Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GI 3 > Infectious Diarrhea 1 > Flashcards

Infectious Diarrhea 1 Flashcards

1
Q
  • _____ diseases are the second leading cause of morbidity and mortality worldwide
  • Leading cause of childhood death worldwide.
  • No good incidence studies b/c most self-limited
A

Infectious diarrheal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Acute Diarrhea Clinical Course

A
  • Usually self limited – Usually infectious – But even non-infectious causes will typically resolve
  • Average 3-7 BM per day
  • Volume <1 L / day
  • Most occur in winter months (viral).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Function of intestine

A
  • The length of the adult small intestine: – 3 to 8 meters (Mean 6 M)
  • Most macronutrients – Carbohydrates, fat, and protein

– Absorbed in the proximal 100 to 150 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Infectious diarrhea causes what kind?

A

• Watery diarrhea, large volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  • Large Bowel:Functions as storage and fluid absorption
  • Lack of function –> Lack of absorption –>_____ stools
  • Inflammation –>intracelluar leakage –>____ stools
A

Frequent

Frequent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Painful BM, tenesmus, urgency

  • Fever, bloody, mucoid stools
  • RBCs and WBC on stool smear
A

Large bowel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

• Most gastroenteritis is_____ – cultures only positive in 1.5-5.6% of cases.

A

viral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

– defined as ≥4 fluid stools per day

– > three days

– 87% bacterial

A

• Severe community acquired diarrhea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Gram negative encapsulated bacilli

  • Poultry, eggs and milk association
  • Pet turtles association
A

Salmonella typhi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Salmonella typhi

• _______ is much more common in US than typhoid type – 40% in patients <15 y/o

A

Non-Typhoid Salmonella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Risk factors for salmonella typhi

A

summer and fall, young age, IBD, immune deficiencies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

• ________ may be associated with gallstones and a chronic carrier state – Carrier state may cause falsely elevated frequency in Typhoid Fever

A

Gallbladder colonization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

•Symtoms of Acute infection of Typhoid Fever

A

: anorexia, abdominal pain, bloating, nausea, vomiting, and bloody diarrhea.

Can develop bacteremia with associated fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

• Patients with sickle cell disease are particularly susceptible to ______

– S. Aureus is still the most common cause of osteomyelitis, even in this population

A

Salmonella osteomyelitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Salmonella quickly adapts to the _____ but the microbiome protects against pathogenesis which is why what is bad?

A

adapts to low pH

Antibiotics are BAD in salmonella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does salmonella survive in host and cause immune respone?

A
  • Uptake into cell, survive in modified phagosome, and replicate
  • Induce migration of neutrophils to cause inflammatory response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

• Non-typhoid Salmonella generally is self-limited, except:

A

– High-fevers, Severe Diarrhea (>10 stools/day), Hospitalized patient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Gram-negative bacilli that are unencapsulated, facultative anaerobes.

A

Shigella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Shigella

  • Responsible for ~ 10% of pediatric diarrheal disease but ___ of diarrheal deaths
  • Fecal oral route, highly contagious with As few as____ organisms

– Acid resistant

• Daycare and institutional settings, can be transmitted person to person.

A

75%

10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe disease processes in Shigella and its symptoms

A
  • Self-limited disease
  • ~6 days of diarrhea, fever, and abdominal pain.
  • Most commonly effect the left colon, but the ileum may also be involved. (can mimic Crohn’s disease)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What should we and shouldn’t we use to treat Shigella?

A
  • Antibiotic treatment shortens the clinical course
  • Antidiarrheal medications are contraindicated – Delay bacterial clearance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Rare complication of Shigella

A

• Rarely: Hemolytic Uremic Syndrome, Seizures, or Reactive arthritis – Shiga-like toxin of other organisms can lead to these events

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q
  • Leading cause of acute bacterial diarrhea worldwide
  • 33% of foodborne illnesses
  • Undercooked poultry, unpasteurized milk or contaminated water
A

Campylobacter jejuni

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Campylobacter jejuni:

  • Ingestion of as few as____ C. jejuni organisms
  • Incubation period of up to __ days.
A

500

8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Disease process in Campylobacter jejuni

A
  • Usually an influenza-like prodrome – Fever, malaise, myalgias
  • Dysentery develops in 15% to 50% of patients.
  • Self limited and therefore antibiotic therapy generally is not required
  • Watery or hemorrhagic, both small and large bowel symptoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q
  • Self limited and therefore antibiotic therapy generally is not required
  • Watery or hemorrhagic, both small and large bowel symptoms
A

Campylobacter jejuni

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Complications of campylobacter jejuni

A
  • Can result in reactive arthritis or erythema nodosum
  • Guillain-Barré syndrome.

– Peripheral –> Central progressive paralysis caused by autoimmune-induced inflammation of peripheral nerves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q
  • Can result in reactive arthritis or erythema nodosum
  • Guillain-Barré syndrome.

– Peripheral –> Central progressive paralysis caused by autoimmune-induced inflammation of peripheral nerves.

A

Camplobacter jejuni

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Causes pseudoapendicitis; RLQ pain and yersinia also does this

A

campylobacter jejuni

30
Q

describe campylobacter jejuni

A

pseudoappenticitis

erythema nodosum, reactive arthrtis

Guillian barre

water or hemorrhagic diarrhea; sm and large bowel involvemnt

influenza like prodrome

31
Q
  • Flagellated protozoan
  • Most common pathogenic parasitic infection in humans
  • Fecally contaminated water or food.
A

Giarda lamblia

32
Q

Where do we aquire Giardia lamblia

A

• Endemic in unfiltered public and rural water supplies – Well water / “drinking from mountain streams”

33
Q

What disease does Giardia cause?

A
  • Acute or chronic diarrhea with upper abdominal bloating
  • Small bowel disease
34
Q

Gram-negative bacilli that colonize the healthy GI tract; most are nonpathogenic, but a subset cause human disease

A

Eschericia coli

35
Q

– Principal cause of traveler’s diarrhea

– Fecal-oral route

– Express either LT or ST, or both

A

• Enterotoxigenic E. coli (ETEC) organisms

36
Q
  • Heat labile toxin (LT) that is similar to____ toxin
  • Heat-stable toxin (ST) that increases intracellular____ with effects similar to the cAMP elevations caused by LT

Both are in ETEC/travelers diarrhea

A

cholera

cGMP

37
Q

Why does incresae cGMP cause diarrhea

A

– cAMP ==>

  • (1) Secretion of Cl- thru its channel
  • (2) Prevent reabsorption of NaCl at villus tips

THUS: Net Water Secretion or osmotic diarrhea

38
Q

– Resemble Shigella in its pathogenesis

– Invade the gut epithelial cells

– Produce a bloody diarrhea

A

• Enteroinvasive E. coli (EIEC) organisms

39
Q

• Enteroaggregative E. coli (EAEC) organisms

– Attach to enterocytes by _____

– Flagellan –> ↑ ____ –> Intestinal Inflammation

A

adherence fimbriae

IL-8

40
Q

– Attach to enterocytes by adherence fimbriae

– Flagellan –> ↑ IL-8 –> Intestinal Inflammation

– Although they produce a LT and Shiga-like toxins, histologic damage is minimal from these

A

Enteroaggregative E. coli (EAEC) organisms

41
Q

Undercooked ground beef or mishandling of ground beef.

  • 4% of foodborne illness.
  • 39% of cultured pathogens in visibly bloody specimens
  • Association with Hemolytic Uremic Syndrome (HUS)
A

Enterohemorrhagic E.Coli (EHEC)

• E. coli 0157:H7

42
Q

antibiotics can induce:

– Hemolysis, Thrombocytopenia and Renal Failure

A

HUS in Enterohemorrhagic E.Coli (EHEC)

43
Q
  • Gram-negative bacteria
  • Contaminated drinking water
  • Seafood-associated disease: animal reservoirs are shellfish and plankton
A

Vibrio cholerae

44
Q

What causes disease in vibrio cholera

A

• Enterotoxin, cholera toxin, which causes disease

45
Q

Mechanism by which cholera cuaes watery diarrhea

A

– Causes increased in intracellular cAMP which

– Opens the (CFTR)–> Releases Cl- ions into the lumen –>Draws water into the lumen

46
Q

HOw does vibrio cholera present?

A

most asymptomatic or mild diarrhea

severe: abrupt onset watery diarrhea up to 1 L/hour!!!

47
Q

incubation of vibrio cholera

A

1 to 5 days

48
Q

Concners with severe vibrio cholera infectionDehydration, hypotension, electrolyte imbalances, anuria, shock, and death.

A
49
Q
  • Approximately half of all gastroenteritis outbreaks worldwide
  • Contaminated food or water, but person-toperson transmission as well.
  • Schools, hospitals, and nursing homes and, most recently, on cruise ships.
  • Nausea, vomiting, watery diarrhea, and abdominal pain.
  • Self-limited
A

Norovirus

50
Q

Pre-vaccine: 10% of diarrhea “requiring treatment” & 50% of “required hospitalization”

– If in hospital for diarrhea & winter: 70-90%

A
51
Q

Previously: Most common cause of childhood diarrhea and diarrhea-related deaths worldwide.

A

rotavirus

52
Q

Who is susceptible to rotavirus?

whre are outbreaks?

What are symptoms?

A

children 6 to 24 months most vulnerable

outbreaks in hospital and daycare

vomit and watery diarrhea for several days

vaccines now available

53
Q

– Nematode

– Infects more than 1 billion people worldwide

– Fecal-oral

– Can cause Ascaris pneumonitis

A

• Ascaris lumbricoides

54
Q

Lifecycle of Ascarisis lumbricoides

A

person ingest feces with worms–> to intestine–> travesl to liver = abcess–> to lungs = cough and swallow and autoinnoculte

shit out fertalized eggs

55
Q

Strongyloides lifecyle– Larvae live in fecally contaminated ground soil – Can penetrate unbroken skin, such as feet – Migrate through the lungs to the trachea from where they are swallowed – Mature into adult worms in the intestines. – Eggs can hatch within the intestine and release larvae that penetrate the mucosa • creates a vicious cycle referred to as autoinfection. – Persist for life, and immunosuppressed individuals can develop overwhelming infections.

A

– Larvae live in fecally contaminated ground soil

– Can penetrate unbroken skin, such as feet

– Migrate through the lungs to the trachea from where they are swallowed

– Mature into adult worms in the intestines.

– Eggs can hatch within the intestine and release larvae that penetrate the mucosa

• creates a vicious cycle referred to as autoinfection. – Persist for life, and immunosuppressed individuals can develop overwhelming infections.

56
Q

– Hookworms

– Infect 1 billion people worldwide

– Infection by larval penetration through the skin.

A

Necator americanus and Ancylostoma duodenale

57
Q

Lifecycle of necator americanus and ancylostoma duodenale

A

– Infection by larval penetration through the skin.

– After further development in the lungs, the larvae migrate up the trachea and are swallowed.

– Once in the duodenum, the larvae mature and the adult worms attach to the mucosa, suck blood, and reproduce.

58
Q

Leading cause of iron deficiency anemia in the developing world.

A

Necator americanus and Ancylostoma duodenale.

59
Q

Immunocompromised host: have Lymphoma, BMT, HIV worry about what other

parasites and Bacteria

A

Parasites: Cryptosporidium parvum, Isospora belli, Cyclospora, and Microsporia. – Bacteria: MAC

Viral: CMV, HIV, adenovirus

60
Q

New diarrhea at least 72 hours after admission to hospital.

• Increases the length of stay from one week to one month

A

Nosocomial diarrhea

61
Q

Causes of nosocomial diarrhea

A
  • Clostridium difficile
  • Tube feeds (Osmotic)
  • Medications
  • Fecal impaction (Overflow incontinence)
  • Ischemic Colitis
  • BMT patients – Besides infection: GVHD
62
Q

History of a fever with diarrhea suggests:

A
  • Invasive bacteria
  • Enteric viruses
  • Cytotoxic organism – Clostridium difficile or Entamoeba histolytica
  • Ischemia
  • IBD
63
Q

• Began within 6 hours

– Suggest ingestion of a toxin

– _______ (potato salad) or _____ (Chinese food/rice)

A

Staphylococcus aureus

Bacillus cereus

64
Q

Diarrhea began 8-14 hours w/in food consumption is suggestive of infection with:

A

Clostridium perfringens

65
Q

For infectious colitis, Most bacterial infections all induce a similar histopathology Termed _______

You need what do diagnose this?

A

“acute self-limited colitis”

stool study (endoscopy not helpful in acute diarrhea)

66
Q

Pt has Acute diarrhea, non-toxic appearing, non-bloody diarrhea

to test or not?

A

– No testing is needed

67
Q

Key points for BACTERIAL stool studies

A

Bacterial pathogens generally are excreted continuously.

  • Negative culture usually not a false negative
  • Repeat specimens are rarely required
68
Q

When should we order a stool study?

A
  • Severely Ill
  • Outbreaks
  • Require hospitalization
  • Immunocompromised patients, e.g. HIV
  • Patients with comorbidities (e.g. IBD)
  • Some employees, such as food handlers or daycare providers, may require negative stool cultures to return to work
69
Q

What is the challenge we face when ordering O and P tests if we suspect parasites?

A

• Many false negative b/c ova shed intermittently • Repeated X3 – 3 consecutive days – 24 hours apart • Useless in most patients • Not cost effective

70
Q

When should we order O and P test?

A

• Persistent diarrhea >14 days • Travel to mountainous regions • Exposure to infants in daycare centers • Immune-compromised. • A community waterborne outbreak

71
Q

ELISAs and DFA microscopy are useful in diagnosising which pathogens?

A

Giardiasis & Cryptosporidium antigen in stool

– Sensitivities >90%

– Specificities close to 100%

GI 3 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions