1. Infectious diarrhea is caused by a variety of bacterial, viral and parasitic organisms spread through contaminated food, water, or poor hygiene. It is characterized by loose or watery stools and can range from mild to severe and potentially life-threatening. 2. Treatment involves rehydration through oral rehydration solutions or intravenous fluids. Antimotility agents like loperamide are also used. Antibiotics may be used for specific bacterial causes. Probiotics, zinc supplementation and vaccination can help prevent or treat cases. 3. A case study describes a child with bloody diarrhea, dehydration and later convulsions who is diagnosed with hemolytic uremic syndrome caused by E

1. INFECTIOUS DIARRHEA
(infectious disease)
Dr. Imran Masood, PhD
drimranmasood@iub.edu.pk

2. Contents
• Introduction
• Classification
• Prevalence
• Diarrhea in Pakistan
• Transmission
• symptoms
• Evaluation
• Prevention
• Role of Health Care Professional
• Treatment
• Algorithm of infectious diarrhea
• Case study

3. Introduction

4. Introduction
Definition
“Diarrhoea is the passage of 3 or more loose or liquid stools per day, or more
frequently than is normal for the individual. It is usually a symptom of
gastrointestinal infection, which can be caused by a variety of bacterial, viral and
parasitic organisms. Infection is spread through contaminated food or drinking-
water, or from person to person as a result of poor hygiene.
Severe diarrhoea leads to fluid loss, and may be life-threatening, particularly in
young children and people who are malnourished or have impaired immunity.”
(World Health Organization, WHO)

5. Introduction
“Diarrhea is defined as an increase in the frequency and looseness of stools
compared to one’s normal bowel pattern. Th e overall weight and volume of the
stool is increased ( 200 g or mL/day), and the water content is increased to 60% to
90%. In general, diarrhea results when the intestine is unable to absorb water from
the stool, which causes excess water in the stool.”
• Acute (<14 days)
• Persistent (between 14 and 29 days)
• Chronic (>29 days)
(Comprehensive Pharmacy Review)

6. Classification
a. Classification by mechanism
(1) Osmotic diarrhea occurs when excess water is pulled into the intestinal tract. Osmotic
diarrhea ceases when the patient converts to a fasting state. This may be the result of
hypermagnesemia, undigested lactose or fructose, or celiac disease.
(2) Secretory diarrhea occurs when the intestinal wall is damaged, resulting in an
increased secretion rather than absorption of electrolytes into the intestinal tract. This can
occur with the ingestion of bacterial enteropathogens (e.g., Escherichia coli, Salmonella,
Shigella).
(3) Motility-related diarrhea occurs when food moves through the intestines at such a
rapid pace (hypermotility) that insufficient time is allowed for water and nutrient
absorption.
• Those with diabetic neuropathy, or a vagotomy are susceptible to this type of diarrhea.
Medications that can also cause hypermotility include parasympathomimetic agents
(e.g., metoclopramide, bethanechol), digitalis, quinidine, and antibiotics.

7. Classification
b. Classification by origin
1. Viral gastroenteritis is typically caused by the noroviruses, which are
transmitted by contaminated water or food.
• rotaviruses,
• adenoviruses,
• hepatitis A virus.
• Duration: for 2 to 3 days but may last up to 2 weeks.

8. Classification
2. Bacterial gastroenteritis Common contributors include
• E. coli,
• Staphylococcus aureus,
• Vibrio cholerae,
• Shigella,
• Salmonella,
• Campylobacter
• Clostridium difficile.
• Toxin-producing bacteria affect the small intestines, resulting in a watery stool. Invasive bacteria
affect the large intestines, resulting in dysentery-like stools (e.g., extreme urgency to defecate,
abdominal cramping, tenesmus, fever, chills, and small-volume stools that contain blood or pus).
• Onset of diarrhea may range between 1 and 72 hrs, depending on the infecting bacteria.
Symptoms typically subside over 3 to 5 days.

9. Classification
3. Protozoal diarrhea,
• caused by Giardia lamblia, Entamoeba histolytica, or Cryptosporidium, may
be described as profuse watery diarrhea, which may be accompanied by
flatulence and/or abdominal pain.
• Due to the extent of fluid loss over an extended duration of time,
individuals are at risk for dehydration.
• Self-care is inappropriate for this type of diarrhea; infected persons should
be referred to a medical provider.
4. Diet-induced diarrhea. Diarrhea induced by foods results from food
allergies, high-fiber diets, fatty or spicy foods, large amounts of caffeine, or
lactose intolerance. The best treatment is prevention by avoiding
troublesome foods.

13. Prevalence
• 4% of hospitalizations in children and 5000 deaths due to foodborne
illness yearly.
• 89% of deaths from acute diarrheal illness occur in elderly persons 65
years of age and older.
• According to the report of WHO published at 2nd May 2017,
Diarrhoeal disease is the second leading cause of death in children
under five years old, and is responsible for killing around 525 000
children every year.

14. Diarrhea in Pakistan
• More than 350,000 children die annually in country.
• January 09, 2018 around 53,000 children die of diarrhea caused by
contaminated water every year.
• Causes:
• Poor quality water, sanitation and hygiene especially hand washing, poultry, live
stock, uncooked food, dairy, soil, feces of animals and infected persons.

15. Transmission

16. Symptoms
• Loose or watery stools
• Severe Dehydration
• Anorexia
• Nausea, Vomiting
• Abdominal Cramps
• Fever, Chills, Malaise
• Sweating, Pain
• Bloody Stool
• Rarely Arthritis,
• Hemolytic Uremic Syndrome (HUS)

17. Evaluation
 Assessment
• include age,
• onset and duration of diarrhea,
• description of stool (i.e., frequency, consistency, volume, and
presence of blood or pus),
• other symptoms (i.e., abdominal pain, fever, chills), aggravating or
remitting factors, recent travel, and medical history.

18. Diagnosis and examination
Step by Step Approach:
• Check Medication History OR underlying disease if any
• Check Travelling Status
If above parameters are cleared then check following:
• Stool analysis studies include examination for microorganisms, blood, mucus, fat,
osmolality, pH, electrolyte and mineral concentration, and cultures
• Total daily stool volume
• C. Difficile toxins culture test in hospitalized patients
• Enzyme Immunoassay (95% Sensitive)
• Antigen Testing
• Endoscopy, Biopsy, Sigmoidoscopy, Anoscopy, Radiology etc

19. Prevention & Role of Health Care Professional
• Access to safe drinking-water
• Hand washing with soap & antiseptics
• Exclusive breastfeeding for the first six months of life
• Good personal and food hygiene
• Health education about how infections spread
• Rotavirus vaccination
• Poultry, meat, or shellfish are thoroughly cooked
• Take extra care to wash all fruits and vegetables and avoid eating raw
shellfish
• Cutting boards and utensils should also be cleaned immediately after coming
into contact with raw meat, poultry, or seafood.
• Finally, if traveling overseas, make sure your vaccinations are up to date.

20. Treatment
1. Nonpharmacological. Normal dietary intake should be
recommended during bouts of diarrhea.
• However, fatty foods, caffeinated beverages, foods rich in simple
sugars, and spicy foods should be avoided. The most important
recommendation for treating acute diarrhea is to keep the individual
hydrated.

21. Treatment
 Fluid and electrolyte replacement.
• If mild to moderate fluid loss is present, oral rehydration solution
(ORS) that contains water, salt, and sugar can be recommended.

22. Treatment

23. Oral Rehydration Therapy & IV Fluids:
• In adults, 2 L of oral rehydration fluid should be given in the first 24 h,
followed by unrestricted normal fluids with 200 mL of rehydration
solution per loose stool or vomit.
• For children, 30–50 mL/kg of an ORS should be given over 3–4 h.
Then 10ml/kg of ORS per loose stool or vomit.

24. Intravenous Rehydration Therapy: (ICE)
• Intravenous delivery may be required if there is a decreased level of
consciousness or if dehydration is severe.
• Ringer Lactate Infusion (Brand: Ringolact by Otsuka Pvt.)
• Ringer Lactate Infusion with 5% Dextrose (Brand: Ringolact-D by
Otsuka Pvt.)
• 5% Dextrose with Electrolytes (Brand: Plabolyte-M by Otsuka Pvt.)
• Dextrose + Sodium Chloride (Brand: Pladexsal 1/5) Neonates and
Infants)
• Normal Saline 0.9% (Brand: Plasaline by Otsuka Pvt.)

26. Treatment
2. Pharmacologic
• antidiarrheal agents: loperamide and bismuth subsalicylate. Self-
treatment of diarrhea with these products is limited to 2 days;
individuals experiencing longer bouts of diarrhea should be referred
for medical care.

28. Treatment
1. Antimotility agents: (Drugs that decrease passage of gut contents)
Loperamide. : (Drug of Choice due to low CNS effects)
• an antiperistaltic agent,
• is approved as a nonprescription treatment for acute, nonspecific diarrhea, including traveler’s
diarrhea.
• Loperamide (e.g., Imodium A–D) provides effective control of diarrhea as quickly as 1 hr after
administration.
(1) Availability and dosing.
• available for ages 6 years in several oral formulations, including a syrup, capsule, and chewable
tablet.
• The adult dose is 4 mg followed by 2 mg after each loose stool, not to exceed 16 mg/day.

29. (2) Mechanism of action. Loperamide stimulates micro opioid
receptors on the circular and longitudinal musculature of the small and
large intestines to normalize peristaltic intestinal movements. They
slow intestinal motility and affect water and electrolyte movement
through the bowel. Thus, the frequency of bowel movements is
decreased, and the consistency of stools is increased.
(3) Adverse effects abdominal pain, distention, or discomfort;
drowsiness, dizziness, and dry mouth.

31. Treatment
• Diphenoxylate/Atropine:
• The initial dose for adults is 5 mg (two pills), taken three or four times
a day. Then the dose is usually reduced to 5 mg (two pills) once a day.
• Codeine & Morphine:
• Rare. Use due to their constipating side effects (PolyPharmacy)

33. Bismuth Subsalicylate:
• Adult: 524 mg orally every 30 to 60 minutes as needed not to exceed 8
doses in any 24 hour period but not longer than 2 days if diarrhea not
stopped.
• Children: 87 mg to 262 mg every 30 minutes to 1 hour as needed.
Zinc:
• zinc supplementation (20 mg per day for 10 days in children older than
six months) may play a crucial role in treating and preventing acute
diarrhea.

35. • Antibiotics:

36. Treatment
Points to Remember while giving antibiotics to Diarrheal Patient
• In both amoebic dysentery and giardiasis, metronidazole is the drug of
choice.
• The role of antibiotics is unclear; they are generally avoided because
of their association with hemolytic uremic syndrome.
• Doxycycline and tetracycline are not recommended in children
because of possible tooth discoloration.

38. Treatment
Probiotics:
• Probiotics are thought to work by stimulating the immune system and
act against pathogens by competing for binding sites on intestinal
epithelial cells.
• Very effective for children

39. Treatment
Octreotide:
• Serotonin blocker  carcinoid tumors is 100 to 600 mcg/day in two to
four divided doses, subcutaneously for 2 weeks.
Adsorbants (drugs that increase viscosity of luminal contents)
• Ispaghula Husk and Attapulgite are effective as Absorbants in mild to
moderate diarrhea.
Vaccination:
• Rotavirus vaccine has been shown to protect against the most common
strains of rotavirus (G1 and G3)

40. Algorithm of treatment of acute infectious
diarrhea

43. Case study
• Case 14.4
• A 7-year-old boy in previous good health was admitted to hospital with
bloody diarrhoea and dehydration 4 days after attending a children's
birthday party. He was treated with intravenous fluids and given nothing by
mouth. The day after admission to hospital a colonoscopy revealed
haemorrhagic colitis. His diarrhoea seemed to be improving up to day 5
when he experienced a generalised convulsion following which he was
transferred to a children's intensive care bed. He was irritable, pale and
hypertensive, and an emergency laboratory report revealed
thrombocytopenia, hyponatraemia and hyperkalaemia.
• Questions
• 1. What is the likely diagnosis in this child?
• 2. What specific therapy is required?

44. • Answers
1. This patient probably has haemolytic uraemic syndrome caused by E. coli
• Haemolytic uraemic syndrome is the most common form of acquired renal insufficiency
in young children. It is characterised by nephropathy, thrombocytopenia and
microangiopathic haemolytic anaemia.
• Although there are an number of potential causative factors, the most common is the
toxin-producing O157 strain of E. coli. In 1996, 21 people died from E. coli O157 after
eating contaminated meat from a butcher's shop in Scotland.
• The syndrome typically has a pro-drome of bloody diarrhoea occurring 5–7 days before
onset of renal insufficiency. Colonoscopy is usually non-specific and shows
haemorrhagic colitis. At diagnosis most children are pale and very irritable.
Hypertension and hyponatraemia may be associated with convulsions and are generally
a consequence of a disorder of fluid and salt balance.
• Laboratory findings may include anaemia and thrombocytopenia, hyponatraemia,
hyperkalaemia, hypocalcaemia and metabolic acidosis. The kidney typically shows signs
of glomerular endothelial injury.

45. 2. Treatment is usually supportive. Fluid and electrolyte balance need
to be corrected and the hypertension controlled.
• In cases with prolonged oliguria or anuria, peritoneal dialysis may be
used. Approximately 85% of patients recover normal renal function.

47. References
• Comprehensive Pharmacy Review Book by Alan H. Mutnick and Leon
Shargel
• Clinical Pharmacy and Therapeutics by Roger Walker 5th edition
• Oxford Handbook Of Clinical Medicine 9th edition
• Lipponcots pharmacology
• Davidson’s Principle and Practice of Medicine
• Katzun pharmacology Examination and Board Review