| Popis: |
In this chapter, we examine the second of the five overlapping drivers of disease emergence and re-emergence shown in Figure II.1—technology and industry. Technological developments have yielded immeasurable benefits to society. In the field of medicine, for example, improvements in sanitation and hygiene, along with the widespread use of vaccines and antimicrobial drugs, have served to control and prevent the spread of infectious diseases. Likewise, improvements in intensive care, surgical techniques, cancer therapy, and therapies for other conditions have led to prolonged survival and an enhanced quality of life for many millions of people. But negative effects, too, have sometimes resulted from technological developments. Not least, such developments can provide, occasionally unwittingly, supportive environments for the proliferation and spread of pathogenic micro-organisms. Following Breiman (1996), Figure 5.1 identifies several key areas to these developments. The impact of technology on food production, distribution, and processing has had a substantial effect on the spread of infectious diseases, with potential contamination occurring at all stages of production and processing. The centralization of production and the increased international sourcing of foodstuffs has also had an impact on foodborne disease activity. In addition, current methods of storing foods have resulted in the emergence of foodborne pathogens; an example is provided by outbreaks of Listeria monocytogenes. This bacterium has been found in a variety of raw foods, such as uncooked meats and vegetables, as well as in processed foods that become contaminated after processing, such as soft cheeses and cold cuts from delicatessens, in unpasteurized (raw) milk, and in foods made from unpasteurized milk. Listeria thrives in refrigerated environments and, in its presence, widespread contamination of stored refrigerated food products can occur. Legionnaires’ disease is the paradigmatic disease associated with technological innovation, with cooling towers, evaporative condensers, whirlpools, spas, and showers providing temperatures which promote the survival and proliferation of the causative bacterium, Legionella pneumophila. Municipal water systems are efficient conduits for the dissemination of pathogenic micro-organisms. While most water supplies in developed countries are effectively treated in municipal water treatment facilities, the treatment may occasionally be ineffective owing to faulty procedures or the development of resistance of an organism to routine procedures. |
