Water and sera were collected from 4 sewage treatment plants whose workers were exposed to raw untreated sewage samples, which may accumulate the HEV virus. Two methods of water concentration were used (PEG and U-APB) and samples analyzed by nested RT-PCR. The 24 samples (inlet and outlet) of sewage treatment plants were negative for virus. HEV IgG was detected in 205 workers sera, the age of 20-40 years old, exhibited the highest HEV IgG infection (50.9% - 50.4), between 41-50 and 51-60 years old were lower and almost the same (43.2%, 46.2%, respectively). The highest infections between workers were in Balaks sewage treatment plant, and the persistence of HEV IgG was until 60 years old.