Infectious Diseases – The Big Three

Infectious diseases, also known as communicable diseases, are those that can be transmitted either directly or indirectly. Although reducing in prevalence, they still account for 6 out of the top 10 causes of death and disability in low-income countries (LICs). As well as deaths, communicable diseases can pose a major international health security threat, as seen during the COVID-19 pandemic. In this chapter, we are going to focus on the ‘Big Three’—HIV/AIDS, Tuberculosis (TB) and Malaria; however, we recognise there are many more infectious diseases that have a significant impact globally.