Helicobacter pylori (H. pylori) infection is one of the most common infection in humans, affecting more than half of the population. The prevalence of the infection varies widely in rural developing areas (more than 80%) compared to urban developed ones (less than 40%), as a consequence of different socioeconomic and hygienic conditions. H. pylori infection is usually acquired during childhood; infected people usually remain asymptomatic, but about 30% of individuals may develop mild to severe upper gastrointestinal diseases such as gastritis, peptic ulcer, gastric cancer or MALT lymphoma. The transmission route is not clear yet; the person-to-person transmission, especially within the same family appears to be prevalent, but also environmental contamination is possible. The eradication without a specific therapeutic regimen is very unlikely and the reinfection rate after an effective eradication therapy is quite rare. The reinfection rate will increase if there are family members affected.

Usually, non-invasive tests are the first methods for diagnosing Helicobacter pylori (HP) infection. Among these, serological test, stool antigen research and urea breath test are the most used. Antibodies anti-HP are not recommended in low prevalence population, moreover they cannot reveal an ongoing infection, but they only prove a contact with the bacterium. Also, they can persist for a long time after the eradication of the infection, therefore, they should not be used to verify the success of eradication therapy. Stool antigen research and Urea Breath Test (UBT) are useful both in diagnosis and during follow-up after eradication treatment. The stool antigen test is cheaper than Urea breath test with similar sensitivity and specificity. Non-invasive tests are not able to diagnose the associated complications to HP infection.

AIMS To compare two strategies for the eradication of Helicobacter pyloriinfection. METHODS Groups 1 and 2 each consisted of 75 consecutive patients. Patients in group 1 were treated with two antibiotics based on antibiotic susceptibility testing; those in group 2 received amoxycillin and clarithromycin for eight days, together with either ranitidine or omeprazole. Eradication rate was assessed in both groups six months after treatment. RESULTS In group 1,H pylori grew in culture in 63/75 cases. Susceptibility testing showed that 35/63 isolates were resistant to metronidazole, 10/63 to clarithromycin, 2/63 to ampicillin, 1/63 to tetracycline, and 5/63 to both clarithromycin and metronidazole. In group 1 the infection was eradicated in 96% of the initial 75 subjects, and in 98% of the subjects treated according to the antibiotic assay (62/63). As two patients were lost at follow up the overall eradication rate was 99%. In group 2, eradication was achieved in 61/75 subjects (81%). This was significantly lower than the percentage of eradication observed in group 1 (81% versus 99%). CONCLUSIONS Antibiotic susceptibility tests are useful in childhood as a very high percentage of subjects are cured. This approach is costly, but selective antibiotic treatment contributes to limit further development of antibiotic resistance, and money is saved in terms of reinvestigation and further repeated treatments.

The eradication therapy ofHelicobacter pylori(H. pylori) infection is still a challenge for gastroenterologists. One of the main causes of failure inH. pylorieradication is the antibiotic resistance mainly to clarithromycin. Culture from biopsies is maybe the most used method among the antimicrobial susceptibility techniques. In this study, we compared the antimicrobial susceptibility changes in children withH. pyloriinfection over 13 years and we confirmed that clarithromycin resistance has been increased (16% versus 26%) though with no statistically signficant value. Therefore, clarithromycin should not be used in empiric treatment ofH. pylorieradication therapy in children, but its use should be limited only to children with known antimicrobial susceptibility. On the other hand, metronidazole resistance has decreased over this time period in statistically significant manner (56% versus 33%,p=0.014). Furthermore, ampicillin resistance has been confirmed to be very rare (3% versus 0%) in children withH. pyloriinfection. In conclusion, inH. pyloriinfection, if we do not know the antibiotic susceptibility of patients, we should recommend an eradication therapy based on the local distribution of antibiotic resistance rates trying to limit the therapeutic failures.