Hepatitis B: Risk & Affects

Hepatitis B: Risk & Affects

Introduction

Infection with hepatitis B virus (HBV) remains a global health problem, and it is estimated that about 2 billion people worldwide have been infected with the virus, more than 350 million people are sick. In recent years, more and more important in developed countries acquire sexual way of transmission of the virus. In the United States, the occurrence of severe hepatitis B has decreased by 81 percent from 1990 to 2006, with the biggest fall among children including adolescents (Wasley et al, 2008). The incidence in 2007 was approximated to be 1.5 per 100,000 persons. There were 4519 acute, symptomatic cases reported but an estimated 43,000 new infections overall, with most infections occurring in men ages 25 to 44 (www.cdc.gov). The most widespread risk factors were sexual exposure and injection drug use. These data indicate that vaccination programs targeted at high risk adults are needed to further reduce transmission of Hepatitis B Virus in the USA.

Discussion

Epidemiology

The data from NHANES 1988 to 1994 was compared with NHANES 1999 to 2006 to investigate the effect of the vaccination effort (Wasley, 2010). Overall, the prevalence of past and present hepatitis B infection increased with age, from 0.6 percent for children between the ages of 6 and 11 years to 7.3 percent for those older than 60 years. Conversely, vaccine-induced immunity was significantly higher among individuals between 6 and 11 years old (54 compared with 5 percent among those more than 60 years old). The prevalence of HBV decreased from 1.9 to 0.6 percent among children 6 to 19 years old and 5.9 to 4.6 percent among those 20 to 49 years old, but it remained unchanged among those above 50 years old. Foreign-born participants of the study showed a noteworthy cut in incidence of chronic Hepatitis B Virus infection from 1.75 to 0.89 percent. Although this reduction in prevalence was significant, it was still 15-fold higher than US-born participants. The reduction was most evident among foreign-born children 6 to 19 years old with prevalence decreasing from 12.8 to 2.0 percent. Among the US-born children surveyed from 1999 to 2006, there was no longer any difference in the incidence of chronic HBV infection among the different races and ethnic groups, with prevalence ranging from 0.1 to 0.6 percent (Wasley,2010). These results showed that the vaccination program in the United States has been doing well in reducing the incidence of Hepatitis B Virus infection, especially among the higher risk populations.

In a separate analysis examining nearly 40,000 participants in the National Health and Nutrition Examination Survey in the United States (1999 to 2008), 0.127 percent of those older than six had chronic HBV infection (approximately 704,000 persons), while 4.6 percent (approximately 12 million persons) had evidence of prior exposure to HBV (Ioannou, 2011). Infection and past exposure were rare in those ages 6 to 19.

Data on prevalence of HBV infection from NHANES may be underestimates since the study did not include certain groups at increased ...