Explore the vast range of titles available.

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 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 . The mitogenomes showed an average length of 15,038 bp, average AT content of 79.3%, positive AT-skews, negative GC-skews, and comprised 37 functional subunits (13 PCGs, 22 tRNA, and 02 rRNA). The PCGs showed ATN as start codon, TAA as stop codon, and signs of purifying selection. The tRNAs had the typical leaf clover structure, except tRNA Ser1 . Phylogenetic analyzes of Bayesian inference and Maximum Likelihood, based on concatenated sequences from all 13 PCGs, produced identical topologies and strongly supported the monophyletic relationship between the Haemagogus and Conopostegus subgenera, and corroborated with the known taxonomic classification of the evaluated taxa, based on external morphological aspects. The information produced on the mitogenomes of the Haemagogus species evaluated here may be useful in carrying out future taxonomic and evolutionary studies of the genus.

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. While early seroconverters presented the increasing levels of CCL2 along the timeline, late seroconverters displayed decreasing levels of CCL2, CXCL10, and IL-6 following days of disease onset. Noteworthy was that IFN-α was revealed as universal biomarker of human OROV fever, while CXCL8 & IL-5 and CXCL10 & IL-17 were consistently observed in early and late seroconverters, respectively. Thus, our results suggest that the production of IFN-α, CXCL10, and IL-17 precede the seroconversion bringing novel insights on the immunological events triggered by the OROV disease.

Background The emergence and re-emergence of infectious diseases are a cause for worldwide concern. The introduction of Zika and Chikungunya diseases in the Americas has exposed unforeseen medical and logistical challenges for public health systems. Moreover, the lack of preventive measures and vaccination against known and emerging mosquito-transmitted pathogens, and the occurrence of unanticipated clinical complications, has had an enormous social and economic impact on the affected populations. In this study, we aimed to measure the seroprevalence of endemic and emerging viral pathogens in military personnel stationed in Manaus, Amazonas state. Methods We measured the seropositivity of antibodies against 19 endemic and emerging viruses in a healthy military personnel group using a hemagglutination inhibition assay (HIA). Results Overall, DENV positivity was 60.4%, and 30.9% of the individuals reacted against ZIKV. Also, 46.6%, 54.7%, 51.3% and 48.7% individuals reacted against West Nile virus (WNV), Saint Louis encephalitis virus (SLEV), Ilheus virus (ILHV) and Rocio virus (ROCV), respectively. Individuals with high DENV HIA titer reacted more frequently with ZIKV or WNV compared to those with low HIA titers. Observed cross-reactivity between Flaviviruses varied depending on the virus serogroup. Additionally, 0.6% and 0.3% individuals were seropositive for Oropouche virus (OROV) and Catu virus (CATUV) from the family Peribunyaviridae, respectively. All samples were negative for Eastern Equine Encephalitis virus (EEEV), Western Equine Encephalomyelitis virus (WEEV), Mayaro virus (MAYV), Mucambo virus (MUCV) and CHIKV from the family Togaviridae . Conclusions A high proportion of individuals in our high-risk population (~ 60%) lacked antibodies against major endemic and emerging viruses, which makes them susceptible for further infections. Military personnel serving in the Amazon region could serve as sentinels to strengthen global infectious disease surveillance, particularly in remote areas. Graphical abstract

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.

The Culicidae family is distributed worldwide and comprises about 3587 species subdivided into the subfamilies Anophelinae and Culicinae. This is the first description of complete mitochondrial DNA sequences from Aedes fluviatilis, Aedeomyia squamipennis, Coquillettidia nigricans, Psorophora albipes, and Psorophora ferox. The mitogenomes showed an average length of 15,046 pb and 78.02% AT content, comprising 37 functional subunits (13 protein coding genes, 22 tRNAs, and two rRNAs). The most common start codons were ATT/ATG, and TAA was the stop codon for all PCGs. The tRNAs had the typical leaf clover structure, except tRNASer1. Phylogeny was inferred by analyzing the 13 PCGs concatenated nucleotide sequences of 48 mitogenomes. Maximum likelihood and Bayesian inference analysis placed Ps. albipes and Ps. ferox in the Janthinosoma group, like the accepted classification of Psorophora genus. Ae. fluviatilis was placed in the Aedini tribe, but was revealed to be more related to the Haemagogus genus, a result that may have been hampered by the poor sampling of Aedes sequences. Cq. nigricans clustered with Cq. chrysonotum, both related to Mansonia. Ae. squamipennis was placed as the most external lineage of the Culicinae subfamily. The yielded topology supports the concept of monophyly of all groups and ratifies the current taxonomic classification.

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.

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. Consequently, their neonates showed fetal neuropathology, such as cerebral hemorrhage, lissencephaly or malformations of the brain grooves, ventriculomegaly, and craniofacial malformations. Thus, our study demonstrated the relevance of pregnant squirrel monkeys as a model for the study of ZIKV infection in neonates due to the broad clinical manifestations presented, including the typical congenital Zika syndrome manifestations described in humans.

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. Histopathological and immunohistochemical analyses of early-infected newborns (2/4) revealed damage to various areas of the brain and ZIKV antigens in the cytoplasm of neurons and glial cells, indicative of CZS. The changes caused by ZIKV infection were intrauterine developmental delay, ventriculomegaly, simplified brain gyri, vascular impairment and neuroprogenitor cell dysfunction. Our data show that the ZIKV infection outcome in squirrel monkeys is similar to that in humans, indicating that this model can be used to help answer questions about the effect of ZIKV infection on neuroembryonic development and the morphological changes induced by CZS.

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. To detect antibodies that promote the classical and alternative pathways of macrophage activation, immunohistochemical analysis was performed to detect CD163, CD68, inducible nitric oxide synthase (iNOS), arginase 1, interleukin (IL)-4, IL-10, interferon (IFN)-γ, IFN-β, tumour necrosis factor (TNF)-α, IL-13, and transforming growth factor (TGF)-β. There was a difference in the marker expression between fatal cases of YFV and control samples, with increased expression in the cortical region of the renal parenchyma. The immunoexpression of CD68 and CD163 receptors suggests the presence of activated macrophages migrating to infectious foci. The rise in IL-10, IL-4, and IL-13 indicated their potential role in the inactivation of the inflammatory macrophage response and phenotypic modulation of M2 macrophages. The altered expression of IFN-γ and IFN-β demonstrates the importance of the innate immune response in combating microorganisms. Our findings indicate that the polarisation of M1 and M2 macrophages plays a vital role in the renal immune response to YFV.