Clinical pathology of foodborne diseases: notes on the patient with foodborne gastrointestinal illness.

The symptoms and signs in persons with food- or waterborne infections provide clues to the nature of the infecting microbe. Proper treatment of the affected individual, and protection of those exposed to the same source, is dependent on time-honored methods of diagnosis: exposure history, and physical examination. Laboratory testing may help to identify the responsible agent. Spontaneous recovery is the most likely outcome once supportive measures such as fluid and electrolyte replacement are addressed. Antibiotics are often unnecessary and may prolong fecal excretion of certain microorganisms. In immunosuppressed persons or those weakened by marginal nutrition, foodborne infection can be more severe, mandating more specific therapy. Management requires knowing the level of tissue invasion and organ infected by each of the commonly encountered microbes. Some of the most life-threatening infections (cholera, for example) are associated with no visible tissue injury, yet they have a profound impact on gut function. In contrast, salmonellosis and shigellosis can cause severe gut injury, and when foodborne infections extend beyond the confines of the gut, skilled care is essential. Examples are hemolytic uremic syndrome of Escherichia coli infections, or listeriosis, both of which require urgent attention. Long-term consequences of gut infections such as the paralytic Guillain-Barre syndrome following Campylobacter infections illustrates the long-term problems sometimes encountered. Because it is unlikely that all infectious agents will ever be removed from food and water in any country, sound medical intervention tailored to the extent of illness will be the mainstay of handling such illnesses.