Last updated: 2026-09-13

The 2023 Hong Kong consensus recommendations on Helicobacter pylori and the Department of Health's June 2024 stomach cancer prevention and screening document both distinguish population-wide screening from testing and eradication for people with a clinical reason for it. The consensus recommends testing for adults at high risk of gastric cancer, for peptic ulcer disease and for specified precancerous lesions of the stomach, and treatment where the test is positive; it does not recommend screening asymptomatic persons at average risk, which is not the same as saying that gastric symptoms need no assessment. IARC classifies chronic Helicobacter pylori infection as a Group 1 carcinogen, but carrying the bacterium does not mean cancer will follow. A re-test is still needed after eradication, and the type of test, the drugs taken and the timing of the test all affect the result.

What is Helicobacter pylori? Why can it live inside the stomach?

Helicobacter pylori (H. pylori) can survive inside the stomach, causing chronic inflammation of the gastric mucosa, and is associated with peptic ulcer disease and stomach cancer. The press release of 10 July 2017 from the Faculty of Medicine of The Chinese University of Hong Kong explains the relationship between gastric infection and ulcers; statement 3 of the 2023 Hong Kong consensus likewise links infection to gastric and duodenal disease.

Most people who carry the bacterium have no obvious symptoms. The 2017 CUHK press release states: "Most individuals infected with H pylori have few or no symptoms. They may experience minor belching, bloating, nausea, vomiting and abdominal discomfort when the condition progresses to gastritis. Once H pylori is detected in a person, a course of eradication treatment consisting of proton pump inhibitors and antibiotics will be prescribed." The specific arrangements depend on age, condition and assessment of resistance. The next paragraph of the CUHK press release raises antibiotic resistance, and adds that the number of gastric ulcer cases related to long-term usage of painkiller drugs has increased in recent years, and that if these patients are also infected with H. pylori their risk of developing stomach ulcer-related bleeding will be greatly increased.

The Hong Kong Adventist Hospital page "Helicobacter pylori infection" describes the route of transmission as an estimate:

The medical field is still unsure of the exact cause of Helicobacter pylori infections and how it is spread. It is believed that infections are mainly transmitted via saliva, bodily fluids, vomit, excrement, sewage and food. Due to the variety of channels the infection can spread, it is very difficult to prevent.

The hospital page quoted above writes the organism's Chinese name in a variant form; the Traditional Chinese edition of this article uses the standard form in its own text and keeps the source's own wording inside the quotation.

Assessing gastric symptoms and screening people without symptoms are two different things. The Department of Health's Cancer Online Resource Hub page "Stomach Cancer" lists persistent indigestion and loss of appetite, rapid weight loss, swelling of abdomen, feeling bloated after eating, vomiting and even blood in vomitus, blood in stools or black stools, and anemia, fatigue and weakness; the same page states that these symptoms can be caused by other more common illnesses such as gastritis, stomach or duodenal ulcer, and that if in doubt one should consult a doctor as soon as possible. A test result for the bacterium cannot substitute for the overall diagnosis of a gastric symptom.

Who made the "Group 1 carcinogen" classification, and when?

The carcinogenicity classification is made by IARC, under the World Health Organization. IARC stands for the International Agency for Research on Cancer, a specialised agency under the World Health Organization. Hong Kong government documents explain this as well: the Cancer Expert Working Group on Cancer Prevention and Screening (CEWG) document Recommendations on Prevention and Screening for Stomach Cancer of June 2024 states:

The World Health Organization's International Agency for Research on Cancer (IARC) classified H. pylori as a carcinogenic agent with sufficient evidence in causing stomach cancer in humans.

IARC's own conclusion sentence, from the HELICOBACTER PYLORI chapter of IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 100B, Biological Agents, reads:

Chronic infection with Helicobacter pylori is carcinogenic to humans (Group 1).

The same evaluation section also sets out the cancer sites involved and the evidence:

There is sufficient evidence in humans for the carcinogenicity of chronic infection with Helicobacter pylori. Chronic infection with Helicobacter pylori causes non-cardia gastric carcinoma and low-grade B-cell MALT gastric lymphoma.

For oesophageal adenocarcinoma, there is evidence suggesting lack of carcinogenicity of chronic infection with Helicobacter pylori in humans.

There is sufficient evidence in experimental animals for the carcinogenicity of infection with Helicobacter pylori.

The conclusion is about chronic infection; the cancers named are non-cardia gastric carcinoma and low-grade B-cell MALT gastric lymphoma; and the same section records that, for oesophageal adenocarcinoma, there is evidence suggesting lack of carcinogenicity.

2009 is the year of this re-evaluation, and 2012 is the year Volume 100B was published. The IARC list of classifications gives both Volume 61 and Volume 100B, so 2009 cannot be described as the year carcinogenicity was first established. Group 1 means there is sufficient evidence of carcinogenicity in humans; it is not a statement that a carrier will certainly get cancer, nor a percentage chance of cancer for an individual.

Does carrying the bacterium mean stomach cancer is certain? How many times higher is the risk?

The research estimates below cannot be merged into a single multiplier that applies to every carrier. The studies cited by the CEWG, IARC and the Hong Kong consensus overlap; some of the figures are the overall or stratified results of the same study, not independent pieces of evidence. An odds ratio (OR) is not an absolute chance of cancer, and it cannot be read directly as a risk ratio. Each is listed below with the conditions attached to it:

  • The CEWG (June 2024) cites a meta-analysis of 19 qualified studies: the odds ratio (OR) for stomach cancer in H. pylori-infected patients is 1.92 (95% confidence intervals [95% CI] 1.32-2.78).
  • The same document cites another pooled analysis of 12 prospective studies: the odds ratio of H. pylori infection for non-cardia cancer was 2.97 (95% CI, 2.34-3.77).
  • IARC Volume 100B records the detail of that same pooled analysis: 762 cases of non-cardia gastric carcinoma and 2,250 control subjects, derived from 12 independent prospective cohort studies in nine countries; an overall matched odds ratio of 2.97, with odds ratios for individual studies varying from 1.52–11.1.
  • The same pooled analysis stratified by age: for those aged less than 50 years at diagnosis, the OR was 7.10 (95%CI: 2.93–17.2).
  • The same pooled analysis stratified by period of follow-up: the OR for cases diagnosed less than 10 years after recruitment was 2.39 (95%CI: 1.82–3.12), and for cases diagnosed 10 or more years after recruitment, 5.93 (95%CI: 3.41–10.3).
  • Hong Kong's own consensus recommendations (Hong Kong Medical Journal, December 2023) give a range:

The odds ratio of gastric cancer onset among patients with H pylori infection ranges from 5.9 to 34.5.

Research on precancerous lesions concerns a different group of people. The section of the same CEWG document immediately following the risk paragraph states: "Studies showed that the adjusted relative risk (RR) of stomach cancer in patients with severe atrophic gastritis was 5.76, while that in H. pylori-infected individuals with intestinal metaplasia was 6.4 (95% CI, 2.6-16.1)." ⚠️ Those two figures are about people who already have a precancerous lesion, and cannot be taken to represent carriers in general.

"Almost all stomach cancer patients have carried the bacterium" is a statement running in the other direction. The CEWG:

Epidemiological studies showed that more than 90% of patients with stomach cancer have had current or past H. pylori infection.

⚠️ That sentence is about how many stomach cancer patients have carried the bacterium, not about how many carriers will get stomach cancer — the denominators are different, and it cannot be turned around.

Hong Kong's stomach cancer figures are as follows. The Centre for Health Protection page "Stomach Cancer" (revision date 23 January 2026) states that in 2023 stomach cancer was the seventh commonest cancer in Hong Kong, with 1 284 new cases, accounting for 3.4% of all new cancer cases. On mortality, the same page says:

Stomach cancer was the sixth leading cause of cancer deaths in Hong Kong. In 2024, it claimed 597 deaths, accounting for 4.0% of all cancer deaths.

⚠️ The two figures are not from the same year. The 1 284 new cases are 2023; the 597 deaths are 2024. That is how the page itself prints them, and this article reproduces them as printed — they are not combined here, and they cannot be used to derive a survival rate.

⚠️ There are two sets of age-standardised rates, and they cannot be mixed. The Centre for Health Protection prints 2023 age-standardised incidence rates of 9.1 for males and 6.1 for females per 100 000 standard population, and the footnote on that page states that age-standardised incidence rates are compiled based on the world standard population specified in GPE Discussion Paper Series: No.31, EIP/GPE/EBD, World Health Organization, 2001. The Hong Kong Cancer Registry of the Hospital Authority, in Stomach Cancer in 2023 (document self-printed date August 2025), prints 8.0 for males and 5.3 for females for the same year and the same cancer, and its footnote reads:

Age-standardised rates (ASR) are age-adjusted to the World Standard Population of Segi (1960) and expressed per 100,000 population. Comparisons with these rates from other sources are valid only under the same standard population for calculations.

In other words: both sets are correct, and the difference is only that two different standard populations were used. Comparing age-standardised rates requires the same standard population.

How many people in Hong Kong actually carry the bacterium?

The 2023 Hong Kong consensus states that, apart from children, epidemiological data for Hong Kong are limited. This is not an estimate of the 2026 adult carrier rate for Hong Kong. The consensus is based on a literature search from January 2011 to August 2021, and statement 1 reads:

Statement 1: Although the prevalence of H pylori infection in many developed countries has declined in recent decades, epidemiological data for Hong Kong, except in children, are limited.

The same passage also contains this sentence:

No prevalence data for Hong Kong have been reported since 2011.

That sentence has to be read together with statement 1's exception for children, the literature search period and the 2023 publication date. The consensus itself sets out that in 2008 the estimated rate of H. pylori infection in healthy school children (n=2480) was 13.1%; and that among 602 children who underwent esophagogastroduodenoscopy at a tertiary centre for peptic ulcer symptoms, the infection rate decreased from 25.6% in 2005 to 12.8% in 2017. Rates among children, and especially among children investigated because they had symptoms, cannot stand for a figure for adults across Hong Kong.

The "more than half in Hong Kong" line in the 2017 CUHK press release is a synthesis of historical research. That press release reviews literature published from 1970 to 2016, and reports prevalence in 62 countries and regions; its six regional estimates are Africa 79%, Latin America and the Caribbean 63%, Asia 55%, Europe 47%, Northern America 37% and Oceania 24%. The press release states that Hong Kong and nearby countries and regions also had over half of the population infected with H. pylori, but it does not set out the sample or survey year of any individual Hong Kong study, and so is not enough to represent the 2026 adult infection rate in Hong Kong.

The 30%–50% given on the CUHK Medical Centre's Helicobacter pylori information page is expressly a global estimate, not a Hong Kong proportion. None of the three sources cited in this article — the 2023 Hong Kong consensus, the 2017 CUHK press release and the CUHK Medical Centre information page — provides a representative survey proportion for adults in Hong Kong in 2026; that limit is not a statement that no other literature contains such data.

Who does the Hong Kong consensus recommend for testing and eradication?

Statements 5 to 10 of the consensus make testing and treatment recommendations for specified groups. The following are this site's summaries; for every adult group listed, the sequence is to test first and treat if the test is positive:

  • Statement 5: adults without gastric symptoms who are at high risk of gastric cancer, for example those with a family history of gastric cancer (strong; level of consensus 90%). The same statement adds that, apart from such risk, routine testing of asymptomatic household members or family members of H. pylori–infected adults is not recommended.
  • Statement 6: adults with non-ulcer dyspepsia, peptic ulcer disease, and early gastric cancer after endoscopic treatment (strong; level of consensus 100%).
  • Statement 7: adults with gastric biopsy results showing atrophy, intestinal metaplasia, or dysplasia (strong; level of consensus 100%).
  • Statements 8 and 9: adults planning to begin long-term low-dose aspirin treatment, or other non-aspirin non-steroidal anti-inflammatory drugs, antiplatelets and anticoagulants (conditional; level of consensus 90% and 70% respectively). The supporting paragraph acknowledges that the evidence on the benefit of testing all users of these agents is limited and conflicting, and that the assessment turns particularly on the risk of gastrointestinal bleeding; this is not an instruction to stop any medicine on your own.
  • Statement 10: adults with unexplained iron deficiency anaemia, vitamin B12 deficiency, or immune thrombocytopenic purpura (conditional; level of consensus 90%).

Children are drawn on a different line. Statement 11 does not recommend routine H. pylori testing in asymptomatic children, but recommends that children with peptic ulcer disease be tested and, if positive, treated; where gastrointestinal symptoms appear, the focus of assessment is the cause of the symptoms, not simply whether Helicobacter pylori is present. The adult medication and eradication recommendations above cannot be applied directly to children.

How can you find out whether you carry it? What does it cost, and how accurate is it?

Statement 12 of the Hong Kong consensus holds that the urea breath test and the monoclonal stool antigen test can be used for initial diagnosis and follow-up. Statement 13 takes the position that serological testing is not recommended for initial diagnosis and post-eradication follow-up, but it is a conditional recommendation (level of consensus 100%) and does not rule serology out in every clinical situation. Its supporting paragraph notes that where bacterial load is decreased — gastrointestinal bleeding, atrophic gastritis, gastric MALT lymphoma and gastric cancer — other tests can lose sensitivity, and serological testing may still be useful. Statement 12 (level of consensus 90%) reads:

Statement 12: Non-invasive tests, including the urea breath test and (preferably monoclonal) stool antigen test, are highly accurate for the initial diagnosis and follow-up of H pylori.

Its supporting paragraph:

The carbon-13 urea breath test has a sensitivity of 95% to 98% and a specificity of 90% to 97%.52,53 The monoclonal stool antigen test has a sensitivity of 90% to 98% and a specificity of 90% to 97%.52,54

95%–98% is a range of sensitivity, not a blanket "more than 95% accurate" for every test. The sensitivity of the carbon-13 urea breath test is 95% to 98%, but the lower bound of specificity is 90%. Sensitivity is the proportion of those with the bacterium in whom it is detected; specificity is the proportion of those without it who are not falsely reported as having it — talking about a single vague "accuracy" hides two different kinds of error. The supporting paragraph to statement 12 does not state the reference standard used for each of those figures; these research data are not a guarantee of any individual test result.

The timing of the re-test after eradication and the drugs taken beforehand both affect the result. The consensus:

For post-eradication therapy follow-up, reliable results can be obtained at 2 weeks after discontinuation of proton pump inhibitors (PPIs) and at least 4 weeks after discontinuation of antibiotics and bismuth.32

Preparation before the test also depends on the particular testing service. The MedDx breath test page gives two weeks for PPIs and four weeks for antibiotics, the same intervals for those two drug classes as the consensus above; the CUHK Medical Centre breath test page puts antibiotics and acid-suppressing drugs alike at two weeks. That difference between sources cannot be treated as two interchangeable sets of instructions. The MedDx page itself states that stopping medication should follow healthcare advice; this article does not provide individual arrangements for stopping medicines. The CUHK Medical Centre page also states that people who have had gastric surgery are not suitable for its breath test.

Below are the published breath test prices of two service providers, and one gastroscopy package example; what the services include is not the same.

Examples of Helicobacter pylori (H. pylori) test prices (Hong Kong dollars). Sources: MedDx breath test page (Chinese only; the rendering here is this site's translation), Hong Kong Adventist Hospital Clinical Laboratory & Pathology fee schedule, Gleneagles Hospital Hong Kong endoscopy packages 2025END02; Last updated: 2026-09-13. Only these three sources are listed; this is not a comparison of quotations across Hong Kong.
Source and itemPrice and what it coversPrice effective date
MedDx carbon-13 breath test$680, not including a doctor's explanation of the report; an abnormal result may be explained by its gastroenterologist for a further $300, which does not cover explanation of a normal result or other medical consultationThe page does not state a price effective date; its publication data give 13 September 2023, which does not mean the price took effect on that day
Hong Kong Adventist Hospital urea breath testOut-patient $1,000; standard ward $1,210; semi-private $1,570; VIP or private room $1,820. Charges will be adjusted for urgent care service and services provided during non-office and non-clinic hours1 January 2024; subject to the latest version
Gleneagles gastroscopy IV sedation day packageEND08A excluding polypectomy and biopsy: normal risk $11,100, intermediate risk $14,430; END08B minor polypectomy and / or biopsy (no more than 3): $14,400, $18,720; END08C major polypectomy and / or biopsy (more than 3): $16,800, $21,84014 April 2025

A gastroscopy package is not the same thing as a standalone test for the bacterium. Page 4 of the Gleneagles price list sets out that the package excludes pre-admission consultation and post-consultation, as well as pre-operative advanced diagnostic procedure charges. END08A does not include biopsy; the rapid urease test, histology and culture described in statement 14 of the Hong Kong consensus all involve a gastric biopsy, so a price that excludes biopsy cannot be treated as the total price of completing those diagnoses. The consensus also notes that specimens with low bacterial loads can yield false-negative rapid urease test results, and that culture-based detection has comparatively low sensitivity and is usually reserved for instances where antimicrobial susceptibility testing is needed.

This site's calculation: the MedDx $680 test plus $300 for explanation of an abnormal result comes to $980; that figure applies only under that add-on condition, it is not a general consultation package, and a $20 gap between $980 and the Adventist Hospital out-patient $1,000 cannot be used to infer which provider is cheaper for the same service. Price, clinical suitability and downstream costs are different questions.

Is eradication the end of it? What else should you know?

First, what the Hong Kong authorities say about whether to test at all. The CEWG recommendations of June 2024 (endorsed by the Cancer Coordinating Committee at its 19th meeting on 28 June 2024):

  1. Screening for stomach cancer (by upper gastrointestinal series, upper endoscopy or biomarkers, such as H. pylori serology) is not recommended in asymptomatic persons at average risk. Screening for H. pylori infection (by urea breath test, serology or stool antigen test) among asymptomatic persons in the general population is also not recommended.
  1. Persons at increased risk, e.g. with precancerous lesion of stomach cancer or family history of stomach cancer, may consider seeking advice from doctors regarding the need for and approach of screening.

⚠️ The same document is explicit that "treatment" and "screening" are two different things. Paragraph 25:

  1. Screening of H. pylori in the local general population is not recommended in view of the declining and relatively low incidence of stomach cancer in Hong Kong. On the other hand, eradication of H. pylori in persons known to be infected is important in reducing their risk of developing stomach cancer.

Eradication success depends on the regimen and on resistance. The CUHK Medical Centre information page lists 80%–90%, but that passage does not specify the regimen or the study population; the Hong Kong Adventist Hospital information page gives a triple therapy of at least 7 to 14 days with a success rate of up to 85%, and explains re-testing and further treatment if it is not cured. These institutional summaries are not a guarantee of any individual result, and they do not cover the conditions the Hong Kong consensus sets on the choice and length of regimen.

Statements 15 and 16 of the 2023 Hong Kong consensus give more specific conditions (the following are this site's summaries):

  • Statement 15 (level of consensus 100%) states that the choice of eradication therapy should be based on H. pylori microbial resistance patterns and antibiotic stewardship in Hong Kong, as well as the efficacy of gastric acid suppression, and that the regimen should be simple to use and well-tolerated, with good compliance and high efficacy (>85%).
  • The consensus cites a meta-analysis published in 2018: in Hong Kong the prevalence of resistance to clarithromycin was 10% (95% confidence interval=5%-17%) and to metronidazole 53% (39%-66%); another report gave levofloxacin resistance of 17%.
  • The consensus also cites a population-based study in Hong Kong: the overall failure rate of clarithromycin-based triple therapy was 10.1% during the period from 2003 to 2018.
  • Statement 16 sets out two first-line options: triple therapy with a PPI, clarithromycin and amoxicillin for 14 days, or bismuth quadruple therapy with a PPI, tetracycline, metronidazole and a bismuth salt for 10 to 14 days; and states that triple therapy remains the first-line option in regions with clarithromycin resistance <15% and a local eradication rate of ≥85%.

A re-test is needed after eradication. Statement 24 of the consensus (level of consensus 100%; grade of recommendation strong) reads:

Statement 24: All patients should be tested for H pylori after eradication therapy.

The same passage states that non-endoscopic tests should be performed at least 4 weeks after eradication therapy and/or 2 weeks after PPI treatment. ⚠️ As for reinfection, statement 2 of the consensus (level of consensus 80%) puts the rate below 2% in the Chinese population but says it may be higher in children than in adults; data for adults in Hong Kong are limited, and the figures cited in the supporting paragraph come from Taiwan and mainland China.

⚠️ Eradication is not all benefit, and the Hong Kong consensus itself lists two consequences. Statement 22 (level of consensus 90%):

Statement 22: H pylori eradication may worsen gastroesophageal reflux disease in some patients.

The supporting paragraph to that statement also records that, in one meta-analysis, the pooled results of five cohort studies suggested an increased risk, but that this risk was not supported by the pooled results of seven randomised controlled trials in the same meta-analysis. The paragraph goes on to say that meta-analyses in the past decade have found eradication therapy not significantly associated with the development of gastroesophageal reflux disease, and that generally H. pylori treatment does not have a clinically significant effect on acid production. Statement 23 (level of consensus 90%) notes that patients may gain weight after eradication, and that lifestyle advice should be offered as needed.

⚠️ An interest has to be declared: the acknowledgement section of the consensus recommendations states that meeting logistics support and medical writing support were funded by a pharmaceutical company, and declares that the company had no role in study design, data collection/analysis/interpretation, or manuscript preparation.

Common questions

  • How many people in Hong Kong carry it now? The 2023 consensus, the 2017 CUHK press release and the CUHK Medical Centre information page cited in this article do not provide a representative survey proportion for adults in Hong Kong in 2026. The consensus statement about limited data carries an exception for children, and its literature search runs to August 2021, so it cannot be written up as proof that no new data exist for Hong Kong in 2026.
  • Does carrying the bacterium mean stomach cancer is certain? IARC Group 1 is a classification of the evidence of carcinogenicity, not an outcome for every carrier. The odds ratios differ with study design and population; and how many stomach cancer patients have been infected is not the same as how many carriers will get stomach cancer.
  • Is the breath test more than 95% accurate? The Hong Kong consensus gives the carbon-13 breath test a sensitivity of 95%–98% and a specificity of 90%–97%; the two measures cannot be combined into "more than 95% accurate every time". The timing of a re-test, acid-suppressing drugs, antibiotics and bismuth all affect the result.
  • Who is recommended to be tested? The consensus recommends testing, and eradication if positive, for adults at high risk of gastric cancer, for ulcer disease, and for specified precancerous lesions of the stomach; conditional recommendations cover people about to start specified medicines and people with unexplained anaemia — see statements 5 to 10 above. Not recommending screening for asymptomatic persons at average risk is not the same as saying that symptoms need no assessment.
  • What does one test cost? The two breath test prices in the table above are $680 not including a doctor's explanation of the report, and $1,000 for a hospital out-patient. The former charges a further $300 for explanation of an abnormal result, within a defined scope; ward types carry other prices. These are not the total price of all investigation and treatment.
  • Do I still need a re-test after eradication? Statement 24 of the consensus recommends that all patients be tested after eradication therapy, to confirm whether it succeeded; reinfection is not a zero risk either. Gastro-oesophageal reflux may worsen in some people, but the randomised trials in the supporting paragraph and the more recent meta-analyses have not shown a consistent risk of new disease; weight may also change, and follow-up should suit the clinical situation.

Related article: Acid reflux (GERD): 〈what to do about chest pain, whether you need a gastroscopy, and how long you can take a PPI〉 Related article: 〈Are $4,600 and $13,250 the same colonoscopy? A full breakdown of where private quotations differ, the three public routes and the risk tiers〉

What this article does not state

  • This article does not give an adult carrier rate for Hong Kong in 2026; the three sources cited — the 2023 Hong Kong consensus, the 2017 CUHK press release and the CUHK Medical Centre information page — do not provide that estimate, which does not mean other literature contains none.
  • IARC Volume 100B, the CEWG stomach cancer document of June 2024 and the 2023 Hong Kong consensus do not, between them, fix the stomach cancer risk of carriers in general at four to six times; this article does not assemble the various research figures into a single multiplier.
  • This article does not substitute a test result for the diagnosis of someone with symptoms, and does not decide for any individual, by age, family history or symptoms, whether to be tested, to stop a medicine, or to undergo an eradication regimen.
  • This article does not give a standalone public-sector charge for the urea breath test, and draws no inference from that about whether public bodies provide the service. The private prices represent only the items and conditions listed.
  • This article cites the Centre for Health Protection "Stomach Cancer" statistics page using the WHO 2001 standard population and the Hong Kong Cancer Registry rates using Segi 1960, and does not compare the two directly as higher or lower. The Traditional Chinese edition's Chinese renderings of English-language sources are that edition's own summaries, not official Chinese translations.
  • This is the English edition. The Traditional Chinese edition is the authoritative version of this article. Quotations above are reproduced from the official English text published by the Government of the Hong Kong Special Administrative Region and by the bodies named, not translated by this site. Two sources are published in Chinese only — the CUHK Medical Centre breath test page and the MedDx breath test page — and what this article reports from them is this site's translation.

Sources

English-language documents are quoted in their original English; the Chinese explanations in the Traditional Chinese edition are that edition's own summaries rather than official Chinese versions of those documents. Official recommendations, statistics and charges may all be updated, and what the bodies concerned publish governs. This article is health information, not medical advice, and it cannot judge whether any individual needs testing or treatment. The Department of Health's stomach cancer information page advises anyone with the relevant gastric symptoms to consult a doctor as soon as possible for investigation.