Primary Helicobacter pylori resistance to metronidazole and clarithromycin in the Finnish population

AIM: To systematically determine Helicobacter pylori primary antimicrobial resistance in Finland and the associated demographic and clinical features. METHODS: A total of 342 adult patients referred for gastroscopy at 23 centres in different parts of Finland and positive for the rapid biopsy urease test were recruited. Clinical and demographic data were collected via a structured questionnaire. Patients with positive H. pylori culture and successful antibiotic sensitivity determination by the E-test method (n = 292) were included in the present analysis. RESULTS: The study population consisted of 134 men and 158 women, mean age 56 years (95% CI, 55-58 years). Resistance to metronidazole was 38% (110 of 292) and to clarithromycin 2% (seven of 292). Resistance to metronidazole was higher in women than in men (48% vs. 25%, P < 0.001). Previous use of antibiotics for gynaecological infections predicted metronidazole resistance (P = 0.01), and previous use of antibiotics for respiratory (P = 0.02) and dental infections (P = 0.02) the clarithromycin resistance. We observed no major geographical variations in metronidazole resistance. CONCLUSIONS: The primary metronidazole resistance of H. pylori was 38% and was common in women previously treated for gynaecological infections. Primary clarithromycin resistance was uncommon (2%) and may associate with previous dental and respiratory infections.     

Accelerated decline in Helicobacter pylori seroprevalence rate during the screen and treat project in Vammala, Finland, as demonstrated in 29- to 45-year-old pregnant women

The potential preventability of serious helicobacter-associated diseases - especially gastric cancer - has evoked interest in eradicating this pathogen from the population. We assessed the efficacy of the pioneering screen and treat intervention project in Vammala by studying helicobacter seroprevalence in pregnant women representing the normal population. Consecutive maternity clinic samples from native Finnish females at five different localities in 1995 (n=701) and 2000 (n=772) were investigated for class IgG H. pylori antibodies by enzyme immunoassay (Pyloriset EIA-G III, Orion Diagnostica, Espoo, Finland). In Vammala the change in helicobacter seroprevalence was -13%-units (between 1995 and 2000; p=0.0125, chi-square test) in > or =29-year-old females, +1.6%-units (difference statistically non-significant) in <29-year-old females, and -5.5%-units (difference statistically non-significant) in the whole study population. In the four reference localities studied, all the corresponding changes remained statistically non-significant. Thus, in Vammala the programme applied accelerated the decline of helicobacter infections in 29- to 45-year-old females and in 2000 the seroprevalence rate had also become significantly lower than that of the four reference communities combined (7.6% versus 13.5%, respectively, p=0.0433, chi-square test). The final outcome of the intervention project, i.e. the long-term effect of this decline on gastric cancer and peptic ulcer disease, remains to be evaluated.     

Age-dependent accuracy of Helicobacter pylori antibody assays for adults, with special emphasis on atrophic gastritis

The accuracy of Helicobacter pylori antibody assays for 561 consecutive adult outpatients who had undergone gastroscopy was studied. The sensitivity of an immunoglobulin G test was 99 to 100% for all age groups, but the specificity declined by age group, from 99% for those aged 15 to 49 years to 75% for those aged > or =65 years. The exclusion of false-positive results for patients with atrophic gastritis improved the specificity to 93 to 97% for the older age groups.     

Decreasing prevalence of helicobacter antibodies in Finland, with reference to the decreasing incidence of gastric cancer

Time trends and geographical variation of Helicobacter pylori antibodies in Finland were investigated by enzyme immunoassay in 20- to 34-year-old randomly selected females from six localities during 1969-73 (n = 375), and 15- to 45-year-old females representing nine communities and four geographical areas in 1983 (n = 882) and 1995 (n = 842). In the six communities investigated at three different time points, the overall prevalence declined from 38 to 12%, with an emphasis on the latter 12 years. The regionally varying rate of decrease in helicobacter prevalence changed the pre-existing geographical variation, leaving northern Finland with the highest rate. A 10%-units higher local helicobacter prevalence seemed to predict a 23% (95% CI 3-44%) higher gastric cancer incidence 20 years later. The overall decline in helicobacter seropositivity is consistent with earlier reports from Finland and other developed countries, and supports the cohort theory as an explanation for the age-related increase in H. pylori seroprevalence.     

Cure of Helicobacter pylori Infection after Failed Primary Treatment: One-Center Results from 120 Patients

Background: Treatment with a proton pump inhibitor (PPI) and antimicrobials cures Helicobacter pylori infection in about 90% of patients. This is a retrospective overview of our studies aiming to cure the infection in all compliant patients with failed initial therapy. Methods: We retreated 120 (19% of 644) H. pylori-infected patients whose initial therapy had failed. The retreatments included (i) triple therapy (TT): colloidal bismuth subcitrate, metronidazole, amoxicillin (or tetracycline); (ii) quadruple therapy (QT): TT and a PPI; or (iii) high doses of both a PPI and clarithromycin combined with a further 1-3 individually selected antimicrobials. The eradication results were determined after 6-12 months. Results: The 1st retreatment was successful in 70 of 120 patients. The 2nd retreatment cured 25 of the remaining 42 patients, the 3rd 13 of 17, and the 4th the last 4 patients. The cumulative eradication rate (ITT) was 93% (95% CI: 88.9%-97.9%; 8 patients withdrew after a failed 1st retreatment) and the rate was 100% in the remaining 112 patients who accepted several retreatments. The 1st retreatment with TT cured 23% (95% CI: 12%-34%) of 57 patients and QT 85% (95% CI: 74%-96%) of 41 patients who had initially undergone a failed metronidazole-based treatment. All retreatments were well tolerated. Conclusions: In this study, high doses of a PPI and clarithromycin combined with 1-3 antimicrobials according to susceptibility data proved to be the best drug combination in the cure of H. pylori infection after failed primary treatment. Giving imidazole- and bismuth-based QT (without clarithromycin) as the first-line treatment of H. pylori infection ensures that the number of failures remains low.     

Multilocus Sequence Typing (MLST) and Whole-Genome MLST of Campylobacter jejuni Isolates from Human Infections in Three Districts during a Seasonal Peak in Finland

A total of 95 human Campylobacter jejuni isolates acquired from domestic infections and collected from three districts in Finland during the seasonal peak (June to September) in 2012 were analyzed by PCR-based multilocus sequence typing (MLST) and by whole-genome sequencing (WGS). Four predominant sequence types (STs) were detected among the isolates: ST-45 (21%) and ST-230 (14%, ST-45 clonal complex [CC]), ST-267 (21%, ST-283 CC), and ST-677 (19%, ST-677 CC). In districts 1 and 3, most of the infections occurred from early July to the middle of August, with a peak at weeks 29 to 31, but in district 2, the infections were dispersed more evenly throughout 3 months (June to August). WGS data were used for further whole-genome MLST (wgMLST) analyses of the isolates representing the four common STs. Shared loci of the isolates within each ST were analyzed as distance matrices of allelic profiles by the neighbor-net algorithm. The highest allelic variations (>400 different alleles) were detected between different clusters of ST-45 isolates (1,121 shared loci), while ST-230 (1,264 shared loci), ST-677 (1,169 shared loci), and ST-267 isolates (1,217 shared loci) were less diverse with the clusters differing by <40 alleles. Closely related isolates showing no allelic variation (subclusters) were detected among all four major STs. In some cases, they originated from different districts, suggesting that isolates can be epidemiologically connected and may have the same infection source despite being originally identified as sporadic infections.