Infectious diseases--past, present, and future.

Abstract

In 1962 Sir McFarland Burnett stated, ‘By the end of the Second World War it was possible to say that almost all of the major practical problems of dealing with infectious disease had been solved.’ At that time, his statement was logical. Control and prevention measures had decreased the incidence of many infectious diseases, and with the ability to continue to identify new antibiotics, to handle new problems, and the ongoing development of appropriate vaccines, his statement appeared to be appropriate. In the US, similar feelings were expressed and funding for infectious disease fellowships began to decline with federal resources being directed elsewhere. The history of the world is intertwined with the impact that infectious diseases have had on populations. Evidence of smallpox has been found in 3000-year-old Egyptian mummies. Egyptian papyrus paintings depict infectious diseases such as poliomyelitis. Hippocrates wrote about the spread of disease by means of airs, water, and places, and made an association between climate, diet, and living conditions. Investigators described miasmas as the source of infections. Fracastoro discussed the germ theory in the 1500s and three routes of contagion were proposed—direct contact, fomites, and contagion from a distance (airborne). Epidemics of leprosy, plague, syphilis, smallpox, cholera, yellow fever, typhoid fever, and other infectious diseases were the norm. The development of the microscope by Leeuwenhoek in the 1600s allowed scientists to visualize micro-organisms for the first time. The 1800s brought knowledge of the cultivation and identification of micro-organisms. Vaccines were developed and used which introduced specific methods to our storehouse of measures for control and prevention. Pasteurization was another important contribution to disease control. An appreciation of the environment and its relationship to infectious diseases resulted in implementation of broad control measures such as community sanitation, personal hygiene, and public health education. The importance of nutrition was appreciated for its impact on infectious diseases. The 20th century brought chemotherapy and antibiotics into our infectious disease armamentarium. Greater dependency upon vaccination programmes and health education became important allies in our efforts at reducing the occurrence of infectious disease. So Sir McFarland’s statement was not an off hand remark. But we are now aware that emerging and re-emerging infections have become a significant worldwide problem. In 1991,