(left) Structure of Helicobacter pylori. (right) Scanning electron micrograph of Helicobacter bacteria (originally classified as Flexispira rappini, now deprecated). Obtained from the CDC Public Health Image Library. Image credit: CDC/Dr. Patricia Fields, Dr. Collette Fitzgerald (PHIL #5715), 2004.
- The human gastrointestinal tract is the primary source.
- Person-to-person spread by the fecal-oral route.
- In developing countries, 70%-90% of individuals are colonized by the age of 10; in developed countries, colonization is low during children but increases to around 45% in older adults.
- Between 70% and 90% of people with gastritis, peptic ulcers, or doedonal ulcers are infected with H. pylori.
- Appears as gastritis (def), peptic ulcers (def), gastric adenocarcinoma (def), and certain B-cell lymphomas (def).
- Chronic gastritis is a risk factor for gastric carcinoma.
From Helicobacter pylori Infection, by Luigi Santacroce, MD, Assistant Professor, Department of Dentistry and Surgery, Section of General Surgery, Medical and Dentistry School, State University at Bari, Italy and Giuseppe Miragliotta, MD, Chairman, Professor, Section of Microbiology, University Hospital of Bari, Italy; Manoop S Bhutani, MD, Associate Professor of Medicine, Division of Gastroenterology, University of Texas Medical Branch at Galveston