Seroepidemiology of HBV infection in South Korea, 1995 through 1999

Abstract

Background: We analyzed serologic data that were obtained from the Korea Association of Health from 1995 to 1999 to estimate the reliable prevalence of HBV in South Korea.

Methods: 603,375, 639,465, 621,476, 612,705 and 650,398 serum samples were annually tested for HBsAg. Of HBsAg positive persons whose serum samples were available, HBeAg positivity was checked.

Results: HBsAg positivities among subjects between 6 and 19 years old were 8.2%, 3.9%, 2.1%, 2.6% and 1.3%. HBsAg positivities among subjects above 20 years old were 8.9%, 6.4%, 5.9%, 5.4% and 5.4%. The positive rates of HBeAg were 39.8 to 62.9% among subjects between 6 and 19 years old, and 18.3 to 37.9% among persons above 20 years old, in each year. In both subgroups, HBsAg positivity in the latter year was significantly lower than that in the former year (p < 0.001). It also showed that HBsAg positivities among subjects between 6 and 19 years old have been significantly lower than those among subjects above 20 years old, but those of HBeAg the exact reverse of HBsAg since 1996 (p < 0.001).

Conclusions: It was observed that prevalence of HBV infection in the late 1990s, especially in the group between 6 and 19 years old, was conspicuously lower than that in the past. The nationwide vaccination programme might be one of the most important contributors to this tendency in Korea.

Figure 1A, B.

The changes of HBsAg (A) and HBeAg (B) seroprevalences among groups between 6 and 19 years old and above 20 years old are demonstrated. The positive rate of HBsAg in more recent years was lower than that in the past in both subgroups (*; p<0.001), except for that among subjects above 20 years old in 1999 (; p=0.83), and that among those between 6 and 19 years old in 1998. The positive rates of HBeAg among subjects between 6 and 19 years old were always higher than those among persons above 20 years old since 1996(; p=0.34, § ; p<0.001).