Helicobacter pylori infection plays an important role in the pathogenesis of peptic ulcer diseases and stomach cancers. It is classified as group I carcinogen by the World Health Organization’s International Agency for Research on Cancer in 1994. Back in 1940, Freedburg and Barron have already reported the histopathological finding of spirochetes in surgically removed stomach specimens, preceding the success in culturing this organism by Warren and Marshall in 1983 in Perth, Western Australia. Its prevalence worldwide is approximately 50%, but highly variable among socioeconomic and geographical factors. The infection is usually acquired in childhood, and strongly associated with low socioeconomic status. The prevalence in children can be as low as 5% in developed countries compared with over 80% in developing countries. In Hong Kong, recent data suggest that its prevalence in adult patients has dropped from 50% to 32% over the last decade.
Different diagnostic modalities are available. Non-invasive methods include 13C-Urea breath test, stool, urine and blood tests. 13C-Urea breath test is particularly convenient for patients without any alarming symptoms. For patients whom more sinister disease is anticipated, upper endoscopy to obtain stomach wall specimens is recommended. Treatment regimens include the use of proton pump inhibitors to suppress stomach acidity and a combination of antibiotics targeting Helicobacter pylori for 1-2 weeks. Successful rate of eradication is around 90%. At least 4 weeks after treatment, another 13C-Urea breath test can confirm treatment success.
幽門螺旋菌
幽門螺旋菌是一種只存活於胃壁的細菌，但全球約一半人口都已受感染。對於此細菌的傳播途徑，醫學界還沒有定案，但相信是在兒童時期受感染的。幽門螺旋菌引發的胃病可輕可重，他可引發慢性胃炎，胃潰瘍，十二指腸潰瘍及甚至胃癌。世界衛生組織已將幽門螺旋桿菌列為第一級的胃癌致癌因數。可幸是此細菌的發病率只是約10%，即大部分受感染人士都沒有病徵。而因為香港居住環境衛生有所進歩，受感染人口已由過往的50%下降至約30%，年輕一代的感染率應該更低。
上消化道內視鏡及抽取胃壁組織檢查可準確診症。對於非胃癌高危人士，C13吹氣測試是相對較方便的檢查來確認患者是否有感染幽門螺旋菌。治療方法是使用包括 proton pump inhibitors 的藥物減低胃酸及服用針對幽門螺旋菌的抗生素，服用七至十四曰後，清除幽門螺旋菌的機會率約百分之九十，患者可在服藥後最少四個星期再進行C13吹氣測試，以確認是否仍有病菌。病菌清除後翻發機會低於1%，而且清除病菌是有效防止胃潰瘍或胃癌的方法。
