Acute diarrheal disease, which has an incidence of ∼4.6 billion cases worldwide per year, is the second most common infectious cause of death worldwide (after lower respiratory tract infection). The wide range of clinical manifestations is matched by the wide variety of infectious agents involved (Table 91-1). An approach to pts with infectious diarrhea is presented in Fig. 91-1.
TABLE 91-1GASTROINTESTINAL PATHOGENS CAUSING ACUTE DIARRHEA |Favorite Table|Download (.pdf) TABLE 91-1GASTROINTESTINAL PATHOGENS CAUSING ACUTE DIARRHEA
|Mechanism ||Location ||Illness ||Stool Findings ||Examples of Pathogens Involved |
|Noninflammatory (enterotoxin) ||Proximal small bowel ||Watery diarrhea ||No fecal leukocytes; mild or no increase in fecal lactoferrin ||Vibrio cholerae, enterotoxigenic Escherichia coli (LT and/or ST), enteroaggregative E. coli, Clostridium perfringens, Bacillus cereus, Staphylococcus aureus, Aeromonas hydrophila, Plesiomonas shigelloides, rotavirus, norovirus, enteric adenoviruses, Giardia lamblia, Cryptosporidium spp., Cyclospora spp., microsporidia |
|Inflammatory (invasion or cytotoxin) ||Colon or distal small bowel ||Dysentery or inflammatory diarrhea ||Fecal polymorphonuclear leukocytes; substantial increase in fecal lactoferrin ||Shigella spp., Salmonella spp., Campylobacter jejuni, enterohemorrhagic E. coli, enteroinvasive E. coli, Yersinia enterocolitica, Listeria monocytogenes, Vibrio parahaemolyticus, Clostridium difficile, A. hydrophila, P. shigelloides, Entamoeba histolytica, Klebsiella oxytoca |
|Penetrating ||Distal small bowel ||Enteric fever ||Fecal mononuclear leukocytes ||Salmonella typhi, Y. enterocolitica |
Clinical algorithm for the approach to pts with community-acquired infectious diarrhea or bacterial food poisoning. Key to superscripts: 1. Diarrhea lasting >2 weeks is generally defined as chronic; in such cases, many of the causes of acute diarrhea are much less likely, and a new spectrum of causes needs to be considered. 2. Fever often implies invasive disease, although fever and diarrhea may also result from infection outside the GI tract, as in malaria. 3. Stools that contain blood or mucus indicate ulceration of the large bowel. Bloody stools without fecal leukocytes should alert the laboratory to the possibility of infection with Shiga toxin–producing enterohemorrhagic Escherichia coli. Bulky white stools suggest a small-intestinal process that is causing malabsorption. Profuse "rice-water" stools suggest cholera or a similar toxigenic process. 4. Frequent stools over a given period can provide the first warning of impending dehydration. 5. Abdominal pain may be most severe in inflammatory processes like those due to Shigella, Campylobacter, and necrotizing toxins. Painful abdominal muscle cramps, caused by electrolyte loss, can develop in severe cases of cholera. Bloating is common in giardiasis. An appendicitis-like syndrome should prompt a culture for Yersinia enterocolitica with cold enrichment. 6. Tenesmus (painful rectal spasms with a strong urge to defecate but little passage of stool) may be a feature of cases with proctitis, as in shigellosis or amebiasis. 7....