1. DIARRHOEAL DISEASES Causes of diarrhea: @ Over-indulgence in food @ Chemical intoxication @ Long-term antibiotic use. @ Viral causes: # Rotavirus # Norwalk virus

3. @ Bacterial causes (70% of cases): # E. coli # Salmonella spp. # Campylobacter jejuni # Shigella spp. # Vibrio cholerae & other Vibrio spp # Y. enterocolitica

5. E. Coli Strains causing diarrhea @ Produce 50% of diarrheal cases. @ Enteropathogenic E. coli: Causes infantile gastroenteritis. @ Enterotoxigenic E. coli: Major cause of diarrhea @ Enteroinvasive E. coli: Causes an illness similar to Shigella dysentery @ E. coli 01H57 (produces cytotoxin) : Has toxin similar to shiga toxin

7. Lab, Diagnosis of Diarrhea @ Microscopy for Vibrio @ Stool culture. @ Rapid detection of viral antigen by latex particle agglutination. Pathogenicity of Shigellosis : @ S. dysenteriae is commonest in Sudan @ Spread of infection is by water & food @ Shigella spp. produces an enterotoxin that causes the watery diarrhea

9. Aetiology of Water-borne Diarrhoea Bacteria: @ Shigella spp. @ Campylobacter spp. @ Enteric fever salmonellae @ V. cholerae, and Vibrio spp. @ E. coli Viruses: @ Hepatitis A virus @ Norwalk-like viruses @ Rotavirus

11. Antibiotic-associated Diarrhoea @ Due to toxin produced by Cl. difficile in patients using antibiotics for long periods @ Cl. difficile also causes perforation, pseudomembranous colitis, & megacolon @ Diagnosis is done by detection of toxin in stool and neutralized by Clostridium antitoxin

13. YERSINIA ENTEROCOLITICA @ Gram negative rods, capsulated, non- motile, facultatively anaerobic, catalase positive, oxidase negative. Pathogenicity Causes diarrhea, abdominal pain, arthritis enterocolitis, bacteraemia, liver abscess Diagnosis @ Culture of faeces, and joint fluid @ Serology: Rise in antibodies