Molecular epidemiology of chronic hepatitis B virus infection in northern Poland.
ABSTRACT Hepatitis B virus (HBV) infection is a global health problem, with more than 350 million people chronically infected worldwide. The chronic HBV infection in Poland is also an essential medical and social problem. Starting from 1993, a steady decline of the incidence of HBV has been observed, reaching the estimated rate of 4.5 per 100 000 in 2004. Nothing is known about the genetic variability of HBV in Poland, the occurrence and spreading of genetic variants and mutants of hepatitis B virus in the population of Polish patients during the course of the disease and in relation to antiviral treatment. It is very interesting to study the molecular epidemiology of the Polish population regarding hepatitis B virus infection as Poland is still ethnically a uniform country, with no more than 3-4% of ethnic minorities. The first results regarding distribution of HBV genotypes and serotypes in northern Poland have been published by our group in 2003 and 2004. This work was part of a scientific project supported by the Fifth Framework Programme initiative of the European Union, entitled "Emerging variants of hepatitis B virus: new tools for epidemiological survey, diagnosis of infection, and monitoring of drug resistance". In the course of the project more than 200 hepatitis B infected patients from the northern part of Poland have been enrolled, diagnosed and - if the viral load of HBV was suitable for analysis - genotyped by sequencing of the HBV pol/S gene fragment. This review presents the main characteristics and some interesting aspects of the studied cohort of chronically infected patients from northern Poland as well as the molecular epidemiology.
- SourceAvailable from: Ljudmilla Priimägi[show abstract] [hide abstract]
ABSTRACT: The genotypes and subtypes of 205 HBV isolates collected during 1989-2002 in Estonia and 14 other regions of the former USSR were determined by sequencing and phylogenetic analysis of the S gene. The in Europe prevailing genotypes, A and D, were also circulating in the whole territory of the former USSR including Estonia and accounted for 18.5 and 81% of the strains, respectively. All genotype A strains specified adw2, and a single genotype C strain specified adrq+. Most genotype D strains specified ayw3 and ayw2, although, three strains from Estonia and Siberia specified ayw4. Due to unique substitutions, Ser122 and Ala127, four strains could not be classified according to the subtype. One strain specifying ayw3 encoded Leu143 and Ala145 and was possibly an immune "escape" mutant. At phylogenetic analysis 93% of the Estonian genotype D strains belonged to a cluster specifying mainly ayw3 and were more similar to isolates from Siberia and the Far-East of Russia than to isolates originating from Central Russia which belonged to another cluster of strains specifying mainly ayw2. This pattern might be explained by part of the Estonian population, has roots east of European Russia, based on linguistic evidence. Eight dominant HBV strains represented by identical S gene sequences were identified, one within genotype A and seven within genotype D, three of which included isolates from Estonia and Siberia. Some of these strains were collected over a period of at least 13 years indicating there are genetically stable variants of HBV that remain conserved over decades.Journal of Medical Virology 11/2004; 74(2):221-7. · 2.37 Impact Factor
- Journal of Hepatology 02/2003; 39 Suppl 1:S64-9. · 9.86 Impact Factor
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ABSTRACT: The incidence of hepatitis B virus (HBV) infection varies considerably in countries in Central and Eastern Europe and the Newly Independent States, but data are difficult to compare between countries because of the large differences in levels of diagnosis, particularly serological identification, and levels of notification. Poland has high levels of diagnosis, including laboratory diagnosis. In the past, the incidence of hepatitis B in Poland was approx. 45 reported cases per 100,000 population, but following the introduction of improved sterilization of medical equipment in 1986 and a selective programme of vaccination in 1991, the incidence fell to about 35 per 100,000 by 1993. In 1993, an intensive vaccination campaign was launched, which has reduced the incidence to under 15 per 100,000. The incidence of HBV infection has decreased across all age groups and in both men and women, and in the under 3 years age group only 32 cases in total were reported in 1997. In 1996 and 1997, there was a slight relative increase in the incidence of HBV infection in men aged 20-24 years. This group may be a target for future vaccination programmes and other activities of control for the infection.Vaccine 03/2000; 18 Suppl 1:S13-6. · 3.49 Impact Factor