Explore the vast range of titles available.

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.

Yellow fever (YF) is an acute and potentially fatal hemorrhagic disease caused by the Yellow Fever virus (YFV), endemic to sub-Saharan Africa and several tropical countries, including Brazil. In Brazil, the Amazon region is considered the main endemic area. YFV is maintained in a sylvatic cycle involving Neotropical primates and mosquitoes of the genera Haemagogus and Sabethes, acting as primary and secondary vectors, respectively. In March 2024, entomovirological surveillance was conducted in Santa Bárbara do Pará, Pará, Brazil. A total of 286 mosquitoes were collected, classified into 13 species across nine genera, and grouped into 33 pools. Seventeen pools were tested by RT-qPCR for Orthoflavivirus (YFV, DENV, WNV, SLEV), Alphavirus (CHIKV, MAYV), and Orthobunyavirus (OROV). YFV was detected in four Haemagogus janthinomys pools, with Ct values ranging from 22.2 to 27.9. Metagenomic sequencing confirmed the presence of YFV with assigned reads and >99% protein identity. Notably, the detection occurred without human cases or primate deaths, enabling timely vaccination of the local population. These findings confirm YFV circulation in forested areas of the Belém metropolitan region and reaffirm Hg. janthinomys as a key vector. Our study reinforces the relevance of early entomovirological surveillance and preventive strategies, such as vaccination, to mitigate yellow fever reemergence.

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.

In the eastern Brazilian Amazon, the Viseu municipality has almost 70% of its territory deforested. Monitoring viruses from wildlife hosts enables the prevention and control of epizootic events and outbreaks. Seven samples from three marsupials and two rodents were screened by high-throughput sequencing for virome analysis. The three samples from the two Proechimys roberti rodents, one from the liver, one from the brain, and one from a pooled viscera sample, showed the highest results in terms of viral abundance and richness. From these we obtained two strains of a new rodent hepacivirus (RHV), which belongs to a new putative genotype of an unclassified RHV species previously described in Panama and Northeast Brazil. The findings expand the host range of the cited RHV species, imply virus circulation in the study area, and suggest a viral tropism in the liver and perhaps in the brain.

Oropouche fever, an orthobunyavirus disease endemic in Brazilian Amazon, has caused many febrile epidemics. In 2024, an epidemic of Oropouche fever spread in Brazil, with more than 7930 cases reported between Jan 1 and Aug 31. Infections in pregnant people have suggested the possibility of negative fetal consequences, therefore we tested newborns with microcephaly for known congenital pathogens and Oropouche virus (OROV). In this case series, we assessed historical cases of infants born with microcephaly, arthrogryposis, and other congenital malformations without a confirmed cause and their mothers for potential OROV congenital infections. The study population consisted of infants born in Brazil with samples from 2015–21 and 2024. Serum and cerebrospinal fluid (CSF) from this case series were analysed for: syphilis, toxoplasmosis, rubella, cytomegalovirus, herpes simplex, HIV, Zika, dengue, and chikungunya. Individuals that were negative for these pathogens were then tested for OROV. Pathogen testing included ELISA and haemagglutination inhibition testing for antibodies and RT-PCR for virus RNA. We tested 68 samples from 65 historical cases of congential malformations and three cases from 2024. All cases were from ten states in Brazil. Three historical cases tested positive for OROV and 62 historical cases tested negative. The three cases from 2024 all tested positive for OROV. Of the positive cases, five were female and one was male. Not all pathogens were tested for each case, and some did not have maternal samples available. One of the newborns (case 6) died aged 47 days and tissue samples were tested by real-time RT-PCR, histopathology, and immunohistochemistry assays. One other newborn died in 2016 but no post-mortem samples were available. OROV IgM was detected in five of five newborn CSF samples, and five of five newborn serum samples. Four of five maternal serum samples were positive for OROV IgM. One of four newborn CSF samples (case 6 at age 44 days) was OROV positive by real-time RT-quantitative PCR and 0 of four newborn serum samples were positive, as were 0 of three maternal serum samples. Case 6 had major tissue changes of the brain macroscopically and microscopically, including necrotic and apoptotic changes of neurons, microglia and astrocytes, vacuolisation, and tissue atrophy. OROV RNA was detected in brain, lungs, kidney, CSF, and pleural fluid; OROV antigens were found in CNS, liver, kidney, heart, and lung, mainly in neurons and microglia and also in endothelial cells, suggesting vasculitis. We detected OROV IgM in six of 68 newborns with microcephaly of unknown cause. One infant who died had OROV RNA and antigen in several tissues, including the brain. The possibility of OROV vertical transmission and potential fetal harm must be investigated with urgency. The evidence presented here does not completely confirm vertical transmission or congenital malformations due to OROV, but thorough case finding and detailed investigation of maternal or fetal OROV infection is a priority. Evandro Chagas Institute, Secretaria de Vigilância em Saúde e Ambiente, and Ministry of Health and National Institute of Science and Technology for Emerging and Reemerging Viruses.

The Oropouche virus (OROV) is an arbovirus (Peribunyaviridae: Orthobunyavirus) that traditionally causes febrile outbreaks in Latin America’s Amazon region. Previously, OROV was not associated with severe pregnancy outcomes. During the 2022–2024 outbreak in Brazil, OROV expanded geographically, revealing links to adverse pregnancy outcomes. This study describes six cases with varied fetal outcomes, including miscarriage, antepartum, intrauterine fetal demise (IFD), and normal development, correlating with maternal symptoms but not symptom severity. Vertical transmission was confirmed by detecting OROV through RT-qPCR, ELISA, and immunohistochemistry in fetal tissues. Genome sequencing from an IFD case identified a novel reassortment pattern reported in the 2022–2024 outbreak. Severe encephalomalacia, meningoencephalitis, vascular compromise, and multi-organ damage were evident, underscoring the significant risk OROV poses to fetal development and emphasizing the need for further investigation.

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.

The rapid and disorderly urbanization in the Amazon has resulted in the insertion of forest fragments into cities, causing the circulation of arboviruses, which can involve hematophagous arthropods and free-ranging birds in the transmission cycles in urban environments. This study aimed to evaluate the circulation of arboviruses in free-ranging birds and hematophagous arthropods captured in an Environmental Protection Area in the Belem metropolitan area, Brazil. Birds were captured using mist nets, and hematophagous arthropods were collected using a human protected attraction technique and light traps. The birds’ sera were subjected to a hemagglutination inhibition test to detect antibodies against 29 arbovirus antigens. Arthropod macerates were inoculated into C6/36 and VERO cell cultures to attempt viral isolation and were tested using indirect immunofluorescence, subsequent genetic sequencing and submitted for phylogenetic analysis. Four bird sera were positive for arbovirus, and one batch of Psorophora ferox was positive for Flavivirus on viral isolation and indirect immunofluorescence. In addition, the Ilheus virus was detected in the sequencing and phylogenetic analysis. The presence of antibodies in sera from free-ranging birds and the isolation of Ilheus virus in Psorophora ferox indicate the circulation of arboviruses in forest remnants in the urban center of Belem.

Viruses with encephalitogenic potential can cause neurological conditions of clinical and epidemiological importance, such as Saint Louis encephalitis virus, Venezuelan equine encephalitis virus, Eastern equine encephalitis virus, Western equine encephalitis virus, Dengue virus, Zika virus, Chikungunya virus, Mayaro virus and West Nile virus. The objective of the present study was to determine the number of arboviruses with neuroinvasive potential isolated in Brazil that corresponds to the collection of viral samples belonging to the Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute (SAARB/IEC) of the Laboratory Network of National Reference for Arbovirus Diagnosis from 1954 to 2022. In the analyzed period, a total of 1,347 arbovirus samples with encephalitogenic potential were isolated from mice; 5,065 human samples were isolated exclusively by cell culture; and 676 viruses were isolated from mosquitoes. The emergence of new arboviruses may be responsible for diseases still unknown to humans, making the Amazon region a hotspot for infectious diseases due to its fauna and flora species characteristics. The detection of circulating arboviruses with the potential to cause neuroinvasive diseases is constant, which justifies the continuation of active epidemiological surveillance work that offers adequate support to the public health system regarding the virological diagnosis of circulating arboviruses in Brazil.

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.