Helicobacter pylori mediated Gastritis, Peptic Ulcer and Gastric Cancer

Abstract

It is established that Helicobacter pylori infection is a major cause of gastritis, duodenal ulcer, stomach cancer, and also causes gastric mucosa-associated lymphoid tissue lymphoma. Now, H. pylori infection is considered to be one of the major public health issues in developing countries. At least 50% of world population are infected with H. pylori especially in developing countries. The prevalence of H. pylori is highly variable in relation to geography, age, and socio-economic factors. The causative agent is a Gram negative microaerophile and motile with multiple polar flagella. The main mode of transmission is through person to person contact via fecal-oral and Oral-Oral route. Lack of personal hygiene, poor sanitation and overcrowding facilitates transmission of the organism. The organisms have been isolated from treated water sources. Infection is usually acquired in childhood and often goes unnoticed. The organism has different mechanisms to escape from natural innate immunity and produce powerful cytotoxins that are associated with gastric cancer. Cytotoxin associated gene A is present in more than 90 % of the strains in developing countries. The cytotoxins and released interlukins upgrade the mucosal inflammation. The main risk factors include smoking, consumption of alcohol, and non-steroidal anti-Inflammatory drugs. The progressive stages described include normal stomach mucosa lining, chronic gastritis, atrophic gastritis, intestinal metaplasia, dysplasia, and stomach cancer. In laboratory diagnosis various tests employed are histological assessment, culture, urease based test, fecal antigen test and serological tests. The polymerase chain reaction is also used to detect the organisms. High resistance to commonly used antibiotics are reported by many studies. In the absence of vaccine, it is important to study the prevalence rate of H. pylori, the genotypes, biomarkers, and antimicrobial resistance pattern, effective treatment and eradication. In addition, morbidity and mortality can be reduced by early detection, diagnosis, and effective treatment.