Robert Logan

ABC of the upper gastrointestinal tract: Epidemiology and diagnosis of Helicobacter pylori infection

Helicobacter pylori is a small, curved, highly motile, Gram negative bacillus that colonises only the mucus layer of the human stomach. Since its discovery in 1984, it has been recognised as the principal cause of peptic ulcer disease and as the main risk factor for the development of gastric cancer. However, most infected people (>70%) are asymptomatic. We therefore need to discover how infection is acquired, why ulcers or cancer occur in so few of those infected, and how this subgroup can be identified and treated. H pylori is one of the commonest bacterial pathogens in humans. The prevalence of infection varies but is falling in most developed countries. Seropositivity increases with age and low socioeconomic status. Retrospective seroepidemiological studies have shown a cohort effect consistent with the hypothesis that infection is mainly acquired in early childhood. Until recently, however, it has been difficult to assess accurately the incidence (or route) of infection because of the inaccuracy and cost of detecting (non-invasively) H pylori in young children. Primary acquisition in adults, or reinfection after successful eradication, does occur but is less common, with an annual incidence of 0.3-0.7% in developed countries and 6-14% in developing countries. Prevalence of H pylori infection by age in developing and developed countries How H pylori is usually acquired and its route of transmission are unknown. Since humans are the only known reservoir of infection, it is likely that in developed countries H pylori is picked up from siblings, other children, or parents, predominantly via the gastro-oral route. In developing countries faecal-oral transmission may also occur. Various risk factors are associated with H pylori infection, but the extent to which these are simply markers of childhood socioeconomic deprivation is unclear. H pylori infection …

Eradication of Helicobacter pylori with clarithromycin and omeprazole.

Clarithromycin, a new and well tolerated, acid stable macrolide antibiotic, has a similar antimicrobial spectrum to erythromycin but a better in vitro MIC90 (0.03 microgram/l-1) against Helicobacter pylori (H pylori). This study aimed at determining the eradication rate using clarithromycin 500 mg thrice daily and omeprazole 40 mg daily for two weeks. Patients were given an endoscopy and H pylori status assessed by antral culture (microaerobic conditions, for up to 10 days), antral and corpus histology tests (haematoxylin and eosin/Gimenez stains), and 13C-urea breath test (13C-UBT, European standard protocol, positive result = excess delta 13CO2 excretion > 5 per mil). Compliance was assessed by returned tablet counts. H pylori clearance at the end of treatment and eradication four weeks after finishing treatment were assessed by the 13C-UBT. Seventy three patients (54 men, median age 45 years) with duodenal ulcers (n = 42) or duodenitis/non-ulcer dyspepsia (n = 31) all with a positive 13C-UBT (mean (SEM) excess delta-13CO2 excretion = 26.6 (4.9) per mil) and either positive antral histology (n = 72) or positive antral culture (n = 35) were studied. Before treatment 2/27 (7%) isolates of H pylori were resistant to clarithromycin and five isolates were resistant to metronidazole. In 70/73 (96%) the 13C-UBT was negative immediately after finishing treatment. Four weeks later the 13C-UBT was negative in 57/73 (mean (SEM) excess delta 13CO2 excretion = 1.2 (0.3) per mil, eradication rate = 78%). Forty eight (66%) patients experienced a metallic taste while taking the tablets. Although four (5%) patients, however, could not complete the course of treatment, in only one of these four was H pylori not eradicated. These results show that duel therapy with clarithromycin and omeprazole is well tolerated. With an eradication rate of 78% it is an effective treatment for metronidazole resistant H pylori and may be an alternative to standard triple therapy.

One week eradication regimen for Helicobacter pylori.

Although Helicobacter pylori is both a frequent cause of gastritis and an important factor in duodenal ulcer recurrence, no treatment regimen exists that is completely safe and effective. We have studied a short eradication regimen of tripotassium dicitrato bismuthate 120 mg four times daily and amoxycillin 500 mg four times daily for seven days with metronidazole 400 mg five times daily for three days (days 5-7). 106 patients with peptic ulceration and non-ulcer dyspepsia, who were also infected with H pylori, were entered into the study. H pylori was successfully eradicated in 76/106 (72%) patients (median follow-up 9.3 months). The rate of eradication was higher among patients with metronidazole-sensitive H pylori (40/43, 93%). In 17/30 patients in whom eradication failed, pretreatment metronidazole-resistant strains were subsequently isolated. Side-effects were mild, the commonest (24/106, 24%) being taste disturbance with metronidazole. A one-week eradication regimen is a safe, effective, cheap, and well-tolerated treatment for metronidazole-sensitive H pylori.

Epstein-barr virus associated oesophageal ulcers in AIDS

Epstein-Barr virus (EBV) associated ulceration has not previously been included in the differential diagnosis of oesophageal ulcers in AIDS. We report five cases of oesophageal ulceration in homosexual men with advanced human immunodeficiency virus infection in whom this was considered to be the most likely cause. DNA in situ hybridisation studies showed EBV in biopsy material from three of four patients with oesophageal ulcers and in none of three controls. Of other viruses studied, only human papillomavirus was present, and this was found in both patients and control subjects. These findings support the hypothesis that EBV is an aetiological factor in some cases of AIDS-associated oesophageal ulceration.

Eradication of Helicobacter pylori with lansoprazole and clarithromycin.

Background: Helicobacter pylori eradication with omeprazole and clarithromycin varies between 40 and 80%. The dose, frequency and duration of treatment may account for these differences. Lansoprazole, a recently introduced proton pump inhibitor, is a more potent H. pylori bacteriostat in vitro than omeprazole. The aim of this open, comparative, randomized study was to investigate the efficacy and safety of lansoprazole 30 mg once or twice a day (and for 2 vs. 4 weeks) plus clarithromycin 500 mg t.d.s. for 2 weeks, in the eradication of H. pylori.

Campylobacter pylori in the upper gastrointestinal tract of patients with HIV-1 infection.

Fifty one patients with human immuno-deficiency virus (HIV-1) infection who had been consecutively endoscoped for upper gastrointestinal symptoms were biopsied (stomach or duodenum, or both) and compared with 59 age and sex matched controls for the presence of Campylobacter pylori. In 28 (47%) of the control group but in only seven (14%) of the HIV seropositive patients were C pylori seen on histological examination (p less than 0.001, odds ratio 5.6, 95% confidence interval 2.2-14.5). Sixteen patients who were HIV antibody positive had other index diseases for the diagnosis of AIDS in the biopsy material and, when these were excluded, comparison with the control group still showed a significant difference; p less than 0.01, odds ratio 3.6, 95%, confidence interval 1.4-9.6. In this series, therefore, C pylori were far less common in HIV antibody positive patients than in controls. Among the HIV positive patients, a higher proportion of C pylori negative cases had AIDS but this trend was not significant. The findings of this study indicate that whatever abnormalities of cell mediated mucosal immunoregulation are caused by HIV infection, they do not seem to be important in the response to infection by C pylori.

Concept for a rapid point-of-care calprotectin diagnostic test for diagnosis and disease activity monitoring in patients with inflammatory bowel disease: Expert clinical opinion

No abstract available Keywords: Crohns disease; Diagnostic tests; Inflammatory bowel disease; Irritable bowel syndrome; Ulcerative colitis.

Two-week eradication regimen for metronidazole-resistant Helicobacter pylori

At present there is no generally accepted treatment regimen for eradicating metronidazole‐resistant Helicobacter pylori. This study determines the eradication rate after treatment with 40 mg omeprazole o.m. and 500 mg amoxycillin q.d.s. for 14 days, with 120 mg tripotassium dicitrato bismuthate q.d.s. for the first week (Days 1–7) and 750 mg ciprofloxacin b.d. for the second week (Days 8–14). Thirty patients (16 male, mean age 45 years, range 16–80 years) with duodenal ulcers (n= 18) or non‐ulcer dyspepsia (n= 2) and metronidazole‐resistant H. pylori detected by histology, culture, in vitro sensitivity tests and a positive 13C‐urea breath test entered the study. Follow‐up was by 13C‐urea breath test at the end of treatment and at 1, 3, 6, and 12 months. Eradication was denned as a negative 13C‐urea breath test at least 1 month after finishing treatment. H. pylori was successfully eradicated in 21/30 (71%) patients (median follow‐up 10.2 months, range 4–12 months). A pre‐treatment ciprofloxacin‐resistant strain was isolated in 1/9 patients in whom eradication failed. Of 30 patients 29 completed the 2‐week regimen; one patient experienced dizziness after 3 days of treatment. The most common side‐effect was increased stool frequency (n= 6). This 2‐week treatment regimen for metronidazole‐resistant H. pylori is well tolerated and achieves an eradication rate of 70%.

Quality improvement perspective and healthcare funding decisions

Efforts to apply explicit prioritisation processes to healthcare funding decisions have had mixed results in New Zealand. But a quality improvement approach has advantages over existing prioritisation approaches New Zealand, along with other countries, developed more transparency in making decisions about prioritising healthcare funding during the 1990s.1 2 In New Zealand, prioritisation approaches drew heavily on economic principles and used empirical evidence. This paper reflects on experience with prioritisation of healthcare funding in New Zealand, identifying the benefits and also the shortcomings. It examines whether quality improvement, which is receiving increasing attention in New Zealand and internationally, is useful in making funding decisions both across and within services. We argue that a quality improvement approach has several advantages over existing prioritisation approaches, and we provide examples of how such an approach might be applied. In the late 1980s and early 1990s, many developed countries restructured their healthcare systems, in part to improve efficiency and address rising costs. In New Zealand, major reforms in 1992 resulted in a purchaser-provider split with a strong emphasis on contracting and regulated competition. The Core Services Committee, now the National Health Committee, was established to advise the minister of health on the health services priorities.3 A key task of the committee was to advance public debate and understanding of limited healthcare resources and the need to ration services. The committee proposed that prioritisation decisions should be explicit and transparent and based on four principles, which have underpinned much of its subsequent work: effectiveness, efficiency, equity, and acceptability.4 Drawing on this work, a number of regional and national funding agencies developed prioritisation processes and attempted to apply these to funding allocation decisions. In 1999, the national Health Funding Authority added the principle of Maori health to those of the National Health Committee when …

Faecal calprotectin for the diagnosis of inflammatory bowel disease.

A useful test in secondary care but not enough evidence to support its use in primary care