Prevalence of hepatitis B and C markers in a population of an urban university in Rio de Janeiro, Brazil: a cross-sectional study.

BACKGROUND AND RATIONALE: Epidemics of hepatitis B and C are a public health burden, and their prevalence in Brazil varies among regions. We determined the prevalence of hepatitis markers in an urban university population in order to support the development of a comprehensive program for HBV immunization and HBV/HCV diagnosis. Students, employees, and visitors (n = 2,936, 31 years IQR 24.5-50, female = 69.0% and 81.1% with at least 12 years of education) were enrolled from May to November 2013. Antibodies against hepatitis B surface antigen (anti-HBs), against hepatitis B core antigen (anti-HBc), and hepatitis B surface antigen (HBsAg) were detected with enzyme immunoassays and anti-hepatitis C virus (anti-HCV) antibodies with a chemiluminescence immunoassay. The results were confirmed with polymerase chain reaction for HCV and nucleic acid amplification test for hepatitis B virus (HBV). RESULTS: The overall prevalence of markers among the participants was 0.136% (95% confidence interval [CI]: 0.003-0.270) for HBsAg, 6.44% (95% CI: 5.55-7.33%) for anti-HBc, 50.8% (95% CI: 48.9-52.7%) for anti-HBs > 10 mIU/mL, and 0.44% (95% CI: 0.20-0.68) for anti-HCV. Almost 30.4% had anti-HBs titers > 100 mIU/mL. Participants with a detectable HCV viral load (n = 9) were infected with genotype 1a. CONCLUSIONS: In an urban university population, in which 80% of participants had > 11 years of education, prevalence increased with age, and self-declared ethnicity for anti-HBc and with age, marital status and professional activity for anti-HCV antibodies. A periodical offer of HCV rapid testing should be implemented, and HBsAg rapid testing should be offered to individuals above 20 years of age.

High frequency of hemolytic and cytotoxic activity in Aeromonas spp. isolated from clinical, food and environmental in Rio de Janeiro, Brazil.

Molecular study of aerolysin and cytotonic enterotoxin genes by PCR and colony blot hybridization was performed in 117 strains of Aeromonas spp. isolated from different sources. Homogeneous distribution of these genes in A. hydrophila complex strains was observed. For A. caviae and A. sobria complex strains, aerolysin genes were more frequent than cytotonic enterotoxins genes. Of 64 A. caviae complex strains, only one (1.5%) amplified the 451 bp product for the aer gene, however, the same primers detected a 400 bp product in 50 (78%) strains. This product was sequenced and had two short regions with homology to several hemolysin genes. The genotype aer (+)/aerA(+)/hly (+)/ast (+)/alt (+) was detected in six A. hydrophila strains from food and environmental source. The most common genotype found in A. hydrophila strains was hly (+) (85%) and aerA(+) (78.7%), while in A. caviae complex strains was aerA(+) (32.8%). All A. veronii complex sobria strains were aer (+)/aerA(+). All A. caviae and A. hydrophila were positive when tested with aer probe using the colony blot test. Thirty-seven percent of A. hydrophila and 53% of A. caviae tested were positive for ast probe. Eighty-nine percent of samples were cytotoxic in Vero cells. Our data demonstrated that Aeromonas spp. can harbor and express virulence genes and reinforce the potential of Aeromonas as a human pathogen.