What is Diarrhoea name different Causative agents and how will you Diagnosis?

What is Diarrhoea name different Causative agents and how will you Diagnosis?
Prof Riaz Bhutta cited from labpedia
Prof Mulazim Hussain Bukhari
This disease occurs when secretion of water into the intestinal lumen exceeds absorption. … This change results in prolonged opening of the chloride channels that are instrumental in secretion of water from the crypts, allowing uncontrolled secretion of water.

Definition of diarrhea: When there are loose motions at least three per day. This may last for a few days and leads to dehydration, decreased urination, tachycardia and death if not treated.
It can occurs in any age group but children are more prone to develop this disease and mortality rate is high in this group. This is a treatable disease which can lower the mortality rate of humans.
Diarrhoea is caused by various microorganisms like:
1.Viruses.
Commonest viruses are rotaviruses, coronaviruses, parvoviruses (canine and feline), norovirus
2.Bacteria.
3.parasites. coccidia species, Cryptosporium, Giardia
4.Motility disorder
Diarrhea may be:

  1. Watery diarrhea.
  2. Bloody diarrhea.
    Watery Diarrhoea may be caused by:
  3. Bacteria, Shigella, Escherichia coli and others producing enterotoxin.
  4. Usually seen in travelers.
  5. Protozoa, Giardia lamblia, and others.
  6. This may be seen in travelers and contaminated water supply.
  7. In child care center this may be a chronic problem.
  8. Pre-formed enterotoxin by staphylococcal aureus, Bacillus cereus and Clostridium perfringens.
  9. This is due to food poisoning.
    Bloody Diarrhoea or dysentery is caused by:
  10. Shigella, and Salmonella.
  11. Campylobacter.
  12. Entamoeba histolytica.
  13. This may be common for travelers.
  14. The fresh stool is needed for the first culture and then can advise more tests.
  15. Fresh stool for ova and parasites.
    Common causes of bacteria causing diarrhea are:
  16. Shigella.
  17. Salmonella.
  18. Esch.coli.
  19. Staph. aureus.
  20. Campylobacter.
  21. Cl.perfringens.
  22. V.cholerae.
    Shigella
  23. This causes bacillary dysentery.
  24. This is a worldwide problem and fatal in young children, especially in the third world.
  25. Shigella are of four types:
  26. Sh.dyenteriae.
  27. Sh.boydii.
  28. Sh.sonnei.
  29. Sh.flexneri.
  30. The incubation period is 1 to 9 days.
  31. The stool has blood and mucus.
  32. There may be pus in the stool.
  33. Sh.dysentery is due to Sh.dysenteriae is severe and life-threatening and seen in tropical countries.
  34. There are fever and abdominal pain.
  35. There is diarrhea.
  36. This produces a strong neurotoxin.
  37. This is an invasive disease.
  38. While dysentery from other species is mild.
  39. It can be diagnosed with stool or rectal culture.
  40. Culture is done on selective media like MacConkey, desoxycholate citrate agar, and XLD agar.
  41. Serological identification can be done.
  42. Treatment:
  43. Antibiotics usually are not needed.
  44. In few cases may use Trimethoprim.
    Escherichia Coli
  45. This is common normal commensal gut flora.
  46. Some of the strains lead to diarrhea.
  47. Esch.coli diarrhea may be seen as:
  48. Hemorrhagic colitis and hemolytic uremic syndrome.
  49. There may be a life-threatening syndrome with a bleeding tendency.
  50. This may be due to toxins that are cytopathic.
  51. Hemorrhagic colitis was seen in children and adults as a sporadic infection.
  52. There may be death in older patients.
  53. The hemolytic uremic syndrome is seen in children as an outbreak or sporadic cases.
  54. This is usually seen with a serotype of 0157.
  55. There is diarrhea followed by uremia.
  56. There is thrombocytopenia.
  57. There is a hemolytic anemia.
  58. Traveler diarrhea.
  59. This has different names like:
  60. Montezuma’s revenge.
  61. Delhi belly.
  62. Tokyo two-step.
  63. This is caused by the strains of Esech.coli producing enterotoxins and the common ones are 06, 078.
  64. This can spread through contaminated foods and drinks.
  65. There are diarrhea and abdominal pain.
  66. There may be vomiting.
  67. This usually self-limiting disease.
  68. Damage is due to heat-labile or heat resistant toxins.
  69. Infantile gastroenteritis.
  70. These are by the enteropathogenic strains, serogroup 055, 011.
  71. The incubation period is 1 to 3 days.
  72. There is acute diarrhea.
  73. There is hypernatremia (increased sodium).
  74. Culture from the feces can diagnose.
    Salmonella
  75. Salmonella diarrhea is called food poisoning but this term is misleading.
  76. S.enteritidis phage type 4 was common in the UK in 1980, and the commonest cause of incidents in poultry flocks.
  77. S.typhi, paratyphi A, B, and C mainly cause enteric fever and in the late stage, these patients develop diarrhea.
  78. S.paratyphi cause enteric fever and diarrhea.
  79. The incubation period is short, 12 to 36 hours.
  80. Food derived from domestic animals and poultry are the main source.
  81. When these meats are not properly cooked and stored at room temperature.
  82. The eggs may also be the source.
  83. Another source may be the contaminated milk, and sometimes cheese.
  84. Human carriers may also play for the spread.
  85. Early symptoms are abdominal pain and diarrhea.
  86. There may be fever and vomiting.
  87. The patient may get dehydrated.
  88. In severe cases, septicemia may be seen.
  89. For diagnosis, do a culture of the feces on MacConkey and selective media.
  90. It can confirm by the biochemical test on culture material.
  91. Treatment with antibiotics is contraindicated except in cases of septicemia.
  92. Rehydration is necessary.
    Campylobacter
  93. This is recognized as a major source of diarrhea.
  94. Campylobacter is a small vibrio-like organism.
  95. These are curved gram-negative bacilli.
  96. These have characteristic darting motility.
  97. These are oxidase reactions positive.
  98. The main cause of human infection is C.jejuni.
  99. Rarely cause is C. jejuni subspecies as doylei, C. coli, and C.lari.
  100. The incubation period is 3 to 10 days.
  101. The main source of infection is poultry.
  102. Other sources are milk and water.
  103. Dogs and cats are also reported as the source.
  104. The mode of spread is the fecal-oral route by eating contaminated food.
  105. Main symptoms are:
  106. Fever.
  107. A headache.
  108. A backache.
  109. Limb pain.
  110. Abdominal pain. This is a prominent feature of Campylobacter infection.
  111. After 24 hours or later patient develops diarrhea.
  112. Diarrhea sometimes is severe with mucus and blood.
  113. There may be up to 20 stool per day.
  114. In severe cases may see septicemia.
  115. Typically there is enterocolitis which involves the small intestine, the ileum.
  116. In some cases, there may colitis.
  117. Diagnosis, advise the stool culture on the selective media containing antibiotics at 43 °C.
  118. Treatment: usually it is self-limiting.
  119. Erythromycin can reduce the duration of the disease, but should be reserved for severe cases.
  120. Another drug is ciprofloxacin.
    Cholera
  121. This is caused by Vibrio cholerae.
  122. The causative agent is V.cholerae 01.
  123. In Bengal, the epidemic was due to type 139.
  124. The incubation period is 6 hours to 5 days, usually by contamination of the sewage water.
  125. Sometimes this may by contamination of the foods.
  126. Foods are contaminated by flies.
  127. The spread is feco-oral.
  128. Symptomless carriers are common in epidemics.
  129. The patient develops a pain abdomen and diarrhea.
  130. Watery diarrhea like rice water.
  131. There may be mucous.
  132. The patient may have vomiting and dehydration.
  133. There are acidosis and patient may collapse.
  134. Cholera is seen in two forms:
  135. Classical cholera (severe).
  136. A mild form of cholera is associated with the El Tor biotype.
  137. Pathogenesis: V. cholerae produces potent protein exotoxin.
  138. This can be diagnosed by:
  139. The culture of feces on selective media.
  140. There are typical colonies.
  141. This can be identified by slide agglutination with polyvalent antisera.
  142. Antigen capture test.
  143. Latex agglutination test.
  144. This is treated by replacing the fluids.
  145. When tetracycline given the disease course may be short.
    Staphylococcus aureus
  146. This is due to toxic food poisoning.
  147. This is due to enterotoxin contamination of the foods by Staph. aureus.
  148. This is very rapid in onset due to the preformed toxin in the food.
  149. Staphylococcus about 40% produces five antigenically different types of enterotoxins.
  150. These are named as Enterotoxin A, B, C, D, and E.
  151. The preformed toxins present in the contaminated foods have local action on the gut mucosa.
  152. Toxins are resistant to high temperatures, that will kill the bacteria.
  153. So food contains toxins and no viable bacteria.
  154. Symptoms are:
  155. Acute onset of nausea and vomiting.
  156. This may be followed by diarrhea.
  157. This is a self-limiting disease
  158. Diagnosis: Check the suspect food, vomitus or feces.
  159. Culture on ordinary media or mannitol salt agar.
  160. Can perform a coagulase test.
  161. Also, can do phage typing.
    Clostridium perfringens (Cl. perfringens)
  162. This is fairly common and is due to contamination of foods by Cl. perferingens.
  163. The Cl. perfringens are spores - bearing, heat resistant and anaerobic organism.
  164. These are non-hemolytic strains.
  165. This bacteria can resist heat at 100 °C for 30 minutes.
  166. During cooking, spores germinate into vegetative form.
  167. If food is kept at room temperature then these bacteria rapidly multiply.
  168. After the ingestion of vegetative form, sporulation takes place in the small intestine with the release of enterotoxins.
  169. These toxins mainly act on membrane permeability of the small intestine.
  170. Cl. perfringens may be present as commensals in the humans and animals intestine.
  171. The incubation period is 8 to 24 hours after eating the contaminated food.
  172. Symptoms are:
  173. Abdominal pain.
  174. Diarrhea.
  175. Rarely there may be vomiting.
  176. This is a self-limiting disease.
  177. Diagnosis: Take a sample of the feces and suspected food.
  178. Culture the sample on blood agar anaerobically.
  179. Colonies are typical, β-hemolytic or non-hemolytic.
  180. can identify by the Nagler reaction.
  181. Can do serotyping by slide agglutination.
  182. can detect enterotoxin in the stool by ELIZA.
  183. Treatment is symptomatic, by rehydration.
  184. Antibiotic therapy is not needed.
    Signs and Symptoms:
  185. Watery diarrhea may be seen in travelers, due to contaminated water, and food-related poison.
  186. Bloody diarrhea may also be seen in travelers.
  187. There may be fever, abdominal and cramps.
  188. Sometimes there may be vomiting.
    Diagnosis:
  189. Stool examination for the presence of WBCs and RBCs.
  190. Fresh stool for ova and parasite.
  191. There is Giardia lamblia’s rapid antigen detection test.
  192. E. Histolytica can be seen by microscopy or antigen detection.
  193. The serum antibody test for an amoebic liver abscess.