110 resultados para Inativação Viral


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INTRODUCTION: Little information regarding hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among Brazilian female prisoners exists. This study investigated the prevalence and risk factors associated with HBV and HCV infections and identified viral genotypes among female prisoners in Goiás, Central Brazil. METHODS: Women incarcerated in the largest prison in the State of Goiás were invited to participate in the study. All female prisoners were interviewed and tested for the detection of hepatitis B surface antigen (HBsAg), antibodies against HBsAg (anti-HBs), against hepatitis B core antigen (anti-HBc), and antibody against HCV (anti-HCV) by ELISA. HBsAg and anti-HCV positive samples were tested for HBV DNA and HCV RNA and genotyped, respectively. RESULTS: Participants (n=148; 98.6%) completed the study with an overall HBV prevalence of 18.9%. Age >30 years, a low education level, sex with a sexually transmitted diseases carrier, and a male sexual partner serving in the same penitentiary were associated with HBV infections. Only 24% of the women were anti-HBs positive suggesting previous HBV vaccination. Nine female prisoners (6.1%) were anti-HCV positive. Age >40 years, injecting drug use and length of incarceration were statistically associated with anti-HCV antibodies. Five samples were HCV RNA positive and classified as genotypes 1 (subtypes 1a; n=3 and 1b; n=1) and 3 (subtype 3a; n=1). The HBsAg-reactive sample was HBV DNA positive and genotype A. CONCLUSIONS: These findings highlight the necessity of public policies to control hepatitis B and C infections and emphasize the importance of hepatitis B vaccination in prison environments.

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Introduction Despite the great advances in serological testing for transfusion-transmitted infections, the selection of blood donors by blood bank operators remains the only way to avoid transmission within the testing window period. Part of this selection is the self-exclusion form, on which the donors can exclude their blood from donation without any explanation. This study assessed the clinical and epidemiological characteristics related to positivity for viral hepatitis and to the use of the confidential self-exclusion (CSE) form. Methods This transversal study analyzed the data collected from blood donors' files in a hospital in Southern Brazil. Univariate and multivariate analyses identified the clinical and epidemiological variables related to positive serologies of viral hepatitis and to whether the donor was self-excluded. Results Of the 3,180 donors included in this study, 0.1% tested positive for HBsAg, 2.1% for anti-HBc, and 0.9% for anti-HCV. When the 93 donors with positive serologies for viral hepatitis were compared with those who were negative, a greater proportion of the positive serology group was found to have had a history of blood transfusions (OR=4.908; 95%CI=1.628 - 14.799; p<0.01), had repeatedly donated (OR=2.147; 95%CI=1.236 - 3.729; p<0.01), and used the CSE form for self-exclusion (OR=7.139; 95%CI=2.045 - 24.923; p<0.01). No variables were independently associated with self-exclusion. Conclusions A history of blood transfusion, repeated donations, and self-exclusion are factors that should be considered during viral hepatitis screenings in blood banks.

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Introduction: The genomic heterogeneity of hepatitis C virus (HCV) influences liver disorders. This study aimed to determine the prevalence of HCV genotypes and to investigate the influence of these genotypes on disease progression. Methods: Blood samples and liver biopsies were collected from HCV-seropositive patients for serological analysis, biochemical marker measurements, HCV genotyping and histopathological evaluation. Results: Hepatitis C virus-ribonucleic acid (HCV-RNA) was detected in 107 patients (90.6% with genotype 1 and 9.4% with genotype 3). Patients infected with genotype 1 exhibited higher mean necroinflammatory activity and fibrosis. Conclusions: HCV genotype 1 was the most prevalent and was associated with greater liver dysfunction.

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Introduction This study reports the pediatric epidemiology of respiratory syncytial virus (RSV), influenza (IF), parainfluenza (PIV), and adenovirus (ADV) at Hospital de Clínicas de Porto Alegre. Methods Cases of infection, hospitalizations in intensive care units (ICUs), nosocomial infections, and lethality rates were collected from 2007 to 2010. Results RSV accounted for most nosocomial infections. Intensive care units admission rates for ADV and RSV infections were highest in 2007 and 2010. During 2008-2009, H1N1 and ADV had the highest ICU admission rates. ADV had the highest fatality rate during 2007-2009. Conclusions Each virus exhibited distinct behavior, causing hospitalization, outbreaks, or lethality.

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ABSTRACTINTRODUCTION:Since women are frequently the minority among blood donors worldwide, studies evaluating this population usually reflect male features. We assessed the features of female blood donors with positive serology for HBV and compared them with those of men.METHODS The study comprised consecutive blood donors referred to a specialized liver disease center to be evaluated due to HBsAg- and/or anti-HBc-positive tests.RESULTS: The study encompassed 1,273 individuals, 219 (17.2%) of whom were referred due to positive HBsAg test and 1,054 (82.8%) due to reactive anti-HBc test. Subjects' mean age was 36.8±10.9 years, and 28.7% were women. Female blood donors referred for positive HBsAg screening tests demonstrated higher prevalence of healthcare workers (9.3% vs 2.5%) and lower prevalence of sexual risk behaviors (15.1% vs 41.1%) and alcohol abuse (1.9% vs 19.8%) compared to men. Women had lower ALT (0.6 vs 0.8×ULN), AST (0.6 vs 0.8×ULN), direct bilirubin (0.2 vs 0.3mg/dL), and alkaline phosphatase (0.5 vs 0.6×ULN) levels and higher platelet count (223,380±50,293 vs 195,020±53,060/mm3). Women also had a higher prevalence of false-positive results (29.6% vs 17.0%). No differences were observed with respect to liver biopsies. Female blood donors referenced for reactive anti-HBc screening tests presented similar clinical, epidemiological, and biochemical characteristics to those reported for positive HBsAg screening tests and similarly had a higher prevalence of false-reactive results.CONCLUSIONS: Compared to men, female blood donors with positive HBsAg and/or anti-HBc screening tests demonstrated higher prevalence of professional risk and false-positive results and reduced alteration of liver chemistry.

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Quantitative method of viral pollution determination for large volume of water using ferric hydroxide gel impregnated on the surface of glassfibre cartridge filter. The use of ferric hydroxide gel, impregnated on the surface of glassfibre cartridge filter enable us to recover 62.5% of virus (Poliomylitis type I, Lsc strain) exsogeneously added to 400 liters of tap-water. The virus concentrator system consists of four cartridge filters, in which the three first one are clarifiers, where the contaminants are removed physically, without significant virus loss at this stage. The last cartridge filter is impregnated with ferric hydroxide gel, where the virus is adsorbed. After the required volume of water has been processed, the last filter is removed from the system and the viruses are recovered from the gel, using 1 liter of glycine/NaOH buffer, at pH 11. Immediately the eluate is clarified through series of cellulose acetate membranes mounted in a 142mm Millipore filter. For the second step of virus concentration, HC1 1N is added slowly to the eluate to achieve pH 3.5-4. MgC1, is added to give a final concentration of 0.05M and the viruses are readsorbed on a 0.45 , porosity (HA) cellulose acetate membrane, mounted in a 90 mm Millipore filter. The viruses are recovered using the same eluent plus 10% of fetal calf serum, to a final volume of 3 ml. In this way, it was possible to concentrate virus from 400 liters of tap-water, into 1 liter in the first stage of virus concentration and just to 3 ml of final volume in a second step. The efficiency, simplicity and low operational cost, provded by the method, make it feasible to study viral pollution of recreational and tap-water sources.

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Toddia França, 1912 under the light microscope occurs as inclusion corpuscles in the cytoplasm of erythrocytes of cold-blooded vertebrates sometimes accompanied by crystalloid bodies. Its position among the protozoans or the viruses has been discussed by some authors, but remained unclear. To elucidate this problem we studied Toddia from a Brazilian frog (Leptodactylus ocellatus) by electron microscopy. In the cytoplasm of the infected cells we found no protozoan, but rather virus-like particles often hexagonal in outline, averaging 195 nm excluding their two involving membranes, and presenting a central area of variable electron density. Particles at different stages of development were generally found around or on area lighter density than the cytoplasm. which resembled a virus synthesis site. At high magnification, the nuclear or cytoplasmic crystals allied to Toddia resembled the crystalline lattice of the inclusion bodies associated with the polyhedrosis viruses and poxviruses from insects, of the capsules of granulosis viruses and of other protein crystals in ultrathin sections. Cytochemical tests in Toddia corpuscles displayed exclusively the presence of deoxyribonucleic acid. These findings indicate that Toddia is not a protozoan and demonstrate that it is in all probability a viral inclusion corpuscle. Taking into account the nucleic acid type found in its structure (DNA) and the hexagonal shape usually shown in ultrathin sections by its component particles, which have a cytoplasmic site of synthesis and assembly, we tentatively relate Toddia with the so-called "Icosahedral Cytoplasmic Deoxyriboviruses". We believe that the present paper gives the first report of virus-like particles in L. ocellatus.

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O aquecimento de soros chagásicos a 56 grausC por 30 minutos, não só inativa o complemento, como altera a mobilidade iônica das proteínas séricas. Com a inativação, os títulos dos soros por fixação de complemento decrescem sendo a queda do poder fixador relacionada com a diminuição da avidez do complexo-imune, formado com o antígeno de Trypanosoma cruzi para o complemento. Não se observaram diferenças na reatividade específica dos soros chagásicos, antes e depois de inativados, quando os títulos foram determinados por técnicas que não envolvem o complemento, tais como a imunofluorescência e a hemaglutinação.

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The presence of viral antigen in sections from formalin-fixed and paraffin-embedded human tissues was demonstrated by trypsin digestion followed by direct or indirect immunofluorescence. The specimens may be used for retrospective diagnosis. The immunofluorescence technique has to be adapted to the suspected virus infection on the basis of previous histopathology study. Variations of trypsin concentration time and temperature of incubation, expose different viral antigens and have to be previously tested for each unknown system. For measles virus detection in lung a stronger digestion has to be applied as compared to adenovirus or respiratory disease viruses in the same tisue. Flavivirus in liver tissue needs a weaker digestion. The reproducibility of the method makes it useful as a routine technique in diagnosis of virus infection.

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In this study, HIV-1 viral load quantitation determined by Nucleic Acid Sequence Based Amplification (NASBA) was compared with other surrogate disease progression markers (antigen p24, CD4/CD8 cell counts and b-2 microglobulin) in 540 patients followed up at São Paulo, SP, Brazil. HIV-1 RNA detection was statistically associated with the presence of antigen p24, but the viral RNA was also detected in 68% of the antigen p24 negative samples, confirming that NASBA is much more sensitive than the determination of antigen p24. Regarding other surrogate markers, no statistically significant association with the detection of viral RNA was found. The reproducibility of this viral load assay was assessed by 14 runs of the same sample, using different reagents batches. Viral load values in this sample ranged from 5.83 to 6.27 log (CV = 36 %), less than the range (0.5 log) established to the determination of significant viral load changes.

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In order to investigate purin and primidin metabolism pathways in hepatitis, adenosine deaminase (ADA) and guanosine deaminase (GDA) activities in sera of patients with different types and manifestations of viral hepatitis disease (A, B, C, D, E, chronic, acute) were investigated and compared with the control group of healthy individuals. Hepatitis cases were classified with respect to their serological findings and clinics. When compared all the hepatitis cases with the controls, levels of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase enzymes, as well as ADA and GDA, were significantly higher than the control group (p<0.01). Levels of ADA and GDA in hepatitis cases were determined as 26.07±11.98 IU/l and 2.37±1.91 IU/l, respectively. When compared their ADA and GDA levels amongst the classified hepatitis groups, there was no difference in ADA levels amongst cases (p>0.05). However, GDA levels in hepatitis A group were closed to the controls. Increase in serum ADA activities in hepatitis forms may be dependent on and reflect the increase in phagocytic activity of macrophages and maturation of T-lymphocytes, and may be valuable in monitoring in viral hepatitis cases.

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Presently, the State of Ceará reports the largest percentage of human rabies cases originated from wild animals in Brazil, transmitted by the principal simian species, the tamarin (Callithrix jacchus), found in various locations throughout the State, but concentrated along the coast. Epidemiological studies indicated that possibly the same virus caused the deaths in humans and non-human primates. This rabies virus seem to be different from all other identified so far.