Despite a significant public health burden the epidemiology of human Campylobacter infection remains blurred. The identification of demographic determinants for Campylobacter infection is therefore essential for identifying potential areas for intervention. Demographic data from an active, population-based sentinel surveillance system for Campylobacter infection (from 2000 until 2003, n=15 907) were compared with appropriate denominator data from the 2001 United Kingdom Census. Incidence was higher in males from birth until the late teens and in females from 20 to 36 years. Age- and gender-specific differences in Campylobacter incidence were observed in different ethnic and socioeconomic groups and hence are all major drivers for Campylobacter infection. Epidemiological studies on Campylobacter infection need to take these factors into consideration during design and analysis. The collation of detailed epidemiological data and its comparison with appropriate denominator data provides a valuable epidemiological tool for studying infection.