ABSTRACT
Despite confidence in the mid-20th century that modern medicine had conquered infectious disease, morbidity and mortality due to infectious diseases remains a serious threat to global population health in the 21st century (Burnet and White, 1962). Diarrheal diseases, HIV/AIDS, tuberculosis and other infectious diseases rank in the top 10 causes of mortality (World Health Organization (WHO) 2011). The continued significance of infectious diseases is due to three phenomena: the emergence of novel infectious diseases, the re-emergence of “old” infectious diseases in places where they had previously been nearly or totally eradicated, and the persistence of infectious disease despite decades of international public health efforts, particularly in low and middle income countries.
