Hepatitis E virus infection : an emerging occupational risk in pig handlers?

Introduction Hepatitis E virus (HEV) infection is endemic in many developing countries, causing substantial morbidity. Transmission is primarily faeco-oral and is associated with both sporadic infections and epidemics in areas without drinkable water. In industrialised countries, HEV infection was thought to occur only in individuals infected in endemic areas. However, sporadic cases have been reported in persons from industrialised regions with no history of recent travel. Such reports and the availability of more comprehensive molecular and serological data have changed HEV epidemiology, accepting that autochthonous HEV is a problem and an endemic disease in industrialised countries. Moreover, a porcine reservoir and growing evidence of zoonotic transmission have been reported in these countries, suggesting the possibility of occupational transmission to man. This review summarises the current knowledge on the epidemiology and prevention of transmission of HEV infection in occupational settings. Methods The following keywords were used to explore PubMed: hepatitis E, disease, epidemiology, profession(al), occupation(al). The results were further screened and 107 publications were retained. Results In nonendemic regions, seroprevalence varies from a few percent (2–7.8%) in Europe, Japan and South America to several percent (18.2–20.6%) in the USA, Russia, UK, southern France and Asia. A meta-analysis of 12 cross-sectional studies evaluating potential association between HEV IgG seroprevalence in individuals occupationally exposed to swine showed greater odds of seroposivity in the exposed group but also a high degree of heterogeneity. The funnel plot suggests publication bias. Conclusions There is a significant association between occupational exposure to swine and HEV IgG seroprevalence, but the level of prevalence detected depends also on the type of HEV IgG kits used. Further research, including on mechanisms and risk factors for infection, as well as the development of better serological tests for identification of infection, are required.