High proportion of asymptomatic infections in an outbreak of hepatitis E associated with a spit-roasted piglet, France, 2013

Publié le 1 octobre 2015
Mis à jour le 6 septembre 2019

Background: on 11 December 2013, 3 clustered cases of hepatitis E were reported on a French coastal island. They had taken part in a wedding meal where one of the courses was a spit-roasted piglet. The piglet had been stuffed with a raw stuffing partly made from the liver. Investigations were carried out to identify the vehicle of contamination and evaluate the dispersion of the Hepatitis E virus (HEV) in the environment. Methods: a questionnaire was administered to 98 wedding participants who were asked to give a blood sample. Cases were identified by reverse transcription polymerase chain reaction and serological tests. A retrospective cohort study was conducted among 38 blood sampled participants after the exclusion of 14 participants with evidence of past HEV infection. Relative risks and 95% confidence intervals were calculated by food item consumed during the wedding through univariate and multivariable Poisson regressions. Phylogenetic analyses were performed to compare the clinical HEV strains, with strains detected in the liquid manure sampled at the farm where the piglet was born and in the untreated island wastewater. Results: seventeen cases were identified, 70.6% were asymptomatic. Acute HEV infection was independently associated with piglet stuffing consumption (RR=1.69 [1.04-2.73], p=0.03). Clinical strains from the index cases, veterinary and environmental HEV strains were identical. Conclusions: our investigation attributed this large HEV outbreak to the consumption of an undercooked pig liver-based stuffing. After infection, the cases became a temporary reservoir for HEV, which was detected in untreated wastewater of the island.

Auteur : Guillois Y, Abravanel F, Miura T, Pavio N, Vaillant V, Lhomme S, Le Guyader FS, Rose N, Le Saux JC, King LA, Izopet J, Couturier E
Clinical Infectious Diseases, 2015, p. 18 p.