Background: A decreased incidence of Helicobacter pylori infection has been prospected to occur nowadays.
Aim: To evaluate the exposure to H. pylori, prevalence and incidence of active infection, and related risk factors in the general population.
Methods: In a small town of Southern Italy (932 inhabitants), 595 (3-97 years) and 157 (12-82 years) subjects among those with no evidence of active H. pylori infection participated at baseline and 10 years later, respectively. A questionnaire was administered. Active H. pylori infection was assessed by (13) C-urea breath test (UBT). Serum VacA and CagA antibodies were determined.
Results: Of 518 subjects who were evaluated by both UBT and serology, 310 (59.8%) were UBT positive, 479 (92.4%) VacA positive, and 369 (71.2%) CagA positive. Subjects UBT negative and serology positive were 169 (32%), ranging 1 (14.2%) to 29 (82.8%) from last to first decades of life. Age, female gender, and people per room were independent risk factors for subjects UBT positive compared to those UBT negative and serology positive. Ten years later, subjects who became UBT positive were four of 157 (0.25% per year) while those who became seropositive for VacA and/or CagA were 17 of 26 (6.5% per year).
Conclusions: H. pylori infection is highly dynamic with wide range of spontaneous clearance. It is easily cleared in the first decades of life, more recent years, less crowded homes, and males. It disappears and recurs more often than it was previously thought, implying that the current decline in its prevalence is due to real clearance instead of a fall in infection rate.
Keywords: CagA; Helicobacter pylori; VacA; epidemiology; urea breath test.
© 2014 John Wiley & Sons Ltd.