Publications by authors named "Livia Melo Villar"

Article Synopsis
  • - A study was conducted in Piauí State, Brazil, to assess the prevalence of Hepatitis E Virus (HEV) among blood donors, involving 890 participants with a median age of 33.4 years, mostly males from the Mid-Northern region.
  • - Blood samples were tested for anti-HEV IgG and IgM antibodies using advanced techniques, alongside PCR testing for HEV RNA.
  • - The findings showed low prevalence rates for anti-HEV IgG (1.35%) and IgM (0.11%), with no HEV-RNA detected, indicating minimal HEV infection among blood donors in the area.
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MicroRNAs (miRNAs) can act as biomarkers and descriptors of the association between infections and other diseases, such as hepatitis and COVID-19. This study aims to investigate the role of miRNA serum expression according to laboratory data concerning hepatitis and COVID-19. Seventy individuals recruited in Southern and Southeastern Brazil donated serum samples and were divided into four groups: (i) 20 negative subjects, (ii) 20 presenting hepatitis, (iii) 19 with COVID-19 and (iv) 11 with hepatitis and COVID-19.

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Article Synopsis
  • Existing vaccines for hepatitis B are effective, but the virus remains a significant health issue due to challenges like cccDNA and potential reinfection.
  • RNA interference (RNAi) is being explored as a promising treatment strategy for chronic hepatitis B, offering a new approach to silence the virus.
  • A review analyzed 76,949 studies, narrowing it down to 226 key reports, highlighting RNAi's potential while calling for more research to bridge the gap between laboratory findings and real-world treatment applications.
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Background: Viral hepatitis is a disease that is more prevalent among individuals residing in remote regions and in contexts of social vulnerability. The objective of this study was to ascertain the seroprevalence of hepatitis A (HAV), B (HBV), and C (HCV) in vulnerable communities in the rural area of São João do Piauí (SJP), northern Brazil.

Methods: Immunoenzymatic assays were employed to detect the presence of anti-HAV (total and IgM), HBsAg, anti-HBc, anti-HBs, and anti-HCV serological markers in serum samples.

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This study aimed to estimate the prevalence and identify social factors and preventive strategies associated with the coronavirus disease 2019 (COVID-19) in socio and economically vulnerable people (recyclable waste pikers, immigrants/refugees, and homeless people) in Goiânia, Goiás State, Central-Western Brazil. A cross-sectional study was conducted from July 2020 to October 2020. COVID-19 positivity was defined as a positive total anti-SARS-COV-2 antibody test and/or RNA test for SARS-COV-2.

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  • The study investigates the impact of COVID-19 across various systems, focusing on liver damage and inflammation, and aims to correlate biomarkers with clinical outcomes and respiratory symptoms.
  • Conducted at Hospital Regional do Baixo Amazonas from 2020 to 2022, the retrospective cohort included 397 COVID-19 patients, utilizing data from their medical records over hospitalization and discharge periods.
  • Findings revealed that higher AST levels on day 14 and consistent lymphopenia were linked to increased mortality, and distinct biomarker changes were observed between patients on Non-Invasive and Invasive Mechanical Ventilation.
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  • * A cross-sectional approach was used, enrolling 1,138 individuals over nearly two years, with tests revealing a 20% prevalence of IgM antibodies and a remarkable 97.5% for IgG antibodies against HSV-1.
  • * The presence of HSV-1 DNA was confirmed in over a quarter of individuals with positive IgM results, indicating a significant silent prevalence of the virus within this community, particularly in individuals with certain urinary and genital symptoms.
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  • The study investigates how the host immune system affects the genetic variability of the hepatitis B virus (HBV), focusing on patients with different stages of infection.
  • It analyzes DNA samples from 113 individuals to evaluate HBV genetic diversity, resistance to antiviral drugs, and mutations that help the virus evade detection by the immune system.
  • Results show that most patients carry genotype A HBV and that those with lower viral loads exhibit higher genetic diversity, indicating they face greater selective pressure from the immune response.
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The serological markers for the diagnosis of COVID-19 plays an important role in the epidemiological investigation of the pandemic. This study aims to assess the prevalence of anti-SARS-CoV-2 in hepatitis B and C patients in a pre-vaccination of COVID-19 period. Between March 2020 and January 2021, 199 serum samples from individuals with HBsAg/HBV DNA or anti-HCV/HCV RNA positivity were tested for antibodies (IgM and IgG) against SARS-CoV-2 using Electrochemiluminescent Immunoassay (ECLIA).

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Background: Patients with kidney disease on Hemodialysis (HD) are susceptible to Coronavirus Disease (COVID-19) due to multiple risk factors.

Aim: This study aims to report the prevalence of antibodies against SARS-CoV-2 among patients on hemodialysis before vaccination in Brazil and to compare with clinical, demographic, and laboratory data.

Methods: Blood samples from 398 Chronic Kidney Disease (CKD) patients treated in three different private institutions in Rio de Janeiro State, Brazil were submitted to the total anti-SARS-CoV-2 testing.

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Introduction: Severe acute hepatitis (SAH) is defined by a severe inflammation of hepatocytes in the liver parenchyma which can lead to an acute liver failure, a clinical condition with high mortality rate that can be triggered by several factors but is usually associated to hepatotropic viruses' infection. In 2022, cases of children with severe acute hepatitis of unknown origin hospitalized in Glasgow, Scotland, were reported. Possible causes of this condition include, but are not limited to, undiagnosed viral (and non-viral) infections, autoimmune hepatitis, drug and/or chemical toxicity, mitochondrial chain respiratory and metabolic disorders.

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Background: Viral hepatitis is a significant health concern among indigenous population in the Americas. In Brazil, reports find high endemicity of HBV and HDV infections has been reported in several indigenous groups. However, few studies have documented the prevalence of HBV, HCV and HDV in the Yanomami.

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A transversal study was conducted among 472 vulnerable individuals (recyclable waste pickers, immigrants and refugees, homeless individuals, as well as lesbian, gay, bisexual, and transexual individuals) in Goiânia City, the capital of the State of Goiás, Brazil, to investigate the prevalence of hepatitis E virus (HEV) infection. A total of 459 (97.2%) serum samples were tested for anti-HEV IgG and IgM antibodies using fully automated chemiluminescence immunoassays (Liaison Murex Anti-HEV IgG and IgM assays, DiaSorin, Saluggia, Italy).

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Article Synopsis
  • * Using Sanger and next-generation sequencing, researchers found a mean HBV viral load in serum and identified various genotypes (with A1 being the most common at 55%).
  • * While there was a 100% agreement in genotypes between serum and oral fluid, only 80% agreement was found with DBS, revealing some genotypic differences and the presence of a resistance mutation in all individuals.
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Immunoglobulin Y (IgY) could be used in serological diagnosis focused on several infectious agents. This study aims to produce IgY anti-hepatitis B virus surface antigen (anti-HBs) and to assess its use in enzyme immunoassays. Antibodies were produced by immunizing chickens with Hepatitis B vaccine associated (group A), or not, with adjuvant CpG-ODN (group B).

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Hepatitis Delta is a disease caused by exposure to hepatitis B (HBV) and hepatitis D (HDV) viruses, usually with a more severe clinical outcome when compared to an HBV monoinfection. To date, the real prevalence of HDV infection is underestimated and detection methods are poorly available, especially in more endemic regions. Therefore, a one-step RT-qPCR method for quantification of HDV-RNA was developed.

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Article Synopsis
  • * Females exhibited a higher prevalence of HSV-2 antibodies (59.5%) compared to males (49%), with significant associations found between antibody presence and various health issues like urinary problems and genital wounds.
  • * The seroprevalence of HSV-2 in this community was significantly higher than in the general adult Brazilian population, suggesting a need for targeted health interventions to address contributing factors and improve public health policies.
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Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a rapid method that can replace RT-qPCR. A simple molecular assay for SARS-CoV-2 RNA detection in gold-standard diagnosis through swabs and alternative specimens such as saliva could be helpful in promoting genomic surveillance. A multicenter study was conducted to evaluate the RT-LAMP assay method as an alternative for the molecular detection of SARS-CoV-2 lineages in swab and saliva samples.

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Environmental surveillance of water sources is important to monitoring viral hepatitis transmission in clinical settings. This study investigated the circulation of hepatitis A (HAV) and E (HEV) viruses in sewage and clinical samples from Argentina. Between 2016 and 2017, 80 raw sewage samples and 86 clinical samples (stool and serum) from suspected cases of hepatitis A and hepatitis E were obtained.

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Background: Agile, accessible and cheap diagnosis of hepatitis C virus (HCV) infection is essential to achieve the elimination of this infection, worldwide, as mandated by the World Health Organzation as part of its strategy for 2030. Dried blood spots (DBS) can be an attractive alternative for sample collection among people living in remote areas and vulnerable populations due to the less invasive collection, its biosafety, and storage & transportation of samples at room temperature.

Design: This study aims to estimate the usefulness of dried blood spot samples for the diagnosis and the assessment of HCV infection rates in three different settings in Brazil.

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The emergence of clinically relevant mutations in the hepatitis B virus (HBV) genome has been a matter of great debate because of the possibility of escape from the host's immune system, the potential to cause more severe progression of liver diseases and the emergence of treatment-resistant variants. Here we characterized the circulating variants of HBV in Rondônia State, in the north of Brazil. Serum samples of 62 chronic HBV carriers were subjected to PCR assays and clinical data were collected.

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Transgender women (TGW) have limited access to affordable viral hepatitis testing, hepatitis B vaccination, and treatment. We aimed to estimate the prevalence of viral hepatitis A, B, and C, as well as to compare the adherence and immunogenicity of two hepatitis B vaccine schedules among TGW in Central Brazil. A total of 440 TGW were interviewed and tested for hepatitis A, B, and C serological markers from 2017 to 2018.

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The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has become a major public health worldwide. Hepatic dysfunction has been seen in patients with COVID-19 and could be related to a viral cytopathic effect, an exacerbated immune reaction, or drug-induced liver damage. Currently, routine modification of immunosuppressive therapy in patients with autoimmune hepatitis (AIH) before and after SARS-CoV-2 infection remains an important topic to be discussed.

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Chronic kidney disease (CKD) patients undergoing hemodialysis (HD) are more vulnerable to blood-borne viral infections due to frequent invasive procedures. Hepatitis B virus (HBV) infection in this cohort of patients has been a matter of concern worldwide. The objective of this cross-sectional study was to evaluate the frequency of serological markers for hepatitis B, and the occurrence of overt and occult HBV infection (OBI) and its molecular characterization in serum samples from 644 CKD patients in HD units located in Rio de Janeiro, Brazil, from 2013 to 2017.

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