Changes in Seroprevalence of Helicobacter pylori Infection over 20 Years in Jinju, Korea, from Newborns to the Elderly

BACKGROUND: The objective of this study was to examine changes in the prevalence of cytotoxic-associated gene A (CagA) positive Helicobacter pylori infection in Jinju, Korea, over the last 20 years. METHODS: Three cross-sectional analyses were conducted concurrently. A total of 1,305 serum samples were collected from 1994–1995, 2004–2005, and 2014–2015, respectively. The presence of immunoglobulin (Ig) G, IgA, and IgM antibodies against H. pylori CagA protein was examined by western blotting. RESULTS: Overall, seropositivity for anti-CagA IgG antibody was significantly decreased from 63.2% to 42.5% over the last 20 years (P < 0.001). Anti-CagA IgG seropositivities in children and young adults aged 10–29 years decreased from 1994 (60.0%–85.0%) to 2015 (12.5%–28.9%). The age when plateau of increasing IgG seropositivity was reached in each study period shifted from the 15–19 year-old group in 1994–1995 (85.0%) to the 40–49 year-old group in 2014–2015 (82.5%). Overall seropositive rates of anti-CagA IgA and IgM antibodies did not change significantly either over the last 20 years. CONCLUSION: H. pylori infection rate in children and young adults declined over 20 years in Jinju, probably due to improved sanitation, housing, or economy.