Thursday, May 12, 2016: 11:00 AM
Kokkali Room (Megaron Athens International Conference Center)
Annemarie Pielaat, RIVM - Centre for Infectious Disease Control, Bilthoven, Netherlands
Angelina Kuijpers, RIVM - Centre for Infectious Disease Control, Bilthoven, Netherlands
Peter Teunis, RIVM - Centre for Infectious Disease Control, Bilthoven, Netherlands
Ellen Delfgou-van Asch, RIVM - Centre for Infectious Disease Control, Bilthoven, Netherlands
Wilfrid Van Pelt, RIVM - Centre for Infectious Disease Control, Bilthoven, Netherlands
Lucas Wijnands, RIVM - Centre for Infectious Disease Control, Bilthoven, Netherlands
Introduction: Despite a declining trend,
Salmonella is with 82,694 confirmed human cases in 2013 still the second most important zoonosis in the EU. The Netherlands reported 992 laboratory confirmed cases of salmonellosis corresponding to an estimated number of 28,000 cases in the general population of 16.8 million people. The Dutch food and consumer product safety authority (NVWA) monitors the presence of
Salmonella according to EU-regulation 2073 (2005), which on several occasions reveal serovars that differ from those most frequently found in human reported cases. This raises questions about the current
Salmonella regulation in relation to the potential hazard of these infrequently found serovars.
Purpose: Put the virulence of infrequently found Salmonella serovars in relation to the potential hazard of more frequently found laboratory confirmed serovars from human cases in The Netherlands.
Methods: We investigated the phenotypic behavior of 70 strains of 35 different Salmonella serovars in an in vitro gastro-intestinal tract (GIT) system as proxy for virulence. Virulence was expressed as the probability of infection, P(inf), i.e. fraction of the overnight culture invading into Caco-2 cells after GIT passage. In addition, the phenotypic in vitro GIT results are put into perspective of human cases and molecular virulence properties related to these serovars.
Results: Results show that the (average) P(inf) of Salmonella serovars ranges from 1.7 10-8 (S.Kedougou) to 5.3 10-5 (S.Typhimurium). In general, the P(inf) corresponds to available epidemiological and virulotypic data. Still, individual exceptions exist and it is hypothesized that the public health risk from Salmonellais associated with exposure (prevalence, dose and/or acquired immunity) rather than difference in virulence.
Significance: Knowledge about the relative phenotypic virulence of different Salmonella serovars in relation to epidemiological and genomic data may provide guidance to policy makers for future regulation strategies.
