Helicobacter pylori infection and sexual risk factors: data from the heatlh in men study
The routes of transmission of Helicobacter pylori (H. pylori) remain in question and studies about possible sexual transmission have been inconclusive. Understanding transmission routes may have important implications for prevention and treatment. Therefore, we decided to study the possible association between sexual risk factors and H. pylori infection in a community based cohort of HIV-negative homosexual men in Sydney.
Participants were 1,427 men from the Health in Men cohort study recruited from 2001 to 2004 and followed till 2007. Participants underwent annual face-to-face interviews regarding demographics, sexual risk factors and sexual transmitted infections, and blood samples were collected and stored. Stored sera were analyzed using H. pylori multiplex serology based on a GST capture immunosorbent assay combined with fluorescent bead technology (Luminex). Seropositivity was defined as reactivity with at least three out of 6 recombinant proteins.
At baseline, 1333 men had serum available for analysis and 249 (18.7%, 95% CI 16.6 – 20.9) were seropositive for H. pylori. In multivariate analyses, prevalent H. pylori infection was significantly associated with increasing age (p<0.001), positive syphilis serology (OR=2.03, 95% CI 1.03-4.00) and HSV 1 seropositivity (OR=2.65, 95% CI 1.70-4.14). Circumcised men were less likely to test positive (OR=0.59, 95% CI 0.43-0.81). Among those who were seronegative at baseline, 30 seroconverted during the study, an incidence of 0.85 per 100 person-years (95% CI 0.60-1.23). In multivariate analyses, H. pylori seroconversion was significantly associated with urethral gonorrhoea in the last 12 months (HR=5.95, 95% CI 1.98-17.86) and reporting receptive fisting with casual partners (HR=4.62, 95% CI 1.59-13.93). Circumcised men were less likely to seroconvert to H. pylori (HR=0.39, 95% CI 0.19-0.80).
The association of H pylori infection with some sexual practices, circumcision, syphilis, gonorrhoea and HSV1 infection, suggests a role for sexual transmission. Further studies to elucidate these assocations are warranted.
