Hepatitis E virus infection in North Italy: high seroprevalence in swine herds and increased risk for swine workers

Abstract

We determined the hepatitis E virus (HEV) seroprevalence and detection rate in commercial swine herds in Italy's utmost pig-rich area, and assessed HEV seropositivity risk in humans as a function of occupational exposure to pigs, diet, foreign travel, medical history and hunting activities. During 2011-2014, 2700 sera from 300 swine herds were tested for anti-HEV IgG. HEV RNA was searched in 959 faecal pools from HEV-seropositive herds and in liver/bile/muscle samples from 179 pigs from HEV-positive herds. A cohort study of HEV seropositivity in swine workers (n = 149) was also performed using two comparison groups of people unexposed to swine: omnivores (n = 121) and vegetarians/vegans (n = 115). Herd-level seroprevalence was 75·6% and was highest in farrow-to-feeder herds (81·6%). Twenty-six out of 105 (24·8%) herds had HEV-positive faecal samples (25 HEV-3, one HEV-4). Only one bile sample tested positive. HEV seropositivity was 12·3% in swine workers, 0·9% in omnivores and 3·0% in vegetarians/vegans. Factors significantly associated with HEV seropositivity were occupational exposure to pigs, travel to Africa and increased swine workers' age. We concluded that HEV is widespread in Italian swine herds and HEV-4 circulation is alarming given its pathogenicity, with those occupationally exposed to pigs being at increased risk of HEV seropositivity.

Prevalence of hepatitis E virus infection among people and swine in mainland China: A systematic review and meta‐analysis

“…were lower than those reported in Norway and North Italy (90% and 75.6%, respectively) (Lange et al, 2017;Mughini-Gras et al, 2017).…”

“…Some studies conducted in developing countries demonstrated that the seroprevalence of occupational population ranged from 3% to 80% (Hoofnagle, Nelson, & Purcell, ; Wilhelm et al, ). The current study has also indicated that the anti‐HEV IgG antibodies in swine (66.4%; 95% CI: 61.7–71.1) were lower than those reported in Norway and North Italy (90% and 75.6%, respectively) (Lange et al, ; Mughini‐Gras et al, ).…”

Detection of hepatitis E virus RNA in rats caught in pig farms from Northern Italy

“…Rats and pigs can easily be exposed to each other faeces, where a high level of the virus could be released. Faeces could contaminate environment representing a source of contamination for pigs but also for pig workers although the detection of RNA is not sufficient to state that the virus is infectious (Mughini‐Gras et al, 2017; Huang, Huang, Wagner, Chen, & Lu, ). Since rats and mice are synanthropic and can have a role on human infections, as reported by the detection of rat HEV strains in patients affected by acute hepatitis (Sridhar et al, ; Andonov et al, ), further investigation is required.…”

Seroprevalence of Hepatitis E Virus in Forestry Workers from Trentino-Alto Adige Region (Northern Italy)

“…Several studies have also suggested that working exposures to pigs or wild boar may represent a risk to be infected by HEV. A higher HEV IgG seroprevalence has been reported in veterinarians working with swine (9.6%) [ 10 ], pig farmers (14.1%) [ 11 ], abattoir workers (28.3%) [ 12 ], hunters (22.2%) [ 13 ] and forestry workers (18.0%) [ 14 ].…”

“…In Italy, the consumption of raw or undercooked wild boar meat and pork products containing the liver has been associated with an increased risk of HEV infection [ 15 ]. Furthermore, HEV seropositivity has been significantly associated with occupational exposure to pigs (12.3%) [ 11 ].…”