Newborns with microcephaly in Brazil and potential vertical transmission of Oropouche virus: a case series.

Background: 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).

Human outbreaks of a novel reassortant Oropouche virus in the Brazilian Amazon region.

The Brazilian western Amazon is experiencing its largest laboratory-confirmed Oropouche virus (OROV) outbreak, with more than 6,300 reported cases between 2022 and 2024. In this study, we sequenced and analyzed 382 OROV genomes from human samples collected in Amazonas, Acre, Rondônia and Roraima states, between August 2022 and February 2024, to uncover the origin and genetic evolution of OROV in the current outbreak. Genomic analyses revealed that the upsurge of OROV cases in the Brazilian Amazon coincides with spread of a novel reassortant lineage containing the M segment of viruses detected in the eastern Amazon region (2009-2018) and the L and S segments of viruses detected in Peru, Colombia and Ecuador (2008-2021).

Isolation of Flaviviruses and Alphaviruses with Encephalitogenic Potential Diagnosed by Evandro Chagas Institute (Pará, Brazil) in the Period of 1954-2022: Six Decades of Discoveries.

Viruses with encephalitogenic potential can cause neurological conditions of clinical and epidemiological importance, such as , , , , , , , and . 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.

Immunological impact of cytokines on the chikungunya virus pathophysiology: A literature narrative review.

The chikungunya virus (CHIKV) is a member of the genus Alphavirus, family Togaviridae. CHIKV causes an acute systemic febrile condition, accompanied by severe polyarthralgia, intense muscle pain, and maculopapular exanthema, which may still occur in many patients. In rare cases, unusual symptoms may occur, eventually worsening the condition and resulting in a fatal outcome.

Antibody cross-reactivity and evidence of susceptibility to emerging Flaviviruses in the dengue-endemic Brazilian Amazon.

Objectives: Several Flaviviruses can co-circulate. Pre-existing immunity to one virus can modulate the response to a heterologous virus; however, the serological cross-reaction between these emerging viruses in dengue virus (DENV)-endemic regions are poorly understood.

Methods: A cross-sectional study was performed among the residents of Manaus city in the state of Amazonas, Brazil.

Co-infection of and associated with neurological diseases in horses from Brazil.

In 2018, during the surveillance for West Nile virus (WNV) in horses with neurological clinical signs in the state of Espírito Santo (Brazil), 19 animals were investigated, and 52 biological samples were collected for WNV diagnostic. One brain sample was positive for WNV by RT-qPCR and the virus was isolated in C6/36 cell culture and sequenced. We obtained a nearly complete genome of WNV co-infected with Peruvian horse sickness virus (PHSV) in the cell culture.

Arboviruses in Free-Ranging Birds and Hematophagous Arthropods (Diptera, Nematocera) from Forest Remnants and Urbanized Areas of an Environmental Protection Area in the Amazon Biome.

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.

Emergence of New Immunopathogenic Factors in Human Yellow Fever: Polarisation of the M1/M2 Macrophage Response in the Renal Parenchyma.

Macrophages in the kidney play a pathogenic role in inflammation and fibrosis. Our study aimed to understand the polarisation of the M1 and M2 phenotypic profiles of macrophages in injured kidney tissue retrieved from fatal cases of yellow fever virus (YFV). A total of 11 renal tissue biopsies obtained from patients who died of yellow fever (YF) were analysed.

Factors Involved in the Apoptotic Cell Death Mechanism in Yellow Fever Hepatitis.

Yellow fever (YF), a non-contagious infectious disease, is endemic or enzootic to the tropical regions of the Americas and Africa. Periodic outbreaks or epidemics have a significant impact on public health. Programmed cell death, or apoptosis, is generally characterised by distinct morphological changes and energy-dependent biochemical pathways.

Serological evidence of Eastern equine encephalitis circulation in equids in Pará state, Brazil.

Serum samples from 89 equids were analyzed (75 horses, 9 donkeys, and 5 mules) from the municipality of Viseu, Pará state, Brazil. Samples were collected in November 2014 and August 2015. The antibody prevalence against the following alphaviruses was estimated: Eastern equine encephalitis virus, Western equine encephalitis virus, Mucambo virus, and Mayaro virus.

Histopathological lesions of congenital Zika syndrome in newborn squirrel monkeys.

The absence of an adequate animal model for studies has limited the understanding of congenital Zika syndrome (CZS) in humans during the outbreak in America. In this study, we used squirrel monkeys (Saimiri collinsi), a neotropical primate (which mimics the stages of human pregnancy), as a model of Zika virus (ZIKV) infection. Seven pregnant female squirrel monkeys were experimentally infected at three different gestational stages, and we were able reproduce a broad range of clinical manifestations of ZIKV lesions observed in newborn humans.

Prenatal disorders and congenital Zika syndrome in squirrel monkeys.

During the Zika virus (ZIKV) outbreak in Brazil (2015-2016), the clinical manifestations associated with its infection were complex and included miscarriage and congenital malformations, not previously described. In this study, we evaluated the prenatal conditions of pregnant female squirrel monkeys (Saimiri collinsi) infected during different gestational thirds (GTs) and assessed all clinical aspects, diagnostic imaging, viremia and the immune response. In our study, 75% of the infected animals in the 1st GT group had significant clinical manifestations, such as miscarriage and prolonged viremia associated with a late immune response.

Mitochondrial genome sequencing and phylogeny of Haemagogus albomaculatus, Haemagogus leucocelaenus, Haemagogus spegazzinii, and Haemagogus tropicalis (Diptera: Culicidae).

The genus Haemagogus (Diptera: Culicidae) comprises species of great epidemiological relevance, involved in transmission cycles of the Yellow fever virus and other arboviruses in South America. So far, only Haemagogus janthinomys has complete mitochondrial sequences available. Given the unavailability of information related to aspects of the evolutionary biology and molecular taxonomy of this genus, we report here, the first sequencing of the mitogenomes of Haemagogus albomaculatus, Haemagogus leucocelaenus, Haemagogus spegazzinii, and Haemagogus tropicalis.

IFN-α as a time-sensitive biomarker during Oropouche virus infection in early and late seroconverters.

In the present study, patients with acute OROV fever were classified as early seroconverters (IgM/IgG positive at baseline) or late seroconverters (IgM/IgG negative at baseline) and the timeline kinetics of the production of chemokines and cytokines were assessed at 1-3, 4-7, 8-10 and ≥11 days after patients have reported the first symptoms. Regardless immunoglobulin profile, all OROV fever patients presented higher levels of CXCL8, and IFN-α and lower levels of TNF and IL-10 at baseline as compared to healthy donors (HD). Lower levels of CCL2, CXCL10, and IFN-γ and higher levels of CCL2, CXCL10, IL-6, and IL-17A were detected in early and late seroconverters, respectively, as compared to HD.

Experimental infection of golden hamsters with Guama virus (Peribunyaviridae, Orthobunyavirus).

The Guama virus (GMAV) is a member of Peribunyaviridae family, Orthobunyavirus genus. Several strains of the virus were isolated in South and Central Americas from several hosts, such as humans, wild animals, including nonhuman primates, wild rodents and mosquitoes as well as mice used as sentinels. The virus is able to cause febrile disease in humans.

First isolation of West Nile virus in Brazil.

Background: Serological evidence of West Nile virus (WNV) infection has been reported in different regions of Brazil from equine and human hosts but the virus had never been isolated in the country.

Objectives: We sought to identify the viral etiology of equine encephalitis in Espírito Santo state.

Methods: We performed viral culture in C6/36 cells, molecular detection of WNV genome, histopathology and immunohistochemistry from horse cerebral tissue.

Characterization of Triniti virus supports its reclassification in the family Peribunyaviridae.

Triniti virus (TNTV) has been isolated in Trinidad and Tobago and in Brazil. To date little is known about this virus, which is classified as an ungrouped virus within the family Togaviridae. Here, three isolates of TNTV were characterized both genetically and antigenically.

In situ inflammasome activation results in severe damage to the central nervous system in fatal Zika virus microcephaly cases.

Zika virus (ZIKV) has caused substantial concern worldwide owing to its association with severe birth defects, such as microcephaly and other congenital malformations. Inflammasomes, i.e.

Genomic characterization and evolution of Tacaiuma orthobunyavirus (Peribunyaviridae family) isolated in Brazil.

Tacaiuma virus (TCMV) is antigenically characterized as a member of the Anopheles A complex in the Orthobunyavirus genus, Peribunyaviridae family (Bunyavirales order). Clinically, the TCMV infection is characterized by acute febrile illness with myalgia and arthralgia lasting three to five days. However, the genomic and evolutionary aspect of this virus has not been elucidated.

Characterization of the Gamboa Virus Serogroup ( Genus, Family).

Comprehensive comparative phylogenetic analyses were performed on 17 Gamboa serogroup viruses (GAMSVs) from distinct geographic regions in the Americas and other representative members of the genus (Peribunyaviridae), based on small (S), medium (M), and large (L) open reading frame full-length and partial sequences. Genome characterization showed that the GAMSVs divide into four clades or genotypes. The GAMSVs have a genetic organization similar to other orthobunyaviruses, except that they have a larger NSm protein than other orthobunyaviruses.

Clinical and serological tests for arboviruses in free-living domestic pigeons (Columba livia).

Background: In this study, we evaluated the role of free-living domestic pigeons (Columba livia) as a reservoir of arboviruses in the city of Belém, state of Pará, Brazil. We investigated the presence of antibodies against the most prevalent arboviruses.

Objectives: This study was aimed at evaluating some clinical and physical parameters of domestic pigeons, including the presence of antibodies to Amazon-endemic arboviruses.

Detection of antibodies to Oropouche virus in non-human primates in Goiânia City, Goiás.

Introduction: Arboviruses are associated with human disease, and non-human primates (NHPs) are important primary hosts. This study shows the detection of antibodies to Oropouche virus (OROV) in NHPs either living in urban parks or acclimatized at the Wild Animal Screening Center, Goiânia city.

Methods: Fifty blood samples were analyzed by hemagglutination-inhibition and neutralization assays.