Infectious diseases

Infectious diseases are a major cause of morbidity, disability, and mortality worldwide. During the last century, substantial gains have been made in public health interventions for the treatment, prevention, and control of infectious diseases. Nevertheless, recent decades have seen a worldwide pandemic of the human immunodeficiency virus (HIV), increasing antimicrobial resistance, and the emergence of many new viral, bacterial, fungal, and parasitic pathogens.

As a result of changes in a variety of different environmental, social, economic, and public health factors, morbidity and mortality due to infectious diseases have declined in industrialized countries during the last 150 years with the result being a gradual transition to chronic diseases including cardiovascular disease, diabetes mellitus, and cancer as major causes of mortality in these countries today. However, in contrast, in less developed countries, infectious diseases continue to contribute substantially to the overall burden of disease.

Detailed information on the definitions of infectious diseases, modes of transmission, and their control are provided in Chapter 12.6, by Robert J. Kim-Farley. An overview of issues related to emerging and re-emerging infections is provided in Chapter 9.17. Similarly, detailed information on diseases caused by prions, sexually transmitted infections, human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), tuberculosis, and malaria can be found in Chapters 9.11–9.15. This chapter will review the global burden of common infectious diseases in children and adults, determinants of the high infectious disease burden in resource-poor countries, and important aspects of the clinical manifestations, diagnosis, and treatment of the handful of infectious diseases that account for the major share of morbidity and mortality in children and adults worldwide.