Helicobacter pylori and Related Species

Abstract

Helicobacter pylori, originally classified as Campylobacter pyloridis, is a spirillar or coccoid Gram-negative bacterium that infects the stomach. The incidence of H. pylori (HP) infection is decreasing, in part due to eradication, but it remains one of the most common bacterial infections worldwide and reportedly infects over half of the entire human race. Person-to-person transmission via fecal–oral, oral–oral, and gastric–oral routes accounts for most cases, but the possibility of acquisition from zoonotic or environmental sources cannot be excluded. Risk factors include young age and low socioeconomic status.