Setting a course for preventing hepatitis E in low and lower-middle-income countries: A systematic review of burden and risk factors

Abstract BackgroundHepatitis E virus is responsible for outbreaks of acute jaundice in Africa and Asia, many of which occur among displaced people or in crisis settings. While an efficacious vaccine for HEV has been developed, we lack key epidemiologic data needed to understand how best to use the vaccine for hepatitis E control in endemic countries. MethodsWe conducted a systematic review of articles published on hepatitis E in low and lower-middle-income countries (LMIC) in Africa and Asia. We searched PubMed, Scopus, and Embase databases to identify articles with data on anti-HEV IgG seroprevalence, outbreaks of HEV, or risk factors for HEV infection, disease, or death, and all relevant data were extracted. Using these data we describe the evidence around temporal and geographical distribution of HEV transmission and burden. We estimated pooled age-specific seroprevalence and assessed the consistency in risk factor estimates. ResultsWe extracted data from 148 studies. Studies assessing anti-HEV IgG antibodies used 18 different commercial assays. Most cases of hepatitis E during outbreaks were not confirmed. Risk factor data suggested an increased likelihood of current or recent HEV infection and disease associated with fecal-oral transmission of HEV, as well as exposures to blood and animals. ConclusionHeterogeneity in diagnostic assays used and exposure and outcome assessment methods hinder public health efforts to quantify burden of disease and evaluate interventions over time and space. Prevention tools such as vaccines are available, but require a unified global strategy for hepatitis E control to justify widespread use.