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There is ongoing debate in the literature about which is the best test to request for the detection of infection with Helicobacter
. The most appropriate test is influenced by several factors, such as the pre-test probability of H.pylori
(reflected by prevalence), the patient’s specific clinical circumstances and the cost and availability of the test.1
New Zealand, like many other countries, the advice has changed over recent years, however, the current thinking is that the H.
faecal antigen test is now the preferred option in patients who require investigation for H. pylori
“The New Zealand Schedule and Test Guidelines update
). Infection with H. pylori
is known to increase
the risk of peptic ulcer disease and gastric cancer due to chronic inflammation and atrophy of the stomach mucosa.2
In this article
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The prevalence of H. pylori in New Zealand is low by world standards
In New Zealand the overall prevalence of H. pylori is lower than many other developed countries, although there is limited
data and prevalence differs throughout the country.3 A recent small study in South Auckland, traditionally an area with
rates of H. pylori > 30%, recruited patients undergoing endoscopy, and reported an overall prevalence of H. pylori
for adults of all ethnicities of 18.6%. However, rates varied between people from different ethnic groups: for New Zealand
Europeans, prevalence was reported as 7.7%, which ranks among the lowest rates for H. pylori in the world,4,5 but a significantly
higher prevalence was noted in Māori (34.9%), Pacific (29.6%), Asian (23.8%) and Indian (19.2%) peoples.4
The overall global prevalence of H. pylori is > 50%. Prevalence has declined in many countries due to improvements
in treatment and in standards of living, however, there continues to be a marked variation between, and within, countries.5,
6 This is because infection with H. pylori is influenced by a number of factors, including ethnicity, socioeconomic status,
gender and age.5 Rates remain higher in developing countries due to associations with increased transmission in areas
with overcrowded living conditions, poor sanitation and unsafe drinking water.1, 5, 6
H. pylori is typically acquired during childhood and does not usually resolve spontaneously. Infection tends to be acquired
at a very young age in children in developing countries compared to developed countries.5 For example, in Bangladesh,
50 – 82% of children aged < 9 years are infected with H. pylori and this rises to > 90% in adults.5 In comparison,
a rate of 7.1% is reported for young people aged 5 – 18 years in Canada, rising to 20 – 30% in adulthood.5
Prevalence of H. pylori in adults is high in most Asian countries, e.g. Japan and China (50 –70%), South American, Eastern
European and Middle Eastern countries, e.g. Chile (73%), Bulgaria (61.7%), Egypt (90%) and Saudi Arabia (80%).5,
rates are reported for countries such as the United Kingdom (13.4%), Switzerland (11 – 26%), and Australia (15 – 20%).5,
Do we still need to test patients for H. pylori?
The decreasing prevalence of H. pylori-related peptic ulcer disease and gastric cancer has begun to alter management
recommendations when a patient presents with dyspepsia, or H. pylori is suspected.7, 8 It is suggested that testing
for H. pylori may not be needed, or helpful, in people who live in areas with low prevalence,8, 9 which applies to people
in many areas of New Zealand.
When a person first presents with dyspepsia, therefore, the clinician should consider how likely it is that H. pylori
will be present, whether red flags are present (see: “Red flags”), if there are other factors that may be influencing
their symptoms, such as NSAID use, and how the test result will influence the management of the patient.9 Routinely testing
all patients with dyspeptic symptoms for H. pylori or prescribing empiric eradication treatment for H. pylori without
testing is not recommended.10
The decision to treat dyspeptic symptoms empirically with a proton pump inhibitor (PPI) in people who are less likely
to have H. pylori , or to “test and treat” for H. pylori can be, in part, based on:
- Where they live – prevalence is generally higher in the north of New Zealand than in the south3
- Their ethnicity – if the person is of New Zealand European ethnicity, the prevalence is likely to be approximately
≤7%, but in Māori, Pacific, Asian and Indian peoples prevalence will be much higher4
- Where they were born – even allowing for expected differences due to ethnicity, if the person was born in New Zealand,
the chance that they will have H. pylori is likely to be lower than many people born overseas (depending
on their country of origin). If the person was born in a developing country, there is at least a 50% chance
that they will have H. pylori, and research shows that adults who immigrate retain a prevalence of H. pylori similar
to their country of origin.11
- The presence of any red flags (see: “Red flags”)
There is also evidence that the majority of people with dyspeptic symptoms and an absence of red flags will have normal
findings at endoscopy and that empiric treatment with a PPI for symptom control is considered an effective, safe strategy.12
Taking these factors into account for an individual patient can help determine the most appropriate management strategy.
For patients with dyspepsia who are at:
Lower risk of H. pylori infection – the most pragmatic approach is to prescribe a PPI and
review the patient in a month to assess whether their symptoms have improved. If the patient’s symptoms have not improved,
reassess for the presence of red flags and consider testing for H. pylori. Ideally the PPI should be stopped
for two weeks prior to testing for
H. pylori to reduce the rate of false negative results.
Higher risk of H. pylori infection – consider testing for H. pylori with a faecal antigen test. If the patient has a
positive result for H. pylori, they should be prescribed eradication treatment. If the result is negative, empiric
treatment with a PPI can be initiated after reassessing for red flag features.
Red flags for people presenting with dyspepsia
A patient with any of the following factors has an increased risk of significant organic disease and may require referral
- Age ≥ 50 years at first presentation (the incidence of gastric cancer increases with age)
- Age ≥ 40 years at first presentation for people of Māori, Pacific or Asian descent (gastric cancer tends to occur
a decade earlier in these groups)
- Family history of gastric cancer with age of onset < 50 years
- Dyspeptic symptoms that are severe or persistent
- Previous history of peptic ulcer disease, particularly if complicated
- The use of aspirin or NSAIDs (also check over-the-counter use)*
- Signs and symptoms of chronic gastrointestinal bleeding, such as malaena, anaemia
- Iron deficiency anaemia
- Difficulty in swallowing
- Persistent regurgitation or protracted vomiting
- Palpable abdominal mass
- Unexplained weight loss
* If a person taking NSAIDs has no other red flags and symptoms are mild, initial management is to stop the NSAID and
then re-assess symptoms
For further information, see: “Managing dyspepsia and heartburn in
general practice – an update”, BPJ 34 (Feb, 2011).
Faecal antigen testing is now recommended to detect H. pylori infection
There are three non-invasive tests for H. pylori. These are the:
- Faecal antigen test
- Carbon-13 urea breath test
- Serum antibody test
Table 1 summarises the advantages and disadvantages of these three tests.
Faecal antigen testing is now included as a Tier 1 test on the New Zealand Laboratory Schedule, and is widely available
throughout community laboratories in New Zealand. When faecal antigen tests for H. pylori were first introduced they relied
on polyclonal antibodies and the results were often unreliable.13 The use of monoclonal antibody-based techniques to assess
faecal samples has improved the accuracy of the test.13, 14 The test detects the presence of antigens to H. pylori in
a faecal sample and can be used to diagnose active infection and, if required, to confirm that eradication treatment has
been successful.14 Sensitivity and specificity of faecal antigen testing is similar to that reported for carbon-13 urea
breath testing.1, 13, 14 False negative results can occur if the patient has been taking medicines that may decrease the
load of H. pylori in the stomach, or the contents of the stomach are less acidic, e.g. if a patient has been taking a
PPI (Table 1).1, 7 However, there is some limited evidence that monoclonal antibody-based faecal antigen tests may be
less influenced by PPI use than urea breath tests.15
Carbon-13 urea breath testing is still regarded in the literature as the gold standard for testing for H. pylori, however,
the test is time consuming and expensive to perform.7 In New Zealand the test has limited availability and is not funded.
The test provides an indirect measure of the presence of H. pylori-associated urease which is detected by a change in
CO2 in the patient’s breath after ingestion of labelled urea.16 Both sensitivity and specificity of the test are comparatively
high, although, as with faecal antigen testing, false negative results can occur with medicines that decrease the bacterial
load or suppress gastric acid.13
Serum antibody testing (serology) for H. pylori has previously been recommended as the most appropriate test in New
Zealand. However, with the improved availability and accuracy of faecal antigen tests, serology is no longer the preferred
test, and it is no longer funded in New Zealand. Serological testing detects the presence of IgG antibodies to the H.
pylori bacteria. Although the sensitivity of the test is comparable with the other non-invasive tests, the specificity
is variable and when prevalence of H. pylori is low the positive predictive value of the test declines.1, 9 Serology also
cannot distinguish between infection that is past or current, and because antibody levels decrease slowly over 6 – 12
months or longer after eradication treatment, it cannot be used as a test of cure.1, 7
Invasive testing for H. pylori requires endoscopy which can provide biopsy material for histology, rapid urease testing
Table 1. Advantages and disadvantages for non-invasive tests for H. pylori:5, 7, 9 ,13 ,14
Positive predictive value
Faecal antigen test
94 – 95%
94 – 97%
Determines active infection
Can be used as a test of cure
No cost to patient as the test is funded in New Zealand
The accuracy of the test may be reduced if the patient has upper gastrointestinal bleeding or if the stool sample
is unformed or watery
Patient should not have antibiotics for four weeks, or PPIs or bismuth for two weeks, prior to testing. Advice varies
regarding whether H2-receptor antagonists and antacids are able to be continued.
Urea breath test
Determines active infection
Can be used as a test of cure
Cost to patient as test is not funded in New Zealand
Patient needs to be fasted
The patient should not have antibiotics for four weeks, or PPIs for two weeks, or H2-receptor antagonists for 24
hours, prior to testing
85 – 92%
79 – 83%
Convenient for the patient
The test is not affected by medicines such as antibiotics, PPIs or H2-receptor antagonists
No longer funded in New Zealand (however, the test is relatively inexpensive)
Variable specificity; most accurate if there is high prevalence of H. pylori
Cannot distinguish between past and present infection – a positive result means the patient has been exposed but
may not mean the patient has active infection
Cannot be used as a test of cure
Sensitivity – reflects the ability of the test to correctly identify patients with the condition being tested for, therefore
a test with high sensitivity reduces the likelihood of a false negative result
Specificity – reflects the ability of the test to correctly identify patients without the condition, therefore a test
with high specificity reduces the likelihood of a false positive result
Positive predictive value – reflects the probability that if a result is positive, the patient does have the condition
being tested for
For further information see “Deciding when a test is useful: how to
interpret the jargon”, Best Tests (Feb, 2013).
Eradication treatment for H. pylori
If a positive result for H. pylori is obtained, the patient should be prescribed eradication treatment, i.e. “do not
test if not intending to treat”. 5
A recommended triple treatment regimen for the eradication of H. pylori is a seven day course of:17
- Omeprazole 20 mg, twice daily
- Clarithromycin 500 mg, twice daily
- Amoxicillin 1 g, twice daily (or metronidazole 400 mg twice daily, if allergic to penicillin)
Other regimens using different dosing intervals, or other PPIs e.g. lansoprazole, can also be used.17 For
further information refer to the New Zealand Formulary.
Confirmation of eradication of H. pylori after a triple treatment regimen is not required for the majority of patients.3 A
test of cure may be considered in patients with a recurrence of symptoms, a peptic ulcer complication or with important
co-morbidities.3 Faecal antigen testing can give accurate confirmation of eradication if required.14
Recently there have been concerns in New Zealand and worldwide about increasing resistance of H. pylori to the antibiotics
used in the various eradication regimens.4, 7 Resistance to clarithromycin and metronidazole was reported
in a recent New Zealand study and, in particular, resistance to clarithromycin has doubled since the 1990s.4 Although
the study was based on a small number of participants, rates of clarithromycin resistance varied with ethnicity – no resistance
was reported in New Zealand Europeans while a rate of 25% was reported for Māori.4
If an initial seven day eradication regimen has failed (i.e. symptoms have recurred) an alternative two week quadruple
regimen can be used or referral for endoscopy considered. Bismuth-based quadruple treatment is comprised of:4,10
- Omeprazole 20 mg, twice daily
- Tripotassium dicitratobismuthate 120 mg, four times daily (to be taken as: one dose 30 minutes before breakfast,
midday meal and main evening meal, and one dose two hours after main evening meal)
- Tetracycline hydrochloride 500 mg, four times daily
- Metronidazole 400 mg, three times daily
In New Zealand, tripotassium dicitratobismuthate (or colloidal bismuth subcitrate) and tetracycline hydrochloride are
unapproved medicines, supplied fully subsidised under Section 29. Tetracycline hydrochloride requires a Special Authority,
which only applies to its use in this H. pylori eradication regimen.17 Doxycycline is not recommended as an
alternative tetracycline as it results in a significantly lower eradication rate for H. pylori.4 Adhering
to optimal timing of the medicines in the quadruple regimen can be challenging for patients.
Thank you to Dr John Wyeth, Gastroenterologist, Clinical Leader, Capital & Coast DHB,
Medical Director PHARMAC and Dr Rosemary Ikram, Clinical Microbiologist, Christchurch, for expert review of this article.
- Wang A, Peura D. The prevalence and incidence of Helicobacter pylori-associated peptic ulcer disease and upper gastrointestinal
bleeding throughout the world. Gastrointest Endosc Clin N Am 2011;21:613–35.
- Zhu Y, Zhou X, Wu J, et al. Risk factors and prevalence of Helicobacter pylori infection in persistent high incidence
area of gastric carcinoma in Yangzhong City. Gastroenterol Res Pr 2014;[Epub ahead of print].
- New Zealand Guidelines Group (NZGG). Management of dyspepsia and heartburn. Evidence-based best practice guideline
summary. NZGG, 2004. Available from:
- Hsaiang J, Selvaratnam S, Taylor S, et al. Increasing primary antibiotic resistance and ethnic differences in eradication
rates of Helicobacter pylori infection in New Zealand – a new look at an old enemy. N Z Med J 2013;126:64–76.
- World Gastroenterology Organisation Global Guidelines. Helicobacter pylori in developing countries. 2010. Available
- Peleteiro B, Bastos A, Ferro A, et al. Prevalence of Helicobacter pylori infection worldwide: A systematic review
of studies with national coverage. Dig Sci 2014;[Epub ahead of print].
- Malfertheiner P, Megraud F, O’Morain C, et al. Management of Helicobacter pylori infection – the Maastricht IV/ Florence
Consensus Report. Gut 2012;61:646–64.
- Vakil N. Dyspepsia, peptic ulcer, and H pylori: A remembrance of things past. Am J Gastroenterol 2010;105:572–5.
- Gisbert J, Calvert X. Helicobacter pylori ‘Test-and-Treat’ strategy for management of dyspepsia: A comprehensive
review. Clin Transl Gastrolenterol 2013;4:[Epub ahead of print].
- Harmon R, Peura D. Evaluation and management of dyspepsia. Ther Adv Gastroenterol 2010;3:87–98.
- Perez-Perez G, Olivares A, Foo F, et al. Seroprevalence of Helicobacter pylori in New York City populations originating
in East Asia. J Urban Health 2005;82:510–6.
- Zagari R, Law G, Fuccio L, et al. Dyspeptic symptoms and endoscopic findings in the community: The Loiano-Monghidoro
study. Am J Gastroenterol 2009;105:565–71.
- Gisbert J, de la Morena F, Abraira V. Accuracy of monoclonal stool antigen test for the diagnosis of H. pylori infection:
A systematic review and meta-analysis. Am J Gastroenterol 2006;101:1921–30.
- Shimoyama T. Stool antigen tests for the management of Helicobacter pylori infection. World J Gastroenterol 2013;19:8188–91.
- Kodama M, Murakami K, Okimoto T, et al. Influence of proton pump inhibitor treatment on Helicobacter pylori stool
antigen test. World J Gastroenterol 2012;18:44–8.
- Di Rienzo T, D’Angelo G, Ojetti V, et al. 13C-Urea breath test for the diagnosis of Helicobacter pylori infection.
Eur Rev Med Pharmacol Sci 2013;17:51–8.
- New Zealand Formulary (NZF). NZF v22. 2014. Available from: www.nzf.org.nz (Accessed