Helicobacter 

About: Helicobacter is an academic journal published by Wiley-Blackwell. The journal publishes majorly in the area(s): Helicobacter pylori & Clarithromycin. It has an ISSN identifier of 1083-4389. Over the lifetime, 2029 publications have been published receiving 66794 citations.

Epidemiology of Helicobacter pylori Infection

Abstract: The study of Helicobacter pylori genetic variability brought us interesting data on the history of mankind. Based on multilocus sequence typing and more recently on whole-genome sequencing, paleomicrobiology still attracts the attention of global researchers in relation to its ancestor roots and coexistence with humans. Three studies determining the prevalence of virulence factors illustrates the controversial results obtained since 30 years by studies trying to associate prevalence of different virulence markers and clinical outcomes of H. pylori infection. Three articles analyzed the prevalence and risk of multiple (genetically distinct isolates) and mixed (susceptible and resistant isolates) infections. A number of studies confirm that H. pylori prevalence is falling worldwide especially in the developed world and in children but that the level of infection is higher in certain ethnic minorities and in Migrants. There is little new in identifying the mode of H. pylori transmission though intrafamilial spread appears to be important. There have, however, been some interesting papers on the presence of the organism in food, water, and the oral cavity.

Eradication of Helicobacter pylori Using One‐week Triple Therapies Combining Omeprazole with Two Antimicrobials: The MACH I Study

Abstract: The discovery of Helicobacter pylori (H. pylori) opened the doors to new insight and therapy for peptic ulcer disease. Earlier eradication treatment modalities based on bismuth compounds, with or without additional antimicrobials, were not well accepted mainly because of the, at least hypothetical, risks for neurological and/or renal side effects. The first proton pump inhibitor, omeprazole, had been proven as a very effective short-term anti-ulcer therapy, but after withdrawal of the drug, the recurrence rate was high. theoretically, acid suppression was believed to increase the H. pylori infestation as the environment became more neutral. On the other hand, acid suppression could increase the effect of acid labile antimicrobials. This was not investigated before the studies presented in this thesis were performed.A small pilot study (Paper I) in 24 patients showed that 7 out of 8 patients treated for fourteen days with omeprazole 40 mg o.m. + amoxicillin 750 mg b.i.d. were cleared of H. pylori, while it remained in 7/8 patients on omeprazole as monotherapy and in 2/7 patients on amoxicillin as monotherapy. However, the eradication rates 4 weeks after treatment were 5/8, 0/8 and 1/7 in the three groups, respectively. These results were confirmed in a large study (Paper II) comprising 248 consecutive patients with active duodenal ulcer disease. All had an initial treatment period for two weeks with omeprazole 40 mg o.m., followed by continued omeprazole in combination with amoxicillin 750 mg b.i.d. or amoxicillin placebo for a further two weeks. In the dual therapy group, 54% of patients were H. pylori eradicated compared to 4% in the omeprazole mono therapy group. Furthermore, the duodenal ulcer relapse rate was significantly lower in the combination group compared to the monotherapy group (p<0,001). Paper III represents a study that was preformed to assess whether improved results could be obtained by adding two antimicrobials to omeprazole. In total 787 patients were randomized to six treatment arms, where omeprazole was combined with two of the three antimicrobials amoxicillin, metronidazole and c!arithromycin in various doses and combinations. The results showed that one week's treatment was sufficient for a very high eradication rate. A combination of omeprazole 20 mg b.i.d. + amoxicillin 1000 mg b.i.d. + clarithromycin 500 mg b.i.d. was superior to a combination with a lower clarithromycin dose of 250 mg b.i.d. or amoxicillin in combination with metronidazole, but not significantly better than the other two arms containing metronidazole+ clarithromycin in a dose of 250 mg b.i.d. 500 mg b.i.d. Paper IV was designed to establish whether or not acid suppression is necessary during antimicrobial treatment. In total 539 patients were randomized. Eradication rates with omeprazole added to antimicrobials were much higher than in treatment groups not receiving omeprazole. In metronidazole resistant strains, only 76% were eradicated in comparison to 95% in susceptible strains. Amoxicillin resistance did not occur and clarithromycin resistance was found in only 3% of patients. Thus, papers I-IV proved the efficacy ofthe new treatment modality, which, however, represented high costs in the short-term perspective.The cost-effectiveness of various treatment strategies in regular use at that time was evaluated in paper V. The economic model showed that in comparison to continuous therapy with gastric acid suppressive drugs, the extra initial cost for eradication therapy was paid within one year and, in comparison to intermittent therapy, within three years.Conclusion: These studied have shown convincingly that eradication of H. pylori with a combination of gastric acid suppression and two antimicrobials (amoxicillin and clarithromycin) is the most effective treatment in PUD, giving a high eradication rate and consequently lower peptic ulcer recurrence. Thus, this treatment strategy is also very cost-effective for society.

Pathogenesis of Helicobacter pylori infection.

Abstract: Helicobacter pylori infections are thought to eventually lead to symptoms as a result of the long-lasting interactions between the bacterium and its host. Mechanisms that allow this bacterium to cause a life-long infection involve modulation of both the immune response and host cellular processes. Last year many novel findings that improve our knowledge on how H. pylori virulence factors interact with the host were reported, but because of space limitations we can only discuss a limited number of these studies. Among those are studies on the genetic variation of genes encoding outer membrane proteins and the mimicry of host antigens, factors that alter host-cell metabolism and factors that modulate the host’s immune response.

Epidemiology of Helicobacter Pylori Infection and Public Health Implications

Abstract: This review summarizes studies on the epidemiology and public health implications of Helicobacter pylori published in peer-reviewed journals from April 2010 through March 2011. Prevalence rates vary widely between different geographical regions and ethnic groups. An interesting study from the USA identified the degree of African ancestry as an independent predictor of H. pylori infection. Two studies have demonstrated early childhood as the period of transmission of infection and identified an infected sibling as an important risk factor. An oral–oral route of spread has been substantiated with several studies showing the presence of H. pylori in the oral cavity. Studies have shown the presence of H. pylori in drinking water and the role of poor living conditions and sanitation in H. pylori infection, supporting an oral–fecal route of spread. Screening for H. pylori as a gastric cancer pre-screening strategy has been described in Japan, and the importance of H. pylori eradication as a gastric cancer–prevention strategy has now been further emphasized in Japanese guidelines. Two studies have shown a decrease in the burden of dyspepsia and peptic ulcer disease with H. pylori eradication.

Guidelines for the management of Helicobacter pylori infection in Japan: 2009 revised edition.

Abstract: Background: Over the past few years, the profile of Helicobacter pylori infection has changed in Japan. In particular, the relationship between H. pylori and gastric cancer has been demonstrated more clearly. Accordingly, the committee of the Japanese Society for Helicobacter Research has revised the guidelines for diagnosis and treatment of H. pylori infection in Japan. Materials and Methods: Four meetings of guidelines preparation committee were held from July 2007 to December 2008. In the new guidelines, recommendations for treatment have been classified into five grades according to the Minds Recommendation Grades, while the level of evidence has been classified into six grades. The Japanese national health insurance system was not taken into consideration when preparing these guidelines. Results: Helicobacter pylori eradication therapy achieved a Grade A recommendation, being useful for the treatment of gastric or duodenal ulcer, for the treatment and prevention of H. pylori-associated diseases such as gastric cancer, and for inhibiting the spread of H. pylori infection. Levels of evidence were determined for each disease associated with H. pylori infection. For the diagnosis of H. pylori infection, measurement of H. pylori antigen in the feces was added to the tests not requiring biopsy. One week of proton-pump inhibitor-based triple therapy (including amoxicillin and metronidazole) was recommended as second-line therapy after failure of first-line eradication therapy. Conclusion: The revised Japanese guidelines for H. pylori are based on scientific evidence and avoid the administrative restraints that applied to earlier versions.