<p>Recommended by John Plevris</p> <p>There is an obvious, significant, and diachronic reduction of <italic>the
prevalence of HBV infection</italic> in Greece, concerning the general population as
well as some traditionally high-risk groups, mainly as a result of constant
informing and the widespread initiation of preventive and prophylactic
measures, as well as the improvement of health care services. Nevertheless,
there are special groups and populations (economical refugees, religious
minorities, HIV-positive patients, abroad pregnant women, prostitutes, etc.) who
represent sacs of high HBV endemicity and need epidemiological supervision and intervention, in order to limit the spread of the infection and to further
improve the existing epidemiological data.</p>
<p>Hepatitis B virus (HBV) infection is a major public
health problem worldwide, as more than 2 billion people have been infected,
whereas more than 350 million present chronic HBV infection. It is estimated
that a significant proportion (15–40%) of chronic HBV infected patients develop
liver cirrhosis, liver failure, and primary hepatocellular carcinoma (HCC),
making chronic hepatitis B one of the 10 major causes of death worldwide [##REF##12037146##1##].</p> <p>The prevalence of the infection varies
among different areas of the world and among special populations within the
same area. About 45% of the world population lives in countries in which HBV
infection is hyperendemic (South-Eastern Asia and sub-Saharan Africa),
where the percentage of hepatitis B surface antigen (HBsAg) seropositivity <italic>outranges</italic> 8% of the total
population and the percentage of viral exposure <italic>varies</italic> between 70% and 90%. In these countries, HBV infection
is vertically transmitted usually during the perinatal period and horizontally
during the infancy and early childhood age, leading to extremely high rates of
chronic HBV infection and preserving the reservoir of chronic hepatitis B
patients worldwide [##REF##8786047##2##, ##REF##10921373##3##]. Southern countries of
Central and Eastern Europe <italic>as well as those of the Mediterranean basin, the Amazon’s sink, Middle East, and Northern
Africa</italic> are regions of medium HBV infection
seroprevalence (HBsAg seropositivity between 2–7%), whereas
countries of North-Western Europe and North America are considered to be countries
with low HBV endemicity (HBsAg seropositivity &lt;2%). In
these countries, the infection is basically transmitted horizontally during the
adolescent and early adult period, mainly by high-risk sexual activity [##UREF##0##4##].</p> <p>Moreover, the annual incidence of HCC is extremely
high in hyperendemic regions of HBV infection (10–150 cases/100.000 people per year) <italic>compared</italic> to regions of lower
prevalence (1–3 cases of HCC/100.000 people per year), a finding that
supports the causative relationship of HBV and HCC. The primary HCC is one of
the most common tumours (5th in frequency
worldwide) and is <italic>considered</italic> responsible for 300 000–500 000
deaths annually, representing the 3rd most common cause of death in the
hyperendemic countries of HBV infection [##REF##14996343##5##].</p> <p>Patients with chronic hepatitis B have a threefold
probability to die within a decade compared to general population, mainly by
causes directly related to chronic liver disease (HCC, hepatocellular failure,
variceal bleeding, etc.) [##REF##11772975##6##]. Regarding
the cost of patients’ hospitalization, it seems that patients with chronic HBV
infection spend more time in the hospital and need more specialized and
expensive in-hospital treatment compared to the general population. An
epidemiological and economotechnical study from a set area of Scotland showed a
significant difference in the duration of hospitalization and the mean cost of
treatment, as well as in the number of admissions and readmissions of patients
with chronic HBV infection, compared to the control group [##REF##11772975##6##]. The annual cost of
treating patients with chronic HBV infection has been retrospectively estimated
and seems to significantly differentiate between patients in procirrhotic or
compensated cirrhotic stages of the disease under treatment and those who
exhibit decompensated cirrhosis, especially when they undergo liver
transplantation procedure. Even the palliative treatment of end-stage HCC costs
higher than long-term treatment of early stages of the disease [##REF##15602169##7##].</p> <p>A significant decline of the incidence of acute hepatitis
B cases (67%) has been observed in the USA
after 1990, especially among
high-risk groups (such as intravenous drug users, homosexual men, and health
care professionals), according to Center of Diseases Control (CDC). Widespread
vaccination programs, predelivery evaluation of pregnant women and
passive-active immunoprophylaxis of infants born from chronic HBV infected
mothers, blood donors control, and immunization of the majority of health care
professionals, children and teenagers have resulted in that decline.
Considering the lack of those preventive and precaution measures in many
hyperendemic countries of the world and the massive immigration observed in the
last fifteen years, mainly from countries of median or high prevalence of the
infection to countries of low HBV prevalence, the epidemiological data of HBV
infection <italic>seem</italic> to be
significantly modified nowadays.</p> <p>In Greece,
the existing published epidemiological data are difficult to be representative
to the general population data, mainly because they are referred to specific
populations (blood donors, religious-ethnic minorities, economic immigrants,
soldiers, children, pregnant women) or high-risk groups (prisoners, drug users,
haemodialysis patients, HIV, prostitutes, etc.) over- or underestimating the
problem. The National Institute of Employment and the National Statistical
Service reported that the number of recorded foreign immigrants in Greece at the inventory of 2001 was
approximately 800 000
(7.2% of recorded Greek population) and the majority of them (65%) <italic>came</italic> from Albania, a country of high
endemicity of HBV infection.</p> <p>In general, the comparison of studies from the early
70s with others from the late 80s shows a significant decline of HBV prevalence
in Greece
of about 50–80%. Studies on military recruits exhibit a significant decline of
HBsAg prevalence, from 4% in 1973 to 0.95% in 1999, mainly due to the
modification of socioeconomical and medical practice parameters and to the
significant increase of successfully vaccinated people [##REF##9915034##8##, ##REF##10442470##9##]. General population published data
are limited in Greece
whereas the best-studied group is that of blood donors. In the larger cohort of
blood donors studied for 6 consecutive years in Athens, the mean prevalence of HBsAg was
0.84% [##REF##10972911##10##]. A study
of a large population of blood donors in Crete island for 5 consecutive years revealed that the mean prevalence of HBsAg
(0.4%) was significantly lower than <italic>the
one</italic> reported from other compartments of our country [##REF##10607237##11##]. Equally, low
percentages of HBsAg prevalence were observed in children of school age and
teenagers of a rural population of Crete (0.33%) and in high-risk hospitalized
patients (2.66%), reflecting partially the epidemiological data of the general
population of the island [##REF##9258547##12##, ##REF##11208260##13##]. A significant decline of HBsAg prevalence by 2.15% and of the
percentage of HBV exposure by 22.6% are reported in the first published study
concerning the general population, in the region of South-Western Greece,
whereas in the region of Epirus in a 3-year prospective study of blood donors,
the HBsAg seropositivity <italic>was</italic> of 0.85%, relatively higher than <italic>the
one</italic> reported from other compartments of Greece [##REF##12908721##14##, ##REF##11346702##15##].</p> <p>The immigration of populations from countries of high
endemicity of the infection seems to contribute significantly to the rapid
modification of epidemiological data, especially in areas bearing the high
burden of immigrants. In a serological control of 1020 refugees from South Albania who came and work in Ioannina region, the percentages of HBsAg
seropositivity and HBV exposure were 22.2% and 70.6%, respectively. Moreover, a
significant proportion of chronic HBV infected Albanian patients were also hepatitis
B e antigen-positive [HBeAg(+)] (21.1%) and 12.7% of them were chronic hepatitis
D virus (HDV) infected, representing a<italic/>
population of high infectivity regarding viral hepatitis [##REF##7552639##16##]. Data regarding
immigrants living in Athens
showed that the prevalence of HBsAg was <italic>significantly</italic> high (15.4%) especially among Albanian and Asian
refugees [##REF##12717844##17##].
Likewise, significant differences of the prevalence of HBV infection are
reported in the religious minority of Thrace moslems comparing to Greeks from formal Soviet Union who live in the same area
and the native habitants of Thrace
(9.3% versus 4.3% versus 3.4%, respectively), revealing a population of high
endemicity of HBV infection within our country [##REF##11446899##18##].</p> <p>Perinatal (vertical) transmission is one of the most
common ways of HBV infection dispersion, mainly in hyperendemic areas of the
world and seropositive pregnant women and their neonates represent the basic
target groups for the elimination of vertical transmission, which preserves the
main reservoir of chronic HBV infected patients. In the larger group of women
at reproductive age studied in Greece, the mean prevalence of HBsAg was 1.15%,
but was significantly higher among women of Albanian (5.1%) and Asian origin
(4.2%) compared to Greek women (0.29%). The vast majority (71.34%) of
HBsAg-positive women were of Albanian origin and about a third of them
exhibited significant viral replication at perinatal period [##REF##15653423##19##].</p> <p>Intravenous drug users and prisoners are also
high-risk groups for viral hepatitis who <italic>were studied</italic> epidemiologically in our country. In a study of
544 prisoners who were intravenous drug users concomitantly, 6.5% of them
exhibited HBsAg-positivity whereas among prisoners for sexual
offences the percentage of HBsAg-positivity <italic>was</italic> higher enough (13%) [##REF##9624725##20##, ##REF##12825735##21##]. The widespread of HBV infection in the
Greek drug-users community observed in the past decade, according to published
studies [##REF##3475213##22##] seems
to be changed nowadays. In an our recently published study, we investigated the
presence of serological markers of HBV infection in intravenous drug users
(IVDU) with chronic hepatitis C virus (HCV) infection and the results were
correlated to the time of drug usage initiation. We found that drug use
initiation before 1992 was significantly related to HBV exposure while the vast
majority of relatively newer drug users (drug initiation after 1992) were HBV
seronegatives [##REF##16275544##23##].</p> <p>In Greek oncologic patients with solid tumors, the
percentages of HBsAg-seropositivity were 5.3% and those of HBV
exposure 44%, while a proportion of them (14%) had clinical and/or biochemical
exacerbation of liver disease during the chemotherapy schedule; this percentage
is expected to be much higher in patients with haematological malignancies,
with or without steroid administration according to the international
literature [##REF##10487614##24##].
Furthermore, significantly higher prevalence of HBV infection is observed in
chronic alcoholic patients—with or without
established liver disease—compared to
healthy blood donors or nonalcoholic hospitalized patients, which is ascribed
to their specific and some times unexpected behavior [##REF##8817173##25##].</p> <p>Chronic liver disease due to coexisting chronic viral
hepatitis B and/or C as well as a consequence of hepatotoxicity of the
antiretroviral therapy is one of the most important factors of morbidity and
mortality of human immunodeficiency virus- (HIV-) infected patients, since the
classic opportunistic infections and the complications of severe
immunodeficiency have been significantly diminished. In HIV-seropositive
patients the probability of chronic HBV infection and chronic liver disease
after exposure to HBV is extremely high and is characterized by very high
levels of viraemia (serum HBV-DNA) and extremely low percentages of spontaneous
loss and/or seroconversion of HBeAg [##REF##14738553##26##]. About 13% of a group of HIV-positive patients, mainly
homosexual men (68.5%), were HBsAg-positive and the percentage of their
exposure to HBV infection was 67.4%, representing a high-risk group for viral
hepatitis [##REF##10841086##27##]. In
a cohort study in Greece, regarding 737 HIV-positive patients, the percentage
of HBsAg-seropositivity was 12.1% while the majority of
HIV/HBV coinfected patients (60.9%) were also HBeAg-positive and they exhibited
extremely high levels of HBV viral load, suggesting the direct uptake of
preventive measures for this high-risk group, in order to protect its health
and the public health in general [##REF##15135750##28##].</p> <p>An obvious trend of reduction of the HBV prevalence is
observed in other traditionally high-risk groups, such as prostitutes, since
the percentage of HBsAg-seropositivity (11%) at the early 80s has been
reduced to 3.3% in the late 90s; these data need to be reevaluated because of
the high percentage of people trafficking for sexual reasons, mainly from
countries of median-high HBV prevalence to our country, who are not reported or
sanitary controlled and are thought to represent the most significant cause of
HBV transmission<italic/> in our days [##REF##7358965##29##, ##UREF##1##30##]. Data from a
study of the Department of Public Order were presented in daily press and
according to conservative calculations there are more than 14 000
people who are illegally sexually prostituted in our country.</p> <p>Finally, the professional exposure in the health care
worker field has been studied since the 70s, where the percentages of HBsAg
seroprevalence were 2.4% for medical students and 4.6% for nursing staff. In a
recent study from Hippokration Hospital of Athens including 400 nursing staff,
the percentage of HBsAg-seropositivity was 1.25% and the HBV exposure
rate was 16%, but only 61% of that high-risk group were efficiently vaccinated,
so there is a significant percent of population unprotected for various but 
nonaccepted reasons [##UREF##2##31##].</p> <p>In conclusion, although there is an obvious,
significant, and diachronic reduction <italic>of the prevalence of HBV infection</italic> in Greece, concerning the
general population as well as some traditionally high-risk groups, mainly as a
result of constant informing and the widespread initiation of preventive and
prophylactic measures as well as the improvement of health care services, there
are special groups and populations (economical refugees, religious minorities,
HIV-positive patients, abroad pregnant women, prostitutes, etc.) who represent
sacs of high-HBV endemicity and need epidemiological supervision and
intervention, in order to limit the spread of the infection and to further
improve the existing epidemiological data.</p>
[{"label": ["4"], "surname": ["WHO"], "article-title": ["Global Tuberculosis Control"], "comment": ["WHO Report 2000, Geneva, Switzerland"]}, {"label": ["30"], "surname": ["Tsakris", "Kyriakis", "Chryssou", "Papoutsakis"], "given-names": ["A", "KP", "S", "G"], "article-title": ["Seroprevalence of hepatitis B markers among female and transsexual sex workers in Athens, Greece"], "italic": ["Genitourinary Medicine"], "year": ["1997"], "volume": ["73"], "issue": ["3"], "fpage": ["223"], "lpage": ["224"]}, {"label": ["31"], "surname": ["Antypa-Theothoropoulou", "Pouyiouka", "Karabassi", "Papadouli", "Lamprinoudi", "Kontou-Kastellanou"], "given-names": ["A", "M", "V", "Z", "A", "C"], "article-title": ["Sero-epidemiologic survey of hepatitis B markers in healthcare workers of a major Greek Hospital"], "italic": ["Journal of Chemotherapy "], "year": ["2005"], "volume": ["17"], "fpage": ["p. 129"]}]
Gastroenterol Res Pract. 2008 Apr 6; 2008:580341