2. Infections and Chronic Diseases

The belief that many chronic diseases are infectious in origin goes back to the mid-19th century, when cancer was studied as a possible infectious disease (Institute of Medicine 2002). In the last 15 years, several chronic disorders have been linked to a virus or microorganism, such as peptic ulcer disease with Helicobacter pylori, human papilloma viruses and cervical cancer, Whipple's disease with Tropheryma whippeli, Lyme arthritis and neuroborreliosis with Borrelia burgdorferi, hepatitis viruses with liver cancer, colon cancer with Streptococcus bovis, and HIV with Kaposi sarcoma (see Appendix C). It has been suggested that the incidence of infection-related cancers is underestimated (de Martel and Franceschi 2009; Yeung et al. 2011). Thus, microorganisms that develop resistance to antibiotic or antiviral drugs might contribute to the burden of increasing incidence of chronic and debilitating diseases.