What percentage of individuals over 50 years old in developed countries is affected by H.pylori?

In developed countries, approximately 50% of individuals over 50 years old are estimated to be affected by Helicobacter pylori (H. pylori), a type of bacteria often associated with gastric conditions, including peptic ulcers and chronic gastritis. This prevalence is influenced by various factors, including socioeconomic status, sanitation, and healthcare access during childhood, as H. pylori typically acquires during childhood and persists into adulthood.

The figure of about 50% reflects a significant portion of the adult population, indicating that while H. pylori is common, it is not overwhelmingly pervasive in older adults compared to other potential health concerns. The other percentages provided in the choices either underestimate or overestimate the prevalence, illustrating the balance of H. pylori's occurrence in this demographic.