“Out with the old and in with the new”


An apt post to finish the year off with!

Many laboratory networks (including my own) are currently in the process of changing our testing protocols for Helicobacter pylori over from the traditional serological testing to the more specific faecal antigen test.

The faecal antigen test for H. pylori has the obvious advantage of picking up only current infection, whereas serological testing can also pick up past infection, even if it has been treated. The only caveat to this is that for faecal antigen testing the patient should be off their proton pump inhibitor medication for at least two weeks before testing. If this is not possible, then this would be one of the few indications for serology testing instead.

International guidelines on this topic are moving slowly but surely from serology to faecal antigen testing for the diagnosis of H. pylori infection.

However such a change is not necessarily always easy to effect. Clinicians, for whom H.pylori is only a small part of their day to day work, are very used to ordering Helicobacter pylori serology. They may not be that familiar with the faecal antigen test, or still see it as a research/reference laboratory type of test.

It is our job as microbiologists to help facilitate this transition across to best practice.

How can this be achieved? I would suggest the following:

  • One-off educational updates: Both flyers and talks can educate laboratory users of the latest testing algorhythms.
  • Result comments: Add a comment to every Helicobacter pylori serology result stating that faecal antigen testing is now the preferred test. This modality can be very effective as (depending on the number of H. pylori tests the clinician orders) it can provide continuous feedback, unlike the one-off updates above. This approach often produces a slow but sure switch over to the desired testing algorhythm.
  • Gatekeeping: Only allow serological testing for Helicobacter pylori if it is clear from the clinical details that the patient is unable to stop their proton pump inhibitor therapy.  This is a little harder line, but in my eyes perfectly acceptable. A few laboratories have discontinued Helicobacter pylori serology altogether…

Although this “modernisation” aspect of laboratory practice is often not assessed by accreditation agencies, I believe it is an important quality marker of a laboratory to show that they can both keep up to date with current best practice testing, and encourage their users to do the same….


2 thoughts on ““Out with the old and in with the new”

  1. But… antigen testing more expensive than serology, H. pylori prevalence going down particularly in developed nations, and testing from primary care is can be pretty random from what I have seen – i.e. abdominal pain –> stool for culture and parasites, calprotectin, and H. pylori testing.

    1. Absolutely, well defined and validated testing algorhithms according to symptomatology, and gatekept by lab should be the way of the future.

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