By
Liz Highleyman
A
vaccine series consisting of 3 injections is
effective in preventing hepatitis B virus (HBV)
infection. The HBV vaccine is now included as a recommended childhood immunization
in the United States and many other countries.
In the March 15, 2008 issue
of Clinical Infectious Diseases, researchers reported on changes in the
occurrence of acute hepatitis B 14 years after the implementation of universal
HBV vaccination in Italy. In the 1970s and 1980s, Italy had an intermediate-level
endemicity of the disease; vaccination of infants and adolescents became mandatory
in 1991.
The investigators conducted a case-control study within a population-based
surveillance for acute viral hepatitis. The incidence of acute hepatitis B infection
was estimated for the time since 1991, and the association between acute infection
and various risk factors was analyzed for the 2001-2005 period.
Results
•
The incidence of acute hepatitis B infection progressively decreased from 1991
to 2005.
•
The decline was mainly seen among individuals in the age groups targeted by the
universal vaccination campaign:
•
50-fold decrease in the 0-14 year age group;
•
24-fold decrease in the 15-24 year age group;
•
Decrease by half in the 25 and older age group.
•
In 2004-2005, foreigners accounted for 14% of total acute hepatitis B cases and
for 57% of persons who should have been targeted for vaccination.
•
Missed opportunities for immunization were documented for approximately 50% of
patients with acute hepatitis B who reported living with HBV carriers and for
70% of those who reported injection drug use.
•
The strongest associations with acute hepatitis B were found for blood transfusion
(adjusted odds ratio [OR] 8.4;), cohabitation with HBV carriers (OR 5.3), injection
drug use (OR 3.8), and unsafe sexual practices (OR 2.8).
Conclusion
Based
on these findings, the authors concluded that, "Universal vaccination has
contributed to a decreasing acute hepatitis B incidence in Italy, especially by
reducing the risk of infection among persons aged 15-24 years."
"Most
infections occur in persons aged > or = 25 years in association with injection
drug use, unsafe sexual activity, percutaneous treatment, and iatrogenic exposure,"
they added. "Improvement of vaccine coverage in high-risk groups and adherence
to infection control measures during surgery and percutaneous treatment are needed."
"The
high risk still associated with blood transfusion needs to be further investigated,
with consideration of occult HBV infection in blood donors," they recommended.
"The potential spread of HBV infection from the immigrant population deserves
adequate health policy prevention programs."
3/11/08
References
A
Mele, ME Tosti, A Mariano, and others. Acute Hepatitis B 14 Years after the Implementation
of Universal Vaccination in Italy: Areas of Improvement and Emerging Challenges.
Clinical Infectious Diseases 46(6): 868-875. March 15, 2008.
A
Gervais, P Longuet, and C Leport. A Success Story: Universal Vaccination in Italy-What
Has to Be Done to Eradicate Residual Acute Hepatitis B? Clinical Infectious
Diseases 46(6): 876-877. March 15, 2008.
