Infectious diseases and NCDs

This chapter outlines the relationships between NCDs and infectious diseases. Infectious agents cause a substantial proportion of the global NCD burden and, inversely, NCDs can increase the risk of acquiring infections, highlighting the somewhat artificial dichotomic separation between infectious diseases and NCDs, as many NCDs are partly or even entirely caused by transmissible micro-organisms. The chapter describes examples of infectious agents that cause or are associated with NCDs (e.g. human papillomavirus and cervical cancer, hepatitis B virus and liver cancer, dysbiotic gut microbiota and various NCD conditions, Helicobacter pylori and gastric cancer), mechanisms and interactions linking infectious diseases with NCDs (including COVID-19), the role of vaccinations and treatment against infectious diseases as strategies to reduce the NCD burden and implications for a broader health system response.