Sexual Contact as Risk Factor for Campylobacter Infection, Denmark

Abstract

Campylobacteriosis is a disease of worldwide importance, but aspects of its transmission dynamics, particularly risk factors, are still poorly understood. We used data from a matched case-control study of 4,269 men who have sex with men (MSM) and 26,215 controls, combined with national surveillance data on Campylobacter spp., Salmonella spp., and Shigella spp., to calculate matched odds ratios (mORs) for infection among MSM and controls. MSM had higher odds of Campylobacter (mOR 14, 95% CI 10-21) and Shigella (mOR 74, 95% CI 27-203) infections, but not Salmonella (mOR 0.2, 95% CI 0-13), and were less likely than controls to have acquired Campylobacter infection abroad (χ² = 21; p<0.001). Our results confirm that sexual contact is a risk factor for campylobacteriosis and also suggest explanations for unique features of Campylobacter epidemiology. These findings provide a baseline for updating infection risk guidelines to the general population.

Keywords: Campylobacter; Denmark; Guillain-Barré syndrome; MSM; Salmonella; Shigella; bacteria; campylobacteriosis; enteric infections; epidemiology; food safety; foodborne diseases; risk factors; sexual contact; sexually transmitted infections; shigellosis; zoonoses.

Figure 1

Inverted case-control study design in study of sexual contact as risk factor for Campylobacter infection, Denmark, 2010–2018. mOR adjusted for foreign travel, year of notification, infection with any of the other pathogens, and recurrent infections. mOR, matched odds ratio; MSM, men who have sex with men.

Figure 2

Percentages of clinical notifications of infections acquired through MSM contact (notifiable infections) and Campylobacter, Salmonella, and Shigella infections reported among MSM and controls in study of sexual contact as risk factor for Campylobacter infection, Denmark, 2010–2018. MSM were men >18 years of age notified of any infectious disease acquired through sexual contact with another man. Controls were men >18 years randomly selected from the Denmark population register. MSM and controls <18 years of age or who did not have a valid national civil registration number were excluded from the study. MSM, men who have sex with men.