5 When to test for Helicobacter pylori and what to do with a positive test
Case
A 47-year-old executive consults you because his older brother, aged 61, has recently been diagnosed with gastric cancer. The patient advises you he wants to have testing for the stomach bacteria that causes gastric cancer. The patient is asymptomatic and in particular has no history of epigastric pain, fullness after meals, early satiety, vomiting, weight loss, dysphagia or gastrointestinal bleeding. He is a non-smoker. No other family members have been affected by gastric cancer to his knowledge. The patient was born in Australia to parents of British descent. The patient has been taking low-dose aspirin for cardiovascular health reasons, but has not been taking non-steroidal anti-inflammatory drugs. He has no known drug allergies. Physical examination is completely normal.
After a full discussion, the patient still wishes to go ahead with testing.
Pathogenesis
H. pylori is most often acquired in childhood by close contact with other infected families and, once acquired, persists for life in most cases. The mode of transmission is probably oral (via saliva or vomit) and, in the developing world, faecal spread. Virtually 100% of infected individuals develop gastritis; the lifetime risk of peptic ulcer disease in those infected is approximately 20%.
Management Guidelines
Testing for H. pylori infection
Testing for H pylori infection should be performed only if the clinician plans to offer treatment to patients with a positive result (Box 5.1). The advantages and disadvantages of tests for H. pylori are summarised in Table 5.1.