DECREASING HEPATITIS-D VIRUS-INFECTION IN TAIWAN - AN ANALYSIS OF CONTRIBUTORY FACTORS

Superinfection of hepatitis D virus (HDV) among hepatitis B virus (HBV ) carriers is mainly through heterosexual contact in Taiwan. This stud y investigated the change of HDV endemicity and its associated contrib utory factors. Seventy-seven patients with acute HDV superinfection am ong 527 consecutive exacerbating hepatitis B surface antigen (HBsAg) c arriers were identified over the past 12 years. The prevalence decreas ed significantly by each 3-year period from June 1983 to May 1995 (23. 7, 15.5, 13.1 and 4.2%, respectively, P < 0.001). This trend was more significant in the hepatitis B e antigen (HBeAg)-negative group (P < 0 .001) than in the HBeAg-positive group (P = 0.073). Subjects with a hi story of paid sex and prostitutes were also recruited for analysis bot h in 1989 and 1996. Although not statistically significant, there was a trend showing a decrease in the prevalence of serum antibody against HDV (anti-HDV) in each risk group: it was lower in 1996 among HBsAg-p ositive brothel-goers (10.3 vs 6.9%), licensed prostitutes (54.5 vs 50 %) and unlicensed prostitutes (36.1 vs 30.8%). Accumulation of anti-HD V-positive subjects in risk groups may mask the actual decrease of new HDV-infected cases. The prevalence of the HBsAg carrier rate among al l prostitutes has significantly decreased (18.3 vs 12.2%, P = 0.015). The efficacy of each preventive strategy was examined and mapped with the trend. It was concluded that active preventive measures directed a gainst promiscuity and sexually transmitted disease and the promotion of disposable needles may have contributed to the decrease in HDV ende micity.