[Impact of the use of molecular techniques (PCR) on detection and eradication success against Helicobacter pylori]

Introduction: Helicobacter pylori (H. pylori) infection affects more than 50% of the world population. Increased antibiotic resistance is the main cause of treatment failure. The main objective was to analyze the eradication success after the application of the new ESPGHAN treatment recommendations and the introduction of PCR as a direct diagnosis technique, describe the evolution of the local pattern of antibiotic resistance, and assess the cost-effectiveness of PCR application, isolated or in conjunction with culture as a diagnostic strategy.

Patients and methods: retrospective descriptive study of all microbiological isolates of H. pylori in 2013-2019 in our center, by comparing the percentage of resistance and eradication success between the periods 2013-2016 and 2017-2019. Cost-effectiveness study of direct diagnostic tests, comparing 3 different options: culture and PCR; only culture; PCR only.

Results: 192 patients were included, 98 were detected by culture (2013-2016) and 94 by culture and / or PCR (2017-2019). Antibiotic treatment was established in 153 patients, 90 in the first period (2011 ESPGHAN guidelines: eradication percentage 62.2%), 63 in the second (2017 ESPGHAN guidelines: eradication percentage: 73%). An increase in resistance to clarithromycin was observed, going from 16.3% (n=16) in the first period, to 53.2% (n=48) in 2017-2019 (98% detected by PCR, 60% by culture). There were no differences in the rest of antibiotic resistances. The isolated PCR application presented a cost-effectiveness analysis ratio (CEAR) of 71.91, compared to 92.16 for the culture and 96.35 for the culture and PCR combined.

Conclusions: the application of the ESPGHAN 2017 guidelines achieved greater eradication success, although less than that observed in previous publications, without reaching the target of at least 90%. An increase in resistance to macrolides was observed, without being able to discriminate whether it is a real increase or a greater diagnostic sensitivity of molecular techniques, with the isolated request for PCR being the most cost-effective strategy.