The Spectrum of -Mediated Diseases.

is the leading cause of peptic ulcer disease. The infection has been implicated in more than 75% of duodenal ulcer cases and 17% of gastric ulcer cases. has been classified as a human carcinogen, since it is the main cause of distal gastric adenocarcinoma and B cell mucosa-associated lymphoid tissue lymphoma. Evidence also links with extragastric conditions including iron deficiency anemia, idiopathic thrombocytopenic purpura, and vitamin B deficiency. Studies indicate that may be protective against other conditions of the gastrointestinal tract (e.g., reflux esophagitis and related pathologies) and elsewhere in the body (e.g., asthma). The infection is asymptomatic in the vast majority of cases; more serious outcomes occur in only 10-15% of infected individuals. Despite extensive research over the past 3 decades, there is no effective vaccine, and the circumstances leading to disease development remain unclear. In addition, there is now a growing prevalence of antimicrobial resistance in This review discusses these important issues.