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1.
Infez Med ; 28(suppl 1): 18-28, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32532934

RESUMO

Diagnosis of persons exposed to/infected with severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) is central to controlling the global pandemic of COVID-19. Currently, several diagnostic modalities are available for COVID-19, each with its own pros and cons. Although there is a global consensus to increase the testing capacity, it is also essential to prudently utilize these tests to control the pandemic. In this paper, we have reviewed the current array of diagnostics for SARS-CoV-2, highlighted the gaps in current diagnostic modalities, and their role in community surveillance and control of the pandemic. The different modalities of COVID-19 diagnosis discussed are: clinical and radiological, molecular based (laboratory based and point-of-care), Immunoassay based (ELISA, rapid antigen and antibody detection tests) and digital diagnostics (artificial intelligence based algorithms). The role of rapid antigen/antibody detection tests in community surveillance has also been described here. These tests can be used to identify asymptomatic persons exposed to the virus and in community based seroprevalence surveys to assess the epidemiology of spread of the virus. However, there are few concerns about the accuracy of these tests which needs to evaluated beforehand.


Assuntos
Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Vigilância da População , Algoritmos , Anticorpos Antivirais/análise , Antígenos Virais/análise , Inteligência Artificial , Doenças Assintomáticas , Betacoronavirus/genética , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Betacoronavirus/fisiologia , Líquidos Corporais/virologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Ensaio de Imunoadsorção Enzimática , Humanos , Técnicas de Diagnóstico Molecular , Nasofaringe/virologia , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Testes Imediatos , Utilização de Procedimentos e Técnicas , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Escarro/virologia , Avaliação de Sintomas , Carga Viral
2.
Sci Transl Med ; 12(546)2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32493791

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic has highlighted the need for different types of diagnostics, comparative validation of new tests, faster approval by federal agencies, and rapid production of test kits to meet global demands. In this Perspective, we discuss the utility and challenges of current diagnostics for COVID-19.


Assuntos
Betacoronavirus , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Imunidade Adaptativa , Antígenos Virais/análise , Betacoronavirus/genética , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/economia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Custos e Análise de Custo , Reações Cruzadas , Humanos , Imunidade Inata , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , RNA Viral/análise , RNA Viral/genética , Testes Sorológicos/métodos , Pesquisa Médica Translacional , Estados Unidos/epidemiologia , Carga Viral/imunologia
3.
BMC Infect Dis ; 20(1): 335, 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398134

RESUMO

BACKGROUND: Dengue fever is a hemorrhagic fever caused by flaviviruses. Hemorrhagic manifestations are well known to be associated with dengue fever, though the thrombotic events are only seldom reported. Underlying pathophysiology of thrombotic events is multifactorial and the management is challenging due to associated thrombocytopenia and bleeding tendency. We report a case of dengue shock syndrome with severe thrombocytopenia complicated by ilio-femoral deep vein thrombosis. CASE PRESENTATION: A 16 year old boy presented with dengue fever. He had dengue shock syndrome after entering the critical phase on the fifth day of the illness. With the recovery from the critical phase he developed deep vein thrombosis involving right external iliac, common femoral and superficial femoral veins. There were no provocative factors other than dengue fever itself. His platelet count was 12,000/µl at the time of diagnosis with deep vein thrombosis. Anticoagulation was started with intravenous unfractionated heparin 500 IU/hour while closely being observed for bleeding complications. 1000 IU/hour dose was commenced with the recovery of the platelet count above 50,000/µl. Thrombophilia screening was negative and he was discharged on warfarin. Venous duplex done after 6 weeks showed normal lower limb venous flow and warfarin was omitted after three months. CONCLUSIONS: With dengue fever, complications like deep vein thrombosis can be easily missed given its rarity and that the major concern is on hemorrhagic complications. Management is challenging due to associated thrombocytopenia and hemorrhagic complications.


Assuntos
Vírus da Dengue/imunologia , Veia Femoral/patologia , Extremidade Inferior/irrigação sanguínea , Dengue Grave/complicações , Trombocitopenia/complicações , Trombose Venosa/etiologia , Administração Intravenosa , Adolescente , Anticoagulantes/administração & dosagem , Anticoagulantes/uso terapêutico , Antígenos Virais/análise , Heparina/administração & dosagem , Heparina/uso terapêutico , Humanos , Masculino , Resultado do Tratamento , Trombose Venosa/tratamento farmacológico , Varfarina/uso terapêutico
4.
Arch Virol ; 165(6): 1333-1342, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32266552

RESUMO

Equine infectious anemia (EIA), a disease caused by equine infectious anemia virus (EIAV), is considered an obstacle to the development of the horse industry. There is no treatment or vaccine available for EIA, and its pathogenesis, as well as the immune response against the virus, is not fully understood. Therefore, an immunohistochemistry assay was developed for the detection of viral antigens in tissues of equids naturally infected with EIAV. Sections of organs of six equids from Apodi-RN, Brazil, that tested positive for EIA by serological tests (ELISA and AGID) were fixed in 10% formalin solution and embedded in paraffin. Immunohistochemistry was performed using a polyclonal anti-EIAV antibody. EIAV antigens were observed in red spleen pulp cells and hepatic sinusoids, as well as bronchiolar and alveolar epithelial cells of the lungs and proximal and distal tubules of the kidneys. The presence of EIAV in the spleen and liver was expected due to viral tropism by macrophages, which are abundantly present in these organs. However, EIAV was also found in lung and kidney epithelial cells, indicating that the virus infects cell types other than macrophages. In conclusion, the immunohistochemical assay standardized in this study was able to detect EIAV antigens in spleen, liver, kidney and lung cells from naturally infected EIAV equids. Immunostaining observed in the spleen confirms viral tropism by mononuclear phagocytes; however, the presence of EIAV in lung and kidney epithelial cells indicates that virus may be eliminated in urine and/or oronasal secretions, suggesting new routes for viral excretion.


Assuntos
Anemia Infecciosa Equina/virologia , Vírus da Anemia Infecciosa Equina/isolamento & purificação , Animais , Antígenos Virais/análise , Brasil , DNA Viral/genética , Células Epiteliais/patologia , Células Epiteliais/virologia , Anemia Infecciosa Equina/imunologia , Anemia Infecciosa Equina/patologia , Cavalos/virologia , Vírus da Anemia Infecciosa Equina/classificação , Rim/patologia , Rim/virologia , Leucócitos Mononucleares/virologia , Fígado/patologia , Fígado/virologia , Pulmão/patologia , Pulmão/virologia , Reação em Cadeia da Polimerase , Testes Sorológicos , Baço/patologia , Baço/virologia
6.
Emerg Microbes Infect ; 9(1): 747-756, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32196430

RESUMO

The three unprecedented outbreaks of emerging human coronavirus (HCoV) infections at the beginning of the twenty-first century have highlighted the necessity for readily available, accurate and fast diagnostic testing methods. The laboratory diagnostic methods for human coronavirus infections have evolved substantially, with the development of novel assays as well as the availability of updated tests for emerging ones. Newer laboratory methods are fast, highly sensitive and specific, and are gradually replacing the conventional gold standards. This presentation reviews the current laboratory methods available for testing coronaviruses by focusing on the coronavirus disease 2019 (COVID-19) outbreak going on in Wuhan. Viral pneumonias typically do not result in the production of purulent sputum. Thus, a nasopharyngeal swab is usually the collection method used to obtain a specimen for testing. Nasopharyngeal specimens may miss some infections; a deeper specimen may need to be obtained by bronchoscopy. Alternatively, repeated testing can be used because over time, the likelihood of the SARS-CoV-2 being present in the nasopharynx increases. Several integrated, random-access, point-of-care molecular devices are currently under development for fast and accurate diagnosis of SARS-CoV-2 infections. These assays are simple, fast and safe and can be used in the local hospitals and clinics bearing the burden of identifying and treating patients.


Assuntos
Betacoronavirus , Técnicas de Laboratório Clínico , Doenças Transmissíveis Emergentes/diagnóstico , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Antígenos Virais/análise , Betacoronavirus/genética , Betacoronavirus/imunologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/mortalidade , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/mortalidade , Surtos de Doenças , Humanos , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/mortalidade , Testes Imediatos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testes Sorológicos , Síndrome Respiratória Aguda Grave/diagnóstico , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/mortalidade , Manejo de Espécimes
7.
Gastroenterol. hepatol. (Ed. impr.) ; 43(3): 117-125, mar. 2020. tab
Artigo em Inglês | IBECS | ID: ibc-190784

RESUMO

BACKGROUND: At present only monoclonal EIA (enzyme-immunoassay) stool antigen-tests have obtained optimal accuracy in the diagnosis of Helicobacter pylori. Our aim was to evaluate the accuracy of two stool antigen-tests, the validated Premier Platinum HpSA PLUS (EIA test) and the newly available ImmunoCard STAT! HpSA HD (rapid test) for the initial diagnosis and the confirmation of eradication of H. pylori infection. PATIENTS AND METHODS: Patients with indication of H. pylori diagnosis, or confirmation after treatment were included. Data were coded to protect personal data and ensure blindness between tests. Accuracy was considered as coincident diagnosis with the gold standard (13C-urea breath test, UBT). The EIA was used as a bench standard. All stool tests were performed in duplicate. RESULTS: 264 patients completed the protocol (100 naïve, 164 post-eradication). Average age was 52 years, 61% women, 11% ulcer. Positive diagnoses by UBT were 41% for naïve and 17% for post-eradication. Overall ImmunoCard and EIA accuracies were respectively 91% (95%C. I. =88-94%) and 89% (86-93%), sensitivities 72% (67-78%) and 72% (67-78%), and specificities 98% (96-100%), and 95% (92-97%). Concordance between ImmunoCard and EIA was 95% (93-98%). DISCUSSION: Our results indicate that the newly available ImmunoCard rapid stool antigen-test achieves 90% accuracy, with high specificity but suboptimal sensitivity. The ImmunoCard attained equivalent accuracies as the EIA bench standard, with 95% concordance


ANTECEDENTES: En la actualidad, únicamente los métodos de detección de antígenos en heces monoclonales basados en enzimoinmunoanálisis (ELISA) han obtenido una adecuada precisión para el diagnóstico de la infección por Helicobacter pylori. Nuestro objetivo fue evaluar la exactitud (sensibilidad y especificidad) de 2 métodos de antígenos en las heces, el previamente validado Premier Platinum HpSA® PLUS (ELISA) y el nuevo ImmunoCard® STAT! HpSA® HD (test rápido), para el diagnóstico inicial y la confirmación de la erradicación de la infección por H. pylori. PACIENTES Y MÉTODOS: Se incluyeron pacientes en los que estaba indicado el diagnóstico inicial de la infección por H. pylori o su confirmación tras el tratamiento. Los datos fueron codificados y los evaluadores de ambos test fueron ciegos para los resultados de las pruebas diagnósticas. El resultado principal fue la coincidencia con el resultado del patrón oro (prueba del aliento con 13C-urea). Los test en heces se realizaron por duplicado. RESULTADOS: Doscientos sesenta y cuatro pacientes completaron el protocolo (100 naïve, 164 posterradicación). La edad media fue de 52 años, el 61% fueron mujeres y el 11% tenían úlcera péptica. La prueba del aliento fue positiva en el 41% de los pacientes naïve y en el 17% posterradicación. La exactitud global del método rápido y del ELISA fue, respectivamente, 91% (IC 95%: 88-94%) y 89% (86-93%), la sensibilidad 72% (67-78%) y 72% (67-78%), y la especificidad 98% (96-100%) y 95% (92-97%). La concordancia entre el método ImmunoCard® y ELISA fue del 95% (93-98%). DISCUSIÓN: El nuevo método rápido de antígenos en heces (ImmunoCard® STAT! HpSA® HD) tiene una exactitud diagnóstica del 90%, con una elevada especificidad, pero una sensibilidad insuficiente. El método ImmunoCard® tiene una exactitud equivalente al método ELISA estándar, con una concordancia del 95%


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Antígenos Virais/análise , Helicobacter pylori/isolamento & purificação , Infecções por Helicobacter/diagnóstico , Fezes/química , Helicobacter pylori/imunologia , Ensaio de Imunoadsorção Enzimática , Testes Respiratórios , Curva ROC , Sensibilidade e Especificidade , Estudos Prospectivos
8.
Viruses ; 12(1)2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31936476

RESUMO

Porcine deltacoronavirus (PDCoV) is a porcine enteropathogenic coronavirus that causes watery diarrhea, vomiting, and frequently death in piglets, causing serious economic losses to the pig industry. The strain CHN-JS-2017 was isolated and identified by cytopathology, immunofluorescence assays, transmission electron microscopy, and sequence analysis. A nucleotide sequence alignment showed that the whole genome of CHN-JS-2017 is 97.4%-99.6% identical to other PDCoV strains. The pathogenicity of the CHN-JS-2017 strain was investigated in orally inoculated five-day-old piglets; the piglets developed acute, watery diarrhea, but all recovered and survived. CHN-JS-2017 infection-induced microscopic lesions were observed, and viral antigens were detected mainly by immunohistochemical staining in the small intestine. The neonatal Fc receptor (FcRn) and polymeric immunoglobulin receptor (pIgR) are crucial immunoglobulin (Ig) receptors for the transcytosis ofimmunoglobulin G (IgG), IgA, or IgM. Importantly, CHN-JS-2017 infected five-day-old piglets could significantly down-regulate the expression of FcRn, pIgR, and nuclear factor-kappa B (NF-κB)in the intestinal mucosa. Note that the level of FcRn mRNA in the intestinal mucosa of normal piglets is positively correlated with pIgR and NF-κB. At the same time, the expressions of FcRn, pIgR, and NF-κB mRNA are also positively correlated in infected piglets. These results may help explain the immunological and pathological changes associated with porcine deltacorononirus infection.


Assuntos
Infecções por Coronavirus/veterinária , Coronavirus/classificação , Antígenos de Histocompatibilidade Classe I/imunologia , Mucosa Intestinal/imunologia , Receptores Fc/imunologia , Receptores de Imunoglobulina Polimérica/imunologia , Doenças dos Suínos/virologia , Animais , Antígenos Virais/análise , Coronavirus/isolamento & purificação , Infecções por Coronavirus/imunologia , Diarreia/veterinária , Diarreia/virologia , Regulação da Expressão Gênica , Mucosa Intestinal/virologia , Intestino Delgado/imunologia , Intestino Delgado/virologia , NF-kappa B/imunologia , Filogenia , RNA Viral/análise , Alinhamento de Sequência , Análise de Sequência de DNA , Suínos , Doenças dos Suínos/imunologia , Eliminação de Partículas Virais
9.
Virol J ; 16(1): 158, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-31842897

RESUMO

BACKGROUND: After the isolation of Acanthamoeba polyphaga mimivirus (APMV), the study and search for new giant viruses has been intensified. Most giant viruses are associated with free-living amoebae of the genus Acanthamoeba; however other giant viruses have been isolated in Vermamoeba vermiformis, such as Faustovirus, Kaumoebavirus and Orpheovirus. These studies have considerably expanded our knowledge about the diversity, structure, genomics, and evolution of giant viruses. Until now, there has been only one Orpheovirus isolate, and many aspects of its life cycle remain to be elucidated. METHODS: In this study, we performed an in-depth characterization of the replication cycle and particles of Orpheovirus by transmission and scanning electron microscopy, optical microscopy and IF assays. RESULTS: We observed, through optical and IF microscopy, morphological changes in V. vermiformis cells during Orpheovirus infection, as well as increased motility at 12 h post infection (h.p.i.). The viral factory formation and viral particle morphogenesis were analysed by transmission electron microscopy, revealing mitochondria and membrane recruitment into and around the electron-lucent viral factories. Membrane traffic inhibitor (Brefeldin A) negatively impacted particle morphogenesis. The first structure observed during particle morphogenesis was crescent-shaped bodies, which extend and are filled by the internal content until the formation of multi-layered mature particles. We also observed the formation of defective particles with different shapes and sizes. Virological assays revealed that viruses are released from the host by exocytosis at 12 h.p.i., which is associated with an increase of particle counts in the supernatant. CONCLUSIONS: The results presented here contribute to a better understanding of the biology, structures and important steps in the replication cycle of Orpheovirus.


Assuntos
Vírus de DNA/crescimento & desenvolvimento , Vírus Gigantes/crescimento & desenvolvimento , Replicação Viral , Antígenos Virais/análise , Vírus de DNA/ultraestrutura , Vírus Gigantes/ultraestrutura , Lobosea/virologia , Microscopia , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Vírion/química , Vírion/ultraestrutura
10.
Sensors (Basel) ; 19(19)2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31575036

RESUMO

Hepatitis C virus (HCV) accounts for 15%-20% of cases of acute infection, and chronic HCV infection is developed in about 50%-80% of HCV patients. Unfortunately, due to the lack of proper medical care, difficulty in screening for HCV infection, and lack of awareness resulted in chronic HCV infection in 71 million people on a global scale, and about 399,000 deaths in 2016. It is crucial to recognize that the effective use of antiviral medicines can cure more than 95% of HCV infected people. The Global Health Sector Strategy (GHSS) aim is to reduce the new HCV infections and the HCV associated mortality by 90% and 65%, respectively. Therefore, the methods that are simple, yet powerful enough to detect HCV infections with high sensitivity, specificity, and a shorter window period are crucial to restrain the global burden of HCV healthcare. This article focuses on the technologies used for the detection of HCV in clinical specimens.


Assuntos
Hepacivirus/imunologia , Hepatite C/diagnóstico , Immunoblotting/métodos , Técnicas Imunoenzimáticas/métodos , Anticorpos Antivirais/análise , Antígenos Virais/análise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Hepacivirus/genética , Hepatite C/imunologia , Humanos , Luminescência , Proteínas Virais/metabolismo
11.
Infect Dis Poverty ; 8(1): 71, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31477185

RESUMO

BACKGROUND: Dengue is a global disease, transmitted by the Aedes vectors. In 2018, there were 80 615 dengue cases with 147 deaths in Malaysia. Currently, the nationwide surveillance programs are dependent on Aedes larval surveys and notifications of lab-confirmed human infections. The existing, reactive programs appear to lack sensitivity and proactivity. More efficient dengue vector surveillance/control methods are needed. METHODS: A parallel, cluster, randomized controlled, interventional trial is being conducted for 18 months in Damansara Damai, Selangor, Malaysia, to determine the efficacy of using gravid oviposition sticky (GOS) trap and dengue non-structural 1 (NS1) antigen test for early surveillance of dengue among Aedes mosquitoes to reduce dengue outbreaks. Eight residential apartments were randomly assigned into intervention and control arms. GOS traps are set at the apartments to collect Aedes weekly, following which dengue NS1 antigen is detected in these mosquitoes. When a dengue-positive mosquito is detected, the community will be advised to execute vector search-and-destroy and protective measures. The primary outcome concerns the the percentage change in the (i) number of dengue cases and (ii) durations of dengue outbreaks. Whereas other outcome measures include the change in density threshold of Aedes and changes in dengue-related knowledge, attitude and practice among cluster inhabitants. DISCUSSION: This is a proactive and early dengue surveillance in the mosquito vector that does not rely on notification of dengue cases. Surveillance using the GOS traps should be able to efficiently provide sufficient coverage for multistorey dwellings where population per unit area is likely to be higher. Furthermore, trapping dengue-infected mosquitoes using the GOS trap, helps to halt the dengue transmission carried by the mosquito. It is envisaged that the results of this randomized controlled trial will provide a new proactive, cheap and targeted surveillance tool for the prevention and control of dengue outbreaks. TRIAL REGISTRATION: This is a parallel-cluster, randomized controlled, interventional trial, registered at ClinicalTrials.gov (ID: NCT03799237), on 8th January 2019 (retrospectively registered).


Assuntos
Aedes/fisiologia , Aedes/virologia , Antígenos Virais/análise , Vírus da Dengue/isolamento & purificação , Oviposição , Proteínas não Estruturais Virais/análise , Animais , Vigilância da População , Ensaios Clínicos Controlados Aleatórios como Assunto
12.
Intervirology ; 62(3-4): 145-155, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31533104

RESUMO

BACKGROUND: When infected with the chikungunya virus (CHIKV), 3% to 28% of CHIKV-infected individuals remain asymptomatic, necessitating the development of improved high-throughput screening methods to overcome the limitations of molecular diagnostics or enzyme-linked immunosorbent assays (ELISAs). OBJECTIVE: In this study, two novel monoclonal antibodies (mAbs) targeting envelope 1 (E1) of CHIKV were developed and applied in a fluorescence-linked immunosorbent assay (FLISA) using coumarin-derived dendrimer as the fluorophore. METHODS: The performance of the FLISA was compared with that of ELISA. RESULTS: Using the two novel mAbs (2B5 and 2C8), FLISA could detect 1 × 105 PFU/mL of CHIKV, exhibiting a 2-fold lower limit of detection (LOD) compared to ELISA. The LOD of FICT corresponded to a comparative threshold value of 23.95 and 4 × 106 of RNA copy number/µL. In the presence of human sera and blood, virus detection by FLISA was 3-fold better than ELISA, with an LOD of 2 × 105 PFU/mL. Sera and blood interfered with the ELISA, resulting in 6 × 105 PFU/mL as the LOD. CONCLUSIONS: FLISA using two novel mAbs and coumarin-derived dendrimer is a superior diagnostic assay for detecting CHIKV in human sera and blood, compared to conventional ELISA.


Assuntos
Antígenos Virais/análise , Febre de Chikungunya/diagnóstico , Vírus Chikungunya/isolamento & purificação , Testes Diagnósticos de Rotina/métodos , Fluorometria/métodos , Técnicas Imunoenzimáticas/métodos , Proteínas do Envelope Viral/análise , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/isolamento & purificação , Vírus Chikungunya/imunologia , Humanos , Sensibilidade e Especificidade
13.
J Vet Diagn Invest ; 31(5): 761-765, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31378167

RESUMO

We investigated the histologic findings and viral antigen distribution in 3 cases of natural coinfection of layer hens with subgroup J avian leukosis virus (ALV-J), Marek's disease virus (MDV), and reticuloendotheliosis virus (REV) in hens. At autopsy, diseased hens were found to have hepatosplenomegaly and thickened proventriculi, with white tumor nodules in the liver, spleen, lung, kidney, and ovary. Microscopically, most tissues had been infiltrated by neoplastic lymphocytes; the spleen, lung, proventriculus, heart, and liver had been infiltrated by both neoplastic lymphocytes and myeloblastic cells and/or primitive reticular cells. Fluorescence multiplex immunohistochemistry staining revealed ALV-J, MDV, and REV antigens co-expressed in the same tissue, even the same cell.


Assuntos
Leucose Aviária/virologia , Galinhas , Coinfecção/veterinária , Doença de Marek/virologia , Doenças das Aves Domésticas/virologia , Infecções por Retroviridae/veterinária , Infecções Tumorais por Vírus/veterinária , Animais , Antígenos Virais/análise , Leucose Aviária/imunologia , Leucose Aviária/patologia , Vírus da Leucose Aviária/fisiologia , Coinfecção/imunologia , Coinfecção/patologia , Coinfecção/virologia , Feminino , Herpesvirus Galináceo 2/fisiologia , Doença de Marek/imunologia , Doença de Marek/patologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/patologia , Vírus da Reticuloendoteliose/fisiologia , Infecções por Retroviridae/imunologia , Infecções por Retroviridae/patologia , Infecções por Retroviridae/virologia , Infecções Tumorais por Vírus/imunologia , Infecções Tumorais por Vírus/patologia , Infecções Tumorais por Vírus/virologia
14.
PLoS One ; 14(7): e0219687, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31310636

RESUMO

OBJECTIVE: Screening for hepatitis C in Russia is a complex process that involves several visits and stepwise testing, limiting adherence and substantially reducing the yield in the identification of active infections. We aimed to evaluate the cost-effectiveness of different screening algorithms from a health system perspective. METHODS: A decision analytic model was applied to a hypothetical adult population eligible to participate in a general screening program for hepatitis C in Russia. The standard pathway (I: Screen for anti-HCV antibodies followed by a nucleic acid test for HCV RNA on antibody positives) was compared to three alternatives (II: Screen for antibodies, a reflexed test for HCV antigen on antibody positives, and RNA on antigen negatives; III: Screen for antibodies, a reflexed test for HCV antigen on antibody positives; IV: Screen for antigen). Each strategy considered a cascade of events (referral, adherence, testing, diagnosis) that must occur for screening to be effective. The primary measure of effectiveness was the number of diagnosed active infections. Calculations followed a health system perspective with costs derived from 2017 reimbursement rates and a willingness-to-pay of 2,000RUB ($82) per diagnosed active infection. Model was tested with deterministic and probabilistic sensitivity analyses. RESULTS: Non-adherence to screening stages reduced the capture rate of active infections in Strategy I from 79.0% to 40.6%. Strategies II, III, and IV were less affected and identified 69%, 67%, and 104% more infections. Average costs per diagnosed infection were decreased by 41% from 89,599RUB ($3,681) for I to 53,072RUB ($2,180), 53,004RUB ($2,177), and 59,633RUB ($2,450) for II, III, and IV, respectively. With a probability of 97%, Strategy III was most cost-effective with an incremental cost-effectiveness ratio vs. I of -1,373RUB (CI: -5,011RUB to -2,033RUB; $-56; CI: -$206 to -$84). Below a willingness-to-pay of 91,000RUB ($3,738), Strategy IV was not cost-effective. Sensitivity analyses confirmed the robustness of results. CONCLUSIONS: Testing strategies for hepatitis C with HCV antigen on HCV antibody positive cases offer a streamlining opportunity for population screening programs. Those shall increase the chances for detecting active infections and are cost-effective over current practice in Russia.


Assuntos
Análise Custo-Benefício , Hepacivirus , Hepatite C/diagnóstico , Hepatite C/epidemiologia , Programas de Rastreamento/métodos , Algoritmos , Antígenos Virais/análise , Tomada de Decisões , Hepatite C/economia , Anticorpos Anti-Hepatite C/análise , Humanos , Programas de Rastreamento/economia , Modelos Estatísticos , Cooperação do Paciente , Probabilidade , Anos de Vida Ajustados por Qualidade de Vida , RNA Viral/análise , Federação Russa/epidemiologia
15.
Biosens Bioelectron ; 141: 111476, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31272058

RESUMO

The ability of influenza viruses to rapidly evolve has caused significant challenges in viral surveillance, diagnosis, and therapeutic development. Molecular sequencing methods, though powerful tools for monitoring influenza evolution at the genetic level, are not able to fully characterize the antigenic properties of influenza viruses. Understanding influenza virus antigenicity is critical to vaccine development and disease prevention. Traditional immunoassays which have been widely used for evaluating influenza antigenicity have limited throughput. To alleviate these problems, new bioanalytical tools to investigate influenza antigenicity by measuring antibody-antigen binding are an active area of research. Herein, we review immunosensor technologies from the aspects of various sensing principles, while highlighting recent developments in multiplex, label-free detection strategies. Highlighted technologies include electrochemical immunosensors relying on impedimetric detection; these demonstrate simple design and cost effectiveness for mass production. Antibody arrays implemented on an optical interferometric sensor system allow systematic characterization of influenza antigenicity. Quartz microbalance immunosensors are highly sensitive but have yet to be explored for multiplex sensing. Immunosensors made on lateral flow strips have shown promise in rapid diagnosis of influenza subtypes. We anticipate that these and other technologies discussed in the review will facilitate advances in the study of influenza, and other viral pathogens.


Assuntos
Técnicas Biossensoriais/métodos , Influenza Humana/diagnóstico , Orthomyxoviridae/isolamento & purificação , Animais , Antígenos Virais/análise , Antígenos Virais/imunologia , Técnicas Biossensoriais/instrumentação , Desenho de Equipamento , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Influenza Humana/imunologia , Influenza Humana/virologia , Influenzavirus A/imunologia , Influenzavirus A/isolamento & purificação , Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/diagnóstico , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia
16.
Appl Opt ; 58(11): 2839-2844, 2019 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-31044886

RESUMO

In this study we report the development of a novel viral pathogen immunosensor technology based on the electrochemical modulation of the optical signal from a surface plasmon wave interacting with a redox dye reporter. The device is formed by incorporating a sandwich immunoassay onto the surface of a plasmonic device mounted in a micro-electrochemical flow cell, where it is functionalized with a monoclonal antibody aimed to a specific target pathogen antigen. Once the target antigen is bound to the surface, it promotes the capturing of a secondary polyclonal antibody that has been conjugated with a redox-active methylene blue dye. The methylene blue displays a reversible change in the complex refractive index throughout a reduction-oxidation transition, which generates an optical signal that can be electrochemically modulated and detected at high sensitivity. For proof-of-principle measurements, we have targeted the hemagglutinin protein from the H5N1 avian influenza A virus to demonstrate the capabilities of our device for detection and quantification of a critical influenza antigen. Our experimental results of the EC-SPR-based immunosensor under potential modulation showed a 300 pM limit of detection for the H5N1 antigen.


Assuntos
Anticorpos Monoclonais/imunologia , Antígenos Virais/análise , Imunoensaio/instrumentação , Virus da Influenza A Subtipo H5N1/imunologia , Azul de Metileno/química , Ressonância de Plasmônio de Superfície/instrumentação , Técnicas Biossensoriais/instrumentação , Limite de Detecção
17.
BMC Vet Res ; 15(1): 177, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138202

RESUMO

BACKGROUND: Peste des petits ruminants (PPR) is a severe infectious disease in both domestic and wild small ruminants. Due to its heavy economic burden and hence social and health impacts on human populations, Food and Agriculture Organization of the United Nations (FAO) and The World Organization for Animal Health (OIE) have targeted PPR for eradication by 2030. In order to plan and implement a successful eradication program, factual status assessments prior to devising disease control strategies is a vital criterion. The aim of this study was to isolate and characterize PPR virus from a rising wave of outbreaks in southern Iran. RESULTS: Twenty-one clinical samples, including blood as well as oral, nasal and ocular swabs were collected from ten sick animals in 4 various herds and were examined with ELISA and RT-PCR for the presence of PPR virus antigen and genome, respectively. The virus was successfully isolated in primary lamb kidney cell culture and identified by RT-PCR. Phylogenetic analysis of the sequenced N genes revealed that, while the earliest reports of Iran's outbreaks were grouped into clusters with Saudi Arabia, Turkey and Africa, in this study reported sequences were grouped with samples from Pakistan, Tajikistan and China in particular. This observation suggests a shift in PPRV flow from the western borders of the country to the eastern neighboring countries. CONCLUSIONS: Lineage IV of PPR virus is presently circulating in Iran, with certain levels of genetic diversity. Present study along with previous reports demonstrates the dispersal patterns and movements of PPR virus, which highlights the reversal pattern of virus flow in recent years. Such information is necessary to understand PPRV molecular epidemiology and to develop more proper control strategies to eradicate the disease in the planned time.


Assuntos
Surtos de Doenças/veterinária , Peste dos Pequenos Ruminantes/epidemiologia , Vírus da Peste dos Pequenos Ruminantes/genética , Animais , Antígenos Virais/análise , Células Cultivadas , Ensaio de Imunoadsorção Enzimática/veterinária , Genoma Viral , Doenças das Cabras/epidemiologia , Doenças das Cabras/virologia , Cabras , Irã (Geográfico)/epidemiologia , Peste dos Pequenos Ruminantes/virologia , Vírus da Peste dos Pequenos Ruminantes/isolamento & purificação , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Ovinos , Doenças dos Ovinos/epidemiologia
18.
Arch Virol ; 164(4): 1049-1058, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30778744

RESUMO

Goatpox is an economically significant transboundary viral disease of goats that is caused by goatpox virus (GTPV). This study describes the prokaryotic expression of the GTPV ORF117 protein, a homologue of vaccinia virus A27L, and evaluation of its diagnostic potential in ELISA. The GTPV ORF117 gene was cloned into the pET32a vector to express recombinant ORF117 protein (rA27L) in E. coli BL21-CodonPlus (DE3)-RIPL. The bacterial expression of the protein was confirmed by western blot analysis using anti-GTPV polyclonal antibodies that detected rA27L, which is ~ 35 kDa in size. rA27L was affinity purified under native conditions and used to assess the antibody response in an optimized indirect ELISA. The purified antigen specifically reacted with anti-GTPV and anti-SPPV serum in ELISA. A preliminary screening of random and purposive serum samples (n = 520) from sheep and goats using this optimized ELISA gave a positivity rate of 19.4 % with a diagnostic specificity of 88.7% and diagnostic sensitivity of 98.5% when compared to the gold standard serum neutralization test. Our results suggest that the indirect ELISA based on the rA27L protein has potential for serosurveillance and seromonitoring of GTPV in goats.


Assuntos
Antígenos Virais/análise , Antígenos Virais/genética , Capripoxvirus/metabolismo , Ensaio de Imunoadsorção Enzimática/métodos , Doenças das Cabras/virologia , Infecções por Poxviridae/veterinária , Proteínas Virais/análise , Proteínas Virais/genética , Animais , Antígenos Virais/isolamento & purificação , Antígenos Virais/metabolismo , Capripoxvirus/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Doenças das Cabras/diagnóstico , Cabras , Infecções por Poxviridae/diagnóstico , Infecções por Poxviridae/virologia , Proteínas Virais/isolamento & purificação , Proteínas Virais/metabolismo
19.
Am J Primatol ; 81(1): e22948, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30620103

RESUMO

Diarrhea with secondary decompensation is the main cause of morbidity and mortality in captive young rhesus macaque (Macaca mulatta) colonies. Approximately 25% of diarrhea cases with secondary decompensation are considered to be idiopathic chronic diarrhea. The purpose of this study was to investigate the suspected but not systematically examined association between rotavirus infection and diarrhea with secondary decompensation among young rhesus macaques at the California National Primate Research Center (CNPRC). Blood and stool samples were collected from 89 randomly selected young animals (age range: 6 months to 1.5 years) and were tested for the presence of rotavirus antibody, and rotavirus antigen, respectively, using enzyme-linked immunosorbent assays (ELISA's). Test and clinical data were analyzed using Fisher's exact tests and multivariate logistic regression model. Our analysis indicates that rotavirus is endemic among young outdoor-housed rhesus macaques at the CNPRC. Although the relationship between detectable rotavirus antigen in stool and symptomatic diarrhea with secondary decompensation was not significant, there was a significant association between rotavirus seropositivity and a history of diarrhea with secondary decompensation within the past 6 months. While our cross-sectional and case-control study suggests an association between rotavirus infection and diarrhea with secondary decompensation among captive rhesus macaques, more extensive longitudinal studies on larger cohorts and with more intensive sample collection are needed to confirm these findings.


Assuntos
Diarreia/veterinária , Macaca mulatta , Infecções por Rotavirus/veterinária , Criação de Animais Domésticos , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/análise , California , Estudos de Casos e Controles , Estudos Transversais , Diarreia/virologia , Fezes/virologia , Feminino , Masculino , Doenças dos Macacos/virologia , Rotavirus/isolamento & purificação , Infecções por Rotavirus/virologia
20.
Transbound Emerg Dis ; 66(1): 119-130, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30103259

RESUMO

Porcine enteric alphacoronavirus (PEAV) was first discovered in China in February 2017, and the origin and virulence of this novel porcine coronavirus were not fully characterized. Here, we isolated a strain of PEAV, named GDS04 that is identified by immunofluorescence and typical crown-shaped particles observed with electron microscopy. Genomic analysis reveals that PEAV GDS04 shares a close relationship with SADS-CoV and SeACoV. Furthermore, newborn piglets orally challenged with PEAV GDS04 developed typical clinical symptoms as watery diarrhoea in neonatal piglets. Viral RNA was detected in faeces and various tissues of the infected piglets. Moreover, macroscopic and microscopic lesions in whole intestinal tract were observed, and viral antigen could be detected in the small intestines by immunohistochemical staining and electron microscopy. Importantly, the mortality rate of inoculated-newborn piglets was 100% and half of the cohabiting piglets died. Collectively, we demonstrate that PEAV is highly pathogenic in newborn piglets.


Assuntos
Alphacoronavirus/fisiologia , Infecções por Coronavirus/veterinária , Diarreia/veterinária , Doenças dos Suínos/mortalidade , Doenças dos Suínos/virologia , Alphacoronavirus/isolamento & purificação , Animais , Antígenos Virais/análise , China , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/virologia , Diarreia/virologia , Fezes/virologia , Intestinos/patologia , RNA Viral/análise , Suínos
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