Background: Hepatitis A (HA) incidence declined in most European countries in the past decades. We analysed HA notification data for Switzerland of 29 years looking for disease- and notification system-related factors possibly contributing to observed trends.
Method: Notification data were descriptively analysed using five time intervals (1988-1993, 1994-1999, 2000-2005, 2006-2011, 2012-2016); and notification rates were calculated.
Results: From 1988 to 2016, the HA notification rate decreased from 9.5 to 0.5 per 100'000 population in Switzerland. Median age and the proportion of hospitalised cases increased over time. In the 1988-1993-time period, intravenous drug use was the most frequently mentioned risk exposure while consumption of contaminated food/beverages was most frequently mentioned in the 2012-2016-time period.
Conclusions: Notification data does not allow reliably identifying current risk groups (e.g. travellers) due to low case numbers, limited availability and reliability of information. It is important to document changes in the surveillance system for later analyses and interpretation of long-term trends. Population susceptibility likely increases underlining the importance of continued and continuous surveillance and prevention efforts despite decreasing case numbers. Operational research is recommended to further investigate observed trends of HA and to enhance the abilities for decision making from Swiss HA surveillance data.
Keywords: Communicable diseases; Hepatitis A; Mandatory reporting; Public health surveillance; Vaccination.
Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.