Introduction:
Hepatitis A (HA) is caused by infection with the hepatitis A virus (HAV). The differential etiological diagnosis of acute hepatitis is based on a positive result of the serological test detecting IgM class anti-HAV. For epidemiological studies on past infection and seroprevalence of HAV in populations, the tests measuring IgG class anti-HAV or total anti-HAV are used. Since the 1990s, specific prophylaxis is possible by vaccination against HA. In Poland, vaccination is recommended and in majority is performed at own cost.

Material and methods:
Database was obtained from electronic medical records of the 2 major private health care providers networks (Luxmed and Medicover) operating in Poland. During a 3-year period (2013–2015), 1,124 persons with unknown status of anti-HA vaccination were tested for the presence of total anti-HAV. Objective. The aim of the study was to evaluate the seroprevalence of anti-HAV among working professionals in Poland.

Results:
Anti-HAV were detected in 603 (53.6%) persons, while 521 (46.3%) tested negative. The study group was divided into 2 subgroups: 25–44 and 45–64-years-old. For detailed statistical analysis, the presence of anti-HAV was considered as a dependent variable, and its predictors were gender, age and the year of the test performance. The presence of anti-HAV was significantly more prevalent in older age group. The lack of specific antibodies was more prevalent in younger age group.

Conclusions:
Results of the study show increasing susceptibility to HAV infection in the younger age group, compared with the older age group of corporate professional employees in large cities in Poland. Since the epidemiological situation of HA is currently changing with increasing number of symptomatic cases of HA, it is suggested that employers might consider including an additional procedure of vaccination against HA into their private health insurance portfolio.