHIKV showed predominance of changes in the midzonal area. We also noted that in among of the arboviruses studied, liver involvement in cases of YFV infection was more intense.

The dengue virus (DENV) is an arbovirus belonging to the Flaviviridae family; the species comprises four antigenically distinct serotypes (DENV–1, DENV–2, DENV–3, and DENV–4), which are further subdivided into genotypes. The virus is transmitted to humans through mosquito bites, primarily from the Aedes spp. genus. Dengue is endemic in various parts of the world, including tropical and subtropical regions of Asia, Latin America, Africa, and Oceania. In Brazil, the state of Tocantins, located in north-central Brazil, has experienced a significant number of arboviral disease cases, particularly dengue. This study aimed to monitor DENV circulation within the state by conducting full genome sequencing of viral genomes recovered from 61 patients between June 2021 and July 2022. During this period, both DENV-1 and DENV-2 serotypes were identified. Our findings confirm the circulation of DENV serotypes 1 and 2 in Tocantins, affecting males and females equally, with younger age groups (4 to 43 years old) being the most susceptible. Phylogenetic analysis revealed that the circulating viruses belong to DENV–1 genotype V American and DENV–2 genotype III Southeast Asian/American. The Bayesian analysis of DENV-1 Genotype V sequenced here is closely related to genomes previously sequenced in the state of São Paulo. Regarding DENV-2 genotype III genomes, these are clustered in a distinct, well-supported subclade, along with previously reported isolates from the states of Goiás and São Paulo. In both cases, our results suggest that multiple introductions of these genotypes occurred in the Tocantins state. This observation highlights the significant impact of major population centers in Brazil on virus dispersion, including other Latin-American countries and the USA. In the SNP analysis, DENV-1 displayed 122 distinct missense mutations, while DENV-2 had 44, with significant mutations predominantly occurring in the envelope and NS5 proteins. The analyses performed here reveal the concomitant circulation of distinct DENV-1 and -2 genotypes in some Brazilian states, underscoring the dynamic evolution of the DENV and the ongoing significance of surveillance efforts in supporting public health policies.

The Americas, particularly Brazil, were greatly impacted by the widespread outbreak of Zika virus (ZIKV) in 2015 and 2016. Efforts were made to implement genomic surveillance of ZIKV as part of the public health responses. The accuracy of spatiotemporal reconstructions of the epidemic spread relies on the unbiased sampling of the transmission process. In the early stages of the outbreak, we recruited patients exhibiting clinical symptoms of arbovirus-like infection from Salvador and Campo Formoso, Bahia, in Northeast Brazil. Between May 2015 and June 2016, we identified 21 cases of acute ZIKV infection and subsequently recovered 14 near full-length sequences using the amplicon tiling multiplex approach with nanopore sequencing. We perform a time-calibrated discrete phylogeographic analysis to trace the spread and migration history of the ZIKV. Our phylogenetic analysis supports a consistent relationship between ZIKV migration from Northeast to Southeast Brazil and its subsequent dissemination beyond Brazil. Additionally, our analysis provides insights into the migration of ZIKV from Brazil to Haiti and the role Brazil played in the spread of ZIKV to other countries, such as Singapore, the USA and Dominican Republic. The data generated by this study enhances our understanding of ZIKV dynamics and supports the existing knowledge, which can aid in future surveillance efforts against the virus.

Reported for the first time in 1955 in Malaysia, Tembusu virus (TMUV) remained for a long time in the shadow of flaviviruses with human health importance such as dengue virus or Japanese encephalitis virus. However, since 2010 and the first large epidemic in duck farms in China, the threat of its emergence on a large scale in Asia or even its spillover into the human population is becoming more and more significant. This review aims to report current knowledge on TMUV from viral particle organization to the development of specific vaccine and therapeutic with a particular focus on host-virus interaction.

Many public health-related problems, such as dengue diseases, are caused by the vector Aedes aegypti. The proliferation of arboviruses is due to climate change, intensifying globalization, and the evolution of anthropic activities such as travel from one place to another. This paper's objective is to develop larvicidal activities against the larvae of Ae. aegypti. Standard methods were utilized for the collection, extraction and phytochemical screening of the plant parts and extracts. Different extract concentrations (1000, 500, 250, and 125 ppm) were tested against the larvae of Ae. aegypti mosquitoes. The different toxicities observed were due to changes in the compounds present in each of the plant extracts. The most toxic plant extracts were Nepeta cataria stem, followed by Salvia rosmarinus leaf, Salvia rosmarinus stem, Ageratum conyzoides stem, Lantana camara leaf, and Mentha pulegium leaf, six plant including Nepeta cataria leaf, Psidium guajava leaf, Cymbopogon citratus leaf, Ocimum gratissimum stem, Mentha piperita leaf, Ageratum houstonianum leaf showed same LD50, followed by Lantana camara stem, Melissa officinalis root, Nepeta cataria root, and at the same concentration, no larval death was recorded for these five plant extracts, including Mentha pulegium stem, Mentha piperita L. (peppermint) stem, Azadirachta indica (neem) leaf, Geranium leaf, and Azadirachta indica (neem) stem . Seven phytochemical constituents (saponins, tannins, alkaloids, flavonoids, resins, and steroids) were detected for plant extracts. Nigerian medicinal plants could be used to curb the spread of the dengue vector, Aedes aegypti, and also have potential for further study on the constituents responsible for adulticidal activity.

Dengue virus (DENV) is spread by Aedes aegypti and causes significant global health risks. Alternative techniques are urgently needed because the current control mech-anisms are insufficient to reduce the transmission of DENV. Introducing Wolbachia pipientis into Ae. aegypti inhibits DENV transmission, however, the underlying mechanisms are still poorly understood. Innate immune effector upregulation, the regulation of autophagy, and intracellular competition between Wolbachia and DENV for lipids are among the theories for the mechanism of inhibition. Further-more, mainly three immune pathways Toll, IMD and JAK/STAT are involved in the host for the suppression of the virus. These pathways are activated by Wolbachia and DENV in the host and are responsible for the upregulation and downregulation of many genes in mosquitoes, which ultimately reduces the titer of the DENV in the host. The functioning of these immune pathways depends upon the Wolbachia, host and virus interaction. Here, we summarize the current understanding of DENV recognition by the Ae. aegypti’s immune system, aiming to create a comprehensive picture of our knowledge. Additionally, we investigated how Wolbachia regulates ac-tivation of multiple genes associated with the Toll and IMD pathway, for the reduc-tion of arboviruses.

Dengue virus serotype 2 (DENV-2) is responsible for dengue epidemics on a global scale and is recognized for being associated with severe cases of the disease. This study conducted the phylogenetic investigation of DENV-2 in the Northern region of Brazil. DENV-2 isolates from 2017 to 2021, originating from Northern Brazilian states, were selected. Only one lineage (I) of the Asian-American genotype and one lineage (5) of the cosmopolitan genotype were observed. All sequences of the Asian-American genotype used in this study were segregated into a paraphyletic subgroup aligned with sequences from an American clade. These results indicate a probable geographic link starting from Puerto Rico. Additionally, sequences from Acre were identified and grouped into a monophyletic clade of the cosmopolitan genotype. These results indicate the cocirculation of two DENV-2 distinct lineages: Lineage 1, Asian-American genotype (probable origin from Puerto Rico); Lineage 5, cosmopolitan genotype (probable origin from Peru). Our results provide important data regarding the study of DENV genotypes and lineages distribution, as well as opening up possibilities for probable introduction and dissemination routes.

Arboviruses are infections caused by arboviruses that may be either symptomatic or asymptomatic, according to individuals' resistance and immune response, which dietary patterns can influence. Thus, this study aimed to investigate the possible association between the occurrence of clinical manifestations of arboviruses and the dietary pattern of the population studied. The study was conducted in a rural population in the metropolitan area of Belém, Pará State, Brazil. The sampling consisted of 95 individuals during a febrile outbreak. Two investigations were conducted: clinical-epidemiological-dietary and laboratory investigation based on blood samples taken for arbovirus analysis. Out of the 95 individuals studied, more than half (57.89%) showed clinical manifestations. Following the laboratory serology (HI and IgM ELISA) analyses, viral isolation in C6/36 cells, and viral genome detection (RT-qPCR), the final diagnosis of the cases was 47.37% Oropouche Fever, 2.11% Oropouche Fever and Chikungunya Fever, and 1.05% Mayaro Fever. Regarding dietary pattern, as for the comparison analyses, statistical significance was observed between dietary pattern and classification regarding the presence of symptoms (p<0.05); after the correspondence analysis, symptomatic cases were more associated with a bad dietary pattern, while asymptomatic cases were more associated with a good dietary pattern.

Climate change and globalization have raised the risk of vector-borne disease (VBD) introduction and spread in various European nations in recent years. In Italy, viruses carried by tropical vectors have been shown to cause viral encephalitis, one of the symptoms of arbovirosis, a spectrum of viral disorders spread by arthropods such as mosquitoes and ticks. Arbovirosis are currently causing alarm and attention, and the World Health Organization (WHO) has released recommendations to adopt essential measures, particularly during the hot season, to restrict the spreading of the infectious agents among breeding stocks. In this scenario, rapid analysis systems are required, because they can quickly provide information on potential virus-host interactions, the evolution of the infection, and the onset of disabling clinical symptoms, or serious illnesses. Such systems include bioinformatics approaches integrated with molecular evaluation. Viruses have co-evolved different strategies to transcribe their own genetic material, by changing the host's transcriptional machinery, even in short periods of time. The introduction of genetic alterations, particularly in RNA viruses, results in a continuous adaptive fight against the host's immune system. We suggest an in silico pipeline method to unravel viral sequences that may interact with host RNA binding proteins (RBPs), which play important roles in RNA metabolism and its several related biological processes. Indeed, viral RNA sequences, able to bind host RBPs may compete with cellular RNAs, altering important metabolic processes. Our findings suggest that the proposed in silico approach, could be a useful and promising tool to investigate the complex and multiform clinical manifestations of viral encephalitis, and possibly identify altered metabolic pathways as targets of pharmacological treatments and innovative therapeutic protocols.

Abstract: In 2016, we conducted an entomological survey in a railway transect between Banfora and Ouagadougou, Burkina Faso. The aim was to evaluate the risk factors for arbovirus epidemics, including vector infection status, in areas representative of the country. Aedes aegypti mosquitoes were collected at larval stage from four study sites and reared until adult stage and kept in RNAlater for detection of arbovirus RNA. In the laboratory, the mosquito specimens were screened for dengue virus (DENV) and chikungunya virus (CHIKV) using one step real-time qRT-PCR. We detected one DENV-2 positive pool from Ouagadougou, giving a minimum infec-tion rate (MIR) of 16.67, and 6 CHIKV positive pools, giving a MIR of 66.67 from Ouagadougou, but also in Banfora and Boromo. The qRT-PCR is a useful tool for the surveillance of arboviruses of public health importance in Burkina Faso and may be incorporated into disease surveillance and control programs in Burkina Faso.

Aedes (Stegomyia) albopictus is a mosquito native to Southeast Asia. Currently, it has a wide distribution in America where natural infection with arboviruses of medical and veterinary importance has been reported. In spite of their importance in the transmission of endemic arbovirus, basic information of parameters affecting their vectorial capacity is poorly investigated. The aim of the work was to update the distribution range of Ae. albopictus in the Americas, review the blood-feeding patterns and compare the minimum infection rate (MIR) of the dengue virus (DENV) between studies of vertical and horizontal transmission. The current distribution of Ae. albopictus encompasses 21 countries in the Americas. Extensive review has been conducted for the blood-feeding patterns of Ae. albopictus. The results suggest that the mosquito is capable of feeding on 16 species of mammals and five species of avian. Humans, dogs, and rats are the most common host. Eight arboviruses with the potential to infect humans and animals have been isolated in Ae. albopictus. In the United States of America (USA), Eastern equine encephalitis virus, Keystone virus, La Crosse Virus, West Nile virus, and Cache Valley virus were isolated in the Asian mosquito. In Brazil, Mexico, Colombia, and Costa Rica, DENV (all serotypes) has been frequently identified in field-caught Ae. albopictus. Overall, the estimated MIR in Ae. albopictus infected with DENV is similar between horizontal (10.95) and vertical transmission (8.28). However, in vertical transmission, there is a difference in the MIR values if the DENV is identified from larvae or adults (males and females emerged from a collection of eggs or larvae). MIR estimated from larvae is 14.04 and in adults is 4.04. In conclusion, it has to be highlighted that Ae. albopictus is an invasive mosquito with wide phenotypic plasticity to adapt to broad and new areas, it is highly efficient to transmit the DENV horizontally and vertically, it can participate in the inter-endemic transmission of the dengue disease, and it can spread zoonotic arboviruses across forest and urban settings.

The aim of the work was to update the distribution range of Aedes (Stegomyia) albopictus Skuse in the Americas, review the blood-feeding patterns and compare the minimum infection rate (MIR) of the dengue virus (DENV) between studies of vertical and horizontal transmission. The current dis-tribution of Ae. albopictus encompasses 21 countries in the Americas. Extensive review has been conducted for the blood-feeding patterns of Ae. albopictus. The results suggest that the mosquito is capable of feeding on 16 species of mammals and five species of avian. Humans, dogs, and rats are the most common host. Eight arboviruses with the potential to infect humans and animals have been isolated in Ae. albopictus. In the United States of America (USA), Eastern equine encephalitis virus, Keystone virus, La Crosse Virus, West Nile virus, and Cache Valley virus were isolated in the Asian mosquito. In Brazil, Mexico, Colombia, and Costa Rica, DENV (all serotypes) has been frequently identified in field-caught Ae. albopictus. Overall, the estimated MIR in Ae. albopictus infected with DENV is similar between horizontal (10.95) and vertical transmission (8.28). However, in vertical transmission, there is a difference in the MIR values if the DENV is identified from larvae or adults (males and females emerged from a collection of eggs or larvae). MIR es-timated from larvae is 14.04 and in adults is 4.04. In conclusion, it has to be highlighted that Ae. albopictus is an invasive mosquito with wide phenotypic plasticity to adapt to broad and new areas, it is highly efficient to transmit the DENV horizontally and vertically, it can participate in the inter-endemic transmission of the dengue disease, and it can spread zoonotic arboviruses across forest and urban settings.

The emergence of existing and novel vector-borne disease pathogens is highly unpredictable because there are so many possible causal factors of sociological, ecological, biological, behavioral and political origin. Traditional data-driven forecasting tools have limited use in circumstances featuring low-probability crises for which trend data is unreliable and non-predictive. Commercial and security sectors have been quick to adopt various forms of wargames to address this gap and provide intelligent insights on possible outcomes in the short, mid and long term future. The lack of commitment and action against vector-borne diseases by governments and local authorities requires a new approach that presents risk in terms of potential actions, possible outcomes and resulting consequences.

Background: After serious epidemics of chikungunya (CHIKV) and Zika (ZIKV) in the Americas, dengue (DENV) have reemerged in most countries. We analyzed the incidence, incidence rates, and evolution of DENV cases in Honduras from 2015-2018 and the ongoing 2019 epidemic. Methods: Using epidemiological weeks (EW) surveillance data on the DENV in Honduras, we estimated incidence rates (cases/100,000 population), and developed maps at national, departmental, and municipal levels. Results: From 1 January 2016 to 21 July 2019, a total of 109,557 cases of DENV were reported, 28,603 in 2019, for an incidence rate of 312.32 cases/100,000 pop this year; 0.13% laboratory-confirmed. The highest peak was reached on the EW 28°, 2019 (5,299 cases; 57.89 cases/100,000 pop). The department with the highest number of cases and incidence rate was Cortes (8,404 cases, 479.68 cases/100,000 pop in 2019). Discussion: The pattern and evolution of DENV epidemic in 2019 in Honduras has been similar to that which occurred for in 2015. As previously reported, this epidemic involved the north and central areas of the country predominantly, reaching municipality incidences there >1,000 cases/100,000 pop (1%). Studies using geographical information systems linked with clinical disease characteristics are necessary to attain accurate epidemiological data for public health systems. Such information is also useful for assessment of risk for travelers who visit specific areas in a destination country.

Background: Zika virus (ZIKV) infection has significantly affected Latin America in 2015–2017. Most studies have been reported from Brazil and Colombia, and only a few from Central America. For these reasons we analyzed the incidence, incidence rates and evolution of cases in Honduras from 2016–2017. Methods: Using epidemiological weeks (EW) surveillance data on the ZIKV epidemics in Honduras, we estimated incidence rates (cases/100,000 population), and developed maps at national, departmental and municipal levels. Results: From 1 January 2016 to 31 December 2017, a total of 32,607 cases of ZIKV were reported (98.5% in 2016 for an incidence rate of 36.85 cases/100,000 pop; 1% confirmed by RT-PCR). The highest peak was reached on the EW 6°, 2016 (2,559 cases; 29.34 cases/100,000 pop). The department with the highest number of cases and incidence rate was Cortés (13,128 cases, 791.08 cases/100,000 pop in 2016). Discussion: The pattern and evolution of ZIKV infection in Honduras has been similar to that which occurred for chikungunya in 2015. As previously reported, infection with chikungunya involved predominantly the central and capital area of the country, reaching incidences there >750 cases/100,000 pop. Studies using geographical information systems linked with clinical disease characteristics are necessary to attain accurate epidemiological data for public health systems. Such information is also useful for assessment of risk for travelers who visit specific areas in a destination country.