Helicobacter pylori ( H. pylori ) infection is a common worldwide infection that is an important cause of peptic ulcer disease and gastric cancer. H. pylori may also have a role in uninvestigated and functional dyspepsia, ulcer risk in patients taking low-dose aspirin or starting therapy with a non-steroidal anti-infl ammatory medication, unexplained iron defi ciency anemia, and idiopathic thrombocytopenic purpura. While choosing a treatment regimen for H. pylori , patients should be asked about previous antibiotic exposure and this information should be incorporated into the decision-making process. For fi rst-line treatment, clarithromycin triple therapy should be confi ned to patients with no previous history of macrolide exposure who reside in areas where clarithromycin resistance amongst H. pylori isolates is known to be low. Most patients will be better served by fi rst-line treatment with bismuth quadruple therapy or concomitant therapy consisting of a PPI, clarithromycin, amoxicillin, and metronidazole. When fi rst-line therapy fails, a salvage regimen should avoid antibiotics that were previously used. If a patient received a fi rst-line treatment containing clarithromycin, bismuth quadruple therapy or levofl oxacin salvage regimens are the preferred treatment options. If a patient received fi rst-line bismuth quadruple therapy, clarithromycin or levofl oxacin-containing salvage regimens are the preferred treatment options. Details regarding the drugs, doses and durations of the recommended and suggested fi rst-line and salvage regimens can be found in the guideline. Asia and Central and South America ( 8,22 ). Th ere is, however, preliminary evidence that it may be falling in some previously high prevalence areas ( 22 ). People immigrating to North America from Asia and other parts of the world have a much higher prevalence of the infection than people born in North America ( 23 ). In one study, the seroprevalence among immigrants from East Asia was 70.1% ( 24 ). Hispanic immigrants to North America have higher rates of the infection than fi rst-or second-generation Hispanics who were born here ( 25 ).
QUESTION 2: WHAT ARE THE INDICATIONS TO TEST FOR, AND TO TREAT, H. PYLORI INFECTION?
RecommendationsSince all patients with a positive test of active infection with H. pylori should be off ered treatment, the critical issue is which patients should be tested for the infection (strong recommendation, quality of evidence: not applicable), All patients with active peptic ulcer disease (PUD), a past history of PUD (unless previous cure of H. pylori infection has been documented), low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma, or a history of endoscopic resection of early gastric cancer (EGC) should be tested for H. pylori infection. Th ose who test positive should be off ered treatment for the infection (strong recommendation, quality of evidence: high for active or history of PUD, low for MALT lymphoma, low for history of endoscopic resection of EGC).In patients with uninvestigated d...