DRID Workshop 1 - Monitoring hepatitis B (HBV) vaccination through the existing
EMCDDA data system
Mario Cruciani
Background
Drug users are at high risk of HBV infection, both through parenteral/percutaneous and sexual
transmission. Among notified acute cases of hepatitis B where transmission route is documented, one
in five has been infected by injecting drugs. Prevention of primary infection by vaccination is an
important strategy to decrease the risk of chronic HBV infection and its subsequent complications.
Hepatitis B serologic testing involves measurement of several HBV specific antigens and antibodies.
Different serologic “markers” or combinations of markers are used to identify different phases of HBV
infection and to determine whether a patient has acute or chronic HBV infection, is immune to HBV or
is susceptible to infection.
Problems
In ST9, data are requested on HIV, HCV and HBV. For HBV, the following tests should be performed:
• hepatitis B surface antigen (HBsAg); • hepatitis B surface antibody (anti-HBs); • hepatitis B core
antibody (anti-HBc , IgG and IgM); moreover, If only one HBV marker can be provided, priority is
given to HBsAg. However, while HBsAg is an indicator of acute/chronic liver disease and infectivity,
its absence does not provide any information on immunization status. By contrast, testing antiHBs
and antiHBc” provides information on immunization status as a result of prior infection (antiHBc +,
antiHbs +) or vaccination ((antiHBc -neg, antiHbs +), or on susceptibility to infection. Individuals testing
negative to antiHBs and antiHBc are candidates to HBV vaccine.
The implemention of mass HBV immunization programs is recommended by the WHO since 1991,
and this practice has dramatically decreased the prevalence of HBV infection and its complications in
many countries. Ideally, HBV vaccine should be offered to all PWID, to people at risk of progression to
injecting (e.g., people who are currently smoking heroin and/or crack cocaine, and heavily dependent
amphetamine users) as well as non-injecting users who are living with current injectors. Nonetheless,
HBV vaccination coverage in drug users is still low in many countries.
Other problems that may arise are related to the acceptance of the test, acceptance and compliance
with the vaccine schedule, and need to test antibody response after vaccination
Aims of the workshop
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To discuss ways to improve the reliability and comparability of diagnostic testing data for
DRID monitoring
Discuss ways to promote and offer testing to people at increased risk of HBV infection
What do we expect from participants?
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To prepare a short country report (e.g. less than one page) about the use of HBV
diagnostic testing data for DRID monitoring in their country, what are the difficulties using
this data and how these problems are dealt with.
To participate in the discussion
To think about cost-effectiveness of testing
To appoint someone to make a report (1-2 pages in Word)