In Switzerland, positive laboratory results of Campylobacter spp. and Salmonella spp. are notifiable. Cases registered in the National Notification System for Infectious Diseases (NNSID) have been increasing for Campylobacter and decreasing for Salmonella. The aim of this study is to look at the time trends in positivity rates for these two pathogens between 2003 and 2012. Positivity rates are defined as the number of positive tests divided by the total number of tests performed for a certain pathogen. Multivariable logistic regression models are used to assess associations between a positive test outcome and the year or month of testing, taking into account the patients' age and sex.