Usefulness of seroconversion rates for comparing infection pressures between countries

J. Simonsen*, P. Teunis, W. Van Pelt, Y. Van Duynhoven, K. A. Krogfelt, M. Sadkowska-Todys, K. Mølbak

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review


Salmonella is a frequent cause of foodborne illness. However, since most symptomatic cases are not diagnosed, the true infection pressure is unknown. Furthermore, national surveillance systems have different sensitivities that limit inter-country comparisons. We have used recently developed methods for translating measurements of Salmonella antibodies into estimates of seroincidence: the frequency of infections including asymptomatic cases. This methodology was applied to cross-sectional collections of serum samples obtained from the general healthy population in three European countries. Denmark and The Netherlands had the lowest seroincidence (84169 infections/1000 person-years), whereas Poland had the highest seroincidence (547/1000 person-years). A Bayesian method for obtaining incidence rate ratios was developed; this showed a 6·3 (95% credibility interval 3·3-12·5) higher incidence in Poland than in Denmark which demonstrates that this methodology has a wider applicability for studies of surveillance systems and evaluation of control programmes.

Original languageEnglish
JournalEpidemiology and Infection
Issue number4
Pages (from-to)636-643
Number of pages8
Publication statusPublished - Apr 2011
Externally publishedYes


  • mathematical modelling
  • salmonellosis
  • serology

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