Hepatitis B is caused by infection with the hepatitis B virus (HBV).
The incubation period from the time of exposure to onset of symptoms
is 6 weeks to 6 months. HBV is found in highest concentrations in blood
and in lower concentrations in other body fluids (e.g., semen, vaginal
secretions, and wound exudates). HBV infection can be self-limited or
chronic. Read More
Hepatitis B is caused by infection with the hepatitis B virus (HBV).
The incubation period from the time of exposure to onset of symptoms
is 6 weeks to 6 months. HBV is found in highest concentrations in blood
and in lower concentrations in other body fluids (e.g., semen, vaginal
secretions, and wound exudates). HBV infection can be self-limited or
chronic.
In adults, only approximately half of newly acquired HBV infections
are symptomatic, and approximately 1% of reported cases result in acute
liver failure and death. Risk for chronic infection is inversely related
to age at infection: approximately 90% of infected infants and 30% of
infected children aged <5 years become chronically infected, compared
with 2%� of adults. Among persons with chronic HBV infection, the
risk for premature death from cirrhosis or hepatocellular carcinoma
is 15%�%. HBV is efficiently transmitted by percutaneous or mucous
membrane exposure to infectious blood or body fluids that contain blood.
The primary risk factors that have been associated with infection are
unprotected sex with an infected partner, birth to an infected mother,
unprotected sex with more than one partner, men who have sex with other
men (MSM), history of other STDs, and illegal injection drug use.
CDC抯 national strategy to eliminate transmission
of HBV infection includes
- Prevention of perinatal infection through routine screening
of all pregnant women for HBsAg and immunoprophylaxis of infants
born to HBsAg-positive mothers and infants born to mothers with
unknown HBsAg status
- Routine infant vaccination
- Vaccination of previously unvaccinated children and adolescents
through age 18 years
- Vaccination of previously unvaccinated adults at increased risk
for infection
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. STD clinics
and other settings that provide services targeted to high-risk adults
are ideal sites in which to provide hepatitis B vaccination to adults
at risk for HBV infection. All unvaccinated adults seeking services
in these settings should be assumed to be at risk for hepatitis B and
should receive hepatitis B vaccination.
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