小儿腹泻-英文课件.pptVIP

Malnutrition and Child Mortality Etiology of Diarrhea Etiology of Diarrhea The most important infective causes of acute diarrhea in developing countries in children are: Rotavirus Enterotoxigenic escherichia coli Shigella Campylobacter jejuni Salmonella typhimurium Etiology of Diarrhea Pathophysiological Mechanisms of Diarrhea Pathophysiological Mechanisms of Diarrhea Virus Diarrhea- Rotavirus Enterotoxigenic Enteritis – ETEC, Vibrio Cholerae Entero-Invasive Organisms – Shigella Species, EIEC Dietary Diarrhea Pathogenesis of Virus Diarrhea Pathogenesis of Virus Diarrhea 1- Infected absorptive enterocytes are killed causing patchy epithelial cell destruction and villous shortening 2- Destroyed absorptive cells are rapidly replaced by cells that migrate from the crypts. Villi become covered with immature non-absorptive secretory cells having: - no brush border - no brush border enzymes Pathogenesis of Virus Diarrhea (Osmotic Diarrhea) Pathophysiological Mechanisms of Diarrhea Virus Diarrhea- Rotavirus Enterotoxigenic enteritis – ETEC, Vibrio Cholerae Entero-Invasive Organisms – Shigella Species, EIEC Dietary diarrhea Pathogenesis of Enterotoxigenic Diarrhea Pathogens: Vibrio cholerae (cholera) ETEC Staphylococcus aureus Clostridium difficile Pathogenesis of Enterotoxigenic Diarrhea (Secretory Diarrhea) Pathogenesis of Enterotoxigenic Diarrhea (Secretory Diarrhea) An imbalance in the ratio of intestinal fluid absorption to secretion, so watery stool may occur in clinical observation Enterotoxigenic Diarrhea Clinical finding: Watery diarrhea and vomiting develop after an incubation period of 6 hr- 5 days(2-3days, average) Low-grade fever occurs in some children Profuse, painless, watery diarrhea, sometimes with flecks of mucus but no blood Fluid and electrolyte losses, tachycardia, tachypnea, a sunken anterior fontanel, progress to circulatory collapse Pathophysiolo