Clinical Utility of Upper Endoscopy in Diagnosis of Helicobacter Pylori Infection

Overview

Helicobacter pylori (H. pylori) is a gram-negative flagellated bacterium that inhabits the gastric environment of 60.3% of the world population, and its prevalence is particularly high in countries with inferior socioeconomic conditions, exceeding 80% in some regions of the globe , This phenomenon occurs among other reasons, due to the unsatisfactory basic sanitation and high people aggregations observed in many under developed nations, scenarios that favour the oral-oral and fecal-oral transmissions of H.pylori.Another possible transmission route of this pathogen is the sexual route. Several studies have shown that the colonization of H.pylori could be negatively and positively associated with the induction and progression of several diseases .It has been reported to be linked to gastric and duodenal ulcer, gastric carcinoma, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma and gastritis ,A positive association also reported between H.pylori infection and oesophageal cancer. Moreover, evidence is also available on the positive association between H.pylori and non gastrointestinal diseases such as diabetes mellitus , coronary artery disease , and anaemia. Abdominal pain and discomfort, nausea, burping, and loss of appetite are common symptoms of H.pylori infection. Other symptoms include, bloating, weight loss, and heart burn. Several approaches are used in the detection of H. pylori. Both the invasive and the non-invasive methods are employed in the detection of H. pylori in a patient. Many factors, however, influence choices in the method of diagnosis: availability of diagnostic instruments/materials, sampling population, and competency and experience of the physicians/clinicians . Invasive methods include endoscopic evaluation, histology, rapid urease test (RUT), and bacterial culture. Non-invasive methods include urea breath test (UBT), stool antigen test (SAT), serology, and molecular diagnostic approaches .Endoscopy is an accurate test for diagnosing the infection as well as the inflammation. Endoscopy also allows the determination of the severity of gastritis with biopsies as well as the presence of ulcers, MALT lymphoma and cancer. Real-time endoscopy along with conventional white light imaging (WLI)and image enhanced endoscopic (IEE)techniques, such as narrow-band imaging (NBI), linked color imaging (LCI) and blue laser imaging (BLI), appear to have important roles in clinical practice to identify H. pyloriinfected status . Another endoscopic technique is i-scan digital chromoendoscopy, which is a digital contrast method that enhances minute mucosal structures and subtle changes in color . The overall diagnostic accuracy of i-scan is 97% compared to 78% for WLI .