Helicobacter pylori infection rates in relation to age and social class in a population of Welsh men

Infection of the gastrointestinal tract with the bacteria Helicobacter pylori (H. pylori) is thought to play a causal role in the development of a number of disorders of the stomach and intestines, including gastritis (inflammation of the stomach), peptic ulcer disease (ulceration of the stomach or intestines) and possibly stomach cancer. Over 95 percent of patients suffering from duodenal ulcer, for example, have evidence of H. pylori infection. Not all infected subjects immediately develop gastrointestinal symptoms. It is of interest to know the prevalence of H. pylori infection in the population at large; however, most studies of infection rates in populations other than gastrointestinal disease patients have used selected groups of subjects such as blood donors or health care staff volunteers. To better ascertain the percentage of the population that suffers from H. pylori infection, a sensitive and specific assay (enzyme-linked immunosorbent assay for immunoglobulin G) to detect the presence of H. pylori was used on frozen blood samples from 749 randomly selected men between the ages of 30 and 75 living in South Wales. The overall prevalence of H. pylori infection was 57 percent. Age differences were seen: 30 percent of the subjects between 30 and 34 had evidence of infection, while 59 percent of the subjects over 45 were infected. There was an inverse relationship between social class and infection rate; subjects in the lowest social class were much more likely to carry H. pylori than subjects in higher social classes. The patterns of H. pylori infection are consistent with the patterns of peptic ulcer disease and stomach cancer seen in the general population, further supporting a link between bacterial infection and these diseases. (Consumer Summary produced by Reliance Medical Information, Inc.)