Epidemiological Aspects of Hepatitis B in Community-Based Health
Educating About Hepatitis B
Overview of Hepatitis B Epidemiology
Hepatitis B is caused by infection with the Hepatitis B virus (HBV) ("CDC," 2012). The highest concentrations of HBV are found in blood, while other body fluid, such as semen, vaginal secretions, and wound exudates, show lower concentrations ("CDC," 2012). HBV infection can be either chronic or self-limited ("CDC," 2012). The incubation period can range from 6 weeks to 6 months from the time of initial exposure to the onset of symptoms ("CDC," 2012).
Roughly half of newly acquired HBV infections in adults are symptomatic. Acute liver failure and eventual death occurs in 1% of all reported cases ("CDC," 2012). The age of infection shows an inverse relationship to chronic infection. Accordingly, 2 to 6% of adults suffer from chronic infection, while 30% of children five years and under and 90% of infants become chronically infected ("CDC," 2012). Chronic HBV infection increases the risk for premature death from cirrhosis or hepatocellular carcinoma at a rate of 15 to 25% ("CDC," 2012).
Transmission of HBV is efficient through percutaneous or mucous membrane exposure to blood itself or to body fluids that contain blood ("CDC," 2012). Infection of HBV is primarily associated with these risk factors: Illegal drug use that involves injection; unprotected sex with an infected partner; unprotected sex with more than one partner; borne by an infected mother; men having sex with other men (MSM); and a history of previous or other STD ("CDC," 2012).
Public Health National Strategy
The Centers for Disease Control and Prevention (CDC) heads the national strategy to eliminate the transmission of HBV infection. A multi-pronged approach focuses on prenatal screening and a widespread vaccination program. Specifically, the CDC strategy includes the following:
Routine screening for HBsAg of all pregnant women;
Routine screening for immuniprophylaxis of all infants born to mothers who are hepatitis B surface antigen (HBsAg)-positive;
Routine screening of all infants born to others with unknown hepatitis B surface antigen (HBsAg) status;
Routine vaccination of infants;
Vaccination of all previously unvaccinated children and adolescents through 18 years of age;
Vaccination of adults who at-risk of infection and are previously unvaccinated.
Outcomes To Date of CDC Eradication Strategy
Incidence rates for acute Hepatitis B in infants and adolescents have declined following high vaccination coverage rates. However, the same cannot be said for high-risk adult groups. High-risk adult groups are: men who have sex with other men (MSM), injection drug users, and people who have engaged in sex with more than one partner in the previous six months. Vaccination coverage for the majority of high-risk adults has continued at low rates. Consequently, most new infections occur in the high-risk adult groups. Services targeted to high-risk adults are provided in STD clinics and other similar settings, as these have proven to be ideal situations in which to provide education about HBV infection and to provide Hepatitis B vaccination to high-risk adults. Clinicians are advised to assume that all unvaccinated adults seeking or in need of services in STD and similar purpose clinics are at risk for HBV infection and should be given the Hepatitis B vaccination without delay.
For people who have been exposed to HBV as a result of a discrete and identifiable exposure to blood or body fluids that contain blood (i.e., infants born to mothers who test positive for the following recommendations have been published by CDC MMWR.
For HBsAg-positive source persons, the CDC recommends the following:
Unvaccinated persons or persons known not to have responded to a complete hepatitis B vaccine series should receive both hepatitis B immune globulin (HBIG) and hepatitis B vaccine as soon as possible after exposure (preferably