Consumption of undercooked pork and sausage has been shown to be the main risk factor for a certain genotype of Hepatitis E in Italy.

A rise in hepatitis E cases are being reported in several European countries but the burden of hepatitis E virus (HEV) infection is largely unknown in Italy.

Researchers piloted a strengthened and integrated HEV surveillance system between 2012 and 2016 to better understand epidemiology at the national level in Italy. The work was published in the journal Eurosurveillance.

In the five year period, 169 confirmed hepatitis E cases were identified. Of 65 HEV-RNA positive samples of sufficient quality for molecular analysis, 66 percent were genotype HEV3, 32 percent HEV1 and 1 percent HEV4. Cases with genotype HEV1 had traveled to highly endemic areas but non-travel related cases were associated with genotype HEV3, which was locally acquired.

“HEV infection is more widely distributed in Europe than previously thought and is spread across endemic and non-endemic areas by travel and zoonosis. An increasing number of HEV cases are no longer occurring exclusively among returning travelers from endemic areas,” said researchers.

The most frequent risk factor reported by HEV3 infected cases was consumption of undercooked pork in 45 of 57 cases and undercooked pork sausages in 32 of 52 cases. Of the 135 confirmed cases with available information, 64 reported shellfish consumption (38 percent ate raw shellfish) and all but three were infected by HEV3.

“The multivariate analysis showed a fourfold greater risk of HEV3 infection after the consumption of undercooked pork, particularly an Italian sausage usually consumed raw. This association between HEV3 and undercooked pork was stronger when travel-related cases were excluded from the analysis, thus supporting that autochthonous HEV circulation in Italy is primarily related to food habits,” according to the researchers.

Due to the widespread consumption of pork in Italy, it is difficult to estimate precisely the direct association of hepatitis E with this product.

Of cases with available information, 101 out of 137 presented with jaundice, 22 of 51 with fever, 20 of 51 had unexplained weight loss and 19 of 52 had abdominal pain. Almost all confirmed cases with information (150 of 160) required hospitalization with a range of two to 51 days. Two deaths occurred in 2014 in Italian men in their 80s who had underlying liver cirrhosis.

France has seen a dramatic increase in hepatitis E cases since 2010 attributed to the availability of HEV diagnostic tests and a better understanding of infection. The pork was also the main reservoir in the country.

Viral hepatitis is a notifiable disease in Italy but the statutory surveillance system does not collect data on HEV but more generically on viral hepatitis. Since 2007, notification of acute HEV infection was included in the existing parallel enhanced surveillance system for viral hepatitis called SEIEVA (Integrated Epidemiological System for Acute Viral Hepatitis) run by the Italian Institute of Health (ISS). From 2012 to 2016, 456 of 5,057 cases notified to SEIEVA were possible hepatitis E cases.

The low incidence of hepatitis E could be due to under-notification and under-ascertainment of cases.

“A potential solution would be to make hepatitis E a systematically notifiable disease in Italy, as this would help get a better estimate of the national incidence and burden. Integrated surveillance needs to be systematized through the improvement of case finding and diagnostic capacity across all Italian regions,” added researchers.

An increased incidence in 2013 was due to an outbreak involving eight people between December 2013 and February 2014; the median age of cases was 61 (range 41–67) and all but one were male. Seven reported sausage consumption (no information for one case) and all were infected by genotype HEV3.

Cooking at 71 degrees Celsius for 20 minutes inactivates Hepatitis E virus. The incubation period following exposure to the virus ranges from three to eight weeks.

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