Diseases Caused by Helicobacter pylori Infection
Helicobacter pylori infection causes chronic gastritis, peptic ulcer disease, gastric cancer, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. 1
Primary Gastrointestinal Diseases
Chronic Gastritis
- H. pylori gastritis is an infectious disease that causes chronic active gastritis in all infected individuals, which persists for life if untreated. 1, 2
- The infection is now formally recognized as an infectious disease requiring eradication whenever diagnosed. 1
Peptic Ulcer Disease
- Among those with H. pylori infection, the lifetime risk of peptic ulcer is approximately 1 in 6 (∼17%). 1
- H. pylori is etiologically related to both gastric and duodenal ulcers. 1, 3
- Cure of H. pylori infection prevents ulcer recurrences and development of new cases, transforming peptic ulcer from a chronic disease into a "one-off" condition. 1, 4
Gastric Cancer
- Gastric cancer is the sixth most common cancer worldwide and the third most common cause of cancer death, with over 768,793 deaths in 2020. 1
- H. pylori causes more than 80% of cases of gastric cancer. 5, 2
- The worldwide lifetime risk of developing gastric cancer varies from approximately 0.6% to 22% depending on geographic location. 1
- Atrophic gastritis, caused by H. pylori, is tightly linked to gastric cancer development. 1
- Eradication of H. pylori can both prevent and reduce the incidence of gastric cancer, particularly when treated before development of atrophic changes. 1, 4
Gastric MALT Lymphoma
- H. pylori infection causes gastric mucosa-associated lymphoid tissue lymphoma. 1, 2, 3
- Cure of infection can cure early-stage MALT lymphoma. 4
Risk Factors and Disease Progression
Intrafamilial Clustering
- The infection clusters within families, increasing the risk of peptic ulcer disease and gastric cancer within family units. 1, 6
- H. pylori is primarily acquired in childhood through person-to-person transmission within families. 1, 6
High-Risk Populations
- Immigrants from high-prevalence regions (Central and South America, the Caribbean, Eastern Europe, Asia, and India) retain gastric cancer risk similar to their home country, increasing the healthcare burden in host countries. 1, 6
- In the United States, infection rates are approximately 2.6-fold greater among Hispanics and 3.2-fold greater among East Asians compared with the overall population. 6
Disease Progression Pathway
The pathophysiology follows a predictable sequence:
- Initial infection → Chronic gastritis → Atrophic gastritis → Gastric cancer (in susceptible individuals). 1, 2
- Disease outcome depends on bacterial genotype, host physiology and genetics, and environmental factors such as diet. 2, 4
- Not all infected individuals develop clinical disease; some remain asymptomatic while others progress to severe pathology. 3, 4
Clinical Implications
A proactive approach to testing and treatment is now recommended, including outreach to family members of individuals diagnosed with active infection and high-risk local populations. 1, 6
The current consensus is that H. pylori gastritis is associated with significant risk to the host and provides no proven benefits, warranting eradication whenever diagnosed. 1