Diarrhea clinical diagnosis


Published on

Published in: Health & Medicine, Travel

Diarrhea clinical diagnosis

  3. 3. Leading cause of illness and death among children in developing countries. Estimated 1.3 thousand million episodes and 4 million deaths occur each year in under-fives. Main cause of death from acute diarrhoea is dehydration. Others dysentery and undernutrition. Epidemiology
  4. 4. Gastroenteritis <ul><li>Gastroenteritis is a nonspecific term for various pathologic states of the gastrointestinal tract. </li></ul><ul><li>The primary manifestation is diarrhea, but it may be accompanied by nausea,vomiting,dysentry and abdominal pain. </li></ul><ul><li>A universal definition of diarrhea does not exist, although patients seem to have no difficulty defining their own situation. </li></ul>
  5. 5. Types of GIT Infections and Their Symptoms <ul><li>Gastroenteritis / Food Poisoning – syndrome characterized by GIT symptoms like nausea, vomiting, diarrhoea & abdominal discomfort </li></ul><ul><li>Diarrhea – Excess fluid in the intestinal lumen results in frequent, loose, watery stools. </li></ul><ul><li>Inflammatory diarrhea or dysentery – inflammation of the intestine with passage of frequent stools containing blood and pus; abdominal cramps and fever </li></ul>
  6. 6. Types of GIT Infections and Their Symptoms <ul><li>Enteric fever – fever, headache, lethargy, shock, splenomegaly </li></ul><ul><li>Stomach ulcers – stomach pain </li></ul><ul><li>Worm infestations – blockage of GI tract; malnutrition </li></ul>
  7. 7. Definition <ul><li>Defined as- Inflammation of the mucous membrane of both the stomach and intestine, usually causing nausea, vomiting, and diarrhea . </li></ul><ul><li>Acute gastroenteritis usually causes profuse watery diarrhea, often nausea and vomiting, but without localized findings. </li></ul><ul><li>Between cramps, the abdomen is completely relaxed. </li></ul>
  8. 8. Cause of Gastroenteritis <ul><li>Infectious agents usually cause acute gastroenteritis. </li></ul><ul><li>These agents cause diarrhea by adherence, mucosal invasion, enterotoxin production, and/or cytotoxin production. </li></ul><ul><li>These mechanisms result in increased fluid secretion and/or decreased absorption. </li></ul><ul><li>This produces an increased luminal fluid content that cannot be adequately reabsorbed, leading to dehydration and the loss of electrolytes and nutrients. </li></ul>
  9. 9. Condition <ul><li>Increase in frequency, size or loosening of bowel movements. </li></ul><ul><li>Increase in the frequency and fluid volume of the bowel movement. </li></ul><ul><li>Daily weight of stool is 100-250 grams (g) </li></ul><ul><li>Most patients with diarrhea will produce in excess of 250 g of stool a day </li></ul>
  10. 10. Diarrhea <ul><li>Diarrhea is both a symptom and a sign. </li></ul><ul><li>Symptom : Typically considered as an increased frequency or volume of stool (i.e., 3 or more liquid or semisolid stools daily for at least 2-3 consecutive days). </li></ul><ul><li>Sign : Diarrhea is formally defined as stool weight >200 g/24h </li></ul>
  11. 11. DEFINITIOINS <ul><ul><ul><li>Acute Diarrhoea </li></ul></ul></ul><ul><ul><ul><ul><li>sudden onset and lasts less than two weeks </li></ul></ul></ul></ul><ul><ul><ul><ul><li>90% are infectious in etiology </li></ul></ul></ul></ul><ul><ul><ul><ul><li>10% are caused by medications, toxin ingestions, and ischemia </li></ul></ul></ul></ul><ul><ul><ul><li>Chronic Diarrhoea </li></ul></ul></ul><ul><ul><ul><ul><li>Diarrhoea which lasts for more than 4 weeks </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Most of the causes are non-infectious </li></ul></ul></ul></ul><ul><ul><ul><li>Persistent Diarrhoea </li></ul></ul></ul><ul><ul><ul><li>-Diarrhoea lasting between 2 to 4 weeks </li></ul></ul></ul>
  12. 12. Mechanism <ul><li>1) Osmotic load within the intestine resulting in retention of water within the lumen </li></ul><ul><li>2) Excessive secretion of electrolytes and water into the intestinal lumen </li></ul><ul><li>3) Exudation of fluid and protein from the intestinal mucosa </li></ul><ul><li>4) Altered intestinal motility resulting in rapid transit through the colon </li></ul>
  13. 13. EVALUATION OF DIARRHEA <ul><li>Acute diarrhea – lasts longer than 3-4 days </li></ul><ul><li>Chronic diarrhea – lasts longer than 2 weeks </li></ul><ul><li>The approach to patients with acute or chronic diarrhea is very much the same </li></ul><ul><li>It is not always possible to identify one particular mechanism to account for diarrhea in a given patient </li></ul>
  14. 14. ETIOLOGY <ul><li>Viral : 70-80% of infectious diarrhea in developed countries </li></ul><ul><li>Bacterial : 10-20% of infectious diarrhea but responsible for most cases of severe diarrhea </li></ul><ul><li>Protozoan : less than 10% </li></ul>
  15. 15. Infectious diarrhea <ul><li>Acquired by </li></ul><ul><ul><li>fecal-oral route via direct personal contact </li></ul></ul><ul><ul><li>ingestion of food or water contaminated with pathogens from human or animal feces </li></ul></ul><ul><li>Mostly feco-oral route </li></ul><ul><li>Bacterial </li></ul><ul><li>Viral </li></ul><ul><li>Parasitic </li></ul>
  16. 16. Bacterial <ul><li>Watery </li></ul><ul><ul><li>Enterotoxigenic - </li></ul></ul><ul><ul><ul><li>Vibrio cholera </li></ul></ul></ul><ul><ul><ul><li>Enterotoxigenic E.coli </li></ul></ul></ul><ul><ul><li>Food borne toxins- </li></ul></ul><ul><ul><ul><li>Bacillus cereus </li></ul></ul></ul><ul><ul><ul><li>Clostridium perfringens </li></ul></ul></ul>
  17. 17. Bacterial <ul><li>Bloody </li></ul><ul><ul><li>Invasive </li></ul></ul><ul><ul><ul><li>Campylobacter jejuni </li></ul></ul></ul><ul><ul><li>Destructive </li></ul></ul><ul><ul><ul><li>Shigella </li></ul></ul></ul><ul><ul><ul><li>Enteropathogenic E.coli </li></ul></ul></ul><ul><ul><ul><li>Clostridium difficile </li></ul></ul></ul>
  18. 18. Viral <ul><li>Rotavirus -Children less than 2 years </li></ul><ul><ul><li>Most common cause of diarrhea in children all over the world (*Infantile diarrhea) </li></ul></ul><ul><li>Pentavalent rotavirus vaccine It combines (DPT), hepatitis B and (HIB). </li></ul><ul><li>Norwalk- Older children and adults </li></ul><ul><ul><ul><li>These viruses injure the small intestinal mucosa .Watery diarrhea </li></ul></ul></ul><ul><li>Adenovirus </li></ul><ul><li>Astrovirus </li></ul><ul><li>CMV -Immunocompromised </li></ul><ul><li>Hepatitis A </li></ul><ul><ul><li>Calicivirus </li></ul></ul>
  19. 19. Parasitic <ul><li>Protozoa </li></ul><ul><ul><li>Giardia lamblia </li></ul></ul><ul><ul><li>Entamoeba histolytica </li></ul></ul><ul><ul><li>Cryptosporidium </li></ul></ul><ul><ul><li>Cyclospora </li></ul></ul><ul><ul><li>Balantidium coli </li></ul></ul><ul><li>Helminths </li></ul><ul><ul><li>Ascaris lumbricoides </li></ul></ul><ul><ul><li>Ancylostoma </li></ul></ul><ul><ul><li>Strongyloides stercoralis </li></ul></ul><ul><ul><li>Trichinella spiralis </li></ul></ul><ul><ul><li>Capillaria philippensis </li></ul></ul><ul><ul><li>Schictosomiasis </li></ul></ul><ul><ul><li>Taenia </li></ul></ul>
  20. 20. Opportunistic pathogens <ul><li>Clostridium difficile </li></ul><ul><ul><li>Nosocomial pathogens in healthcare and long term care facility </li></ul></ul><ul><ul><li>Poor handwashing </li></ul></ul><ul><ul><li>Clindamycin, Cephalosporins, Ampicillin </li></ul></ul><ul><ul><li>Exotoxin mediated </li></ul></ul>
  21. 21. In Immunocomromised Hosts <ul><li>Besides the common pathogens </li></ul><ul><ul><li>Giardia </li></ul></ul><ul><ul><li>Legionella </li></ul></ul><ul><ul><li>Candida albicans </li></ul></ul><ul><ul><li>Cryptosporidium species </li></ul></ul><ul><ul><li>Mycobacterium avium-intralcellulare </li></ul></ul><ul><ul><li>CMV </li></ul></ul>
  22. 22. Others <ul><li>Tropical sprue </li></ul><ul><ul><li>In those who live or travel to the tropics </li></ul></ul><ul><ul><li>Overgrowth of predominantly coliform bacteria in the small intestine </li></ul></ul><ul><li>Whipple’s Disease </li></ul><ul><ul><li>Infection by Tropheryma whippelii </li></ul></ul><ul><ul><li>HLA B27 </li></ul></ul>
  23. 23. Causes of Dysentery <ul><li>Shigella </li></ul><ul><li>Enteroinvasive E. coli </li></ul><ul><li>Campylobacter jejeuni </li></ul><ul><li>Salmonella enterica </li></ul><ul><li>Vibrio parahemolyticus </li></ul><ul><li>Entamoeba histolytica </li></ul>
  24. 24. History <ul><li>Is it truly diarrhea? </li></ul><ul><li>Duration- </li></ul><ul><ul><li>acute <3 weeks </li></ul></ul><ul><ul><li>Chronic >4 weeks </li></ul></ul><ul><li>Texture </li></ul><ul><li>Frequency </li></ul><ul><li>Blood? </li></ul>
  25. 25. High Risk Groups <ul><li>Travelers- “traveler's diarrhea” commonly due to enterotoxigenic Escherichia coli , Campylobacter , Shigella , and Salmonella, Giardia, Cyclospora. </li></ul>
  26. 26. High Risk Groups <ul><li>2. Consumers of certain foods- Salmonella or Campylobacter from chicken; </li></ul><ul><li>Enterohemorrhagic Escherichia coli (O157:H7) from undercooked hamburger </li></ul><ul><li>Bacillus cereus from fried rice </li></ul><ul><li>S. aureus from mayonnaise or creams </li></ul><ul><li>Salmonella from eggs </li></ul><ul><li>Vibro species, acute hepatitis A or B from (raw) seafood </li></ul>
  27. 27. RISK GROUPS <ul><li>3 . Immunodeficient person </li></ul><ul><li>4. Daycare participants - Infections with Shigella , Giardia , Cryptosporidium , Rotavirus </li></ul><ul><li>5. Institutionalized person- Clostridium difficile . </li></ul>
  28. 28. Pathogenisis <ul><li>Infectious agents cause diarrhoea in 3 different ways as follows: </li></ul><ul><ul><li>Mucosal adherence </li></ul></ul><ul><ul><li>Mucosa Invasion </li></ul></ul><ul><ul><li>Toxin Production </li></ul></ul>
  29. 29. Mucosal adherence <ul><li>Bacteria adhere to specific receptors on the mucosa, e.g. adhesions at the tip of the pili or fimbriae </li></ul><ul><li>Mode of action: effacement of intestinal mucosa causing lesions, produce secretory diarrhoea as a result of adherence </li></ul><ul><li>Causing moderate watery diarrhoea </li></ul><ul><li>e.g. Enteropathogenic E.coli </li></ul>
  30. 30. Mucosa Invasion <ul><li>The bacteria penetrate into the intestinal mucosa, destroying the epithelial cells and causing dysentery </li></ul><ul><li>e.g. Shigella spp. </li></ul><ul><li>Enteroinvasive E.coli </li></ul><ul><li>Campylobacter spp </li></ul>
  31. 31. Toxin Production- Enterotoxins <ul><li>Toxin produced by bacteria adhere to the intestinal epithelium, induce excessive fluid secretion into the bowel lumen, results in watery diarrhoea without physically damaging the mucosa. </li></ul><ul><li>Some enterotoxin preformed in the food can cause vomiting </li></ul><ul><li>e.g Staph.aureus (enterotoxin B) </li></ul><ul><li>Bacillus cereus </li></ul><ul><li>Vibrio cholerae </li></ul>
  32. 32. TOXIN PRODUCTION- Cytotoxins <ul><li>- damage the intestinal mucosa and sometimes vascular endothelium, leads to bloody diarrhoea with inflammatory cells, decreased absorptive ability. </li></ul><ul><li>e.g. Salmonella spp. </li></ul><ul><li> Campylobacter spp. </li></ul><ul><li>Enterohaemorrhagic E.coli 0157 </li></ul>
  33. 33. Clinical Features <ul><li>Stools </li></ul><ul><ul><li>Loose </li></ul></ul><ul><ul><li>Blood stained </li></ul></ul><ul><ul><li>Offensive smell </li></ul></ul><ul><ul><li>Steatorrhea (floating, oily, difficult to flush) </li></ul></ul><ul><li>Sudden onset of bowel frequency </li></ul><ul><li>Crampy abdominal pain </li></ul><ul><li>Urgency </li></ul><ul><li>Fever </li></ul><ul><li>Loss of appetite </li></ul><ul><li>Loss of weight </li></ul>
  34. 34. HISTORY <ul><li>Age </li></ul><ul><li>Diarrhea pattern </li></ul><ul><li>Differentiating small bowel from large bowel </li></ul><ul><li>Stool characteristics </li></ul><ul><li>Diurnal variation </li></ul><ul><li>Weight Loss </li></ul><ul><li>Medication and dietary intakes </li></ul><ul><li>Recent travel to undeveloped areas </li></ul>
  35. 35. Lab Diagnosis of GIT Infections <ul><li>Specimens- stool,rectal swab,duodenal aspirate </li></ul><ul><li>Specimens must be delivered to lab within 1 hr </li></ul><ul><li>Delay of > 2 hr anticipated use transport medium (Cary-Blair TM) </li></ul><ul><li>Rectal swab in Stuart’s transport or viral TM stored in refrigerated if delay > 2 hrs </li></ul><ul><li>Direct wet mount -Ova & parasites, Fecal leukocytes </li></ul><ul><li>Gram stain –Campylobacter, Vibrio </li></ul><ul><li>Modified Acid fast –Cryptosporidium, Isospora </li></ul><ul><li>Trichrome stain-Parasites </li></ul>
  36. 36. Lab diagnosis <ul><li>Culture- BA / MAC / XLD / SS / TCBS / Selenite F broth </li></ul><ul><li>Antigen detection test </li></ul><ul><li>Fluorescent antibody stain </li></ul><ul><li>ELISA </li></ul><ul><li>Isolation of pathogens in stool samples must be notified to public health authority </li></ul>
  37. 37. Other diagnosis <ul><li>** For unresolved diarrhoea: sigmoidoscopy, rectal biopsy and radiological studies to rule out other organic causes </li></ul>
  38. 38. Treatment <ul><li>Rehydration – oral vs. IV </li></ul><ul><li>Antiemetics </li></ul><ul><li>Antidiarrheals </li></ul><ul><ul><li>Decrease intestinal motility </li></ul></ul><ul><ul><li>Diphenoxylate, loperamide, codeine </li></ul></ul><ul><li>+/- Antibiotics ? </li></ul><ul><ul><li>Shigella, Yersinia, campylobacter, cholera, C.difficile, giardia </li></ul></ul>
  39. 39. Management <ul><li>Fluid therapy </li></ul><ul><ul><ul><li>Persons with moderate to severe diarrhea lose large amounts of Na, CL, K, HCO3 & H20 </li></ul></ul></ul><ul><ul><li>ORS </li></ul></ul><ul><ul><li>IV Fluids </li></ul></ul>
  40. 40. Why not treat everyone with bacterial diarrhea ? <ul><li>Some have no effective specific treatment </li></ul><ul><li>Treatment may not change disease duration or severity </li></ul><ul><li>Treatment may predispose to carrier state </li></ul><ul><li>Treatment may produce complications (HUS, antibiotic resistance, C. difficle, toxic megacolon) </li></ul>
  41. 41. Drug-induced diarrhea <ul><li>Accounts for 7% of all adverse drug effects. </li></ul><ul><li>Over 700 drugs have been implicated. </li></ul><ul><li>Unexplained onset of diarrhea that occurs with the administration of any antibiotic eg: Clindamycin (Pseudomembrane colitis) </li></ul><ul><li>Due to disruption of normal intestinal flora, which leads to either proliferation of pathogenic microorganisms or impairment of the metabolic functions of the microflora </li></ul>
  42. 42. Good nutrition and hygiene can prevent most diarrhea . <ul><li> Thank You! </li></ul>