1. BAHAR PEZÜKLİ NAZLI SEDA GÖKDERELİ
GASTROENTERITIS
BAHAR PEZÜKLİ
NAZLI SEDA GÖKDERELİ

2. the term gastroenteritis is applied to syndromes of diarrhea or vomiting that tend to involve noninflammatory infection in the upper small bowel or inflammatory infection in the colon.

3. Risk of acquiring a gastrointestinal infection varies greatly with age, living conditions, personal and cultural habits, and group exposures

4. Host defense factors Gastric acidity Intestinal motility
Intestinal microflora
Mucus
Systemic and local immune mechanisms
Others (e.g. breast feeding)

5. Bacterial virulence factors
Adherence
Enterotoxin production
Cytotoxin production
Mucosal invasion

6. Defense Barriers of the Enterocytes

7. Mechanisms of infection
Ingestion of preformed toxin (food poisoning)
Fecal-oral contamination
Food, flies, fingers, feces, and fomites
Contaminated food
Animal reservoir
Fecal-oral contamination of food
Infectious dose varies (~100 to 109)

8. DIARRHEA Alteration in a normal bowel movement
Characterized by an increased in the water content, volume, or frequency of stools
>3 or more stools and at least 200 gr
Decrease in consistency (soft or liquid) and an increase in frequency of bowel movement to >3 stools per day

9. Acute diarrhea is an episode of diarrhea of <14 days in duration
Persistent diarrhea is of >14 days in duration
Chronic diarrhea lasts >30 days

10. DIARRHEA Non-inflammatory
Watery diarrhea, no blood or mucus or pus in stool, no fever or systemic signs
Secretory or osmotic mechanism
Dehydration may occur
Generally self-limited and more benign
Therapy generally supportive

11. Inflammatory
Frequent lower volume stool, mucoid, bloody, or purulent. Often with fever or systemic signs, tenesmus, urgency
Exudative mechanism
Dehydration rare
Less benign

12. Osmotic Diarrhea
Increased amounts of poorly absorbed, osmotically active solutes in gut lumen
Interferes with absorption of water

13. Secretory Diarrhea
Excess secretion of electrolytes and water across mucosal surface
Bacterial or viral enterotoxins
Cholera, enterotoxigenic E. coli, B. cereus, S. aureus, Rotavirus, Norwalk virus

14. Exudative Diarrhea Intestinal or colonic mucosa inflamed and ulcerated
Leakage of fluid, blood, pus
Impairment of absorption
Increased secretion (prostaglandins)

15. Infectious, invasive organisms
Shigella, Campylobacter, Yersinia, E. histolytica, EHEC, C diff
Idiopathic inflammatory bowel disease
Crohns disease
Ulcerative Colitis
Ischemia

17. Etiology of Infectious Diarrhea
(in (((8developed countries)
• 70-80% is viral
• 10-20% is bacterial
– Bacterial are responsible for most severe cases
• < 10% is parasitic

18. Acute Diarrhea in Children
The most important infective causes of acute diarrhea in developing countries in children are:
Rotavirus
Enterotoxigenic escherichia coli
Shigella
Campylobacter jejuni
Salmonella typhimurium

19. Bacterial Salmonella Shigella Shiga-toxin producing Escherichia coli
Non-shiga-toxin E. coli
Campylobacter
Yersinia
Clostridium difficile
Vibrio cholerae

20. Salmonella
Contaminated animal products
Normal flora in animals

21. Clinical Symptoms may evolve
Fever; general malaise
Sometimes no GI symptoms
If there are GI symptoms, will see:
Bloody diarrhea
Abdominal pain
Weight loss

22. Salmonellosis
Fever, cramping, abdominal pain, and diarrhea within hours after ingestion of infective dose (contaminated poultry, shell eggs, dairy products, beef, exotic pets such as reptiles)
Inflammatory (neutrophilic) enteritis most typically involving the small bowel mucosa, occasional cause of colitis with crypt abscesses and erosive ulceration of colonic mucosa (Salmonella serotype Typhimurium)
Moderate number of fecal neutrophils, usually fewer than in shigellosis except colitis with blood and pus in stool

23. Diagnosis Stool culture
Salmonella bacilli may be found in stool/blood cultures
Serology: positive Widal test with increased titers

24. Treatment
TMP/SMX 960 mg bid or
Chloramphenicol 250 mg qid for 3 weeks
In case of sepsis, IV therapy is necessary
Shorter regimens are:
ciprofloxacin 500 mg bid or ofloxacin 400 mg bid or ceftriaxone 2 g IV for 7-10 days
Many patients often relapse after treatment and chronic maintenance therapy (TMP/SMX 1 DD daily) is sometimes necessary.

25. Shigella Primarily a human parasite Infects the large intestine
Exotoxin (shiga-toxin)
Enterotoxin
May be complicated by reactive arthritis and rarely HUS
Very infectious ( ~100 organisms cause disease)

26. Clinical Symptoms may evolve
High fever
Abdominal pain
Bloody diarrhea

27. Diagnosis Stool microscopy— fresh examination and after concentration
Multiple stool samples may be necessary
Shigella bacillus found in stool

28. Treatment TMP/SMX 960 mg bid x 5 days or
amoxicillin 500 mg tid x 5 days
If resistant to the above, give
norfloxacin 400 mg bid x 5 days
nalidixic acid 1 g qid x 10 days
ciprofloxacin 500 mg bid

29. E. coli

30. Enterohemorrhagic Escherichia coli
Abdominal cramps and watery diarrhea 3 to 8 days following ingestion of contaminated food (undercooked beef, raw milk, fresh produce) or water
Shiga toxin absorbed from intestine and damages vascular endothelial cells (intestinal mucosa and kidney)
Watery diarrhea followed by grossly bloody diarrhea
Uncomplicated illness lasts 1 to 12 days
Use of antibiotics contraindicated (phage- mediated production of Shiga toxin enhanced by ampicillin, norfloxacin, and other antibiotics)

32. Campylobacter Most common bacterial cause of diarrhea
Related to Guillain-Barre syndrome (GBS) – paralysis
Transmission from infected animals or food products, fresh or salt water
Watery diarrhea or dysentery

33. Clinical Symptoms may evolve
Fever and general malaise, sometimes without GI symptoms
When present, GI symptoms include bloody diarrhea, abdominal pain and weight loss.

34. Treatment Erythromycin 500 mg bid x 5 days (1st choice)
Fluoroquinolones are also effective, but resistance rates of 30-50% have been reported in some developing countries

35. Yersinia High degree of abdominal pain Mistaken for appendicitis
Infects the small intestine
Some can affect the lymphatic system (intracellular)

36. Yersinosis
Febrile diarrhea with abdominal pain 16 to 48 hours following ingestion of an infectious inoculum
Duration of illness ranges from 1 day to a prolonged diarrhea of 4 weeks

37. Treatment Safe food handling
Y. enterocolitica is suscestible to amg,chloram, tetra, TMP/SMZ,pip, cipro,
ß lactamase, resis to pen, ampi, 1. gen. ceph.
Patients with septicemia should receive antb.
Y. pseudotuberculosis usually not require antb, but with septicemia ampi or tetra

38. Clostridium difficile
Pseudomembranous colitis or antibiotic associated colitis
Capable of superinfecting the large intestine due to drug treatments
Enterotoxins

40. Antibiotics – fluoroquinolones, cephalosporins, clindamycins, penicillins
Medications:
Proton pump inhibitor
Histamine-2 receptor blockers
Non-steroidal anti-inflammatories (except aspirin)
Laxatives
Narcotics
Antiperistaltic drugs
Advanced age ( ≥ 65yrs.)
Chemotherapy

41. Medical/Surgical procedures
Gastrointestinal surgery
Enemas
Enteral tube feedings
Endoscopy
Underlying illness and its severity
Inflammatory bowel disease
Diabetes mellitus/Hyperthyroidism
Leukemia/Lymphoma
Liver/Renal failure
History of C. difficile associated diarrhea
Prolonged hospital stay/Nursing home resident

42. Treatment Discontinue the offending agent If unable:
Choose an antibiotic less frequently associated with antibiotic-associated diarrhea (aminoglycosides, sulfonamides, macrolides, vancomycin, tetracyclines)
Prescribe Metronidazole 500mg PO TID throughout the needed course of antibiotic therapy and for 7 days after.

43. Vibrio cholerae Heavy lost of fluid “rice-water stool”
Untreated cases can be fatal

44. VIRAL GASTROENTERITIS

46. Background
Acute viral gastroenteritis is a common cause of morbidity and mortality worldwide.
Conservative estimates put diarrhea in the top 5 causes of deaths worldwide, with most occurring in young children in nonindustrialized countries.
In industrialized countries, diarrheal diseases are a significant cause for morbidity across all age groups.

47. Viruses are responsible for a significant percentage of cases affecting patients of all ages.
Viral gastroenteritis ranges from a self-limited watery diarrheal illness (usually < 1 wk) associated with symptoms of nausea, vomiting, anorexia, malaise, or fever,
to severe dehydration resulting in hospitalization or even death.

48. The clinician encounters acute viral gastroenteritis in 3 settings.
The first is sporadic gastroenteritis in infants, which most frequently is caused by rotavirus.
 The second is epidemic gastroenteritis, which occurs either in semiclosed communities (eg, families, institutions, ships, vacation spots) or as a result of classic food-borne or water-borne pathogens. Most of these infections are caused by caliciviruses.
The third is sporadic acute gastroenteritis of adults, which most likely is caused by caliciviruses, rotaviruses, astroviruses, or adenoviruses.

49. Norovirus
Noroviruses cause approximately 23 million cases of acute gastroenteritis each year and are the leading cause of outbreaks of gastroenteritis.
They are responsible for 68-80% of all outbreaks in industrialized countries.
The genus Norovirus, formerly called the Norwalk-like virus, is a member of the family Caliciviridae.
Noroviruses are now recognized to be a common cause of gastroenteritis in new settings, including nursing homes and other health care settings, cruise ships, in other travelers, and in immunocompromised patients. 

51. The frequency is seasonal
The frequency is seasonal. The highest incidence of rotavirus cases occurs during the months from November to April. Cruise ship outbreaks of noroviruses are more common during the summer months. However, a CDC study by Tate et al demonstrated a decline in the seasonality of rotavirus following the 2006 introduction of the rotavirus vaccine.

52. Rotavirus Responsible for most morbidity and mortality from diarrhea
Babies lacking maternal antibodies are at risk
Unique morphological appearance

54. A feces sample containing Rotavirus, which has a unique “spoked-wheel” appearance.
Fig Rotavirus visible in a sample of feces from
A child with gastroenteritis.

55. Acute viral gastroenteritis is a leading cause of infant mortality throughout the world.
By age 3 years, virtually all children become infected with the most common agents. Rotavirus causes 2 million hospitalizations and 600, ,000 deaths per year.
Noroviruses were attributed to 9 out of the 21 outbreaks of acute gastroenteritis on cruise ships reported to the CDC's Vessel Sanitation Program from January 1, 2002, to December 2, 2002.
The occurrence of noroviruses on cruise ships has led to the use of the term "the cruise ship virus" as another name for these viruses. Some illnesses previously attributed to sea sickness are now recognized to be caused by norovirus infections.

56. Acute viral gastroenteritis occurs throughout life
Acute viral gastroenteritis occurs throughout life. Severe cases are seen in the very young and in the elderly. Etiology also varies with age.
In infants, most cases are due to rotavirus.
In adults, the most common cause is norovirus.

57. Acute diarrhea with vomiting
Food poisoning - toxin
Staphylococcus aureus
Bacillus cereus
Clostridium perfringens

58. Chronic diarrhea Enteroaggregative (EAEC) E. coli
Cyclospora cayetanensis
Giardia lamblia
Entamoeba histolytica

59. MANAGING INFECTIOUS DIARRHEA
Initial rehidration
Perform thorough clinical and epidemiological evaluation
Perform selective fecal studies
Institute selective therapy for
Traveler’s diarrhea
Shigellosis
Campylobacter infection
Avoid administering antimotilty agents
Selectively administer available vaccines

60. Treatment of specific etiology
Non-specific treatment
hydration
Absorptions (Kaopectate®)
Bismuth
Antiperistaltics/opiate derivatives
Fiber supplementation

61. Thank you..

62. sources
bal/programs/globaldiarrhea508c.pdf f
rheaguidelines.html
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