Significant Structural Breaks in the International Incidence of Hepatitis Delta Virus

Abstract

The international incidence of Hepatitis Delta Virus (HDV) is challenging to accurately estimate due to the limited testing and lack of active surveillance for this rare infectious disease. These limitations prevent the detection of low-level and/or geographically dispersed changes in the incidence of HDV diagnoses. A study was designed to enable international active tracking and analyses of HDV epidemiology by aggregating global HDV diagnoses datasets. Publicly accessible datasets containing yearly incidence for HDV and Hepatitis B Virus (HBV) diagnoses were identified for Argentina, Australia, Austria, Brazil, Bulgaria, Canada, Finland, Germany, Macao, Netherlands, New Zealand, Norway, Sweden, Taiwan, Thailand, United Kingdom, and United States. Aggregated analysis of these HDV and HBV datasets spanning 1999-2020 identified structural breaks in the timeline of HDV incidence in 2002, 2012, and 2017. A significant increase in the international HDV incidence, relative to reported HBV diagnoses, occurred in 2013-2017. Secondary analysis identified four distinct temporal clusters of HDV incidence, including Cluster I (Macao, Taiwan), Cluster II (Argentina, Brazil, Germany, Thailand), Cluster III (Bulgaria, Netherlands, New Zealand, United Kingdom, United States), and Cluster IV (Australia, Austria, Canada, Finland, Norway, Sweden). Additionally, analyses of available demographic data identified a decreasing trend of HDV diagnoses in patients 0-19 years of age and an increasing trend of HDV diagnoses in patients ≥60 years of age. Re-evaluation of the testing paradigm for HDV in HBV-positive patients and an active surveillance status of HDV are warranted to define the etiology of the observed international shifts in HDV incidence.