Las infecciones virales son la principal causa de infecciones respiratorias agudas, en la mayoría de los casos requieren tratamiento con medidas generales. Objetivo: realizar una Intervención educativa con madres para el control de las infecciones virales leves en el hogar. Metodología: Investigación cualitativa tipo Investigación acción con madres, de noviembre del 2008 a marzo del 2009. El estudio tuvo una fase diagnóstica de brechas en el manejo de las infecciones virales a través de un estudio etnográfico, etnológico y de observación actitudinal. Una fase de intervención con uso de metodología participativa y una fase de evaluación. Resultados: En la observación actitudinal las madres presentaron características con predominio de ansiedad. En el estudio etnológico desconocimiento de los virus como agentes causales; consideran que los resfriados se tratan con antibióticos; prevalecen pensamientos de no saber qué hacer y desesperación. En el estudio etnográfico predominaron las viviendas en asentamientos humanos, a más de 30 minutos de distancia del Policlínico, con áreas colindantes de tierra, construcción de madera, sin servicios intradomiciliarios de agua y desagüe. Constitución familiar predominante de tipo nuclear. Lograron conocer las infecciones virales, su manejo sintomático en el hogar; cambio de actitud al referir “sentirse más tranquilas, “a seguir paso a paso” y “a saber que pueden aplicar lo aprendido”. Conclusión: Una intervención educativa con metodología participativa considerando aspectos conceptuales, procedimentales y actitudinales logra que las madres controlen las infecciones virales no complicadas en el hogar confiando en sus capacidades desarrolladas. / --- Viral infections are the main cause of acute respiratory infections; in the majority of cases they only require general measurements for treatment. Objective: make on an educational intervention with mothers in order to control the mild viral infections at home. Methods: Qualitative research, actions with mothers from November 2008 to March 2009 The study had a diagnostic phase of breaches in the management of viral infections through an ethnographic study, ethnological and observation of attitudes. One phase of intervention using participation methodology and a phase of evaluation. Results: They presented in the observation characteristics with predominance of anxiety. In the ethnological study, lack of knowledge of the virus as a causal agent; they believe that cold symptoms are treated with antibiotics; it is prevalent in their minds not to know what to do and despair. In the ethnographic study, there was predominance of housing in human settlements, located more than 30 minutes from the policlinics, surrounded by land, wood constructions’, without water and drainage system. The main family type was the nuclear type. They learned about viral infections, the symptomatic management at home; change of attitude while saying “they feel calmer”, “to follow step by step and “to know they can apply what they learned. Conclusion: An educational intervention applying a participation methodology, considering concepts, procedures and changes in attitude get the mothers management at home viral infections not complicate trusting its developed capacities. / Tesis de segunda especialidad

Kenya has experienced severe arboviral outbreaks of public health concern in the recent past, including yellow fever (YF), Crimean Congo hemorrhagic fever (CCHF), chikungunya, and Rift Valley fever (RVF) among others. Most of these infections are under diagnosed and hence neglected due to non-specific nature of their symptoms. Often they are mistaken for endemic tropical diseases such as malaria and typhoid infections and are only recognized during major outbreaks which result in adverse public health and economic consequences to the affected communities. Ongoing inter-epidemic surveillance in RVF virus hotspots in Kenya has indicated continued intense transmission of Bunyamwera virus (BUNV) in the absence or under low level activity of RVF virus. BUNV belongs to the genus Orthobunyavirus of the family Bunyaviridae. These are segmented RNA viruses whose members have the potential for genetic reassotment and/or drift. Recently, Ngari virus (NRIV), a natural reassortant virus associated with hemorrhagic fever was documented to have emerged from BUNV, which previously was not associated with such symptoms. However, the vectors that are involved in the maintenance and transmission of BUNV and NRIV are diverse and their role in virus maintenance/dynamics is poorly known. It is thus important to investigate the dynamics of BUNV and NRIV in selected transmission foci in an effort to understand their circulation better in order to be able to control and predict outbreaks. In this study, we determined the evolutionary and phenotypic diversity of BUNV and NRIV isolates previously obtained from vectors in parts of Kenya. We have provided genetic sequences of two BUNV and three NRIV isolates which contribute to addressing paucity of genetic sequences associated with this group of viruses. Phylogenetic analysis of these sequences in addition to other sequences in GenBank revealed evidence of geographic/temporal clustering that requires further investigation. Next, we demonstrated that plaque purified phenotypes of selected BUNV and NRIV isolates differ in in vivo growth kinetics and pathogenicity in mice, possibly related to specific mutations within the genome. The phenotypic changes and identification of mutations possibly associated with these changes support further investigation of specific mutations using site directed mutagenesis. In addition, we determined the competence of some of the mosquito species implicated in their transmission, Anopheles gambiae, Aedes aegypti and Culex quinquefaciatus and evaluated the dynamics of their transmission in these vectors. We conclude that Anopheles gambiae is likely a more competent vector for NRIV than Aedes aegypti and is a moderately competent vector for BUNV, which has implications for animal movement in malaria endemic areas where the vector is present. We also report evidence of BUNV transovarial transmission in both Aedes aegypti and Anopheles gambiae with the prevalence of transmission related to the ovarian cycle. Finally, we determined the level of human exposure to these viruses in the transmission foci. Orthobunyavirus-specific antibodies were detected by plaque reduction neutralization test in 89 (25.8%) of 345 persons tested. Multivariable analysis revealed age and residence in North Eastern Kenya as risk factors. In conclusion, we propose that acute febrile disease surveillance needs to be implemented in North Eastern Kenya. This study helps identify the virus strains/populations and the vector species that play a critical role in sustenance and transmission of BUNV and NRIV in different ecosystems in the country. All these are important in understanding virus circulation, potential for emergence and risk to populations in areas of circulation, and will help in making decisions for intervention and management. Generated sequence data in this study contributes to global phylogenetic characterization of Orthobunyaviruses worldwide and their molecular epidemiology. The study also shed light/improve our knowledge on the genetic stability or diversity and evolutionary trends of Orthobunyavirus strains in Kenya. / Thesis (PhD)--University of Pretoria, 2015. / Medical Virology / PhD / Unrestricted

No description available.

Background: Unlike other non-hepatitis c viral infection, hepatitis c viral infection is a non-vaccine preventable disease. Thus, effective treatment is an important part in the prevention of complication of chronic hepatitis c infection. The viral genotype plays a significant role in the choice of treatment regimen. Aim: the purpose of this study is to estimate the prevalence of hepatitis c viral infection and the distribution of viral genotype in the US population. Methods: Diagnosis of Hepatitis C viral infection was made by assaying the blood specimen collected from the study participants using Ampiclor monitor (Roche Diagnostic System, Inc Branchburg NJ), and genotype determined from the NS5b region. The data is from NHANSE 2006-2016. SAS v 9.4 software was used to perform the analysis. Results: Of the 356 participants (2006-2016) who tested positive to Hepatitis C virus-RNA, 205 persons had genotype 1a, 1b (n=66), other forms of genotype 1 (n=1), genotype 2(n=41), genotype 3 (n=30), genotype 4 (n=1), genotype 6(n=1), undetermined genotype (n=8). Based on weighted analysis of person infected with genotype 1, 2, 3; genotype 1 was highest across all ages and gender (78.2%). Of 271 participants infected with genotype 1, there were 5.09% Mexican Americans, 3.94% other Hispanics, 56.58% non-Hispanic whites, 28.74% non-Hispanic black, and 5.65% other races including multiracial population. Subjects aged 50 years or above was 27.7% less likely being infected with HCV genotype 1 vs 2 and 3, compared with younger individuals (adjusted Odds Ratio (95% confidence interval) (aOR): 0.72 (0.72-0.73)). Non-Hispanic black were about 13 times (aOR: 13.1 (13.0-13.2)) as likely to be infected with genotype 1 vs 2 and 3 as non-Hispanic white. Conclusion: Hepatitis C virus genotype 1 is predominant among those infected with hepatitis c virus in the US population. Improvement in therapy targeting genotype 1 is essential to reduce the burden and complication of chronic hepatitis C in the United States.

OBJECTIVE: The overarching goal of this study was to examine the immunostimulatory potential of oHSV-1 rQNestin34.5v2 in syngeneic murine GBM models, perform in vitro screens for upregulation of immune checkpoint molecules in infected glioma cells, and evaluate the antitumor activity of the most promising combination immunovirotherapies. METHODS: The oncolytic activity of HSV-1 rQNestin34.5 was evaluated in CT-2A and GL261 syngeneic murine glioma models. Immunoassays were conducted to assess secretion of damage associated molecular patterns including ATP, HMGB1, Calreticulin, HSP70 and other proinflammatory mediators by infected glioma cells. In vitro screens for expression of inhibitory ligands by glioma cells following HSV-1 rQNestin34.5v2 infection at various doses were analyzed by flow cytometry. Intratumoral HSV-1 rQNestin34.5v2 administration and/or intraperitoneal anti-TIGIT (clone 1B4)/anti-NK1.1 treatments were performed in C57BL/6 mice bearing orthotopic CT-2A glioma to determine effect on overall survival. RESULTS: HSV-1 rQNestin34.5v2 exhibited greater capacity to infect CT-2A and minimal capacity to infect GL261 cells suggesting differences in permissiveness in HSV- 1 replication between the two GBM models. Infection stimulated immunogenic cell death as evidenced by surface expression of calreticulin and HSP70 and elevated extracellular release of ATP and HMGB1 in the GL261 model. CD155 and CD112 (both ligands of TIGIT) as well as PD-L1 were significantly highly expressed in glioma cells. TIGIT was found to be overexpressed in tumor infiltrating NK, CD4 and CD8 T cells suggesting systemic therapy with TIGIT blockade antibodies could have therapeutic utility in combination with HSV-1 rQNestin34.5v2 in GBM. Benefit in overall survival was not observed by anti-TIGIT monotherapy, and combination treatment with HSV-1 rQNestin34.5v2 exhibited modest therapeutic effect with a cure rate 25% in mice bearing intracranial CT-2A tumors. Depletion of NK cells prior to HSV-1 rQNestin34.5v2 administration attenuated brain edema and synergized with rQNestin34.5v2 virotherapy. CONCLUSION: Our findings show that the combination of HSV-1 rQNestin34.5v2 virotherapy with anti-TIGIT checkpoint blockade immunotherapy and/or NK cell inhibition represents a promising strategy to overcome primary resistance to immune checkpoint inhibitors in GBM. / 2025-02-03T00:00:00Z

Dengue virus (DENV) is the causative agent of a mosquito-transmitted disease mainly in tropical regions of the earth. Dengue is commonly diagnosed using polymerase chain reaction (PCR) or enzyme-linked immunosorbent assay (ELISA); however, these diagnostic methods both require complicated blood sample preparation, highly trained personnel, and centralized laboratory facilities, all of which are difficult to realize in many clinical settings where resources are limited. In the current study, a novel ultra-sensitive dendrimer-aptamer-based lateral flow assay (LFA) is designed to detect the presence of the DENV by detecting the envelope protein (E-Protein) of the DENV in phosphate-buffered saline (PBS) buffer and bovine serum albumin (BSA) sample. To achieve this, a “bioink”, a muti-handled streptavidin-dendrimer-aptamer conjugation is used to construct the modified test line in order to enhance the capturing efficiency of the signaling gold nanoparticle complexes on the test line. This work is the first time reported aptamer-based LFA of dengue virus detection. Our results show that the new LFA has a limit of detection of 24 pg/mL when tested using samples in PBS buffer (27 pg/mL in BSA solution), which is more sensitive that of a parallel ELISA test of 32 pg/mL and about ten-fold more sensitive than a conventional aptamer-based LFA. In addition, the new LFA shows that no non-specific binding with other E-protein in the flavivirus family and exhibits a long shelf-time for more than five weeks when stored in ambient conditions under subdued light. It can be concluded that the use of “bioink” -- a streptavidin-dendrimer-aptamer -- complex on the T-line can significantly enhance the detection sensitivity of the LFA assay. As a result, it is perceivable that the intrinsic portable, rapid, user-friendly, and cost-effective natures of LFAs in combination with the enhanced sensitivity due to the special fishnet-liked design will find broader applications for the LFAs as an effective and sufficiently sensitive diagnostic tool in many resources limited clinical settings.

The field of immuno-oncology has made tremendous advances in the treatment of cancer. Adoptive cellular transfer (ACT) of tumor-specific T cells and oncolytic viruses (OVs) are powerful anti-tumor agents, but each modality faces significant challenges. Despite the promise of ACT against hematological malignancies, success has been limited in solid tumors. OVs preferentially lyse tumor cells, but have difficulty overcoming antiviral host factors when delivered systemically – therapeutic doses must therefore be quite high to achieve tumor delivery. One means of overcoming viral neutralization is by loading OV onto cellular carriers prior to treatment. Since engineered T cells and OVs both possess anticancer activity, and since viruses naturally associate with nearby circulating immune cells, employing T cells engineered with a T cell antigen coupler (TAC) receptor as viral carriers may offer an ideal combination. Our studies indicated that loading oncolytic maraba virus (MRB) onto T cells – engineered with a TAC receptor targeting HER2 – had no impact on the functionality or receptor expression of these T cells. OV loaded on the surface of these TAC-T cells enabled killing of a variety of tumor targets that may be otherwise resistant to TAC-T cell therapy. Efficacy remains to be elucidated in vivo using xenograft murine models due to the lack of a protective antiviral immune response, which ultimately resulted in encephalopathy. These observed toxicities were likely model-specific, as MRB has shown to be highly attenuated in healthy tissues of wild type models. While conceptually attractive, using TAC-T cells as viral carriers to deliver a multi-pronged, one-pot antitumor therapy directly to the site of the tumor requires further evaluation before considering human studies. / Thesis / Master of Science (MSc)

Many oncolytic virotherapies have shown great advantages for rapid, rational design through recombinant DNA technology to facilitate the targeting of a broad spectrum of malignancies. Newcastle disease virus (NDV), an avian paramyxovirus, is naturally tumor-selective and inherently oncolytic. Our approach is to develop NDV-based nanoparticles (VBNP) for oncolytic virotherapy. VBNPs are non-infectious and non-replicating and are relatively safe. We obtained VBNPs by co-expressing matrix (M), hemagglutinin (HN), and fusion (F) proteins of NDV in avian/ mammalian cells. The budding characteristics, size and morphology of VBNPs were similar to authentic virions. As a proof of concept, we engineered the apoptin (VP3) gene of chicken anemia virus in VBNPs and specifically targeted them to folate-receptor bearing tumor cells by surface conjugation to folate. The VBNPs killed tumor cells by apoptosis and induced proinflammatory and chemotactic cytokines. The VBNPs, although not curative, were able to limit the progression of xenotransplanted fibrosarcoma and malignant glioma tumors and provided a survival advantage in nude mice. We also engineered NDV M based particles with nipah virus surface glycorporteins to target ephrin B receptors. NDV based nipah Virus BNPs (NiV-ndBNP) were morphologically similar to authentic NiV virions. NiV glycoproteins were incorporated into the NDV M based particles, despite poor sequence homology in the transmembrane domain and cytoplasmic tails of glycoproteins. Our results suggest that VBNPs could be used to deliver small molecules, tumor antigens, anti-tumor/ reporter genes and also aid in generating tumor specific immunity by rational design. / Master of Science

España es el principal productor de frutales de hueso y cítricos de la Unión Europea. Las enfermedades virales más importantes asociadas a estos cultivos son la sharka en frutales de hueso, causada por Plum pox virus (PPV; Potyvirus), y la tristeza de los cítricos, causada por Citrus tristeza virus (CTV; Closterovirus), ambas transmitidas mediante pulgones de forma no persistente y de forma semipersistente, respectivamente. Actualmente existe un amplio conocimiento de la epidemiología de ambas virosis en árboles adultos, sin embargo no existen estudios sobre la epidemiología de ambas enfermedades en bloques viveros. Además, las características especiales de éstos como un marco de plantación más reducido hace que el control de la dispersión de la enfermedad sea más complicado. En este contexto se desarrolla esta Tesis Doctoral, cuyo objetivo principal es el estudio de los distintos factores que determinan la epidemiología de PPV en frutales de hueso y CTV en cítricos en condiciones de vivero con el fin de establecer posibles estrategias de control. Además, considerando que toda estrategia de control requiere en algún momento de la aplicación de métodos de detección específicos, sensibles y fiables, capaces de detectar bajas cantidades del patógeno, se ha realizado la validación de métodos serológicos y moleculares para una precoz y precisa detección viral de plantas infectadas en vivero antes de la comercialización del material vegetal. Para ello se establecieron tres parcelas experimentales de vivero durante el año 2006 en diferentes localidades de la provincia de Valencia. En las distintas parcelas experimentales se llevó a cabo el estudio de la susceptibilidad a la infección viral natural de los distintos patrones estudiados y la evaluación del efecto de los tratamientos con aceites minerales sobre la incidencia viral en el cultivo. Los patrones más susceptibles a la infección natural por PPV fueron Adesoto 101 y Mariana GF8-1. Los patrones Nemaguard y Mirobola 29C presentaron una susceptibilidad media, mientras los patrones Cadaman y Garnem resultaron resistentes a PPV-D detectándose únicamente el virus mediante RT-PCR a tiempo real. Sólo los patrones Adesoto 101, Mariana GF8-1 y Nemaguard, resultaron infectados en la parcela sometida a baja presión de inóculo. Además, se confirmó la alta susceptibilidad a la infección natural a CTV del patrón C. macrophylla. / Vidal Izquierdo, E. (2010). Epidemiología de Plum pox virus y Citrus tristeza virus en bloques de plantas de vivero. Métodos de control [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/9314

Le Virus de la Mosaïque de la Papaye (PapMV) est un virus filamenteux flexible. Sa protéine structurale, la capside (CP), est composée de 215 acides aminés. Le but du projet est de déterminer les domaines de la CP du PapMV impliqués dans l'assemblage viral. En utilisant un système d'auto-assemblage dans E. coli, nous avons confirmé que l'extrémité C-terminale de la CP est exposée à la surface des pseudo nucléocapsides virales (PNVs) et que la partie N-terminale est impliquée dans la multimérisation de la protéine. De plus, nous avons identifié les acides aminés importants dans l'interaction avec l'ARN. Les résidus cystéine de la CP sont importants à la stabilité de la protéine et à sa capacité à former des PNVs. La mutation de la Glu128 en alanine a permis d'augmenter l'efficacité de l'auto-assemblage en PNVs. Il s'agit d'un travail original et unique chez les virus filamenteux du genre potexvirus.