Gastric tubes as vectors of Helicobacter pylori transmission

Rational Helicobacter pylori therapy: evidence-based medicine rather than medicine-based evidence

Data are available such that choice of Helicobacter pylori therapy for an individual patient can be reliably predicted. Here, treatment success is defined as a cure rate of 90% or greater. Treatment outcome in a population or a patient can be calculated based on the effectiveness of a regimen for infections with susceptible and with resistant strains coupled with the knowledge of the prevalence of resistance (ie, based on formal measurement, clinical experience, or both). We provide the formula for predicting outcome and we illustrate the calculations. Because clarithromycin-containing triple therapy and 10-day sequential therapy are now only effective in special populations, they are considered obsolete; neither should continue to be used as empiric therapies (ie, 7- and 14-day triple therapies fail when clarithromycin resistance exceeds 5% and 15%, respectively, and 10-day sequential therapy fails when metronidazole resistance exceeds 20%). Therapy should be individualized based on prior history and whether the patient is in a high-risk group for resistance. The preferred choices for Western countries are 14-day concomitant therapy, 14-day bismuth quadruple therapy, and 14-day hybrid sequential-concomitant therapy. We also provide details regarding the successful use of fluoroquinolone-, rifabutin-, and furazolidone-containing therapies. Finally, we provide recommendations for the efficient development (ie, identification and optimization) of new regimens, as well as how to prevent or minimize failures. The trial-and-error approach for identifying and testing regimens frequently resulted in poor treatment success. The described approach allows outcome to be predicted and should simplify treatment and drug development.

[Helicobacter pylori -- 2010]

Helicobacter pylori, discovered 27 years ago, has remained the most prevalent infectious agent in the world. In the author's hypothesis, the increase of peptic ulcer prevalence in the 19-20th century could be attributable to the extended worldwide use of gastric tubes for secretory testing which led to the iatrogenic transmission of pathogenic strains. Helicobacter pylori outer membrane proteins (OMP), and duodenal ulcer promoting (dupA) proteins were identified as novel virulence factors, leading to the production of pro-inflammatory cytokines, which could be future targets of therapy. There is no ideal first-line eradication of the infection and according to expert's opinion, the efficiency of these regimens has fallen gradually in recent years to unacceptably low levels; however, in the author's opinion this is a multifactorial phenomenon which can not be generalized. As alternative drugs, the efficiency of levofloxacin, furazolidone and rifabutin has been proven by meta-analyses. Sequential and bismuth-free quadruple therapies, although highly efficient, are not yet used on a large scale. The recurrence of the infection is 2.27%/year in developed and of 13.0%/year in developing countries. Spontaneous eradication occurred in 8-20% of the children and 5-11% of adults. The prevalence of clarithromycin resistance is increasing worldwide. In Hungary, it has reached 10.9% in county cities, according to a national survey. In a district of Budapest called Ferencváros, the prevalence between 2005 and 2009 was 16-22%, with no increasing trend. The development of enzymatic inhibitors (urease, carbonic anhydrase and gamma-glutamyl transpeptidase), modified antibiotics and efflux pump inhibitors seem promising ways because these compounds do not lead to resistance; however, none have yet been used in humans.