• Department of Epidemiology, University of North Carolina Gillings School for Global Public Health and the Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina.
• Cancer Control and Population Health Sciences Program, Duke Cancer Institute, Durham, North Carolina.
• Division of Epidemiology, Vanderbilt University Medical Center, Nashville, Tennessee.
• Epidemiology Program, University of Hawai'i Cancer Center, Honolulu, Hawaii.
• University of Southern California and USC Norris Comprehensive Cancer Center, Los Angeles, California.
• Department of Population Health, New York University School of Medicine, New York, New York.
• Department of Epidemiology & Population Health, Albert Einstein College of Medicine, Bronx, New York.
• Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
• Division of Gastroenterology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
• Department of Medicine and Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center; Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee.

BACKGROUND: Prevalence of Helicobacter pylori (H. pylori) infection, the main risk factor for gastric cancer, has been decreasing in the United States; however, there remains a substantial racial disparity. Moreover, the time-trends for prevalence of CagA-positive H. pylori infection, the most virulent form, are unknown in the U.S.

POPULATION: We sought to assess prevalence of CagA-positive H. pylori infection over time by race in the United States.

METHODS: We utilized multiplex serology to quantify antibody responses to H. pylori antigens in 4,476 participants across five cohorts that sampled adults from 1985 to 2009. Using log-binomial regression models, we calculated prevalence ratios and 95% confidence intervals for the association between H. pylori-CagA sero-prevalence and birth year by race.

RESULTS: African Americans were three times more likely to be H. pylori-CagA sero-positive than Whites. After adjustment, H. pylori-CagA sero-prevalence was lower with increasing birth year among Whites (P_trend = 0.001), but remained stable for African Americans. When stratified by sex and education separately, the decline in H. pylori-CagA sero-positivity among Whites remained only for females (P_trend < 0.001) and was independent of educational attainment. Among African Americans, there was no difference by sex; furthermore, sero-prevalence increased with increasing birth year among those with a high school education or less (P = 0.006).

CONCLUSIONS: Among individuals in the United States born from the 1920s to 1960s, H. pylori-CagA sero-prevalence has declined among Whites, but not among African Americans.

IMPACT: Our findings suggest a widening racial disparity in the prevalence of the most virulent form of H. pylori, the main cause of gastric cancer.