A spiral shaped bacteria with the human gastric mucosa being its major habitat. It is not routinely cultured in most diagnostic microbiology laboratories because of the organism's very specific growth requirements.

Disease

• major cause of gastritis
• major factor in the development of most cases of duodenal and gastric ulcers
• likely to be a contributing factor in some cases of gastric cancer

Mode of transmission

Most probably acquired by oral-oral transmission

Significance in endoscopy

Helicobacter pylori transmission by contaminated biopsy forceps has been demonstrated. It is probable that endoscopic transmission of H. pylori has been more frequent than has been recognised because of:

• the high background prevalence of symptoms similar to H. pylori infection in the population examined;
• the high background prevalence of H. pylori infection;
• the non-specific nature of symptoms associated with H. pylori induced gastritis
• the frequency of asymptomatic infection

It has been suggested that a significant proportion of "adult reinfection" in some research studies is due to reinfection by inadequately processed biopsy forceps.
An increased occupational risk to endoscopy staff of H. pylori infection has been postulated.
source :  http://www.health.qld.gov.au/EndoscopeReprocessing/module_1/1_3d.asp#Cdiff