[Molecular detection and sequence analysis of hepatitis A virus (HAV) in two outbreaks in 2004 in North East Hungary]

Abstract

Introduction: Hepatitis A virus (HAV) is the most important cause of acute infectious hepatitis worldwide. In Hungary, the reported number of HAV infections decreasing in the last decades, however, in every year approximately 500-800 new cases occur. In Hungary, particularly in North East region not only sporadic cases but also outbreaks of HAV are happen from time to time. Serology is routinely used laboratory method for diagnosis of HAV infections, although, there was no direct molecular detection and sequence analysis for the circulating HAV strains in Hungary.

Aims: Author's aims were to detection and genetic characterization of hepatitis A virus in outbreaks of hepatitis by molecular methods for reason of molecular epidemiology in Hungary.

Materials and methods: Sera samples from symptomatic patients were tested from two acute hepatitis outbreaks in two settlements (Hajdúböszörmény and Kázsmárk) in North East Hungary in 2004 by enzim-immunoassay (EIA) and reverse transcription-polymerase chain reaction (RT-PCR).

Results: Sera in 58 (100%) and 4 (28.6%) symptomatic patients were positive in outbreaks of Hajdúböszörmény and Kázsmárk by HAV IgM EIA, however, 4 (57.1%) and 2 (66.6%) HAV IgM positive samples were positive by RT-PCR. By sequence analysis, outbreaks caused by the same hepatitis A virus which belongs to genotype I, subtype IA. These viruses had 98.4% nucleotide identity to IT-SCH-00 virus detected in year 2000 in Italy the closest match in GenBank.

Conclusions: Methods of molecular biology give new opportunity for surveillance of infectious diseases in public health. Firstly characterized hepatitis A viruses in Hungary show that the subtype IA have an important epidemiological role in outbreaks. It is also suggested that genotype IA HAV play a part in sporadic HAV cases in endemic region in Hungary, too.