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Dengue virus 2 (DENV-2) seriously contributes to dengue-related mortality. It includes five nonsylvatic genotypes, with cosmopolitan being the most widespread with a significant contribution to the total number of DENV-2 cases globally. In South America, the cosmopolitan genotype was first recorded in 2019 in Madre de Dios, Peru, and then in Goias (Midwest Brazil) in November 2021. In this study, we tested 163 human serum samples from Acre (Northern Brazil) collected during a DENV outbreak between 2020 and 2021 for all DENV genotypes by RT-qPCR. Of the 163 samples, 139 were positive for DENV-2, and 5 were positive for DENV-1. Five DENV-2-positive samples from early 2021 were sequenced, and the sequences clustered with the three other DENV-2 cosmopolitan genotype sequences already recorded on the continent. These results create a geographical link, suggesting the possible route of introduction of the DENV-2 cosmopolitan genotype into Brazil through the border with Peru, from which it may have dispersed to Midwest Brazil.

Advances in diagnostic techniques, along with environmental changes driven by human activity, have intensified the surveillance and monitoring of virus and arbovirus circulation on the Amazon. These efforts have increased the detection of insect-specific viruses in field-collected hematophagous arthropods. This study reports the first isolation of the Aguas Brancas virus from mosquitoes collected in the Brazilian Amazon and in a rural area of Brasília, Federal District, Brazil. Arthropods of the family Culicidae, genus Limatus durhamii, were collected at ground level in forest fragments. Sample BEAR812610 originated from Ananindeua, Pará, within the Evandro Chagas Institute’s grounds, and sample BEAR839941 from a forest fragment in Brasília (Ceilândia—Núcleo Rural Boa Esperança, Site B4). Specimens were identified to the species/genus level, macerated, and the supernatant inoculated into C6/36 and Vero cell cultures for viral isolation. The presence of arboviruses was determined by indirect immunofluorescence using antibodies against major arbovirus groups. Positive samples were sequenced for nucleotide and amino acid identification, and phylogenetic analysis confirmed the virus as belonging to the genus Orthoflavivirus. This represents the first report of the isolation and characterization of the insect-specific Aguas Brancas virus.

Arboviruses transmitted by Aedes aegypti cause high number of cases and deaths annually. The aim was to investigate the presence of the presence of Dengue (DENV), Zika (ZIKV) and Chikungunya (CHIKV) viruses in endemic areas of Maranhão, northeastern Brazil. The study was carried out in Caxias, Codó, Peritoró, and São Mateus do Maranhão in 2019 (Caxias) and 2022. The blood samples were subjected to RNA extraction and then tested by RT-qPCR. Cell culture was used to attempt viral isolation and subsequent sequencing. In total, 171 samples were analyzed (32 from 2019, 18.7%) and 72 (42.1%) were found to have arboviruses: 68 (39.7%) from Caxias; 2 (1.1%) from Codó; 1 (0.6%) from Peritoró; and 1 (0.6%) from São Mateus. Overall, 85.3% (n = 58) of the positive samples were infected with DENV-1, 4 (four) (5.9%) with DENV-2 (Caxias), 1 (one) (1.5%) with DENV-3 (Caxias), and in 6 (six) (7.3%) samples CHIKV was detected, with one co-infection of DENV-1 and CHIKV (Caxias). The DENV-1 genotype V and the ECSA genotype of CHIKV were characterized in samples from Caxias. The detection of DENV-1, DENV-2, DENV-3, and more CHIKV in the interior of Maranhão alerts to the importance of virological studies in these areas.

The municipalities of Peixe-Boi and Santa Bárbara do Pará, both in the Pará State (eastern Amazon), have more than half of their territory deforested. Understanding the viral diversity in wildlife that inhabits the surroundings of human communities contributes to strengthening surveillance. Samples from eleven bats, seven opossums, and eight rodents from the two locations were screened by high-throughput sequencing for virome analysis. Viral reads were assigned into twenty viral families, from which the most abundant was Retroviridae. Host order, tissue type, and season showed a significant effect on viral composition. Five viral genomes of bat ERVs with intact genes were recovered, showing the need to understand their endogenous nature. In addition, a new Buritiense virus (Hantaviridae) strain was also obtained, supporting its circulation in Santa Bárbara do Pará and expanding its genomic information. Together, these findings reinforce the need for continuous surveillance in wild animals, especially in the Amazon region, to anticipate potential threats to public health.

The biting midges Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) is highly relevant to epidemiology and public health, as it includes species that are potential vectors of human and animal arboviruses. The aim of this study was to investigate the presence of RNA viruses in species of the genus Culicoides collected in the Carajás mining complex in the state of Pará. The biting midges were collected in the municipalities of Canaã dos Carajás, Curionópolis and Marabá and morphologically identified. A total of 1139 specimens of seven Culicoides species were grouped into eight pools and subjected to metagenomic analysis. Eight new insect-specific viruses (ISVs) were characterized and assigned to the order Tolivirales, the families Chuviridae, Nodaviridae, Iflaviridae, Mesoniviridae, and Flaviviridae, and the taxon Negevirus. All viruses identified were assigned to clades, families and taxa never reported in Culicoides in Brazil. This study demonstrated that biting midges harbor a significant diversity of RNA viruses, many of which are still unknown, highlighting the importance of studies aiming at virome of these insects.

Dengue virus serotype 2 (DENV-2) is responsible for dengue epidemics on a global scale and is associated with severe cases of the disease. This study conducted a phylogenetic investigation of DENV-2 isolates from 2017 to 2021 originating from the northern states of Brazil. A total of 32 samples from DENV-2 isolates were analyzed, including 12 from Acre, 19 from Roraima, and one from Tocantins. Only one lineage of the Asian-American genotype and one lineage of the cosmopolitan genotype were observed: Lineage 1, Asian-American genotype (connection to Puerto Rico); Lineage 5, cosmopolitan genotype (connection to Peru). Our results provide important data regarding the study of DENV genotypes and lineage distribution and open up possibilities for probable introduction and dissemination routes.

To investigate the association between miscarriage and ZIKV and CHIKV infection. The study population consisted of pregnant women who had miscarriages between 2015, 2016 and 2017, comprising a total of 30 women who were treated at the Santa Casa de Misericórdia do Pará Foundation (FSCMPA). The processed samples came from already paraffinized material containing placental and fetal remains, where they were tested with hematoxylin–eosin and immunohistochemistry for ZIKV and CHIKV. Regarding the sociodemographic, clinical and obstetric characteristics of the patients, they correspond to the age group between 20 and 29 years of age; of brown color; women who had abortions for the first time; miscarriages occurring in the first trimester of pregnancy; women belonging to the metropolitan region of Belém; diagnosed with incomplete abortion and who had undergone uterine curettage procedure. Regarding the histopathologic and immunohistochemical findings, an inflammatory infiltrate rich in neutrophils and lymphocytes, among others, was found in the endometrial fragments and chorionic membranes. In addition, placental areas consisting of edema, necrosis and hemorrhage were found. The study identified ZIKV and CHIKV in 40% (n = 12) of samples from spontaneous abortion specimens, and CHIKV was the most prevalent virus in the study, representing 36.11% of the total specimens, with reddish granular material in the cytoplasm of decidua cells and placental villi suggesting that the viruses may be present in these regions of the placenta.

Mycobacterium tuberculosis (Mtb) Central Asian Strain (CAS) Lineage 3 (L3) genotype is predominantly found in East-Africa, Central-Asia, Western-Asia, and South-Asia; however, a new spoligotyping CAS/SIT2545 was found in northern regions of Brazil. We aimed to characterize and describe the genetic diversity and perform a phylogenetic assessment of this novel genotype. We performed 24-MIRU-VNTR loci and Whole-genome sequencing (WGS) of six Brazilian isolates previously spoligotyped. The libraries were prepared using a Nextera-XT kit and sequenced in a NextSeq 550 Illumina instrument. We performed lineage assignment and genomic characterization. From publicly available genomes of Mtb L3 and other lineages, we created a robust dataset to run the MTBSeq pipeline and perform a phylogenetic analysis. MIRU-VNTR and WGS confirmed CAS/SIT2545 belongs to L3. Out of 1691 genomes, 1350 (79.83%) passed in quality control (genomic coverage > 95%). Strain 431 differed in 52 single nucleotide variants (SNV), confirming it does not belong to the same transmission chain. The eight genomes from a global dataset clustered closer to Brazilian strains differed in >52 SNVs. We hypothesized L3 and L1 were introduced in Brazilian Northern in the same historical event; however, there is a need for additional studies exploring the genetic diversity of Mtb Brazilian Northern.

Bats play an essential role in maintaining ecosystems. Their unique characteristics increase the likelihood of interactions with various species, making them a potential source for the emergence and spread of infectious diseases. Hantaviruses are continuously expanding their range of hosts. This study presents the identification of a partial genome associated with Hantavirus in samples collected from neotropical bats. We conducted a metagenomic study using samples from Carollia perspicillata in Maranhão, Brazil. Tissue fragments were used for RNA extraction and subsequent sequencing. The resulting data was subjected to bioinformatic analysis. A sequence showing an identity of 72.86% with the L gene in the reference genome was obtained. The phylogenetic analysis revealed the study sequence, denoted as Buritiense , clustering within the Mobatvirus clade. The intragroup analysis showed a broader dispersion and were markedly asymmetric. This observation suggests the possibility that Buritiense could potentially represent a new species within the bat-borne hantaviruses, but further analyses are needed to provide additional insights if bats plays a role as reservoirs and the potential for transmission to human populations.

The risk of the emergence and reemergence of zoonoses is high in regions that are under the strong influence of anthropogenic actions, as they contribute to the risk of vector disease transmission. Yellow fever (YF) is among the main pathogenic arboviral diseases in the world, and the Culicidae Aedes albopictus has been proposed as having the potential to transmit the yellow fever virus (YFV). This mosquito inhabits both urban and wild environments, and under experimental conditions, it has been shown to be susceptible to infection by YFV. In this study, the vector competence of the mosquito Ae. albopictus for the YFV was investigated. Female Ae. albopictus were exposed to non-human primates (NHP) of the genus Callithrix infected with YFV via a needle inoculation. Subsequently, on the 14th and 21st days post-infection, the legs, heads, thorax/abdomen and saliva of the arthropods were collected and analyzed by viral isolation and molecular analysis techniques to verify the infection, dissemination and transmission. The presence of YFV was detected in the saliva samples through viral isolation and in the head, thorax/abdomen and legs both by viral isolation and by molecular detection. The susceptibility of Ae. albopictus to YFV confers a potential risk of reemergence of urban YF in Brazil.