Hepatitis E virus seroprevalence in Polish soldiers serving in harsh environmental conditions

Hepatitis E virus (HEV) is an under-recognised aetiological factor of viral hepatitis; it is most commonly transmitted via the oral-faecal route, but can also be transmitted by blood or blood products, vertically from an infected mother to the foetus or by transplanted organs. The aim of the study was to present the current seroprevalence of HEV among soldiers from the Polish Special Forces deployed on military operations carried out in harsh environmental conditions. The research conducted between October and November 2016 involved 253 active duty soldiers, 237 men and 16 women, aged 26-57, without clinical symptoms of infection, participants in military operations in Asia and Africa. Accurate HEV diagnosis required the implementation of a two-phase diagnostic protocol. During the first phase, immunoenzymatic ELISA method was used to detect specific anti-HEV antibodies (IgM and IgG) in blood serum samples indicating contact with an infectious agent in the past. During the second phase, serum samples obtained from subjects with positive or inconclusive test results were tested again using confirmatory recomLine HEV IgM/IgG immunoassay. Immunoenzymatic assay found anti-HEV antibodies (IgM and/or IgG) in blood serum samples obtained from 18 soldiers. Confirmatory tests were carried out among soldiers tested positive with ELISA or those with inconclusive test results; the confirmatory tests showed anti-HEV antibodies (IgM and/or IgG) in 16 of the studied soldiers, i.e. 6.3% of the study group. The occurrence of HEV infections in Polish soldiers justifies the need for the introduction of screening tests for HEV in the military environment, especially among blood donors and in cases of whole blood or blood products transfusion.