title: The use of dried blood spots for assessing antibody response to hepatitis A virus after natural infection and vaccination.
abstract: During recent years, vaccination against hepatitis A has been implemented in several countries. It is expected that the increase in mass vaccination against hepatitis A will eventually result in a decreased prevalence of anti-HAV antibodies in the general population. For this reason, a suitable clinical sample for diagnosis of hepatitis A must be sufficiently sensitive to enable detection of lower antibodies titers. In this study, the feasibility of using dried blood spots (DBS) was assessed for the detection of anti-HAV antibodies after a natural infection and vaccination. Seventy-four DBS and paired plasma samples were obtained from a group of college students for a cross-sectional hepatitis A seroepidemiological study. Forty-six students seronegative for anti-HAV were selected randomly and immunized with an inactivated hepatitis A vaccine using an 0-6 month schedule. Seroconversion was monitored in paired plasma and DBS samples 6 months after the first dose followed by a period of 8 and 24 months after the second dose. A strong correlation between OD/CO rates of paired plasma and DBS samples for the detection of anti-HAV was observed. The sensitivity and specificity of the DBS compared with plasma for the detection of anti-HAV antibodies after natural infection was 100%. The sensitivity of DBS in samples collected 24 months after the second dose of hepatitis A vaccine was 95.4%. The results showed that DBS samples can be used for the detection of anti-HAV antibodies both after natural infection or vaccination.
authors.affiliation: Department of Microbiology and Parasitology-Biomedical Institute, Federal Fluminense University, Niterói, Brazil.
authors.forename: J G
authors.initials: JG
authors.lastname: Melgaço
authors.forename: M A
authors.initials: MA
authors.lastname: Pinto
authors.forename: A M
authors.initials: AM
authors.lastname: Rocha
authors.forename: M
authors.initials: M
authors.lastname: Freire
authors.forename: L P
authors.initials: LP
authors.lastname: Gaspar
authors.forename: S M B
authors.initials: SM
authors.lastname: Lima
authors.forename: O G
authors.initials: OG
authors.lastname: Cruz
authors.forename: C L
authors.initials: CL
authors.lastname: Vitral
mesh_terms: D001938:Brazil / Q000453:epidemiology; D005260:Female; D006506:Hepatitis A / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D035922:Hepatitis A Antibodies / Q000097:blood*; D022362:Hepatitis A Vaccines / Q000276:immunology*; D017957:Hepatitis A Virus, Human / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D013048:Specimen Handling; D014611:Vaccination; D055815:Young Adult
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines