Incidence of hepatitis E virus infection among blood donors in a high endemic area of Central Italy

Abstract

Summary In Europe, autochthonous hepatitis E virus (HEV) infection is mainly a foodborne zoonosis, but it is also transmitted by blood transfusion. Despite the numerous prevalence surveys, only a few studies have investigated HEV incidence. We aimed to determine HEV incidence and risk factors among blood donors in a hyperendemic area in Central Italy. Of 296 blood donors who had tested HEV negative in two previous seroprevalence surveys in L'Aquila, 198 agreed to undergo at least another blood sampling for estimating HEV incidence nearly 2 years after the prevalence surveys. Ten newly acquired infections were detected, yielding an overall incidence of 2.1/100 person‐years (95%CI: 1.0‐3.9), with an estimated participant's cumulative probability of becoming HEV infected of 6.5% (95%CI: 3.5‐12.0) at 4 years after enrolment. Seven newly infected blood donors were IgG positive only, two were IgM positive (one also IgG positive) and one was HEV RNA positive only, harbouring subtype 3c. Incident infection was most strongly associated with eating game meat, raw‐dried pork liver sausage and raw‐dried wild boar sausage. None of these exposures was statistically significant, even if eating raw‐dried wild boar sausage approached significance (P = 0.06). The HEV incidence we found was considerable compared with other similar studies. The nearly significant association of incident infection with wild boar and other game meat consumption was in agreement with the 3c subtype isolation in the viremic donor. However, beyond eating habits, also other exposure sources are likely important in hyperendemic areas, where incidence and risk exposure studies need to be undertaken for effectively preventing HEV transmission.

Hepatitis E Virus Occurrence in Pigs Slaughtered in Italy

“…The virus circulates widely in Italy in the human population as proved by several studies on the detection of antibodies against HEV in blood donors [ 27 , 28 , 29 , 30 ]. At the national level, the mean seroprevalence in blood donors is 8.7% with a highly variable range depending on geographical area investigated.…”

“…Both regions are not the main areas of pig farming, mostly located in Northern Italy, where the mean seroprevalence in humans varies between 5 and 10%. The observed high seroprevalence in these hyperendemic regions in Central Italy was deemed to be linked to eating habits such as consumption of raw liver sausages [ 27 , 28 , 29 ].…”

Prevalence of hepatitis E viraemia among blood donors: a systematic review

“…On review of full‐text articles for the remaining 140 citations, 83 did not meet selection criteria. Of the 57 citations selected for final data synthesis , one provided three data sets ; hence, we had a total of 59 data sets from 28 countries (Fig. ).…”

Seroprevalence of hepatitis E virus among blood donors on Corsica, France, 2017

“…Previous studies have shown that antibody levels decrease over time and in some subjects, anti-HEV IgG can disappear after a follow-up ranging between 1 and 22 years [51]. A recent study among blood donors from central Italy using the Wantai assay has reported an HEV seroconversion rate of 2.1 per 100 person-years [52], in the same order of magnitude (1.3-4.6/100 person-years) as those estimated with our models.…”

“…Epidemiological studies in Europe, conducted with the Wantai serological test, showed great geographical heterogeneity of anti-HEV carriers with seroprevalences ranging from 5-6% in Scotland [29,30] to 52% in south-western France [31]. Important variability was observed even within individual countries [32][33][34]. A nationwide seroprevalence study conducted in France reported a 22% anti-HEV IgG seroprevalence in the French blood donor population tested in 2011 and 2012 [32].…”