Serological response of guinea pigs to oily and aqueous inactivated vaccines containing a Brazilian isolate of the Bovine Viral Diarrhea Virus (BVDV)

Bovine Viral Diarrhea Virus (BVDV) is widespread in cattle in Brazil and research shows its large antigenic variability. Available vaccines are produced with virus strains isolated in other countries and may not be effective. In this study, inactivated vaccines containing the Brazilian BVDV-Ib IBSP11 isolate were developed and tested on 6 groups of 10 guinea pigs (Cavia porcellus). Animals in groups A and C received an aqueous vaccine (aluminum hydroxide); B and D groups received an oily vaccine (Montanide ISA50); Group E positive-control animals were given an imported commercial vaccine with BVDV-la Singer; Group F animals were sham vaccinated (negative control). Groups A, B and E received two doses, and Groups C and D, three, every 21 days. Twelve blood samples were taken, at 21-day intervals over 231 days, and evaluated for antibody titer through virus-neutralization (VN), using a homologous strain (IBSP11), and a heterologous strain (BVDV-la NADL). Most animals, 42 days following the first dose, seroconverted to both strains and, after the second dose, there was a significant increase of titers in all groups. The oily formulation induced greater response after the third administration. This increase was not observed with the aqueous vaccines, regardless of the virus used in the VN. Antibody decline was more rapid in animals that received aqueous vaccines. The results showed the importance of studying the influence of endemic strains of commercial vaccines, to improve the efficacy of BVD vaccination. Use of the endemic strain in vaccine formulation presented promising results, as well as the use of guinea pigs as a laboratory model. (C) 2011 Elsevier Ltd. All rights reserved.

Sequence and Structural Analysis of the 5 ` Noncoding Region of Hepatitis C Virus in Patients With Chronic Infection

Hepatitis C virus (HCV), exhibits considerable genetic diversity, but presents a relatively well conserved 5 ` noncoding region (5 ` NCR) among all genotypes. In this study, the structural features and translational efficiency of the HCV 5 ` NCR sequences were analyzed using the programs RNAfold, RNAshapes and RNApdist and with a bicistronic dual luciferase expression system, respectively. RNA structure prediction software indicated that base substitutions will alter potentially the 5 ` NCR structure. The heterogeneous sequence observed on 5 ` NCR led to important changes in their translation efficiency in different cell culture lines. Interactions of the viral RNA with cellular transacting factors may vary according to the cell type and viral genome polymorphisms that may result in the translational efficiency observed. J. Med. Virol. 81: 1212-1219, 2009. (C) 2009 Wiley-Liss, Inc.

Household survey of hepatitis B vaccine coverage among Brazilian children

We conducted a multi-stage household cluster survey to calculate hepatitis B vaccine coverage among children 18-30 months of age in 27 Brazilian cities. Hepatitis B vaccine is administered at birth, 1 month and 6 months of age by Brazil`s national immunization program. Among 17,749 children surveyed, 40.2% received a birth dose within one day of birth, 94.8% received at least one dose of hepatitis B vaccine, and 86.7% completed the three-dose series by 12 months of age. Increased coverage with the birth dose and administration of hepatitis B in combination with diphtheria-tetanus-pertussis-Haemophilus influenzae type b antigens could improve protection against hepatitis B. (C) 2009 Elsevier Ltd. All rights reserved.

Influence of hepatitis G virus (GB virus C) on the prognosis of HIV-infected women

This study was undertaken to evaluate the prevalence of GB virus C (GBV-C) viraemia and anti-E2 antibody, and to assess the effect of co-infection with GBV-C and HIV during a 10-year follow-up of a cohort of 248 HIV-infected women. Laboratory variables (mean and median CD4 counts, and HIV and GBV-C viral loads) and clinical parameters were investigated. At baseline, 115 women had past exposure to GBV-C: 57 (23%) were GBV-C RNA positive and 58 (23%) were anti-E2 positive. There was no statistical difference between the groups (GBV-C RNA + /anti-E2 -, GBV-C RNA - /anti-E2 + and GBV-C RNA - /anti-E2 -) regarding baseline CD4 counts or HIV viral loads (P = 0.360 and 0.713, respectively). Relative risk of death for the GBV-C RNA + /anti-E2 - group was 63% lower than that for the GBV-C RNA - /anti-E2 - group. Multivariate analysis demonstrated that only HIV loads >= 100,000 copies/mL and AIDS-defining illness during follow-up were associated with shorter survival after AIDS development. It is likely that antiretroviral therapy (ART) use in our cohort blurred a putative protective effect related to the presence of GBV-C RNA.

Prevalence of hepatitis B and C serological markers among first-time blood donors in Brazil: A multi-center serosurvey

Little data are available on the seroprevalence of, and risk factors for hepatitis B and C viruses (HBV and HCV) infection in Latin American countries. A multi-center serosurvey was conducted among 3,598 first-time blood donors (65% men) from Sao Paulo, Salvador and Manaus in Brazil. The gender-specific seroprevalences of antibodies against hepatitis B core antigen (anti-HBc) and of the hepatitis B surface antigen (HBsAg) in anti-HBc-positive sera were measured, and risk factors analyzed by gender. The gender-specific seroprevalences of antibodies against HCV (anti-HCV) were measured, but risk factors for HCV were not determined. Anti-HBc and HBsAg seroprevalences were not significantly different in men [101/2,341 (4.31%) and 4/2,229 (0.18%), respectively] and women [65/1,237 (5.25%) and 8/ 1,169 (0.68%), respectively], whereas the seroprevalence of anti-HCV was higher in women (12/1,238 [0.97%] vs. 9/2,353 [0.38%]; odds ratio [OR] = 2.49; 95% confidence interval [Cl]: 1.0-6.0). No significant difference for HBV infection was found across the three study sites or by ethnic group. The seroprevalence of anti-HBc increased with age, but decreased with education level in both genders. Lifetime number of sexual partners was associated with anti-HBc prevalence among men (OR = 1.95; 95% Cl: 1.2-3.1), but not women. The seroprevalence of HBV and HCV was low among Brazilian blood donors, and exposure increased with age in both genders.