23 - Gastrointestinal tract infections

Abstract

Ingestion of pathogens can cause many different infections. These may be confined to the gastrointestinal tract or are initiated there before spreading to other parts of the body. In this chapter, we consider the important bacterial causes of diarrhoeal disease and summarize the other bacterial causes of food-associated infection and food poisoning. Viral and parasitic causes of diarrhoeal disease are discussed, as well as infections acquired via the gastrointestinal tract and causing disease in other body systems, including typhoid and paratyphoid fevers, listeriosis and some forms of viral hepatitis. For clarity, all types of viral hepatitis are included in this chapter, despite the fact that some are transmitted by other routes of infection. Infections of the liver can also result in liver abscesses, and several parasitic infections cause liver disease. Peritonitis and intra-abdominal abscesses can arise from seeding of the abdominal cavity by organisms from the gastrointestinal tract. Several different terms are used to describe infections of the gastrointestinal tract; those in common use are shown in Box 23.1.