HELICOBACTER DISEASE: CLINICAL ASPECTS
Primary infection with H. pylori is either silent or causes an illness with nausea and upper abdominal pain lasting up to 2 weeks. Years later, the findings of gastritis and peptic ulcer disease include nausea, anorexia, vomiting, epigastric pain, and even less specific symptoms such as belching. Many patients are asymptomatic for decades, even up to perforation of an ulcer. Perforation can lead to extensive bleeding and peritonitis due to the leakage of gastric contents into the peritoneal cavity.
The most sensitive means of diagnosis is endoscopic examination, with biopsy and culture of the gastric mucosa. The H. pylori urease is so potent its activity can be directly demon-strated in biopsies in less than an hour. Noninvasive methods include serology and a urea breath test. For the breath test, the patient ingests 13C- or 14C-labeled urea, from which the urease in the stomach produces products that appear as labeled CO2 in the breath. A num-ber of methods for detection of antibody directed against H. pylori are now available. Be-cause IgG or IgA remain elevated as long as the infection persists, these tests are valuable both for screening and for evaluation of therapy. The advantage of direct detection of the organism is that culture is the most sensitive indicator of cure following therapy.
H. pylori is susceptible to a wide variety of antimicrobial agents. Bismuth salts (eg,Pepto-Bismol), which in the past were believed to act by coating the stomach, also have antimicrobial activity. Cure rates approaching 95% have been achieved with various com-binations of bismuth salts and two antibiotics. Metronidazole, tetracycline, clarith-romycin, and amoxicillin have been effective. Relapse rates are low, particularly when acid secretion is also controlled with the use of a proton pump inhibitor. These combina-tion regimens must be continued for at least 2 weeks and may be difficult for some pa-tients to tolerate. Prevention of H. pylori disease awaits further understanding of trans-mission and immune mechanisms. Prophylactic treatment of asymptomatic persons colonized with H. pylori is not yet recommended.