RESUMO
Infection with influenza virus induces antibodies to the viral surface glycoproteins hemagglutinin and neuraminidase, and these responses can be broadly protective. To assess the breadth and magnitude of antibody responses, we sequentially infected mice, guinea pigs and ferrets with divergent H1N1 or H3N2 subtypes of influenza virus. We measured antibody responses by ELISA of an extensive panel of recombinant glycoproteins representing the viral diversity in nature. Guinea pigs developed high titers of broadly cross-reactive antibodies; mice and ferrets exhibited narrower humoral responses. Then, we compared antibody responses after infection of humans with influenza virus H1N1 or H3N2 and found markedly broad responses and cogent evidence for 'original antigenic sin'. This work will inform the design of universal vaccines against influenza virus and can guide pandemic-preparedness efforts directed against emerging influenza viruses.
Assuntos
Anticorpos Antivirais/imunologia , Reações Cruzadas/imunologia , Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Infecções por Orthomyxoviridae/imunologia , Proteínas do Envelope Viral/imunologia , Adolescente , Adulto , Fatores Etários , Animais , Análise por Conglomerados , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Furões , Cobaias , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Imunoglobulina G/imunologia , Vírus da Influenza A/classificação , Masculino , Camundongos , Pessoa de Meia-Idade , Neuraminidase/imunologia , Proteínas Virais/imunologia , Adulto JovemRESUMO
Sewage surveillance provides useful epidemiologic and public health information on viral infections at the population level. We detected monkeypox virus DNA from sewage samples covering 85% of the population in Santiago Metropolitan Region Chile. We also isolated infective viruses from those samples. Wastewater surveillance could complement clinical surveillance for monkeypox virus.
Assuntos
Monkeypox virus , Águas Residuárias , Humanos , Chile/epidemiologia , Vigilância Epidemiológica Baseada em Águas Residuárias , EsgotosRESUMO
BACKGROUND: Inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been widely implemented in low- and middle-income countries. However, immunogenicity in immunocompromised patients has not been established. Herein, we aimed to evaluate immune response to CoronaVac vaccine in these patients. METHODS: This prospective cohort study included 193 participants with 5 different immunocompromising conditions and 67 controls, receiving 2 doses of CoronaVac 8-12 weeks before enrollment. The study was conducted between May and August 2021, at Red de Salud UC-CHRISTUS, Santiago, Chile. Neutralizing antibody (NAb) positivity, total anti-SARS-CoV-2 immunoglobulin G antibody (TAb) concentrations, and T-cell responses were determined. RESULTS: NAb positivity and median neutralizing activity were 83.1% and 51.2% for the control group versus 20.6% and 5.7% (both Pâ <â .001) in the solid organ transplant group, 41.5% and 19.2% (both Pâ <â .0001) in the autoimmune rheumatic diseases group, 43.3% (Pâ <â .001) and 21.4% (P<.01 or Pâ =â .001) in the cancer with solid tumors group, 45.5% and 28.7% (both Pâ <â .001) in the human immunodeficiency virus (HIV) infection group, 64.3% and 56.6% (both differences not significant) in the hematopoietic stem cell transplant group, respectively. TAb seropositivity was also lower for the solid organ transplant (20.6%; Pâ <â .0001), rheumatic diseases (61%; Pâ <â .001), and HIV groups (70.9%; Pâ =â .003), compared with the control group (92.3%). On the other hand, the number of interferon γ spot-forming T cells specific for SARS-CoV-2 tended to be lower in all immunocompromising conditions but did not differ significantly between groups. CONCLUSIONS: Diverse immunocompromising conditions markedly reduce the humoral response to CoronaVac vaccine. These findings suggest that a boosting vaccination strategy should be considered in these vulnerable patients. CLINICAL TRIALS REGISTRATION: NCT04888793.
Assuntos
COVID-19 , Doenças Reumáticas , Vacinas Virais , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Chile/epidemiologia , Humanos , Imunidade , Hospedeiro Imunocomprometido , Estudos Prospectivos , SARS-CoV-2 , Vacinas de Produtos InativadosRESUMO
Lower respiratory tract infections (LRTIs) produced by viruses are the most frequent cause of morbidity and mortality in children younger than 5 years of age. The immune response triggered by viral infection can induce a strong inflammation in the airways and cytokines could be considered as biomarkers for disease severity as these molecules modulate the inflammatory response that defines the outcome of patients. Aiming to predict the severity of disease during respiratory tract infections, we conducted a 1-year follow-up observational study in infants who presented upper or lower respiratory tract infections caused by seasonal respiratory viruses. At the time of enrollment, nasopharyngeal swabs (NPS) were obtained from infants to measure mRNA expression and protein levels of IL-3, IL-8, IL-33, and thymic stromal lymphopoietin. While all cytokines significantly increased their protein levels in infants with upper and lower respiratory tract infections as compared to control infants, IL-33 and IL-8 showed a significant increase in respiratory syncytial virus (RSV)-infected patients with LRTI as compared to patients with upper respiratory tract infection. We also found higher viral loads of RSV-positive samples with a greater IL-8 response at the beginning of the symptoms. Data obtained in this study suggest that both IL-8 and IL-33 could be used as biomarkers for clinical severity for infants suffering from LRTIs caused by the RSV.
Assuntos
Infecções por Vírus Respiratório Sincicial , Infecções Respiratórias , Vírus , Humanos , Lactente , Criança , Infecções por Vírus Respiratório Sincicial/diagnóstico , Interleucina-33 , Interleucina-3 , Interleucina-8 , Vírus Sinciciais Respiratórios , Citocinas , Índice de Gravidade de Doença , Biomarcadores , RNA MensageiroRESUMO
OBJECTIVES: To: 1. Describe the frequency of viral RNA detection in stools in a cohort of patients infected with SARS-CoV-2, and 2. Perform a systematic review to assess the clearance time in stools of SARS-CoV-2. METHODS: We conducted a prospective cohort study in two centers between March and May 2020. We included SARS-CoV-2 infected patients of any age and severity. We collected seriated nasopharyngeal swabs and stool samples to detect SARS-CoV-2. After, we performed a systematic review of the prevalence and clearance of SARS-CoV-2 in stools (PROSPERO-ID: CRD42020192490). We estimated prevalence using a random-effects model. We assessed clearance time by using Kaplan-Meier curves. RESULTS: We included 32 patients; mean age was 43.7±17.7 years, 43.8% were female, and 40.6% reported gastrointestinal symptoms. Twenty-five percent (8/32) of patients had detectable viral RNA in stools. The median clearance time in stools of the cohort was 11[10-15] days. Systematic review included 30 studies (1392 patients) with stool samples. Six studies were performed in children and 55% were male. The pooled prevalence of viral detection in stools was 34.6% (twenty-four studies, 1393 patients; 95%CI:25.4-45.1); heterogeneity was high (I2:91.2%, Q:208.6; p≤0.001). A meta-regression demonstrates an association between female-gender and lower presence in stools (p=0.004). The median clearance time in stools was 22 days (nineteen studies, 140 patients; 95%CI:19-25). After 34 days, 19.9% (95%CI:11.3-29.7) of patients have a persistent detection in stools. CONCLUSIONS: Detection of SARS-CoV-2 in stools is a frequent finding. The clearance of SARS-CoV-2 in stools is prolonged and it takes longer than nasopharyngeal secretions.
Assuntos
COVID-19 , SARS-CoV-2 , Adulto , COVID-19/diagnóstico , COVID-19/epidemiologia , Criança , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , RNA Viral , Eliminação de Partículas ViraisRESUMO
BACKGROUND: Convalescent plasma (CP), despite limited evidence on its efficacy, is being widely used as a compassionate therapy for hospitalized patients with COVID-19. We aimed to evaluate the efficacy and safety of early CP therapy in COVID-19 progression. METHODS AND FINDINGS: The study was an open-label, single-center randomized clinical trial performed in an academic medical center in Santiago, Chile, from May 10, 2020, to July 18, 2020, with final follow-up until August 17, 2020. The trial included patients hospitalized within the first 7 days of COVID-19 symptom onset, presenting risk factors for illness progression and not on mechanical ventilation. The intervention consisted of immediate CP (early plasma group) versus no CP unless developing prespecified criteria of deterioration (deferred plasma group). Additional standard treatment was allowed in both arms. The primary outcome was a composite of mechanical ventilation, hospitalization for >14 days, or death. The key secondary outcomes included time to respiratory failure, days of mechanical ventilation, hospital length of stay, mortality at 30 days, and SARS-CoV-2 real-time PCR clearance rate. Of 58 randomized patients (mean age, 65.8 years; 50% male), 57 (98.3%) completed the trial. A total of 13 (43.3%) participants from the deferred group received plasma based on clinical aggravation. We failed to find benefit in the primary outcome (32.1% versus 33.3%, odds ratio [OR] 0.95, 95% CI 0.32-2.84, p > 0.999) in the early versus deferred CP group. The in-hospital mortality rate was 17.9% versus 6.7% (OR 3.04, 95% CI 0.54-17.17 p = 0.246), mechanical ventilation 17.9% versus 6.7% (OR 3.04, 95% CI 0.54-17.17, p = 0.246), and prolonged hospitalization 21.4% versus 30.0% (OR 0.64, 95% CI, 0.19-2.10, p = 0.554) in the early versus deferred CP group, respectively. The viral clearance rate on day 3 (26% versus 8%, p = 0.204) and day 7 (38% versus 19%, p = 0.374) did not differ between groups. Two patients experienced serious adverse events within 6 hours after plasma transfusion. The main limitation of this study is the lack of statistical power to detect a smaller but clinically relevant therapeutic effect of CP, as well as not having confirmed neutralizing antibodies in donor before plasma infusion. CONCLUSIONS: In the present study, we failed to find evidence of benefit in mortality, length of hospitalization, or mechanical ventilation requirement by immediate addition of CP therapy in the early stages of COVID-19 compared to its use only in case of patient deterioration. TRIAL REGISTRATION: NCT04375098.
Assuntos
COVID-19/terapia , Intervenção Médica Precoce/métodos , Tempo para o Tratamento , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/complicações , COVID-19/mortalidade , COVID-19/patologia , Chile , Progressão da Doença , Intervenção Médica Precoce/estatística & dados numéricos , Feminino , Mortalidade Hospitalar , Humanos , Imunização Passiva/métodos , Imunização Passiva/mortalidade , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Mortalidade , Respiração Artificial/mortalidade , Respiração Artificial/estatística & dados numéricos , Tempo para o Tratamento/normas , Resultado do Tratamento , Soroterapia para COVID-19RESUMO
Andes virus (ANDV) is the only hantavirus transmitted between humans through close contact. We detected the genome and proteins of ANDV in breast milk cells from an infected mother in Chile who transmitted the virus to her child, suggesting gastrointestinal infection through breast milk as a route of ANDV person-to-person transmission.
Assuntos
Infecções por Hantavirus , Orthohantavírus , Criança , Chile/epidemiologia , Feminino , Humanos , Transmissão Vertical de Doenças Infecciosas , Leite HumanoRESUMO
BACKGROUND: Single-nucleotide polymorphisms (SNPs) that impact on the differential expression of interleukin 28B (IL28B) are implicated in the progression of viral-induced diseases. In this prospective longitudinal cohort study, we evaluated the association between IL28B SNPs rs12979860 and rs8099917 and the clinical outcome of bronchiolitis in pediatric patients. METHODS: A total of 682 infants suffering from bronchiolitis, categorized based on the final clinical outcome as mild or severe, were genotyped for IL28B SNPs rs12979860 and rs8099917. RESULTS: When infants were categorized exclusively based on the final clinical outcome, no association was established between IL28B SNPs and the severity of bronchiolitis. However, when stratified by sex, the homozygotes for the minor alleles of rs12979860 (T) and rs8099917 (G) were associated with a mild disease in girls but not in boys. CONCLUSION: SNPs rs12979860 and rs8099917 correlate with the severity of bronchiolitis and display a sex bias, where GG rs8099917 and TT rs12979860 genotypes are associated with a mild disease in girls but not in boys. These findings suggest that innate immunity and female sex links with the outcome of the diseases induced by respiratory viruses, such as RSV.
Assuntos
Bronquiolite/genética , Interferons/genética , Polimorfismo de Nucleotídeo Único , Fatores Etários , Bronquiolite/diagnóstico , Bronquiolite/imunologia , Bronquiolite/virologia , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Lactente , Estudos Longitudinais , Fenótipo , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Fatores SexuaisRESUMO
Infectious endocarditis (IE) by Bartonella species is an emerging problem worldwide. We report two cases of native valve Bartonella-associated IE events, both affecting adult male patients with a history of alcohol abuse and a low socioeconomic status. Admissions were due to pancytopenia and bleeding in one case and embolic stroke in the other. Blood cultures were negative and IgG indirect immunofluorescence assays (IFA) were positive for B. henselae/B. quintana in high titers (1/16,384-1/16,384, and 1/32,768 -1/16,384, respectively). Cases were classified as definitive IE events according to modified Duke criteria due to the presence of valve vegetations with at least three minor criteria. One patient required aortic mechanical valve replacement and survived, and the other died after a massive hemorrhagic transformation of his stroke. PCR amplification and sequencing of the 16S ribosomal bacterial DNA from a valve tissue sample obtained at surgery in the patient who survived, confirmed B. quintana as the etiological agent. Bartonella-associated IE is an emerging problem in Chile, present in disadvantaged populations. It should be suspected in patients with culture-negative IE. IFA does not discriminate between B. henselae and B. quintana infection, but high titers suggest IE. Complementary PCR techniques may help to elucidate the final causative agent.
Assuntos
Bartonella henselae/isolamento & purificação , Bartonella quintana/isolamento & purificação , Endocardite Bacteriana/microbiologia , Idoso , Infecções por Bartonella/diagnóstico por imagem , Infecções por Bartonella/microbiologia , Chile , Endocardite Bacteriana/diagnóstico por imagem , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Tomografia Computadorizada por Raios XAssuntos
Dor Abdominal/epidemiologia , Betacoronavirus , Infecções por Coronavirus/complicações , Infecções por Coronavirus/diagnóstico , Diarreia/epidemiologia , Hospitalização , Pneumonia Viral/complicações , Pneumonia Viral/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19 , Chile , Estudos de Coortes , Infecções por Coronavirus/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/terapia , Fatores de Risco , SARS-CoV-2 , Avaliação de Sintomas , Carga Viral , Adulto JovemRESUMO
BACKGROUND: Andes virus (ANDV) is the sole etiologic agent of hantavirus cardiopulmonary syndrome (HCPS) in Chile, with a fatality rate of about 35%. Individual host factors affecting ANDV infection outcome are poorly understood. In this case-control genetic association analysis, we explored the link between single-nucleotide polymorphisms (SNPs) rs12979860, rs8099917 and rs1800629 and the clinical outcome of ANDV-induced disease. The SNPs rs12979860 and rs8099917 are known to play a role in the differential expression of the interleukin 28B gene (IL28B), whereas SNP rs1800629 is implicated in the expression of tumor necrosis factor α gene (TNF-α). METHODS: A total of 238 samples from confirmed ANDV-infected patients collected between 2006 and 2014, and categorized according to the severity of the disease, were genotyped for SNPs rs12979860, rs8099917, and rs1800629. RESULTS: Analysis of IL28B SNPs rs12979860 and rs8099917 revealed a link between homozygosity of the minor alleles (TT and GG, respectively), displaying a mild disease progression, whereas heterozygosity or homozygosity for the major alleles (CT/CC and TG/TT, respectively) in both IL28B SNPs is associated with severe disease. No association with the clinical outcome of HCPS was observed for TNF-α SNP rs1800629 (TNF -308G>A). CONCLUSIONS: The IL28B SNPs rs12979860 and rs8099917, but not TNF-α SNP rs1800629, are associated with the clinical outcome of ANDV-induced disease, suggesting a possible link between IL28B expression and ANDV pathogenesis.
Assuntos
Infecções por Hantavirus/genética , Infecções por Hantavirus/patologia , Interleucinas/genética , Orthohantavírus/isolamento & purificação , Polimorfismo de Nucleotídeo Único , Índice de Gravidade de Doença , Fator de Necrose Tumoral alfa/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Pré-Escolar , Chile , Feminino , Estudos de Associação Genética , Técnicas de Genotipagem , Infecções por Hantavirus/imunologia , Humanos , Lactente , Recém-Nascido , Interferons , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Andes hantavirus (ANDV) causes hantavirus cardiopulmonary syndrome in Chile and is the only hantavirus for which person-to-person transmission has been proven. We describe an outbreak of 5 human cases of ANDV infection in which symptoms developed in 2 household contacts and 2 health care workers after exposure to the index case-patient. Results of an epidemiologic investigation and sequence analysis of the virus isolates support person-to-person transmission of ANDV for the 4 secondary case-patients, including nosocomial transmission for the 2 health care workers. Health care personnel who have direct contact with ANDV case-patients or their body fluids should take precautions to prevent transmission of the virus. In addition, because the incubation period of ANDV after environmental exposure is longer than that for person-to-person exposure, all persons exposed to a confirmed ANDV case-patient or with possible environmental exposure to the virus should be monitored for 42 days for clinical symptoms.
Assuntos
Infecção Hospitalar/virologia , Características da Família , Infecções por Hantavirus/transmissão , Pessoal de Saúde , Transmissão de Doença Infecciosa do Paciente para o Profissional , Orthohantavírus/isolamento & purificação , Adulto , Idoso , Animais , Chile/epidemiologia , Infecção Hospitalar/transmissão , Surtos de Doenças , Feminino , Orthohantavírus/classificação , Infecções por Hantavirus/epidemiologia , Infecções por Hantavirus/virologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Acute respiratory infections caused by the respiratory syncytial virus (RSV) are important health burdens that affect infants worldwide. RSV is also an important cause of morbidity and disease in adults, which causes enormous economic losses. At the present time, RSV infection is diagnosed by immunofluorescence, test pack and/or PCR, obtaining better results with PCR than with any other technique. The production of new monoclonal antibodies (mAbs) capable of detecting RSV in clinical samples is necessary to generate better and faster diagnosis tools for RSV. In this study, three new mAbs, directed against the RSV N and M2-1 proteins, were evaluated for the detection of RSV in clinical samples. Nasopharyngeal swabs were obtained from: 27 RSV-positive patients; 15 human metapneumovirus (hMPV)-positive patients; and 6 healthy controls. To evaluate RSV presence in these samples, clinical samples and RSV-infected cells were tested by Enzyme-Linked ImmunoSorbent Assay (ELISA), flow cytometry, immunofluorescence, and dot-blot assays. Specificity and sensitivity were determined for each mAb by using purified RSV antigens and antigens from different viruses. Infected cells and clinical samples tested with the three new mAbs resulted positive by immunofluorescence, ELISA, flow cytometry, and dot blot. No false positives were obtained in samples infected with other respiratory virus (hMPV) or from healthy controls. These results suggest that these new anti-RSV mAbs can be considered for the rapid and reliable detection of RSV on infected cells and clinical specimens by multiple immunological approaches.
Assuntos
Anticorpos Monoclonais , Anticorpos Antivirais , Testes Diagnósticos de Rotina/métodos , Infecções por Vírus Respiratório Sincicial/diagnóstico , Vírus Sincicial Respiratório Humano/isolamento & purificação , Adulto , Humanos , Imunoensaio/métodos , Lactente , Nasofaringe/virologia , Vírus Sincicial Respiratório Humano/imunologia , Sensibilidade e EspecificidadeRESUMO
INTRODUCTION: CMV pp65-antigenemia (antigenemia) has been used for monitoring CMV viremia in allogeneic hematopoietic stem cell transplant (aHSCT) recipients. Recently, real time quantitative PCR (RT-qPCR) has been used as a better approach than antigenemia for CMV diagnosis. The objective of this study was to assess the correlation of CMV viremia between RT-qPCR and antigenemia in aHSCT patients. MATERIAL AND METHODS: Observational prospective study of all aHSCT patients during 10 months in our center. CMV RT-qPCR in whole blood was performed weekly from day +7 to +100 after aHSCT. Simultaneous antigenemia was performed from engrafment to day +100. Concordance between both assays was evaluated. RESULTS: Eighteen patients were included. In 120 simultaneous samples, 96 were concordant by both methods (80%). Kappa coefficient was 0.583. In 42% of cases without concordant results, patients were on antiviral therapy. Thirteen patients (72%) developed CMV infection (20 episodes). In 17 episodes, both the antigenemia and CMV RT-qPCR were positive. CMV RT-qPCR was detectable 1-2 weeks before antigenemia in 45% of the episodes. CONCLUSION: Both methods had a moderate concordance and CMV RT-qPCR detects CMV reactivations earlier than antigenemia, especially in neutropenic patients.
Assuntos
Infecções por Citomegalovirus/diagnóstico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Adolescente , Adulto , Antígenos Virais/sangue , Criança , Pré-Escolar , DNA Viral/análise , Diagnóstico Precoce , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Carga Viral , Adulto JovemRESUMO
INTRODUCTION: Nosocomial infections generate high morbidity and mortality in children undergoing cardiac surgery. OBJECTIVE: To determine risk factors for nosocomial infections in children after congenital heart surgery. METHODS: A retrospective case-control study, in patients younger than 15 years undergoing surgery for congenital heart disease from January 2007 to December 2011 admitted to the Pediatric Critical Patient Unit (UPC-P) in a university hospital. For cases, the information was analyzed from the first episode of infection. RESULTS: 39 patients who develop infections and 39 controls who did not develop infection were enrolled. The median age of cases was 2 months. We identified a number of factors associated with the occurrence of infections, highlighting in univariate analysis: age, weight, univentricular heart physiology, complexity of the surgical procedure according to RACHS-1 and cardiopulmonary bypass (CPB) time ≥ 200 minutes. Multivariate analysis identified CPB time ≥ 200 minutes as the major risk factor, with an OR of 11.57 (CI: 1.04 to 128.5). CONCLUSION: CPB time ≥ 200 minutes was the mayor risk factor associated with the development of nosocomial infections.
Assuntos
Infecção Hospitalar/epidemiologia , Cardiopatias Congênitas/cirurgia , Unidades de Terapia Intensiva Pediátrica/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Criança , Chile/epidemiologia , Infecção Hospitalar/etiologia , Feminino , Humanos , Lactente , Masculino , Análise Multivariada , Complicações Pós-Operatórias/microbiologia , Fatores de RiscoRESUMO
The COVID-19 pandemic has resulted in millions of deaths globally, and while several diagnostic systems were proposed, real-time reverse transcription polymerase chain reaction (RT-PCR) remains the gold standard. However, diagnostic reagents, including enzymes used in RT-PCR, are subject to centralized production models and intellectual property restrictions, which present a challenge for less developed countries. With the aim of generating a standardized One-Step open RT-qPCR protocol to detect SARS-CoV-2 RNA in clinical samples, we purified and tested recombinant enzymes and a non-proprietary buffer. The protocol utilized M-MLV RT and Taq DNA pol enzymes to perform a Taqman probe-based assay. Synthetic RNA samples were used to validate the One-Step RT-qPCR components, demonstrating sensitivity comparable to a commercial kit routinely employed in clinical settings for patient diagnosis. Further evaluation on 40 clinical samples (20 positive and 20 negative) confirmed its comparable diagnostic accuracy. This study represents a proof of concept for an open approach to developing diagnostic kits for viral infections and diseases, which could provide a cost-effective and accessible solution for less developed countries.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Teste para COVID-19 , RNA Viral/genética , RNA Viral/análise , Pandemias , Técnicas de Laboratório Clínico/métodos , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Andes virus (ANDV) is a zoonotic Orthohantavirus leading to hantavirus cardiopulmonary syndrome. Although most transmissions occur through environmental exposure to rodent faeces and urine, rare person-to-person transmission has been documented, mainly for close contacts. This study investigates the presence and infectivity of ANDV in body fluids from confirmed cases and the duration of viraemia. METHODS: In this prospective study, 131 participants with confirmed ANDV infection were enrolled in Chile in a prospective study between 2008 and 2022. Clinical samples (buffy coat, plasma, gingival crevicular fluid [GCF], saliva, nasopharyngeal swabs [NPS], and urine) were collected weekly for 3 weeks together with clinical and epidemiological data. Samples were categorised as acute or convalescent (up to and after 16 days following onset of symptoms). Infectivity of positive fluids was assessed after the culture of samples on Vero E6 cells and use of flow cytometry assays to determine the production of ANDV nucleoprotein. FINDINGS: ANDV RNA was detected in 100% of buffy coats during acute phase, declining to 95% by day 17, and to 93% between days 23-29. ANDV RNA in GCF and saliva decreased from 30% and 12%, respectively, during the acute phase, to 12% and 11% during the convalescent phase. Successful infectivity assays of RT-qPCR-positive fluids, including GCF, saliva, NPS, and urine, were observed in 18 (42%) of 43 samples obtained during the acute phase of infection. After re-culture, the capacity to infect Vero E6 cells was maintained in 16 (89%) of 18 samples. Severity was associated with the presence of ANDV RNA in one or more fluids besides blood (odds ratio 2·58 [95% CI 1·42-5·18]). INTERPRETATION: ANDV infection is a systemic and viraemic infection, that affects various organs. The presence of infectious particles in body fluids contributes to our understanding of potential mechanisms for person-to-person transmission, supporting the development of preventive strategies. Detection of ANDV RNA in additional fluids at hospital admission is a predictor of disease severity. FUNDING: National Institutes of Health and Agencia de Investigación y Desarrollo. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.
Assuntos
Infecções por Hantavirus , Orthohantavírus , Viremia , Eliminação de Partículas Virais , Humanos , Estudos Prospectivos , Masculino , Adulto , Infecções por Hantavirus/transmissão , Infecções por Hantavirus/epidemiologia , Infecções por Hantavirus/virologia , Feminino , Orthohantavírus/isolamento & purificação , Chile/epidemiologia , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , RNA Viral , Animais , Criança , Chlorocebus aethiops , Idoso , Células VeroRESUMO
BACKGROUND: Andes virus (ANDV)-related hantavirus cardiopulmonary syndrome (HCPS) has a 35% case fatality rate in Chile and no specific treatment. In an immunomodulatory approach, we evaluated the efficacy of intravenous methylprednisolone for HCPS treatment, through a parallel-group, placebo-controlled clinical trial. METHODS: Patients aged >2 years, with confirmed or suspected HCPS in cardiopulmonary stage, admitted to any of 13 study sites in Chile, were randomized by study center in blocks of 4 with a 1:1 allocation and assigned through sequentially numbered envelopes to receive placebo or methylprednisolone 16 mg/kg/day (≤1000 mg) for 3 days. All personnel remained blinded except the local pharmacist. Infection was confirmed by immunoglobulin M antibodies or ANDV RNA in blood. The composite primary endpoint was death, partial pressure of arterial oxygen/fraction of inspired oxygen ratio ≤55, cardiac index ≤2.2, or ventricular tachycardia or fibrillation within 28 days. Safety endpoints included the number of serious adverse events (SAEs) and quantification of viral RNA in blood. Analysis was by intention to treat. RESULTS: Infection was confirmed in 60 of 66 (91%) enrollees. Fifteen of 30 placebo-treated patients and 11 of 30 methylprednisolone-treated patients progressed to the primary endpoint (P = .43). We observed no significant difference in mortality between treatment groups (P = .41). There was a trend toward more severe disease in placebo recipients at entry. More subjects in the placebo group experienced SAEs (P = .02). There were no SAEs clearly related to methylprednisolone administration, and methylprednisolone did not increase viral load. CONCLUSIONS: Although methylprednisolone appears to be safe, it did not provide significant clinical benefit to patients. Our results do not support the use of methylprednisolone for HCPS. CLINICAL TRIALS REGISTRATION: NCT00128180.
Assuntos
Anti-Inflamatórios/administração & dosagem , Síndrome Pulmonar por Hantavirus/tratamento farmacológico , Metilprednisolona/administração & dosagem , Administração Intravenosa , Adolescente , Adulto , Chile , Método Duplo-Cego , Feminino , Orthohantavírus/genética , Orthohantavírus/isolamento & purificação , Síndrome Pulmonar por Hantavirus/mortalidade , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , Resultado do TratamentoRESUMO
BACKGROUND: HIV in Chile has a notification rate of 0.01%. Coreceptor antagonists are a family of antiretroviral drugs that are used with the prior knowledge of patients HIV-1 tropism. Viral RNA-based tropism detection requires a plasma viral load ≥1000 copies/mL, while proviral DNA-based detection can be performed regardless of plasma viral load. This test is useful in patients with low or undetectable viral loads and would benefit with a proper therapy. The aim of this study was to determine the correlation between HIV RNA and proviral genotypic DNA tropism tests. FINDINGS: Forty three Chilean patients were examined using population-based V3 sequencing, and a geno2pheno false-positive rate (FPR) cutoff values of 5, 5.75, 10 and 20%. With cutoff 5.75% a concordance of 88.4% in tropism prediction was found after a simultaneous comparison between HIV tropism assessment by RNA and DNA. In total, five discrepancies (11.6%) were found, 3 patients were RNA-R5/DNA-X4 and two were RNA-X4/DNA-R5. Proviral DNA enabled the prediction of tropism in patients with a low or undetectable viral load. For cutoff 5 and 5.75% genotypic testing using proviral DNA showed a similar sensitivity for X4 as RNA. We found that the highest sensitivity for detecting the X4 strain occurred with proviral DNA and cutoff of 10 and 20%. Viral loads were higher among X4 strain carriers than among R5 strain carriers (p < 0.05). CONCLUSIONS: A high degree of concordance was found between tropism testing with RNA and testing with proviral DNA. Our results suggest that proviral DNA-based genotypic tropism testing is a useful option for patients with low or undetectable viral load who require a different therapy.