Objectives: The objective of this study was to describe the epidemiology of hepatitis B in Poland in 2010 in comparison to previous years.
Methods: The study included cases that were collected and registered by the State Sanitary Inspection in 2010 in Poland. Data reported was verified, processed and published by National Institute of Public Health - National Institute of Hygiene. Analysis of cases was conducted on case-based data for acute hepatitis B and on aggregated data for all stages of hepatitis B. Case classification included confirmed and probable cases of acute hepatitis B. A confirmed case was defined, in accordance with the EU case definition, as any person meeting the clinical criteria (compatible with hepatitis) and having laboratory confirmation through detection of IgM antibodies for hepatitis B core antigen (IgM anti-HBc+). For probable cases both clinical criteria and presence of an epidemiological link to a confirmed case was required.
Results: A total of 1,633 hepatitis B cases, including 38 cases of co-infection with hepatitis C (HCV) was reported in 2010. Incidence was 4.28 per 100,000 population, higher than the previous year. Acute cases constituted 7.8% of people reported as hepatitis B positive. Since 2005 a steady downward trend in incidence of acute hepatitis B has been observed, in 2010 the lowest ever rate of 0.34 per 100,000 population was recorded. The number of newly detected chronic infections, however have increased in recent years with a different epidemiological profile. There is a distinct geographical variation in acute and chronic hepatitis B incidences in the country, the acute hepatitis B incidence ranges from 0.04 to 0.64/100,000 and that of chronic from 0.18 to 11.6/100,000. Such diversity may be due to differences in reporting and quality of surveillance between regions. As in 2009, chronic hepatitis B was most frequently diagnosed among people aged 15-19, which is most likely connected to the very high incidence observed among children under 4 years in the early 90s. We observed two peaks of acute hepatitis B--among people aged 25-29 living in urban areas and those over 75 years living in rural areas. Both acute and chronic cases were more often among males than females and those residing in urban areas. In 2010, 99% of acute and 54.6% chronic hepatitis B cases were hospitalized, 5 people died because of acute hepatitis B and 42 due to chronic hepatitis B.
Conclusions: The decreasing trend of acute hepatitis B incidence in Poland is attributed primarily to the universal HBV vaccination among infants and healthcare workers over the past 15 years. Acute hepatitis B infection occurred mainly among unvaccinated young males aged 25-29 years who lived in urban areas, pointing to a change in transmission patterns and increasing sexual transmission, tattooing and injecting drug usage. However the main transmission route in Poland is still attributed to medical procedures in hospital and nonhospital health-care associated settings accounting for 59% of acute infections.