Am Fam Physician. 2000;62(10):2334
Helicobacter pylori infection has been associated with the pathogenesis of peptic ulcer disease (PUD) and gastric malignancies. Eradicating this bacteria in selected patients can significantly reduce the incidence of recurrent PUD. Treatment typically includes the use of acid suppressive medications along with antimicrobials. Currently, only patients with complicated gastric or duodenal ulcers or other serious gastric conditions are routinely tested for H. pylori infection. However, a number of medical organizations now recommend that young, otherwise healthy patients with uncomplicated dyspeptic symptoms should be tested and treated for H. pylori infection as well. Assessing for eradication can be reliably accomplished with histology, rapid urease testing and urea breath testing (UBT), but these tests are typically performed no less than four weeks after the completion of treatment. Chey and colleagues evaluated the effectiveness of the 14C-UBT at two weeks after treatment and compared those results with results obtained four to six weeks after treatment.
Patients with active H. pylori infection received proton-pump inhibitor (PPI)–based treatment for 10 to 14 days. Eradication was assessed using the 14C-UBT at two weeks and again at four to six weeks after treatment. A positive test for H. pylori was a carbon dioxide (CO2) excretion of more than 200 disintegrations per minute (dpm), a negative test was less than 50 dpm and an equivocal test was 50 to 200 dpm. Confidence intervals for the two-week UBT were established by using the four-to six-week UBT as the gold standard.
A total of 82 patients completed the protocol. Four had an equivocal UBT test and were excluded. Of the remaining patients, 68 (87 percent) had a negative UBT at four to six weeks. Of the 10 patients who had a positive UBT at four to six weeks, nine also had a positive test at two weeks. Given these data, the two-week UBT had a sensitivity of 90 percent, a specificity of 99 percent and an accuracy rate of 97 percent. In addition, patients with a positive UBT at four weeks also had lower CO2 excretion levels at two weeks than at four weeks.
The authors conclude that the results of the two-week 14C-UBT for H. pylori eradication were similar to those obtained at the standard four- to six-week follow-up interval. Early testing for eradication allows physicians to identify treatment failures sooner and to provide appropriate interventions in a more timely manner.