Surveillance and prevention of hepatitis B virus transmission

Epidemiology of hepatitis B and C viruses: a global overview

This article reviews the prevalence, disease burden, genotype distribution, and transmission patterns of hepatitis B virus (HBV) and hepatitis C virus in the 6 World Health Organization regions. The global epidemiology of hepatitis B and C demonstrates a predominantly declining prevalence of the diseases. Improvement in the control of hepatitis B has been largely achieved with implementation of a more universal HBV vaccine program, although a large gap still remains in the effort toward global prevention of hepatitis B. The transmission of hepatitis C has been greatly impacted by mandatory screening of blood donors in most countries in the world, although intravenous drug use continues to be a major source of infection. Public education regarding the risks of exposure to infected paraphernalia as well as household items such as razors is necessary in the continuing effort to curb this disease.

Predictors of hepatitis B immunization status in Korean American children

This study assesses the predictive factors of social context and ethnicity on childhood hepatitis B immunization status among Korean American children living in an urban area. Logistic regression analysis revealed that maternal perceptions of benefits (OR = 3.24, 95% CI = 1.23-9.63) and barriers (OR = 0.4, 95% CI = 0.25-0.89) were important predictors of hepatitis B immunization status. Among children ages 2-5 years in this study, children born prior to the adoption of new immunization guidelines in 1994 were less likely to have received all three doses of hepatitis B vaccine (adjusted OR = 0.69, 95% CI = 0.43-0.80). An informal social support network providing information concerning parenting and health care of children was also associated with an increased probability of obtaining the immunization (adjusted OR = 2.76, 95% CI = 1.25-7.66). Mother's history of adequate prenatal care (chi2 = 3.98, p < 0.05) was significantly related to immunization status. Major perceived barriers in accessing preventive health care include burden of cost, language barrier, and difficulty remembering the immunization schedule.

Serologic response to hepatitis B vaccine in HIV infected and high-risk HIV uninfected adolescents in the REACH cohort. Reaching for Excellence in Adolescent Care and Health

PURPOSE

To evaluate hepatitis B (HBV) vaccine response rates in HIV infected and high-risk HIV uninfected youth and examine associations with responsiveness in the HIV infected group.

METHODS

Cohorts within the Reaching for Excellence in Adolescent Care and Health (REACH) study population were defined based on receipt of HBV vaccine both retrospectively and prospectively. Sero-responsiveness was determined by HBsAb measurements. Testing was done for HBsAg, HBsAb, and HBcAb. For HBsAb, a value of > 10 International Units per liter was considered a positive response, and the data were collected as either positive or negative from each of the reporting laboratories. Covariates of responsiveness were explored in univariate and multivariate models for each cohort.

RESULTS

Sixty-one subjects had received a three-dose vaccination course at the time of entry into REACH. HIV uninfected subjects had significantly higher rates of response by serology compared with HIV infected subjects (70% vs. 41.1%; chi(2) = .05; RR = .586, 95% CI: .36-.96). By the time of an annual visit 43 subjects had received three vaccinations with at least one occurring in the study period. The rates of response were similar for the HIV infected and uninfected groups (37.1% vs. 37.5%) in this cohort. Univariate and multivariate analysis in the prospective HIV infected group (N = 35) found an association between elevated CD8(+)/CD38(+)/HLA-DR(+) T cells and lack of HBV vaccine responsiveness (6.7% vs. 60%; chi(2) = .03; RR = .12, 95% CI: .02- .55).

CONCLUSIONS

The poor HBV vaccine response rate in the HIV uninfected high-risk adolescents was unexpected and suggests that HBV vaccination doses have not been optimized for older adolescents. This is the first report of decreased responsiveness in HIV infected subjects being associated with elevated CD8(+)/CD38(+)/HLA(-)DR(+) T cells and suggests that ongoing viral replication and concomitant immune system activation decreases the ability of the immune system in HIV infected subjects to respond to vaccination.