Do “developing” countries become "developed"? Lessons from Helicobacter pylori infection recurrence rate after eradication

The World Bank classified "developing countries" as all 135 countries with low or middle-income economies, whose 6.7 billion people represent 84% of the world's population. Other parameters, such as socioeconomic status, health quality indicators, or infrastructures, are often used to refine this definition. Helicobacter pylori infection is prevalent in over half of the world's population and varies from as low as 18.9% in Switzerland to 87.7% in Nigeria. After a successful eradication, as measured by tests such as 13C-UBT (Urea Breath Test), stool antigen, or histology, the recurrence rate of infection could happen due to recrudescence (recolonization of the same strain within one year of eradication) or reinfection (colonization of a new strain after one year). Comparing the results of our two meta-analyses from 2008 and 2024, we found that the disparity between "developed" and "developing" countries in recurrence of Helicobacter pylori infection after a successful eradication has disappeared. We assume that Helicobacter pylori recurrence is a marker for the socioeconomic state, and our results point toward a process in which "developing" countries become "developed".