The Prevalence and Incidence of Helicobacter pylori–Associated Peptic Ulcer Disease and Upper Gastrointestinal Bleeding Throughout the World




Due to heightened awareness regarding testing for and eradication of infection, the prevalence and incidence of H pylori infection (and by extension the prevalence and incidence of peptic ulcer disease) appear to have declined in recent years. However, antimicrobial resistance is mounting and traditional clarithromycin- or metronidazole-containing triple therapies may no longer be highly effective at eradicating the infection. Combined bismuth- and metronidazole-containing quadruple therapy or sequential 4-drug therapy may be better choices for first-line treatment against this unique pathogen that is ideally suited to survive in the human stomach.


Brief history and epidemiology of Helicobacter pylori , peptic ulcer disease, and upper gastrointestinal bleeding


In October 1981 Barry Marshall, working with Robin Warren and Charles Goodwin, cultured stomach specimens in an attempt to identify organisms that had frequently been observed during histologic examination to be nestled in the narrow interface between the gastric epithelial cell surface and the overlying mucus gel. Fortuitously, during the 35th culture attempt, specimens were left to grow during the Australian Easter holiday for 5 days, rather than be discarded after the usual 3-day period. That culture revealed a pure growth of a gram-negative, spiral, urease-producing organism. This bacterium, initially named Campylobacter pyloridis , would later be classified under the new genus Helicobacter . For their discovery of this curved bacillus, Helicobacter pylori , that was later shown to play a role in gastritis and peptic ulcer disease, Marshall and Warren received the 2005 Nobel Prize in Medicine and Physiology ( Fig. 1 ).




Fig. 1


Giemsa stain showing the helical forms of the Helicobacter pylori (original magnification ×1000).

( Courtesy of Christopher A. Moskaluk, MD, PhD, Department of Pathology, University of Virginia.)


H pylori is one of the most common chronic bacterial infections in humans, with more than 50% of the world’s population infected with these bacteria. Genetic sequence analysis has proposed that humans have been infected with H pylori for more than 58,000 years. While H pylori have been demonstrated worldwide in individuals of all ages, infection is commonly acquired at an earlier age in developing countries as compared with industrialized nations. In older children and adults, infection persists so that in the developing areas of the world the overall H pylori prevalence can reach more than 80% in individuals older than 50 years.


H pylori are unique bacteria that are ideally suited to live in the acidic environment of the human stomach. Person-to-person transmission of bacteria from fecal-oral, oral-oral, or gastric-oral exposure seems the most probable explanation for infection. Especially in developing countries, contaminated water might serve as an environmental source of bacteria because the organism can remain viable for several days in water. Iatrogenic infection has occurred during the use of a variety of inadequately disinfected gastric devices, endoscopes, and endoscopic accessories. Gastroenterologists and nurses appear to be at greater risk for acquiring H pylori , presumably because of occupational contact with infected gastric secretions, although this is less likely to occur when universal precautions for infection control in the health care setting are strictly enforced.


The ultimate clinical manifestations of H pylori infection include gastric and duodenal ulcers, gastric marginal zone B-cell lymphoma (formally MALT lymphoma), and gastric adenocarcinoma. Eradicating the infection prevents recurrence and ulcer complications such as bleeding or perforation. However, most infected individuals remain asymptomatic, despite developing chronic histologic gastritis ( Fig. 2 ). Peptic ulcer disease (PUD) is estimated to affect more than 6 million persons in the United States each year, and it places a significant economic burden on the United States health care system. A peptic ulcer is found in approximately 5% to 15% of patients with dyspepsia in North America. In a meta-analysis that included 18 large population-based studies from around the world, the range of prevalence for PUD was 0.1% to 4.7%, with an annual incidence range of 0.3% to 0.19%. H pylori was initially believed to be responsible for up to 95% of all gastroduodenal ulcers, but subsequent studies from the United States have found the prevalence of H pylori in patients with PUD to range from 36% to 73%, which can vary based on geographic location, ethnicity, and socioeconomic factors.


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Sep 12, 2017 | Posted by in GASTOINESTINAL SURGERY | Comments Off on The Prevalence and Incidence of Helicobacter pylori–Associated Peptic Ulcer Disease and Upper Gastrointestinal Bleeding Throughout the World

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