ADONIS D-JRP26-WP3.2 + D-JRP26-WP3.4 Description of basis epidemiological characteristics of human S. Enteritidis cases and other relevant serovars

In conclusion, the SE incidence does not decrease further in the Netherlands and Belgium after 2014. Although some of the studied factors may play a role in the reversal of the decreasing SE trend, they cannot fully explain it. This indicates that the underlying reason might be at primary production or pathogen genomic levels, or is multifactorial. Importantly, we found that changes in notification obligation in Spain was likely the underlying reason for the increasing SE trend since 2013/2014 as reported in the ECDC Surveillance Atlas of Infectious Disease, leading to an increase in the number of laboratories reporting their SE cases. Indeed, a decreasing trend was observed using only SE data from laboratories that reported over the whole study period. This would be particularly important to investigate for countries contributing most SE cases to the total number of cases in the EU/EEA. These include for example Czechia, reporting around 25% of alle SE cases in  the EU/EEA, and Poland, which only started reporting SE cases since 2017, accounting for almost 20% of SE cases since then.