title: Investigation of underlying comorbidities as risk factors for symptomatic human hepatitis E virus infection.
abstract: Symptomatic Hepatitis E virus (HEV) infection occurs in few infected subjects, and the risk factors are not completely known.
  
  
  
  To explore the risk factors for adverse clinical outcomes in acute HEV infections.
  
  
  
  A large retrospective study was conducted. The baseline characteristics, clinical outcomes, and laboratory data of 512 acute HEV infection cases were analysed using logistic regression models.
  
  
  
  All patients exhibited autochthonous sporadic HEV infections, and most were elderly. Their symptoms varied from asymptomatic to severe liver diseases. In all, 215 patients (42.0%) had liver failure and/or decompensation, and 45 (8.2%) patients died within 3 months. Nearly 60% of patients had underlying chronic liver diseases (CLDs), 20% were cirrhotic, and various extrahepatic underlying comorbidities were common. The logistic regression analysis revealed that underlying CLDs, especially cirrhosis, were closely associated with disease severity (OR = 8.78, P < 0.001) but not with mortality in patients with severe liver diseases. In addition to the known factors, including an old age, the male gender and CLDs, we identified pre-existing extrahepatic tumours, diabetes, and chronic respiratory and renal diseases as novel independent predictors for adverse clinical outcomes. Importantly, patients without these four extrahepatic comorbidities showed a much lower mortality rate (4.2%, P < 0.001) than patients with one (18.5%) or more comorbidities (34.5%).
  
  
  
  Previous comorbidities, including tumours, diabetes, and chronic liver, lung and kidney diseases, were independent risk factors for adverse outcomes, especially mortality, in acute HEV infections. This study provides valuable data for improving the prevention and control of HEV infection.
authors.affiliation: Shanghai Public Health Clinical center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.|Key Laboratory of Medical Molecular Virology of Ministries of Education/Health, Institute of Medical Microbiology, Shanghai Medical College of Fudan University, Shanghai, China.
authors.forename: S
authors.identifier: 0000-0002-4749-6790
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Hepatology, Shanghai Public Clinical center, Fudan University, Shanghai, China.|Wenzhou Medical University, Wenzhou, Zhejiang.
authors.forename: C
authors.identifier: 0000-0002-5126-1943
authors.initials: C
authors.lastname: Chen
authors.affiliation: Shanghai Public Health Clinical center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
authors.forename: J
authors.initials: J
authors.lastname: Peng
authors.affiliation: Department of Hepatology, Shanghai Public Clinical center, Fudan University, Shanghai, China.
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Hepatology, Shanghai Public Clinical center, Fudan University, Shanghai, China.
authors.forename: D
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Shanghai Public Health Clinical center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
authors.forename: J
authors.initials: J
authors.lastname: Yan
authors.affiliation: Shanghai Public Health Clinical center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.|School of Life Sciences, Hebei Normal University, Shi-Jiazhuang, Hebei.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Hepatology, Shanghai Public Clinical center, Fudan University, Shanghai, China.
authors.forename: C
authors.initials: C
authors.lastname: Lu
authors.affiliation: Shanghai Public Health Clinical center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.|School of Life Sciences, Hebei Normal University, Shi-Jiazhuang, Hebei.
authors.forename: J
authors.initials: J
authors.lastname: Xun
authors.affiliation: Department of Hepatology, Shanghai Public Clinical center, Fudan University, Shanghai, China.
authors.forename: W
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Hepatology, Shanghai Public Clinical center, Fudan University, Shanghai, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Ling
authors.affiliation: Department of Hepatology, Shanghai Public Clinical center, Fudan University, Shanghai, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Hepatology, Shanghai Public Clinical center, Fudan University, Shanghai, China.
authors.forename: L
authors.initials: L
authors.lastname: Chen
mesh_terms: D000328:Adult; D015897:Comorbidity; D005260:Female; D016751:Hepatitis E / Q000453:epidemiology*; D016752:Hepatitis E virus / Q000302:isolation & purification*; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications / Q000453:epidemiology*; D017093:Liver Failure / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors