Helicobacter stool antigen tests

This is a short newsletter from the Health Protection Agency Helicobacter Working Group. The aim is to update you on recent developments in this area.

Helicobacter stool antigen tests Monoclonal tests produce fewer equivocal results, as a lower number of results appear in the grey zone. Launch Diagnostics have replaced their less sensitive polyclonal antibody-based Meridian HpSA test with a monoclonal test Meridian HpSA PLUS. It is anticipated that the HpSA PLUS will have similar sensitivity and specificity to the Oxoid (previously DakoCytomation) HpStAR monoclonal kit. There has been one direct comparison in 248 patients.^1 Kit Sensitivity % Specificity % Meridian Polyclonal HpSA 92 94 Meridian HpSA PLUS 97 96 Oxoid HpStAR 96 95 ^1Zanetti MV, Mucignat G. Comparison of a new test with monoclonal antibodies versus other analogous tests for detection of H. pylori in faecal specimens. Poster at AMCLI Sept 2006 published on Microbiologia Medica Vol. 21 N3 Year 2006. A business case looking at cost comparisons of stool antigen versus urea breath test versus serology is available at http://www.hpa.org.uk/infections/topics_az/primary_care_guidance/menu.htm

Quality Assurance - Helicobacter stool antigen tests As you know, CPA accreditation requires that laboratories undertake QA for all tests they use. HP QA for stool antigen tests is now available via LabQuality in Finland. LabQuality will be despatch QA simulated patient specimens in May and November. Enquiries should be directed to Yvonne Bjorkman, who is the microbiology EQA scheme coordinator, at [e-mail] or just [e-mail]

Guidance When giving advice to GPs about Helicobacter pylori you may wish to refer them to the Health Protection Agency Helicobacter diagnostic guidance and management of infection (antibiotic) guidance, both of which can be found at: http://www.hpa.org.uk/infections/topics_az/primary_care_guidance/menu.htm Recent data from Hong Kong indicates that prophylactic eradication of H. pylori infection reduces the risk of ulcers in patients on NSAIDs. H. pylori test and treat and prophylactic eradication may be appropriate in patients commencing long-term NSAIDs, who are recognised to be at increased risk of NSAID gastric complications.

Suggested rescue treatments for Helicobacter pylori Principles of treatment: Compliance is the greatest determinant of success. Use a PPI at gastroeosophageal reflux dose. If possible, do not use a macrolides, metronidazole or quinolone if previously used for H. pylori or another infection. Resistance is very rare for amoxicillin and tetracycline. First line use 7 days; after that 14 days treatment. Reinfection is very low in developed countries. In Caucasians, for rescue treatment you may wish to use Rabeprazole as the PPI, as there is evidence it may attain higher concentrations in individuals who metabolise PPIs rapidly.

Suggested Treatment Protocol 1^st Line 7d bd PPI + Amox 1g + Clari 500mg 2^nd Line 14d bd PPI + Amox 1g + Metronidazole 400mg 3^rd Line 14d bd PPI + Bismuth + Tetracycline 500mg qds + Metronidazole 400mg tds 4^th Line 14d bd Bismuth + PPI + Amoxicillin 1g + Levofloxacin 250mg (metanalysis 14 trials 80%) or Rifabutin 300mg od (5 trials 72-78%) or Furazolidone 200mg bd (9 trials, not UK 52-90%) In patients allergic to penicillin 1^st Line 7d bd PPI + Metronidazole 400mg + Clari 500mg 2^nd Line 14d bd PPI + Bismuth + Tetracycline 500mg + Metronidazole 400mg Culture-directed treatment

The HPA Helicobacter Working Group:

Chair, Dr Cliodna McNulty, Secretary, Dr Marjorie Walker, Dr Robert Owen, Dr Louise Teare, Prof David Forman, Dr David Tompkins, Prof Kenneth McColl, Dr Anan Raghunath, Dr Peter Hawtin

Email: [e-mail]

November 2007