The Hungarian epidemiology of clarithromycin resistance in Helicobacter pylori infection

Abstract

Introduction: Clarithromycin is a main component of the eradication regimens for Helicobacter pylori infection. Aims: The purpose of the study is the assessment of the current prevalence of clarithromycin resistance in our district and an overview of the Hungarian data. Methods: A). From the patients examined at the Department of Gastroenterology of Ferencváros Health Center, biopsy samples were randomly selected from 238 cases. The presence of Helicobacter pylori was confirmed by the modified Giemsa stain and rapid urease test. The resistance to chlarithromycin was determined by fluorescence in situ-hybridization. B) Hungarian articles and congress abstracts dealing with resistance to clarithromycin, published between 1995–2006 were reviewed and the data concerning the prevalence of resistance were extracted and analysed. C) The data concerning clarithromycin use since its introduction in 1993 were obtained from the National Institute of Pharmacology. Results: A) The prevalence of primary clarithromycin resistance was 17.3%. The resistance was complete in 47.4% and partial in 52.6%. Secondary resistance in patients with known previous treatment with macrolides was 55.5%. There was a weak positive correlation between age (r=0.15), female gender (r=0.10) and smoking (r=0.16) and prevalence of resistance, while alcohol consumption, the diagnosis and histological severity of the infection did not influence it. B) Claritromycin resistance was addressed in 8 papers, including a total of 775 cases. The prevalence of resistance determined by phenotypic methods was 3.9%, while fluorescence in situ-hybridization detected the resistance in 17.0% of the cases. Regional differences were also encountered. Secondary resistance was met in 55.5% using phenotypic and in 49.0% with genotypic methods. C) The use of clarithromycin increased fivefold between 1993–2005. Discussion: The prevalence of clarithromycin resistance determined by genotypic method is increased as compared to the results of earlier phenotypic methods, which could be due to the more extensive use of macrolides.