Chapter 122. Acute Infectious Diarrheal Diseases and Bacterial Food Poisoning (Part 1) pdf

Acute Infectious Diarrheal Diseases and Bacterial Food Poisoning Part 1 Harrison's Internal Medicine > Chapter 122.. Acute Infectious Diarrheal Diseases and Bacterial Food Poisoning A

Chapter 122 Acute Infectious Diarrheal Diseases

and Bacterial Food Poisoning

(Part 1)

Harrison's Internal Medicine > Chapter 122 Acute Infectious Diarrheal

Diseases and Bacterial Food Poisoning

Acute Infectious Diarrheal Diseases and Bacterial Food Poisoning: Introduction

Ranging from mild annoyances during vacations to devastating dehydrating illnesses that can kill within hours, acute gastrointestinal illnesses rank second only to acute upper respiratory illnesses as the most common diseases worldwide

In children <5 years old, attack rates range from 2–3 illnesses per child per year in developed countries to as high as 10–18 illnesses per child per year in developing countries In Asia, Africa, and Latin America, acute diarrheal illnesses are not only

a leading cause of morbidity in children—with an estimated 1 billion cases per year—but also a major cause of death These illnesses are responsible for 4–6 million deaths per year, or a sobering total of 12,600 deaths per day In some

areas, >50% of childhood deaths are directly attributable to acute diarrheal illnesses In addition, by contributing to malnutrition and thereby reducing resistance to other infectious agents, gastrointestinal illnesses may be indirect factors in a far greater burden of disease

The wide range of clinical manifestations of acute gastrointestinal illnesses

is matched by the wide variety of infectious agents involved, including viruses, bacteria, and parasitic pathogens (Table 122-1) This chapter discusses factors that enable gastrointestinal pathogens to cause disease, reviews host defense mechanisms, and delineates an approach to the evaluation and treatment of patients presenting with acute diarrhea Individual organisms causing acute gastrointestinal illnesses are discussed in detail in subsequent chapters

Table 122-1 Gastrointestinal Pathogens Causing Acute Diarrhea

on

Illness Stool

Findings

Exampl

Pathogens Involved

Noninflamma Proxi

mal small

Watery No fecal

leukocytes;

Vibrio cholerae,

tory (enterotoxin) bowel diarrhea mild or no

increase in fecal lactoferrin

enterotoxigenic

Escherichia coli (LT and/or

ST), enteroaggregati

ve E coli, Clostridium perfringens, Bacillus cereus, Staphylococcus aureus,

Aeromonas hydrophila, Plesiomonas shigelloides,

rotavirus, norovirus, enteric adenoviruses,

Giardia

lamblia, Cryptosporidiu

Cyclospora

spp., microsporidia

Inflammatory

(invasion or

cytotoxin)

Colon

or distal small bowel

Dysent

inflammatory diarrhea

Fecal polymorphonuc lear leukocytes;

substantial increase in fecal lactoferrin

Shigella

spp.,

Salmonella

spp.,

Campylobacter jejuni,

enterohemorrha gic E coli,

enteroinvasive

Yersinia enterocolitica, Vibrio

parahaemolytic

us, Clostridium difficile, ?A hydrophila, ?P shigelloides, Entamoeba histolytica

Penetrating Distal

small bowel

Enteric fever

Fecal mononuclear leukocytes

Salmone lla typhi, Y enterocolitica,

?Campylobacte

r fetus

Abbreviations: LT, heat-labile enterotoxin; ST, heat-stable enterotoxin Source: After Guerrant and Steiner