Routes of transmission of Helicobacter pylori infection

Helicobacter pylori is an important gastroduodenal pathogen, which has been recognized as a Class I carcinogen factor for gastric cancer and gastric m ucosa associated lymphoid tissue limphomas. In spite of the worldwild sprea d of the infection, the route of transmission is still nor known. We review ed data from several sero-epidemiological studies and aimed to identify pot ential sources of Helicobacter pylori infection. Available evidence strongly suggests an inverse correlation between socio-e conomic status and prevalence of Helicobacter pylori. The infection is acqu ired mostly during childhood in the third world, but is rare in children in developed countries, where the prevalence of Helicobacter pylori increases with age. Following the detection of the bacterium in saliva, faeces, and gastric juice, oral-oral or faecal-oral transmission and iatrogenic spread, through the use of unsterile endoscopes, have been proposed as possible ro utes of infection. Helicobacter pylori has also been found in some domestic cats, but at present, the risk of infection from these animals appears sli ght. The mode of transmission of Helicobacter pylori, as is yet, not known. Available information support the hypothesis of spread through close perso nal contact, considering humans as the only significant,reservoir of infect ion.