Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-38747849

RESUMO

This study aimed to provide further insight into the evolutionary dynamics of SARS-CoV-2 by analyzing the case of a 40-year-old man who had previously undergone autologous hematopoietic stem cell transplantation due to a diffuse large B-cell lymphoma. He developed a persistent SARS-CoV-2 infection lasting at least 218 days and did not manifest a humoral immune response to the virus during this follow-up period. Whole-genome sequencing and viral cultures confirmed a persistent infection with a replication-positive virus that had undergone genetic variation for at least 196 days after symptom onset.


Assuntos
COVID-19 , Hospedeiro Imunocomprometido , SARS-CoV-2 , Eliminação de Partículas Virais , Humanos , Adulto , Masculino , COVID-19/imunologia , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Linfoma Difuso de Grandes Células B/virologia , Linfoma Difuso de Grandes Células B/imunologia , Transplante de Células-Tronco Hematopoéticas , Sequenciamento Completo do Genoma
2.
J Med Virol ; 96(2): e29471, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38353496

RESUMO

Human enteroviruses (EV) are the most common cause of aseptic meningitis worldwide. Data on EV viral load in cerebrospinal fluid (CSF) and related epidemiological studies are scarce in Brazil. This study investigated the influence of EV viral load on CSF parameters, as well as identifying the involved species. CSF samples were collected in 2018-2019 from 140 individuals at The Hospital das Clínicas, São Paulo. The EV viral load was determined using real-time quantitative polymerase chain reaction, while EV species were identified by 5'UTR region sequencing. Median viral load was 5.72 log10 copies/mL and did not differ by subjects' age and EV species. Pleocytosis was observed in 94.3% of cases, with the highest white blood cell (WBC) counts in younger individuals. Viral load and WBC count were correlated in children (p = 0.0172). Elevated lactate levels were observed in 60% of cases and correlated with the viral load in preteen-teenagers (p = 0.0120) and adults (p = 0.0184). Most individuals had normal total protein levels (70.7%), with higher in preteen-teenagers and adults (p < 0.0001). By sequencing, 8.2% were identified as EV species A and 91.8% as species B. Age-specific variations in CSF characteristics suggest distinct inflammatory responses in each group.


Assuntos
Infecções por Enterovirus , Enterovirus , Meningite Asséptica , Meningite Viral , Criança , Adulto , Adolescente , Humanos , Lactente , Enterovirus/genética , Meningite Asséptica/líquido cefalorraquidiano , Brasil/epidemiologia , Estudos Retrospectivos , Líquido Cefalorraquidiano
3.
Curr Issues Mol Biol ; 45(9): 6958-6966, 2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37754223

RESUMO

Parvovirus B19 infection is associated with a wide range of clinical manifestations, from asymptomatic to severe neurological disorders. Its major clinical symptoms, fever and rash, are common to multiple viruses, and laboratory tests to detect B19 are frequently not available. Thus, the impact of B19 on public health remains unclear. We report the case of a 38-day old girl admitted to São Paulo Clinical Hospital, Brazil, with an initial diagnosis of bacterial meningitis, seizures, and acute hydrocephalus. Antibiotic therapy was maintained for one week after admission and discontinued after negative laboratory results were obtained. Nine days after symptoms onset, a cerebral spinal fluid (CSF) sample revealed persistent pleocytosis. The complete B19 complete genome was subsequently identified in her CSF by a metagenomic next-generation sequencing approach. This report highlights the possible involvement of B19 in the occurrence of acute neurological manifestations and emphasizes that its possible involvement might be better revealed by the use of metagenomic technology to detect viral agents in clinical situations of unknown or uncertain etiology.

4.
Front Med (Lausanne) ; 10: 1161091, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37547599

RESUMO

Torquetenovirus (TTV) is a commensal virus present in many healthy individuals. Although considered to be non-pathogenic, its presence and titer have been shown to be indicative of altered immune status in individuals with chronic infections or following allogeneic transplantations. We evaluated if TTV was present in amniotic fluid (AF) at the time of in utero surgery to correct a fetal neurological defect, and whether its detection was predictive of adverse post-surgical parameters. AF was collected from 27 women by needle aspiration prior to a uterine incision. TTV titer in the AF was measured by isolation of viral DNA followed by gene amplification and analysis. The TTV genomes were further characterized and sequenced by metagenomics. Pregnancy outcome parameters were subsequently obtained by chart review. Three of the AFs (11.1%) were positive for TTV at 3.36, 4.16, and 4.19 log10 copies/mL. Analysis of their genomes revealed DNA sequences similar to previously identified TTV isolates. Mean gestational age at delivery was >2 weeks earlier (32.5 vs. 34.6 weeks) and the prevalence of respiratory distress was greater (100% vs. 20.8%) in the TTV-positive pregnancies. TTV detection in AF prior to intrauterine surgery may indicate elevated post-surgical risk for earlier delivery and newborn respiratory distress.

5.
PLoS One ; 18(8): e0291027, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37651462

RESUMO

BACKGROUND: Redondovirus (ReDoV) is a DNA virus present in the respiratory tract of many healthy individuals. Since SARS-CoV-2, the virus responsible for COVID-19, also primarily infects the same site, we evaluated whether ReDoV was present at increased frequency in patients with COVID-19 and influenced infection parameters. METHODS: Saliva samples were collected weekly from 59 individuals with COVID-19 and from 132 controls. ReDoV was detected by polymerase chain reaction and the genotypes were identified by metagenomics. Torque Teno Virus (TTV) in these samples were previously reported. RESULTS: ReDoV was detected in saliva more frequently from COVID-19 patients (72.9%) than from controls (50.0%) (p = 0.0015). There were no associations between ReDoV detection and either continuous or intermittent SARS-CoV-2 shedding, the duration of SARS-CoV-2 detection in saliva, patients' sex or if infection was by the B1 or Gamma strain. The two ReDoV strains, Brisavirus and Vientovirus, were present in equivalent frequencies in ReDoV-positive COVID-19 patients and controls. Phylogenetic analysis suggested that the two ReDoV strains in Brazil were similar to strains previously detected on other continents. CONCLUSION: ReDoV expression in saliva is increased in males and females in Brazil with mild COVID-19 but its presence does not appear to influence properties of the SARS-CoV-2 infection.


Assuntos
COVID-19 , SARS-CoV-2 , Feminino , Masculino , Humanos , Brasil/epidemiologia , Filogenia , Saliva
6.
Sci Rep ; 13(1): 11252, 2023 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-37438453

RESUMO

An elevated pro-inflammatory cytokine response is associated with severe life-threatening symptoms in individuals with Coronavirus Disease-2019 (COVID). The inflammasome is an intracellular structure responsible for generation of interleukin (IL)-1ß and IL-18. NALP3, a product of the CIAS1 gene, is the rate-limiting component for inflammasome activity. We evaluated if a CIAS1 42 base pair length polymorphism (rs74163773) was associated with severe COVID. DNA from 93 individuals with severe COVID, 38 with mild COVID, and 98 controls were analyzed for this polymorphism. The 12 unit repeat allele is associated with the highest inflammasome activity. Five alleles, corresponding to 6, 7, 9, 12 or 13 repeat units, divided into 12 genotypes were identified. The frequency of the 12 unit repeat allele was 45.3% in those with severe disease as opposed to 30.0% in those with mild disease and 26.0% in controls (p < 0.0001, severe vs. controls). In contrast, the 7 unit repeat allele frequency was 30.1% in controls as opposed to 14.0% and 12.5% in those with severe or mild disease, respectively (p ≤ 0.0017). We conclude that individuals positive for the CIAS1 12 allele may be at elevated risk for development of severe COVID due to an increased level of induced pro-inflammatory cytokine production.


Assuntos
COVID-19 , Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Humanos , COVID-19/genética , Citocinas , Frequência do Gene , Inflamassomos/genética , Polimorfismo Genético , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética
7.
Viruses ; 15(6)2023 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-37376568

RESUMO

Introduction-The dynamics of SARS-CoV-2 shedding and replication in humans remain incompletely understood. Methods-We analyzed SARS-CoV-2 shedding from multiple sites in individuals with an acute COVID-19 infection by weekly sampling for five weeks in 98 immunocompetent and 25 immunosuppressed individuals. Samples and culture supernatants were tested via RT-PCR for SARS-CoV-2 to determine viral clearance rates and in vitro replication. Results-A total of 2447 clinical specimens were evaluated, including 557 nasopharyngeal swabs, 527 saliva samples, 464 urine specimens, 437 anal swabs and 462 blood samples. The SARS-CoV-2 genome sequences at each site were classified as belonging to the B.1.128 (ancestral strain) or Gamma lineage. SARS-CoV-2 detection was highest in nasopharyngeal swabs regardless of the virus strain involved or the immune status of infected individuals. The duration of viral shedding varied between clinical specimens and individual patients. Prolonged shedding of potentially infectious virus varied from 10 days up to 191 days, and primarily occurred in immunosuppressed individuals. Virus was isolated in culture from 18 nasal swab or saliva samples collected 10 or more days after onset of disease. Conclusions-Our findings indicate that persistent SARS-CoV-2 shedding may occur in both competent or immunosuppressed individuals, at multiple clinical sites and in a minority of subjects is capable of in vitro replication.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , SARS-CoV-2/genética , Teste para COVID-19 , Manejo de Espécimes , Eliminação de Partículas Virais , RNA Viral/genética
8.
Clinics (Sao Paulo) ; 77: 100068, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35767900

RESUMO

OBJECTIVES: The aim of the present study was to evaluate if neutralizing antibody responses induced by infection with the SARS-CoV-2 strain that was dominant at the beginning of the pandemic or by the Gamma variant was effective against the Omicron variant. METHODS: Convalescent sera from 109 individuals, never exposed to a SARS-CoV-2 vaccine, who had mild or moderate symptoms not requiring hospitalization following either a documented SARS-CoV-2 ancestral strain infection or a Gamma variant infection, were assayed for in vitro neutralizing antibody activity against their original strains and the Omicron variant. RESULTS: Following an infection with the ancestral strain, 56 (93.3%), 45 (77.6%) and 1 (1.7%) serum sample were positive for neutralizing antibodies against the ancestral, Gamma variant, and Omicron variant, respectively. After infection with the Gamma variant, 43 (87.8%) and 2 (4.1%) sera were positive for neutralizing antibodies against the Gamma and Omicron variants, respectively. CONCLUSIONS: Neutralizing antibodies generated following mild or moderate infection with the SARS-CoV-2 ancestral strain or the Gamma variant are not protective against the Omicron variant.


Assuntos
Anticorpos Neutralizantes , COVID-19 , Anticorpos Antivirais , COVID-19/terapia , Vacinas contra COVID-19 , Humanos , Imunização Passiva , Testes de Neutralização , SARS-CoV-2 , Soroterapia para COVID-19
9.
Clinics ; 77: 100068, 2022. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1394284

RESUMO

Abstract Objectives: The aim of the present study was to evaluate if neutralizing antibody responses induced by infection with the SARS-CoV-2 strain that was dominant at the beginning of the pandemic or by the Gamma variant was effective against the Omicron variant. Methods: Convalescent sera from 109 individuals, never exposed to a SARS-CoV-2 vaccine, who had mild or moderate symptoms not requiring hospitalization following either a documented SARS-CoV-2 ancestral strain infection or a Gamma variant infection, were assayed for in vitro neutralizing antibody activity against their original strains and the Omicron variant. Results: Following an infection with the ancestral strain, 56 (93.3%), 45 (77.6%) and 1 (1.7%) serum sample were positive for neutralizing antibodies against the ancestral, Gamma variant, and Omicron variant, respectively. After infection with the Gamma variant, 43 (87.8%) and 2 (4.1%) sera were positive for neutralizing antibodies against the Gamma and Omicron variants, respectively. Conclusions: Neutralizing antibodies generated following mild or moderate infection with the SARS-CoV-2 ancestral strain or the Gamma variant are not protective against the Omicron variant. HIGHLIGHTS Individuals previously infected with SARS-CoV-2 ancestral strain do not develop neutralizing antibodies against the Omicron variant. Omicron variant escapes immune response after SARS CoV-2 previous infection with the SARS CoV-2 Gamma variant. Individuals previously infected with SARS-CoV-2 ancestral strain or with SARS-CoV-2 Gamma variant will likely have little protection if subsequently exposed to the Omicron variant.

10.
PLoS One ; 16(8): e0256357, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34428230

RESUMO

Torquetenovirus (TTV) is present in biological fluids from healthy individuals and measurement of its titer is used to assess immune status in individuals with chronic infections and after transplants. We assessed if the titer of TTV in saliva varied with the presence of SARS-CoV-2 in the nasopharynx and could be a marker of COVID-19 status. Saliva from 91 individuals positive for SARS-CoV-2 in nasal-oropharyngeal samples, and from 126 individuals who were SARS-CoV-2-negative, all with mild respiratory symptoms, were analyzed. Both groups were similar in age, gender, symptom duration and time after symptom initiation when saliva was collected. Titers of TTV and SARS-CoV-2 were assessed by gene amplification. Loss of smell (p = 0.0001) and fever (p = 0.0186) were more prevalent in SARS-CoV-2-positive individuals, while sore throat (p = 0.0001), fatigue (p = 0.0037) and diarrhea (p = 0.0475) were more frequent in the SARS-CoV-2 negative group. The saliva TTV and nasal-oropharyngeal SARS-CoV-2 titers were correlated (p = 0.0085). The TTV level decreased as symptoms resolved in the SARS-CoV-2 infected group (p = 0.0285) but remained unchanged in the SARS-CoV-2 negative controls. In SARS-CoV-2 positive subjects who provided 2-4 saliva samples and in which TTV was initially present, the TTV titer always decreased over time as symptoms resolved. We propose that sequential TTV measurement in saliva is potentially useful to assess the likelihood of symptom resolution in SARS-CoV-2-positive individuals and to predict prognosis.


Assuntos
Biomarcadores/análise , COVID-19/diagnóstico , Saliva/virologia , Torque teno virus/isolamento & purificação , Adulto , COVID-19/virologia , DNA Viral/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nasofaringe/virologia , Reação em Cadeia da Polimerase , Prognóstico , SARS-CoV-2/isolamento & purificação , Torque teno virus/genética
11.
J Med Virol ; 93(9): 5603-5607, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33851749

RESUMO

It has been estimated that individuals with COVID-19 can shed replication-competent virus up to a maximum of 20 days after initiation of symptoms. The majority of studies that addressed this situation involved hospitalized individuals and those with severe disease. Studies to address the possible presence of SARS-CoV-2 during the different phases of COVID-19 disease in mildly infected individuals, and utilization of viral culture techniques to identify replication-competent viruses, have been limited. This report describes two patients with mild forms of the disease who shed replication-competent virus for 24 and 37 days, respectively, after symptom onset.


Assuntos
COVID-19/imunologia , COVID-19/virologia , SARS-CoV-2/crescimento & desenvolvimento , Cultura de Vírus , Animais , Chlorocebus aethiops , Feminino , Humanos , Pessoa de Meia-Idade , SARS-CoV-2/patogenicidade , Células Vero/ultraestrutura , Células Vero/virologia , Carga Viral , Eliminação de Partículas Virais
12.
J Virol Methods ; 290: 114064, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33453299

RESUMO

OBJECTIVES: We evaluated the performance of a nucleoprotein-based enzyme-linked immunosorbent assay (ELISA) for detection of IgG antibodies to SARS-CoV-2. METHODS: The ELISA was based on serum IgG reactivity to a 46-kDa protein derived from the recombinant SARS-CoV2 nucleoprotein. Assay sensitivity was assessed using serum samples from 134 COVID-19 confirmed cases obtained > 15 days after symptom onset. Specificity was determined by testing sera from 94 healthy controls. Cross-reactivity was evaluated with sera from 96 individuals with previous dengue or zika virus-confirmed infections, with 44 sera from individuals with confirmed infections to other respiratory viruses or with bacterial and fungal infections that cause pneumonia and with 40 sera negative for SARS-CoV-2 nucleoprotein by commercial ELISA kits. RESULTS: The majority of subjects were male and ≥ 60 years old. Assay sensitivity was 90.3 % (95 % confidence interval 84.1 %-94.2 %) and specificity was 97.9 % (92.6 %-99.4 %). There was no cross-reactivity with sera from individuals diagnosed with dengue, zika virus, influenza virus, rhinovirus, adenovirus, respiratory syncytial virus, seasonal coronavirus, Mycobacterium tuberculosis, Staphylococcus (S. aureus and coagulase-negative), Streptococcus pneumoniae, Klebsiella pneumoniae and the fungus Aspergillus fumigatus. The level of concordance of our test with results from commercial ELISA kits was 100 %. CONCLUSION: The nucleoprotein-based ELISA was specific for detection of IgG anti-nucleoprotein antibodies to SARS-CoV-2. It utilizes a frequently employed low expense assay protocol and is easier to perform than other currently available commercial SARS-CoV2 antibody detection tests.


Assuntos
Teste Sorológico para COVID-19 , COVID-19/diagnóstico , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Ensaio de Imunoadsorção Enzimática , Imunoglobulina G/sangue , SARS-CoV-2/isolamento & purificação , Adulto , Idoso , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Feminino , Humanos , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Fosfoproteínas/imunologia , SARS-CoV-2/imunologia , Sensibilidade e Especificidade
13.
Front Med (Lausanne) ; 8: 809312, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35096897

RESUMO

INTRODUCTION: Torque teno virus (TTV) is a non-pathogenic virus present in body fluids. Its titer in the circulation increases in association with immune suppression, such as in HIV-infected individuals. We evaluated if the TTV titer in saliva from HIV-positive individuals undergoing antiretroviral therapy (ART) was related to the circulating CD4+ T lymphocyte concentration and the HIV titer. METHODS: Saliva was collected from 276 asymptomatic individuals undergoing ART, and an additional 48 individuals positive for AIDS-associated Kaposi's Sarcoma (AIDS-KS). The salivary TTV titer was measured by gene amplification analysis. The circulating CD4+ T lymphocyte and HIV levels were obtained by chart review. RESULTS: TTV was detectable in saliva from 80% of the asymptomatic subjects and 87% of those with AIDS-KS. In the asymptomatic group the median log10 TTV titer/ml was 3.3 in 200 males vs. 2.4 in 76 females (p < 0.0001). TTV titer/ml was 3.7 when HIV was acquired by intravenous drug usage, 3.2 when by sexual acquisition and 2.4 when blood transfusion acquired. The salivary TTV titer was inversely correlated with the circulating CD4+ T lymphocyte level (p < 0.0001) and positively correlated with the circulating HIV concentration (p = 0.0005). The median salivary TTV titer and circulating HIV titer were higher, and the CD4+ count was lower, in individuals positive for AIDS-KS than in the asymptomatic subjects (p < 0.0001). CONCLUSION: The TTV titer in saliva is a potential biomarker for monitoring immune status in individuals undergoing ART.

14.
Transpl Infect Dis ; 22(4): e13330, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32418331

RESUMO

BACKGROUND: The objective was to assess the oral shedding and viremia of human herpesviruses in renal transplant recipients. METHODS: This is a cohort study in which the participants were examined in three different periods: the first within 24 hours before renal transplantation and the second and third ones 15-20 and 45-60 days after the transplantation. Mouthwash and blood samples were collected in each period and then submitted to screening for the presence of eight types of human herpesviruses by using multiplex PCR. RESULTS: HSV-1 and EBV were more frequent in the saliva after renal transplantation, 15- to 20-day period after the transplant. EBV was found in the saliva of 26 (35.6%) patients before renal transplantation and in 56.2% and 46.6% of them, in the 15- to 20-day and 45- to 60-day periods after the transplant, respectively. High detection rates (75.3%-78.1%) were found for HHV-7 despite the lack of significant variations between the study periods. There was no concordance between herpesviruses oral shedding and viremia. CONCLUSION: We concluded that the pattern of excretion of HSV-1 and EBV in saliva is changed immediately after renal transplantation, increasing in the 15- to 20-day period after the transplant surgery. No concordance between herpesviruses oral shedding and viremia was observed.


Assuntos
Infecções por Herpesviridae/diagnóstico , Transplante de Rim/efeitos adversos , Boca/virologia , Transplantados/estatística & dados numéricos , Viremia , Eliminação de Partículas Virais , Adulto , Estudos de Coortes , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/virologia , Feminino , Herpesviridae/isolamento & purificação , Herpesvirus Humano 1/isolamento & purificação , Herpesvirus Humano 4/isolamento & purificação , Herpesvirus Humano 7/isolamento & purificação , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Saliva/virologia , Carga Viral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...