Hepatitis E outbreak in a mechanical factory in Qingdao City, China

Abstract

ObjectiveIn July 2018, recurrent hepatitis E cases were reported from a factory in Qingdao City, China. The aim of this study was to identify additional cases, and help prevent future incidents by identifying possible risk factors for infection. MethodsParticipants were asked to provide blood samples for hepatitis E virus (HEV) IgM and IgG antibodies screening, as well as liver function test. A questionnaire that assessed demographics, potential risk factors, and clinical symptoms was completed by participants. HEV RNA genotyping was performed using a nested Reverse Transcriptional Polymerase Chain Reaction (RT-PCR) method. Adjusted Poisson regression model for participant characteristics and risk factors was constructed for multivariate analysis. ResultsOverall, 41(14.5%, 41/283) participants had recent acute infection (21 of these were symptomatic). The result of multivariate analysis demonstrated a significant association of acute HEV infection with consumption of pig liver within the past two months (Relative Risk 2.61, 95% confidence interval (CI) 1.10–6.17, p=0.0294). Sequencing of HEV RNA from seventeen acute cases indicated three HEV isolates of genotype 4 induced this outbreak. ConclusionsThis was probably a common-source foodborne hepatitis E outbreak, related to the consumption of undercooked pig liver.