Which of the following is a viral carcinogen that affects the stomach?

Helicobacter pylori is recognized as a significant factor in the development of stomach cancer. It is a type of bacteria rather than a virus, but it is well-established in the medical community for its role in causing chronic gastritis, peptic ulcers, and increasing the risk for gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. The inflammation and damage caused by H. pylori infection can lead to alterations in the gastric lining that may eventually contribute to cancer development.

In contrast, while Hepatitis B and Hepatitis C are viral infections that can increase the risk of liver cancer, and Human Papillomavirus is primarily associated with cervical and other anogenital cancers, none of these has a direct link to stomach cancer like Helicobacter pylori does. Focusing on the connection between H. pylori and stomach cancer underscores the importance of understanding how certain infections can influence carcinogenesis in specific organs.