Publications by authors named "Roberta S Medeiros"

Article Synopsis
  • The study focuses on analyzing Brazilian rotavirus strains G12P[6] and G12P[9] from 2011 to 2020 to understand genetic relationships between human and animal-origin strains using RT-PCR and sequencing techniques.
  • Findings indicate that G12P[6] strains show distinct genetic clustering and are associated with African ancestry and American strains, while G12P[9] strains exhibit unique lineages found only in Brazil, suggesting local evolution.
  • The results highlight a common origin for South American G12P[9] strains, supporting the idea of their introduction from Asia, with no recent reassortments from globally circulating strains.
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This study aimed to investigate the frequency and genotypic diversity of human bocavirus (HBoV) in historical fecal samples collected before 2005 in Brazil and understand its natural history in patients with diarrhea. Between 1998 and 2005, 3347 samples were tested for HBoV by RT-PCR, with a detection rate of 5.8% (195/3347).

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There is a dearth of information on the molecular epidemiology of rotaviruses in pets in Brazil. The aim of this study was to monitor rotavirus infections in household dogs and cats, determine full-genotype constellations, and obtain data on evolutionary relationships. Between 2012 and 2021, 600 fecal samples from dogs and cats (516 and 84, respectively) were collected at small animal clinics in São Paulo state, Brazil.

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Rotavirus (RVA) G8 is frequently detected in animals, but only occasionally in humans. G8 strains, however, are frequently documented in nations in Africa. Recently, an increase in G8 detection was observed outside Africa.

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Hepatitis E virus (HEV) is an emerging zoonotic pathogen associated with relevant public health issues. The aim of this study was to investigate HEV presence in free-living capybaras inhabiting urban parks in São Paulo state, Brazil. Molecular characterization of HEV positive samples was undertaken to elucidate the genetic diversity of the virus in these animals.

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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.
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Hand-foot-and-mouth disease (HFMD) is a highly contagious viral disease commonly associated to Enteroviruses (EV). During 2018, Brazil faced massive HFMD outbreaks spread across the country. This study aimed to characterize the EV responsible for the HFMD outbreak that occurred in Paraiba State, Brazilian Northeastern region, in 2018, followed by a phylogenetic analysis to detail information on its genetic diversity.

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Article Synopsis
  • This study focused on the epidemiology of human astroviruses in children under 5 in Tocantins State, Brazil, from 2010 to 2016.
  • Out of 232 stool samples, 16 (6.9%) tested positive for HAstV using both Next-Generation Sequencing (NGS) and conventional RT-PCR methods.
  • The findings highlighted the genotypic diversity of HAstV, with lineages identified as HAstV-1a (9 cases), HAstV-4c (3 cases), and HAstV-5c (4 cases).
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Human adenovirus (HAdV) is recognized as frequent cause of acute gastroenteritis and enteric viruses can be preserved in frozen stored feces for long periods of times. The purpose of the present study was to investigate enteric HAdV genotypic diversity in archival fecal specimens stored from 1998 to 2005 in order to understand the natural history of HAdV in diarrheal patients in Brazil before rotavirus vaccine introduction. A total of 3346 specimens were tested for HAdV using conventional PCR.

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Background: Human sapoviruses (HuSaV) are associated with acute gastroenteritis (AGE), causing sporadic cases and outbreaks in patients worldwide. In Brazil, however, there are few reports describing the prevalence of HuSaV in patients with AGE.

Objective: Describing the diversity of HuSaV in Brazil by detecting and molecularly characterizing HuSaV among patients with AGE during an 8-year period (2010-2017).

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During 2006-2011, 5035 fecal samples were tested by PCR for human adenovirus (HAdV) and sequenced. HAdV was detected in 198 cases (3.9%), with the highest rate in children ≤ 5 years.

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