More than four billion people worldwide infected with Helicobacter pylori
A recent study conducted by the Chinese University of Hong Kong (CUHK) revealed that 4.4 billion people worldwide are infected with Helicobacter pylori, a bacterium associated with both peptic ulcer disease and gastric cancer.
In this first systematic review of 184 population-based prevalence studies from 62 countries published from 1970–2016, an estimate of 4.4 billion individuals were infected with H. pylori after extrapolation to the 2015 world population. [Gastroenterology 2017, doi: 10.1053/j.gastro.2017.04.022]
A pooled prevalence estimate of 257,768 out of 531,880 participants (48.5 percent) tested positive for H. pylori. Regions with the highest reported H. pylori prevalence were Africa (70.1 percent), South America (69.4 percent) and Western Asia (66.6 percent). Regions with the lowest reported H. pylori prevalence were Oceania (24.4 percent), Western Europe (34.3 percent) and North America (37.1 percent).
“Writing this paper gave us new insights and perspectives to approach medicine. With a huge task of screening more than 14,000 papers, extracting information whilst interpreting it was rewarding,” said author James KY Hooi, a 5th year student of the Faculty of Medicine, CUHK.
Among the East Asian countries and regions, Hong Kong was found to have the highest prevalence of H. pylori infection (58 percent), followed by China (56 percent), Korea and Taiwan (54 percent), and Japan (52 percent).
“We confirmed variations in the prevalence of H. pylori between regions and countries, with differences probably attributable to socioeconomic status and level of hygiene, such as access to clean water,” commented author Lily WY Lai, a 5th year student of the Faculty of Medicine, CUHK.
“This paper highlights the significant burden of H. pylori infection globally. Members of the public are advised to consult their physicians if they have persistent symptoms of gastric pain and discomfort,” advised Professor Siew Chien Ng from the Department of Medicine and Therapeutics, CUHK, one of the investigators of the study.
“Our data also provide information for planning appropriate strategies to eradicate H. pylori and allocate healthcare resources,” author Michael MY Suen, a 5th year student of the CUHK Faculty of Medicine, added.
Limitations of the study were inclusion of reports from only 62 out of 196 countries globally, with data lacking in several developing countries. The prevalence studies included were conducted at different time periods, and sampling in some of the studies was done in a selected area only, which probably could not reflect a whole country’s true prevalence.
H. pylori is a bacterium capable of thriving in the highly acidic environment of the stomach and duodenum. It is considered to be the main cause of chronic gastritis and is an important aetiologic agent for both peptic ulcer disease and gastric cancer. [Gut 2007;56:772-781; Am J Gastroenterol 2007;102:1789-1798]