Hepatitis B Epidemiology High vaccination coverage rates with subsequent

Hepatitis b epidemiology high vaccination coverage

This preview shows page 45 - 56 out of 88 pages.

Hepatitis B Epidemiology High vaccination coverage rates, with subsequent declines in acute Hepatitis B incidence, have been achieved among infants and adolescents. In contrast, vaccination coverage among the majority of high-risk adult groups (e.g., persons with more than one sex partner in the previous 6 months, MSM, and injection drug users) have remained low, and the majority of new infections occur in these high-risk groups.
Image of page 45
Hepatitis B Epidemiology An estimated 800,000–1.4 million persons in the United States have chronic HBV infection. Chronic infection is an even greater problem globally, affecting approximately 350 million persons. An estimated 620,000 persons worldwide die from HBV-related liver disease each year.
Image of page 46
Hepatitis B Prevalence of chronic infection with hepatitis B virus, 2006 Source: CDC YellowBook
Image of page 47
Hepatitis B Epidemiology Source: CDC DVH
Image of page 48
Hepatitis B Source: Semin Liver Dis. 2010 Feb;30(1):3-16. Hepatocellular carcinoma: epidemiology, surveillance, and diagnosis. Sherman M.
Image of page 49
Hepatitis B Similar to nonviral liver diseases, HBV and HCV infection can cause chronic injury to the liver, with subsequent progression to severe fibrosis and cirrhosis. The presence of cirrhosis is a major risk factor for the development of HCC. However, HCC can occur in the absence of cirrhosis, suggesting that both HBV and HCV may be directly involved in hepatocarcinogenesis.
Image of page 50
Hepatitis B Several HBV factors have been implicated in hepatocarcinogenesis, including the HBx gene, the pre-S2/S gene and the HBV spliced protein. Furthermore, HBV can be integrated into the host genome, leading to changes in genomic function or chromosomal instability. By contrast to HBV, HCV cannot integrate into the host genome. Various HCV proteins, including the core, envelope and nonstructural proteins, have been shown to have oncogenic properties.
Image of page 51
Hepatitis B Source: Clin Microbiol Infect. 2009 Nov;15(11):964-70. Hepatitis B and C virus-related carcinogenesis.
Image of page 52
Hepatitis B For HBV infection, antiviral therapy and vaccination have been shown to decrease the risk of HCC. Antiviral therapy for HCV can also reduce the risk of HCC.
Image of page 53
Hepatitis C Hepatitis C virus (HCV) infection is the most common chronic bloodborne infection in the United States; approximately 3.2 million persons are chronically infected. By contrast to Chronic HBV, patients with chronic hepatitis C almost always develop HCC in the presence of established cirrhosis. The annual risk of HCC development in HCV patients with cirrhosis is in the range of 1–4%, and an estimated 1–3% of patients chronically infected with HCV will develop HCC after 30 years.
Image of page 54
Hepatitis C Hepatitis C virus (HCV) is a positive-stranded RNA virus containing approximately 9500 nucleotides. The genome is organized into three structural proteins at the N-terminal end and four functional proteins at the C-terminal end.
Image of page 55
Image of page 56

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture