GI E2- ID of GI tract

What. is inflammation of the stomach lining?

Gastritis

What is inflammation of the stomach and intestines?

Gastroenteritis

What term refers to diseases caused after consuming toxins in food?

Food poisoning

What kind of food poisoning?

• can be detected in food

• shorter incubation- 1-6 hrs

• ssx: usually vomiting, fever not usually present

• ex: s. aureus, b. cereus

Preformed toxins

What kind of food poisoning?

• toxin detected in stool specimens

• longer incubation- 8-16 hrs

• ssx: less vomiting, more abd cramping, ± fever

• ex: c. perfringens

Microbe produces toxin after ingestion

Acute diarrhea lasts ______

< 2 weeks

Persistent diarrhea lasts _______

> 2 weeks

Chronic diarrhea lasts _____

> 30 days

What term describes ≤ 3 stools/day?

Mild diarrhea

What term describes ≥ 4 stools/day with local symptoms (abd cramps, N, tender)?

Moderate diarrhea

What term describes ≥ 4 stools / day with systemic symptoms (fever, chills, dehydration)?

Severe diarrhea

What kind of diarrhea?

• involve invasion of colon by bacteria, parasites, or toxin production

• complaints of frequent bloody, small volume stools

• common sx: fever, abd cramps, tenesmus, fecal urgency

Inflammatory/bloody diarrhea

Pathogens that cause inflammatory diarrhea

What kind of diarrhea?

• milder; caused by viruses or toxins that invade small intestine

• interfere with salt & water balance → large volume watery diarrhea

• local sx: N, V, cramps

Non-inflammatory, non-bloody, watery diarrhea

Pathogens that cause non-inflammatory diarrhea

Food/water borne pathogens that cause non-inflammatory diarrhea

What condition?

• transmitted by food and water (both types)

• 12-72 hr incubation

• profuse watery diarrhea that is prolonged but self limited (1-2 wks)

  • *can be longer if immunocompromised

Acute infectious diarrhea

What pathogen for acute infectious diarrhea does recent hospitalization or abx use suggest?

C. diff

What pathogens for acute infectious diarrhea do recent foreign travel suggest?

Salmonella, shigella, campylobacter, e. coli or v. cholerae

What pathogen for acute infectious diarrhea does an undercooked hamburger suggest?

E. coli 0157:H7

What pathogen for acute infectious diarrhea does an outbreak in a longterm care facility, school, or on a cruise ship suggest?

Norovirus

What pathogen for acute infectious diarrhea does the consumption of fried rice suggest?

B. cereus toxin

How is acute infectious diarrhea diagnosed?

Clinical- look at history and environmental factors

What is the treatment for acute infectious diarrhea?

RX not recommended → most self limited

Fluid/elyte replacement, oral glucose based rehydration solns (pedialyte, ceralyte, gatorade), antiemetics

What should be done for acute infectious diarrhea if symptoms last > 1 wk, the initial onset is of fever or bloody stools, or patient is immunocompromised?

Stool cultures- WBC, O&P, etc

can order specific tx if specific organism identified and sx persist (but most resolve by time culture is returned)

Antibiotics for acute infectious diarrhea would be helpful for with pathogens?

Shigella or campylobacter infections

Acute infectious diarrhea caused by which pathogens would antibiotics worsen the disease?

E. coli 0157:H7 (risk developing HUS)

C. diff (prolongs dz)

What pathogen?

• affects all ages, esp kids

• frequently in summer mos

• transmission: ingestion of contaminated food, drink

• vector: domestic pets (dogs, cats, turtles)

• large numbers must be ingested to produce illness

Salmonella (salmonellosis)

What are sources that can contain salmonella?

Unpasteurized milk, turkey, chicken, duck, eggs (esp raw), hollandaise sauce, homemade eggnog, caesar salad dressing

What can decrease the possibility of salmonella infection but doesn’t eliminate it?

Cooking contaminated foods (might not reach lethal temperature range or deep in foods like large turkeys or soft cooked eggs)

How much salmonella must be ingested to produce illness?

Large numbers

In general, what amount of shigella is sufficient to induce symptoms?

10-100 bacteria

What pathogen?

• Worldwide distribution; common in countries w/o effective sanitation

• fecal oral route

• source: food or water contaminated with human feces

Shigella aka bacillary dysentery

What pathogen?

• infx MC in children and elderly

• produces cytotoxin (shiga toxin/STEC) → endothelial damage, hemolysis and renal damage

• uncomplicated infx resolves spontaneously in 5-10 days

E. coli 0157:H7 (enterohemorrhagic)

What have E. coli 0157:H7 outbreaks been attributed to?

Undercooked ground beef, unpasteurized apple juice and milk, raw fruits and vegetables

What are complications of E. coli 0157:H7?

Hemolytic uremic syndrome (HUS), esp in kids < 5 y/o

Why are antibiotics contraindicated in e.coli 0157:H8 infx?

increases risk of HUS

What does the CDC recommend for all patients with bloody diarrhea or HUS?

Test for E. coli 0157:H7

What pathogen is an enterotoxin forming strain of staphylococcus that multiplies in food before ingestion and is commonly found on skin?

S. aureus

What are the sources of growth for s. aureus?

Protein rich foods- ham, eggs, hardboiled eggs, mayonnaise, custard filled pastries, potato salad

Also cold ready to eat foods and raw milk

What pathogen?

• typical sx: stomach pain and vomiting

• average onset period- 1-6 hrs

• recovery- usually 4-6 hrs, occasionally 24 hrs

• dx: high suspicion; multiple cases in people eating the same meal

S. aureus

What is the most common botulism in the US?

Infant botulism

What causes infant botulism?

ingestion from honey & spores in the environment

What pathogen?

• 3 types of botulism- food, infant, wound

• grows in anaerobic acidic environemnts- canned foods, fermented fish, foods kept warm for extended periods

• sx begin 12-36 hrs after ingestion

  • may occur up to 14 days after in infants

Clostridium botulinum

What are sx of botulism?

Double or blurred vision, droopy eyelids, slurred speech, difficulty swallowing, dry mouth, muscle weakness that starts in shoulders and descends through body

What is the treatment for c. botulinum?

maintain airway and breathing, may require ventilator, IV polyvalent antitoxin

What condition?

• majority caused by Enterotoxigenic e coli, shigella species, or c. jejuni

• onset 5-15 days, can occur w/in 2-10 days of travel, esp in area of poor sanitation

• contaminated foods or drinks- unpeeled fruits, leafy vegetables, unsanitary drinking water or ice

Traveler’s diarrhea

What is there a significant risk of developing with traveler’s diarrhea?

IBS

What sx are associated with traveler’s diarrhea?

Watery diarrhea (≥ 10 loose stools/day), nausea, abd cramping, fever (< 1/3 of pts)

Are stool cultures needed for travelers diarrhea?

Nope- no blood or leukocytes present

How long does traveler’s diarrhea last?

Usually spontaneously resolves in 5 days

What is the treatment/prevention for traveler’s diarrhea?

Give antimicrobials to take if diarrhea occurs during trip

loperamide 4mg loading dose following by 2mg after each loose stool (max 16 mg/day)

peptobismol

What antimicrobials can be given to a patient about to travel to prevent traveler’s diarrhea?

Cipro (or levo or ofloxacin) single dose

Azithro 1g single dose

Rifaximin

What is a broad spectrum abx that is specific for enteric pathogens of the GI tract?

Rifaximin

What condition?

• toxin mediated disease causes severe inflammatory response w/ formation of pseudomembranes made of necrotic debris, mucus, inflammatory cells

• cause- C. diff

• MC in hospitalized patients - 20% of those after taking abx

• fecal oral transmission

Pseudomembranous colitis (PMC)

How can abx cause pseudomembranous colitis?

Disrupts normal bowel flora → overgrowth of C. difficile

What pathogen is an obligate anaerobe, gram positive, spore forming bacilli?

C. difficile

What antibiotics cause pseudomembranous colitis?

Ampicillin, lincosamides (clindamycin), 3rd gen cephalosporins, FQs

Describe the toxins associated with PMC

Destroy colonic mucosa, don’t induce fluid or elyte secretion, & appear as raised yellowish white plaques (pseudomembranes) loosely adherent to the mucosa, occurring in patches MC in the rectosigmoid area

The following sx are associated with what condition?

• mild-mod greenish, foul smelling, watery diarrhea

  • 5-15 stools/day

• lower abd cramping, LLQ tenderness

• positive for mucous in stool but no blood

PMC

What is the diagnostic workup for PMC?

Cytotoxicity assay (definitive), rapid EIA for toxin A & B, rapid PCR (preferred), fecal WBCs, flex sigmoidoscopy (white or yellow fluffy loose plaques + copious mucus), and abd XR/CT if megacolon suspected

What is the treatment for PMC?

D/c offending antibiotic

Vancomycin PO or fidaxomicin (if both not available → flagyl)

Fecal microbiota transplant

What should be avoided in PMC?

Antimotility agents and narcotics → delays clearance of toxin

What complications area associated with PMC?

Fulminant disease → hemodynamic instability, resp failure, metabolic acidosis, megacolon. perforation, deaeth

Chronic untreated dz → wt loss, protein losing enteropathy

Why do 25% of patients with PMC relapse within 1-2 weeks after discontinuing the initial rx?

Re-infection or failure to eradicate organism, spores can recreate disease

What is the treatment for a relapse of PMC?

Retreat with same therapy

Multiple relapses → 7 week tapering regimen of vancomycin & concomitant probiotics

What condition?

• common cause of illness

• transmission: person to person, fecal oral route, or water or food borne outbreaks

• rotavirus or norovirus

Viral gastroenteritis

Which virus is associated with viral gastroenteritis in infants and young children?

Rotaviruses

Which virus is associated with viral gastroenteritis in adults and older children?

Noroviruses

Rotavirus or norovirus (Norwalk)?

• outbreaks typically in winter months

• infants & children 6-24 mos

• 24-72 hr incubation

• abrupt onset of vomiting, watery diarrhea, low grade fever, ± abd pain

Rotavirus

Rotavirus or norovirus (Norwalk)?

• family and community wide outbreaks, esp on cruiseships

• school age children, family contacts, and adults

• 1-3 day incubation

• abrupt onset of diarrhea, N, V, mild abd cramps

Norovirus (Norwalk)

What is the MC protozoan GI infx in the US?

Giardia lamblia

What pathogen?

• prevalent in areas with poor water treatment

• contamination of water supplies with cyst-infested feces from humans or animals

  • beavers, muskrats, dogs, cats, raccoons, deer

Giardia lamblia

What type of infection occurs in these areas?

• mountainous west → backpackers diarrhea

  • from drinking fecally contaminated water from mountain streams

• former Soviet Union - Armenia, Georgia, Ukraine, Russia (esp st petersburg)

Protozoal infx

What condition?

• 1-3 week incubation

• half of pts are asx

• sx: pale, explosive diarrhea w/ cysts or trophozoites found in stool

• Treat empirically if high suspicion + treat close contacts + report to board of health

Protozoal gastroenteritis

What is the treatment for protozoal gastroenteritis?

Tinidazone (TOC) or metro

What are supportive treatment options for GI infectious diseases?

Bowel rest, hydration w/ clear fluids, antiemetics, BRAT diet (bananas, white rice, apple sauce, tea/toast)

What should clear fluids used to hydrate patients with infectious disease contain?

Glucose, sodium, K, Cl, bicarb (ex- pedialyte, gatorade, or IV lactate ringers if severe)

What antiemetics can be used in the supportive treatment of GI infectious diseases?

PO or suppository phenergan, promethazine, zofran

What should be avoided in patients with GI infectious diseases?

Lactose products, fried or fatty foods, caffeine, alcohol, whole wheat or high fiber products