ABSTRACT
A number of important pathogens gain entry through the gastro-intestinal tract. Some of these cause diarrhoeal diseases (e.g. Salmonella and Shigella spp.) whilst others pass through the intestinal tract to cause disease in other organs (e.g. poliomyelitis, viral hepatitis). The pathogens include viruses, bacteria, protozoa and helminths. Box 4.1 lists all the infections described in this chapter.
