Lesson 25

Intestinal infectious diseases: cholera, typhoid fever, shigellosis

Key points:
1. Cholera, typhoid fever, salmonellosis, shigellosis: morphogenesis, morphological characteristics, complications, consequences, causes of death.
2. Viral enteritis and diarrhea. Parasitic, campylobacter, yersinia, staphylococcal and colienteritis.

Sources:
1. Kumar, Vinay, Abul K. Abbas, and Jon C. Aster. Robbins and Cotran Pathologic Basis of Disease. Ninth edition. Philadelphia, PA: Elsevier/Saunders, 2015. P.69-99, 186-265.
2. Kumar, Vinay, Abul K Abbas, Jon C Aster, and Stanley L. 1915-2003 Robbins. RobbinsBasic Pathology. Tenth edition. Philadelphia, PA: Elsevier/Saunders, 2018. P. 57-87, 121-184
3. Klatt, Edward C. Robbins and Cotran Atlas of Pathology. Third edition. Philadelphia, PA:Elsevier Saunders, 2015.
4. Klatt, Edward C., and Vinay Kumar. Robbins and Cotran Review of Pathology. Fourth edition. Philadelphia, PA: Elsevier Saunders, 2015. P.18-30, 57-75
5. Harsh Mohan. Essential Pathology for Dental Students.Fourth edition. Jaypee Brothers,Medical Publishers Pvt. Limited, 2011. P.137-159 

Infectious catarrhal colitis, microscopic

Infectious agents such as Shigella, Salmonella, and Campylobacter can produce an acute self-limited colitis with cryptitis, crypt ulcers, and extensive infiltrates of neutrophils and lymphocytes between crypts, as shown here. Additional findings can include edema, abscesses, and small granulomas. The crypt architecture and goblet cells are preserved, unlike in inflammatory bowel disease. Resolution typically occurs within 2 to 3 weeks.

Pseudomembranous colitis, microscopic

The underlying colonic mucosa is intact, so grossly bloody diarrhea is unlikely, but there is a  marked overlying exudate with necrotic epithelial cells admixed with inflammatory cells. The exudate within crypts may be so extensive that it erupts from the surface in volcano-like fashion. C. difficile toxins disrupt the epithelial cytoskeleton, with loss of tight junction barrier function, and promote cytokine release and apoptosis. Recurrent infection may occur.

Typhoid ileitis, "clear" ulcer, microscopic

Ulceration of mucosa with fibrinoid necrosis of epithelial layer provoked by the release of the potent endotoxin. Exactly under the debris there is one clearly visible typhoid nodule (granuloma) composed of the macrophages with abundant clear cytoplasm. In underlying Payer's patch the replacement of lymphocytes by monocytic derivatives has found.

Typhoid ileitis, medullar swelling, grossly

Typhoid fever, roseola and papula rash

Cholera: mechanism of action of exotoxin (CT) 

Cholera: sunken eyes and wrinkled hands (facies hippocratica)

Pseudomembranous colitis, gross: The colonic mucosal surface shown is partially covered by yellow-green exudate. The mucosa is erythematous and superficially denuded, but not eroded
Shigella catarrhal colitis (dysentery), gross: colonic mucosal surface shown is hyperemic with submucosal haemorrhages and covered with excess of mucus. Together with tenesmus and diarrhea it may produce such a symptom as "rectal spit" - slimy-consistent stool with blood and mucus

virtual slides

Case 1: Headache, fatigue, stomach pain, diarrhea or constipation, rash, delirium