title: Hepatitis B surface antigen confirmatory testing for diagnosis of hepatitis B virus infection in Taiwan.
abstract: This study aimed to examine the application of hepatitis B surface antigen (HBsAg) confirmatory testing when diagnosing hepatitis B infection among young persons in Taiwan with a low prevalence rate of hepatitis B infection. HBsAg status, the presence of antibodies against HBsAg (anti-HBs), and the presence of antibodies against hepatitis B core antigen (anti-HBc) were compared among 403 graduate students (mean age 22.8 ± 0.7 years) and 1,745 undergraduate students (18.6 ± 1.0 years) from one university, and 367 adult subjects (41.1 ± 15.8 years) in 2008. Any HBsAg-positive subjects were tested with an HBsAg confirmatory test. Chi-square tests for trend and predictive values of positivity (PVP) when using HBsAg-positive only for determining confirmed cases of hepatitis B infection were compared across the three cohorts. The prevalence of HBsAg positivity among subjects decreased from 16.3% in the adults to 5.2% in the graduate students and then to 2.8% for the undergraduate students (P = 0.0007). The PVP of HBsAg testing when determining cases of hepatitis B decreased from 0.97 for the adults to 0.81 for the graduate students and then to 0.56 for the undergraduate students (P < 0.0001). Thus, a significant decrease in the true-positive rate of HBsAg among the students born after the introduction of hepatitis B vaccination was observed only when HBsAg testing was applied. Additional neutralization tests may therefore become mandatory for persons with a positive HBsAg test result who were born after the commencement of the universal neonatal hepatitis B vaccination program in Taiwan.
authors: Department of Clinical Pathology, Far Eastern Memorial Hospital, New Taipei City, Taiwan; Department of Medical Laboratory Science and Biotechnology, Yuanpei University, Hsinchu, Taiwan. jacphajacpha@yahoo.com.tw
authors: Fang-Yeh
authors: FY
authors: Chu
authors: Fu-Hsiung
authors: FH
authors: Su
authors: Shu-Hsing
authors: SH
authors: Cheng
authors: Yu-Shiang
authors: YS
authors: Lin
authors: Chung-Yi
authors: CY
authors: Li
authors: Chih-Ching
authors: CC
authors: Chien
authors: Yu-Cheng
authors: YC
authors: Lin
authors: Shuo-Ya
authors: SY
authors: Chiang
mesh_terms: D000328:Adult; D005260:Female; D006509:Hepatitis B / Q000175:diagnosis* / Q000453:epidemiology; D006510:Hepatitis B Antibodies / Q000097:blood*; D006512:Hepatitis B Core Antigens / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000032:analysis* / Q000276:immunology; D017325:Hepatitis B Vaccines; D006515:Hepatitis B virus / Q000276:immunology; D006801:Humans; D017589:Immunization Programs; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
chemical_list: D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines