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Helicobacter pylori

Helicobacter pyloriThe eradication of Helicobacter pylori does not relieve non-ulcer functional dyspepsia

There is no evidence to suggest an association between recurrent abdominal pain in children and Helicobacter pylori infection

Helicobacter pylori has a high genetic variability; some strains are more pathogenic than others

Non-invasive diagnosis of infection

Breath tests

The patient swallows a fixed amount of urea, labelled with a carbon isotope (13C or l4C) as a test meal after a 4 h fast. If Helicobacter pylori (HP) is present, the urea is rapidly broken down to l3C or l4C carbon dioxide, which is measured in a breath sample taken 30 min later. As yet, no urea breath test is licensed in the UK, so it is available only on a named patient basis. Urea breath tests are the only non-invasive tests that are specific for active infection. They require careful supervision and cost more than serological assays. To be sure that Helicobacter pylori eradication therapy has succeeded and not just simply suppressed the infection, the test must be done at least 28 days after completing treatment and 14 days after stopping any antibiotic or proton pump inhibitor.

Serological tests

Helicobacter pyloriThe immune response to Helicobacter pylori infection is complex. Two per cent of people fail to mount a response despite proven infection. Serological tests will remain positive for at least 6 months after eradication of the bacteria, so their use to confirm cure is not practical. Laboratory based serological assays have a wide range of sensitivities and specificities, and tests should be validated locally amongst the relevant population. GP-based tests (near-patient) that can be used without laboratory support are also available. Some tests use finger capillary blood and can produce a result within minutes. The Medical Devices Agency has published a report of the poor specificity of these kits compared with breath testing, histology or culture.

To treat or not to treat?

Many arguments have been put forward for the eradication of Helicobacter pylori, namely:

•The deliberate ingestion of Helicobacter pylori leads to antral gastritis and an increased risk of duodenal (30 times) and gastric (eight times) ulceration.

•The prevalence of Helicobacter pylori in symptomatic individuals with duodenal ulceration is 95% and in gastric ulceration 70-80%.

•A 1-week course of antibiotics heals ulcers as fast as omeprazole.

•Relapse rates are 0-3% with triple therapy, compared with 60-90% with no treatment and 10-30% with H2 receptor antagonists.

• A 2-week course of triple therapy is more cost effective than lifelong treatment with H2 antagonists.

• H2 antagonists and proton pump inhibitors are not as safe as originally thought, with increased enteric infections and accelerated gastric atrophy.

However, some have argued against treatment saying that:

Helicobacter pylori has not been found conclusively to be the cause of peptic ulcer disease. Only 50% of those with a perforated duodenal ulcer and 17% of those with a bleeding duodenal ulcer are found to have Helicobacter pylori. Thirty-three per cent of normal adults are colonized with Helicobacter pylori.

• Compliance is poor. With triple therapy, 350 tablets have to be ingested over 4 weeks.

• Thirty per cent of patients experience side effects to treatment.

• The cost implication of eradicating Helicobacter pylori from the 20 million people in the UK that have it is enormous.

Treatment regimens

Optimal therapy is still debated and constantly evolving. Traditional therapy consisted of 14 days of:

• a bismuth compound, plus

• metronidazole, plus

• amoxycillin or tetracycline.

Compliance is a problem with this regimen because of the number and frequency of tablet taking. An easier regimen was then developed consisting of 10-14 days of:

• omeprazole, plus

• amoxycillin or clarithromycin.

The high eradication rates reported in Germany and the UK have not been reported elsewhere. However, 90% eradication rates have been reported with

• omeprazole, plus

•amoxycillin, plus

• metronidazole.

More recent research has shown that a 7-day course of the triple therapies can give good results. A quadruple therapy has also been reported to give good results, for example,

ranitidine or omeprazole, plus

• bismuth, plus

• tetracycline, plus

• metronidazole

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