Immune response-eliciting exposure to Campylobacter vastly exceeds the incidence of clinically overt campylobacteriosis but is associated with similar risk factors: A nationwide serosurvey in the Netherlands

Summary Background We aimed to estimate population-level exposure to Campylobacter and associated risk factors, using three approaches for serological data analysis. Methods Nationwide, population-based serosurvey in the Netherlands (Feb 2006–Jun 2007). Anti- Campylobacter IgG, IgM and IgA were measured using ELISA, and analysed via: a) seroincidence estimation, using reference values of antibody peak levels and decay rates over-time after Campylobacter exposure; b) two normal distributions of true positives/negatives fitted to the IgG distribution to derive seroprevalence and individual probability of being positive/negative; and c) IgG levels. Risk factors were analysed using multiple linear regressions. Results From 1559 respondents, seroincidence was estimated at 1.61 infections/person-year (95%CI:1.58–1.64) and seroprevalence at 68.1% (65.4–70.9). The three approaches identified similar risk factors, although seroincidence had higher power and results were interpretable as risk: seroincidence was higher in females [exp(b) = 1.07(1.04–1.11)], older ages [vs. 15–34 years; for  Conclusion Campylobacter exposure is much higher than clinical infection rates, but risk factors are similar to those previously described.Seroincidence is a powerful measure to study Campylobacter epidemiology, and is preferred over other methods.