Publications by authors named "Mariana Sequetin Cunha"

Yellow Fever (YF) is a viral arbovirosis of Public Health importance. In Brazil, surveillance is focused mainly on detecting epizootic events of Platyrrhini. Herein, we compared the detection and phylogenetic analysis of YF virus in two neotropical primates (NTP), a Callithrix detected in the previous epidemic period (2016-2020), and a Callicebus nigrifons, showing a new introduction of YF in 2023.

View Article and Find Full Text PDF
Article Synopsis
  • * Out of 242 examined primates, 25.6% tested positive for herpesvirus, with varying prevalence among different species and a significant correlation with adult age and human care.
  • * The results emphasize the need for ongoing monitoring of herpesvirus infections in these primate populations to prevent future outbreaks and protect both wildlife and human health.
View Article and Find Full Text PDF

Brazil is a great source of arbovirus diversity, mainly in the Amazon region. However, other biomes, especially the Atlantic Forest, may also be a hotspot for emerging viruses, including Bunyaviruses (Negarnaviricota: Bunyavirales). For instance, Vale do Ribeira, located in the Southeastern region, has been widely studied for virus surveillance, where Flavivirus, Alphavirus and Bunyaviruses were isolated during the last decades, including Bruconha virus (BRCV), a member of Orthobunyavirus genus Group C, in 1976.

View Article and Find Full Text PDF

Viral hemorrhagic fevers caused by arenaviruses are severe zoonotic diseases. In reservoirs, the presence of antibodies may indicate viral circulation in a population of a specific region, and these data can be used as an indicator for further investigations by molecular techniques. The present study aimed to detect the presence of arenavirus antibodies in wild rodents captured from 1998 to 2008 during epidemiological surveillance activities.

View Article and Find Full Text PDF
Article Synopsis
  • Capybaras, the largest rodents in the world, are highly adaptable to urban environments in South America and can carry various zoonotic diseases.
  • A study conducted in São Paulo, Brazil, aimed to check for the presence of fecal-borne viruses in capybara feces by collecting 337 samples from 2018 to 2020 and testing for multiple virus types.
  • Results showed all samples tested negative for fecal-borne viruses, suggesting that they pose a minor public health risk in the studied areas, but ongoing monitoring of wildlife is vital to manage potential viral threats.
View Article and Find Full Text PDF

Dengue infection is the most prevalent arthropod-borne viral disease in subtropical and tropical regions, whose primary vector is Aedes aegypti mosquitoes. The mechanisms of dengue virus (DENV) pathogenesis are little understood because we have no good disease models. Only humans develop symptoms (dengue fever, DF, or dengue hemorrhagic fever, DHF) and research has been limited to studies involving patients.

View Article and Find Full Text PDF

Herein, we describe a unique case of concomitant angioinvasive pulmonary aspergillosis due to Aspergillus fumigatus and yellow fever in a free-ranging howler monkey (Alouatta sp). Lung samples were negative for influenza viruses A and B.

View Article and Find Full Text PDF

Classical insect-flaviviruses (cISFVs) and dual host-related insect-specific flavivirus (dISFV) are within the major group of insect-specific flavivirus. Remarkably dISFV are evolutionarily related to some of the pathogenic flavivirus, such as Zika and dengue viruses. The Evolutionary relatedness of dISFV to flavivirus allowed us to investigate the evolutionary principle of host adaptation.

View Article and Find Full Text PDF
Article Synopsis
  • A study from 2010-2016 analyzed 251 stool samples in rural and low-income urban areas of northern Brazil to assess norovirus prevalence and diversity using next-generation sequencing (NGS).
  • Norovirus was found in 19.9% of the samples, with eight different genotypes identified, the most common being GII.4_Sydney[P31], which accounted for 64% of the infections.
  • The research highlights the genetic diversity of noroviruses, particularly noting distinct variants of GII.6[P7], and emphasizes the need to understand this diversity to gauge potential health risks, especially from the GII.4_Sydney[P31] variant.
View Article and Find Full Text PDF

Zika virus (ZIKV), an emerging arthropod-borne virus (arbovirus) of the family, is a current issue worldwide, particularly because of the congenital and neurological syndromes associated with infection by this virus. As the initial clinical symptoms of all diseases caused by this group are very similar, clinical diagnosis is difficult. Furthermore, laboratory diagnostic efforts have failed to identify specific and accurate tests for each virus of the family due to the cross-reactivity of these viruses in serum samples.

View Article and Find Full Text PDF
Article Synopsis
  • Flaviviruses are a significant public health issue in Brazil, especially in urban areas like São Paulo, where forests coexist with human activities, increasing the risk of transmission.
  • A study conducted from March 2016 to April 2017 involved collecting mosquitoes in the Capivari-Monos Environmental Protection Area to identify flavivirus species, using methods like morphological identification and qRT-PCR analysis.
  • The research found flaviviruses in 2.3% of mosquito pools, with DENV-2 identified in Culex spp. and ZIKV in Anopheles and Wyeomyia species, marking the first report of these viruses in these particular wild mosquito species.
View Article and Find Full Text PDF

Yellow Fever (YF) is a severe disease caused by Yellow Fever Virus (YFV), endemic in some parts of Africa and America. In Brazil, YFV is maintained by a sylvatic transmission cycle involving non-human primates (NHP) and forest canopy-dwelling mosquitoes, mainly Haemagogus-spp and Sabethes-spp. Beginning in 2016, Brazil faced one of the largest Yellow Fever (YF) outbreaks in recent decades, mainly in the southeastern region.

View Article and Find Full Text PDF

Formalin-fixed paraffin-embedded (FFPE) tissues are an important source for investigation of dengue virus (DENV) infection, particularly when blood or fresh frozen (FF) samples are unavailable. Histopathologic features and immunohistochemistry may have poor sensitivity and serotype determination is not always possible. Viral RNA genome detection tests are faster and considered the most sensitive technique for this kind of analysis, however, the use of molecular methods applied to FFPE tissues is still limited.

View Article and Find Full Text PDF

Enterovirus (EV) is commonly associated with central nervous system (CNS) syndromes. Recently, gastroenteric viruses, including rotavirus (RVA), human astrovirus (HAstV), and norovirus (NoV), have also been associated with CNS neurological disorders. The aim of the present study was to investigate the presence of EV, RVA, HAst, and NoV associated to CNS infections with undiagnosed etiology in Northwest region of São Paulo State, Brazil, and to conduct the molecular characterization of the positive samples detected.

View Article and Find Full Text PDF

The aim of this study was to improve flavivirus field monitoring in Brazil using a reliable probe-based RT-qPCR assay. Standard flavivirus strains were employed to evaluate the performance of the assay, and its applicability was evaluated using 235 stored pools of Culicidae samples collected between 1993 and 1997 and in 2016. Flavivirus species were identified by sequencing.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigated historical samples of mosquitoes in São Paulo, Brazil, to analyze the Ilheus virus (ILHV) and Iguape virus (IGUV) strains, confirming their presence in local vectors.
  • 50% of the pooled mosquito specimens tested positive for flaviviruses, with successful genome sequencing and phylogenetic analyses revealing distinct genetic lineages and diversity among the strains.
  • The findings highlight the historical circulation of ILHV and IGUV in the region and suggest that Anopheles mosquitoes may play a significant role in the transmission of IGUV.
View Article and Find Full Text PDF

The southeastern region of Brazil has recently experienced the largest yellow fever disease outbreak in decades. Since July 2016 epizootic events were reported in São Paulo state's north region, where 787 Culicidae were captured as part of public health surveillance efforts and tested using real-time quantitative PCR. One Aedes scapularis pool collected in November 2016 in an agriculture area in Urupês city tested positive for YFV-RNA.

View Article and Find Full Text PDF

Beginning in late 2016 Brazil faced the worst outbreak of Yellow Fever in recent decades, mainly located in southeastern rural regions of the country. In the present study we characterize the Yellow Fever Virus (YFV) associated with this outbreak in São Paulo State, Brazil. Blood or tissues collected from 430 dead monkeys and 1030 pools containing a total of 5,518 mosquitoes were tested for YFV by quantitative RT-PCR, immunohistochemistry (IHC) and indirect immunofluorescence.

View Article and Find Full Text PDF

Background: A number of Zika virus (ZIKV) sequences were obtained using Next-generation sequencing (NGS), a methodology widely applied in genetic diversity studies and virome discovery. However Sanger method is still a robust, affordable, rapid and specific tool to obtain valuable sequences.

Objective: The aim of this study was to develop a simple and robust Sanger sequencing protocol targeting ZIKV relevant genetic regions, as envelope protein and nonstructural protein 5 (NS5).

View Article and Find Full Text PDF

In January 2017, a yellow fever outbreak occurred in Espirito Santo, Brazil, where human immunization coverage is low. Histologic, immunohistologic, and PCR examinations were performed for 22 deceased nonhuman New World primates; typical yellow fever features were found in 21. Diagnosis in nonhuman primates prompted early public health response.

View Article and Find Full Text PDF
Article Synopsis
  • Brazil has faced a significant Zika virus epidemic since May 2015, with around 30,000 reported cases and concerns over microcephaly linked to the virus.
  • Research involved sequencing seven Brazilian ZIKV genomes from various cases, revealing that the virus was likely introduced to the Americas between May and December 2013, well before it was officially detected in Brazil.
  • Although no specific genetic changes were found in ZIKV associated with microcephaly, data suggests a connection between ZIKV incidence and the occurrence of suspected microcephaly cases around week 17 of pregnancy, highlighting a need for further studies on the virus's evolution and impact.
View Article and Find Full Text PDF

We report here the genome sequence of Zika virus, strain ZikaSPH2015, containing all structural and nonstructural proteins flanked by the 5' and 3' untranslated region. It was isolated in São Paulo state, Brazil, in 2015, from a patient who received a blood transfusion from an asymptomatic donor at the time of donation.

View Article and Find Full Text PDF