Hepatitis E virus seroprevalence among the general population in a livestock-dense area in the Netherlands: a cross-sectional population-based serological survey

Abstract

BackgroundRecent serological studies indicate that hepatitis E virus (HEV) is endemic in industrialised countries. The increasing trend in the number of autochthonous cases of HEV genotype 3 in Western European countries, stresses the importance to get insight in the exact routes of exposure. Pigs are the main animal reservoir, and zoonotic food-borne transmission of HEV is proven. However, infected pigs can excrete large amounts of virus via their faeces enabling environmental transmission of HEV to humans. This might pose a risk for of neighbouring residents of livestock farming.MethodsWithin a large study on the health of people living in the vicinity of livestock farming we performed a cross-sectional population-based serological survey among 2,494 non-farming adults from the general population in a livestock-dense area in the south of the Netherlands. Participants completed risk factor questionnaires and blood samples of 2,422 subjects (median age 58 years, range 20–72) were tested for anti-HEV IgG using an enzyme immune assay (Wantai). The aim of this study was to determine the HEV seroprevalence and to assess whether seropositivity in adults was associated with living in the vicinity of pig farms.ResultsThe average seroprevalence of HEV was 28.7% (95% CI: 26.9–30.5). Determinants associated with an increased risk for HEV seropositivity were male gender and low level of education. There was a clear trend of increasing prevalence with increasing age (Chi-square test for linear trend, X2 = 83.1; p < 0.001). A high number of pigs within 1,000 m of the residential address was not a risk factor for seropositivity.ConclusionsThis study confirmed the high HEV seroprevalence (29%) in the general population of the Netherlands, but presence of antibodies was not associated with residential proximity to pig farms. The prevalence increased with age from 10% in adolescents to 33% among those aged 50 and above, supporting the assumption of a cumulative lifetime exposure to HEV in the Netherlands as well as a higher infection pressure in the past. Our findings cannot refute the assumption that transmission is primarily food-borne.

Seroprevalence of hepatitis E virus (HEV) in a general adult population in Northern Norway: the Tromsø study

“…However, the detailed long-term dynamic of naturally acquired anti-HEV IgG is largely unknown (reviewed in (33)), and should be investigated using consecutive samples from patients with acute HEV-infection. The finding that people with higher education were more frequently anti-HEV IgG positive than people with less education is in contradiction to a study from the Netherlands (34). One explanation could be that many people with higher education living in Tromsø may originate from other areas inside or outside Norway where HEV is more prevalent and have moved to Tromsø due to studies or work at the local university or university hospital.…”

The study of seroprevalence of hepatitis E virus and an investigation into the lifestyle behaviours of the aborigines in Malaysia

“…This implies that the aboriginals have a higher seroprevalence of anti‐HEV than the urban Malaysian population. Increasing prevalence of HEV with increasing age has reported in many studies across worldwide (Azarkar, Ebrahimzadeh, Sharifzadeh, Ziaee, & Fereidouni, ; Bricks et al, ; van Gageldonk‐Lafeber et al, ). However, age‐specific prevalence of HEV in Malaysia from both the previous study (Seow et al, ) as well as the current study could not be established due to small sample size.…”

Impacts of Intensive Livestock Production on Human Health in Densely Populated Regions

“…In 2012, the epidemic was declared ended, most likely as a consequence of implemented control measures, including culling of pregnant animals and compulsory vaccination, in combination with a rise in seroprevalence in the human population (Van den Brom et al, ). Although other zoonotic infections, such as hepatitis E, psittacosis, and avian influenza are suspected of environmental transmission via infected farms to neighboring residents, there is limited or no scientific evidence of current health risks for the surrounding, nonfarming population (Hogerwerf et al, ; van Gageldonk‐Lafeber et al, ). For example, in a recent study in more than 2,400 individuals living in a livestock‐dense area in the Netherlands, the presence of hepatitis E virus (HEV) antibodies was strongly age related, but not associated with residential proximity to pig farms, suggesting that airborne spread of HEV is unlikely (van Gageldonk‐Lafeber et al, ).…”

“…Although other zoonotic infections, such as hepatitis E, psittacosis, and avian influenza are suspected of environmental transmission via infected farms to neighboring residents, there is limited or no scientific evidence of current health risks for the surrounding, nonfarming population (Hogerwerf et al, ; van Gageldonk‐Lafeber et al, ). For example, in a recent study in more than 2,400 individuals living in a livestock‐dense area in the Netherlands, the presence of hepatitis E virus (HEV) antibodies was strongly age related, but not associated with residential proximity to pig farms, suggesting that airborne spread of HEV is unlikely (van Gageldonk‐Lafeber et al, ). The increasing incidence of HEV in Europe is more likely a result of HEV‐contaminated pork consumption (Slot et al, ).…”