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GASTROENTERITIS BAHAR PEZÜKLİ NAZLI SEDA GÖKDERELİ 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. Risk of acquiring a gastrointestinal infection varies greatly with age, living conditions, personal and cultural habits, and group exposures Host defense factors Gastric acidity Intestinal motility Intestinal microflora Mucus Systemic and local immune mechanisms Others (e.g. breast feeding) Bacterial virulence factors Adherence Enterotoxin production Cytotoxin production Mucosal invasion Defense Barriers of the Enterocytes 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) 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 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 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 Inflammatory Frequent lower volume stool, mucoid, bloody, or purulent. Often with fever or systemic signs, tenesmus, urgency Exudative mechanism Dehydration rare Less benign Osmotic Diarrhea Increased amounts of poorly absorbed, osmotically active solutes in gut lumen Interferes with absorption of water 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 Exudative Diarrhea Intestinal or colonic mucosa inflamed and ulcerated Leakage of fluid, blood, pus Impairment of absorption Increased secretion (prostaglandins) Infectious, invasive organisms Shigella, Campylobacter,Yersinia, E. histolytica, EHEC, C diff Idiopathic inflammatory bowel disease Crohns disease Ulcerative Colitis Ischemia 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 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 Bacterial Salmonella Shigella Shiga-toxin producing Escherichia coli Non-shiga-toxin E. coli Campylobacter Yersinia Clostridium difficile Vibrio cholerae Salmonella Contaminated animal products Normal flora in animals Clinical Symptoms may evolve Fever; general malaise Sometimes no GI symptoms If there are GI symptoms, will see: Bloody diarrhea Abdominal pain Weight loss Salmonellosis Fever, cramping, abdominal pain, and diarrhea within 848 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 Diagnosis Stool culture Salmonella bacilli may be found in stool/blood cultures Serology: positive Widal test with increased titers 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 710 days Many patients often relapse after treatment and chronic maintenance therapy (TMP/SMX 1 DD daily) is sometimes necessary. 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) Clinical Symptoms may evolve High fever Abdominal pain Bloody diarrhea Diagnosis Stool microscopy— fresh examination and after concentration Multiple stool samples may be necessary Shigella bacillus found in stool Treatment TMP/SMX 960 mg bid x 5 days or amoxicillin 500 mg tid x 5 days If resistant to the above, give or norfloxacin 400 mg bid x 5 days or nalidixic acid 1 g qid x 10 days ciprofloxacin 500 mg bid E. coli 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 (phagemediated production of Shiga toxin enhanced by ampicillin, norfloxacin, and other antibiotics) 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 Clinical Symptoms may evolve Fever and general malaise, sometimes without GI symptoms When present, GI symptoms include bloody diarrhea, abdominal pain and weight loss. 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 Yersinia High degree of abdominal pain Mistaken for appendicitis Infects the small intestine Some can affect the lymphatic system (intracellular) 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 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 Clostridium difficile Pseudomembranous colitis or antibiotic associated colitis Capable of superinfecting the large intestine due to drug treatments Enterotoxins 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 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 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. Vibrio cholerae Heavy lost of fluid “rice-water stool” Untreated cases can be fatal VIRAL GASTROENTERITIS 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. 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. 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. 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. 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. Rotavirus Responsible for most morbidity and mortality from diarrhea Babies lacking maternal antibodies are at risk Unique morphological appearance A feces sample containing Rotavirus, which has a unique “spoked-wheel” appearance. Fig. 22.18 Rotavirus visible in a sample of feces from A child with gastroenteritis. 54 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 600,000875,000 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. 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. Acute diarrhea with vomiting Food poisoning - toxin Staphylococcus aureus Bacillus cereus Clostridium perfringens Chronic diarrhea Enteroaggregative (EAEC) E. coli Cyclospora cayetanensis Giardia lamblia Entamoeba histolytica 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 Treatment of specific etiology Non-specific treatment hydration Absorptions (Kaopectate®) Bismuth Antiperistaltics/opiate derivatives Fiber supplementation Thank you.. sources https://www.cdc.gov/healthywater/pdf/glo bal/programs/globaldiarrhea508c.pdf http://www.who.int/wer/2008/wer8347.pd f https://www.cdc.gov/disasters/disease/diar rheaguidelines.html https://extranet.who.int/sree/Reports?op= vs&path=/WHO_HQ_Reports/G36/PRO D/EXT/FoodborneDiseaseBurden