Chap 34-BOOK (Part 1) Flashcards
Colorful names for Acute diarrheal illness
Montezuma’s revenge, Delhi belly, Greek gallop, Rome runs, Aztec two-step, and back door sprint
Alteration in a normal bowel movement characterized by an increase in the water content, volume, or frequency of stools.
Diarrhea
Having more than 3 bowel per day
Diarrhea
Defined as symptoms lasting less than 14 days. If symptoms last longer than 14 day
Acure diarrhea/Persistent diarrhea
Diarrhea that lasts longer than 30 days,
Chronic diarrhea
Noninfectious cause of diarrhea
Laxative use, tumor-related, malabsorption, inflammatory bowel disease, and problems with motility caused by hyperthyroidism, irritable bowel syndrome, or surgical reduction of the gut.
Normal gastric pH
Lower than 4
Motion in the small intestine
Peristalsis
Colon has what immunoglobulin
IgA
Number of organisms that must be ingested to cause a diarrheal illness in 50% of exposed individuals.
Median infectious dose (ID50)
The absence of hydrochloric acid in gastric secretions
Achlorhydria
Usually caused by enterotoxigenic Escherichia coli. This disease has a short incubation period (usually between 5 and 15 days after arrival) and normally lasts from 1 to 5 days
Traveller’s diarrhea
If a diarrheal illness develops weeks after a traveler returns home, a parasitic infection such as
G. lamblia or E. histolytica
If the patient is currently taking or has recently received antibiotics this organism is an important consideration
C. difficile
Signs suggestive of dehydration
Sunken appearance to the eyes
Dry oral membranes
Loss of skin resiliency known as skin tenting
Decrease blood pressure
Increase heart rate
Lack of fever and absence of blood or pus in the stool suggests an
Enterotoxin-Mediated Diarrhea
The preformed toxin is already present in the ingested food. Because toxin can act proximally in the bowel (the small intestine), the incubation period is relatively short, usually less than 12 hour
Enterotoxin-Mediated Diarrhea
Result of stool examination for Enterotoxin-Mediated Diarrhea
Negative for red and white blood cells
Organism that has the largest percentage of cases of diarrhea in travelers to underdeveloped areas
Enterotoxigenic E. coli
Other organisms responsible for enterotoxin-mediated disease
Vibrio cholerae
Staphylococcus aureus
Clostridium perfringens
Bacillus cereus.
Culprit/source of infection can often be traced to food handlers
S. aureus
Small, localized abscesses in the nail beds known
Paronychias
Noninvasive parasitic invasion that produce afebrile diarrhea
Giardiasis, cryptosporidiosis, or infection with Cystoisospora belli
Organism that caused diarrhea mediated by invasion of the bowel mucosal surface
Salmonella spp.
Campylobacter spp
Shigella spp.
some E. coli strains
Entamoeba histolytica
Organisms that invade the bowel mucosa cause an inflammatory response, characterized by the presence of fecal leukocytes, fever and leukocytosis
Diarrhea Mediated by Invasion of the Bowel Mucosal Surface
T/F: Patient may present with true dysentery syndrome, characterized by gross blood and pus in DMIBMS
True
Most common invasive enteric organism that causes Diarrhea Mediated by Invasion of Full-Bowel Thickness with Lymphatic Spread
Salmonella Typhi and Yersinia enterocolitica.
Incubation period for these infections (Full bowel thickness with Lymphatic spread) is about
1 to 3 days
Salmonella Typhi and Yersinia enterocolitica invade the bowel wall, causing
bacteremia, and mesenteric lymphadenitis which can be mistaken for appendicitis
Present in the stool for Full bowel thickness with Lymphatic spread
Red blood cells and fecal leukocytes
These viruses infect cells of the villi of the small intestine, leading to epithelial atrophy and proliferation of cells with secretory capacity.
Rotavirus
The most common cause of diarrhea in children younger than 5 years
Rotavirus
Implicated in many illnesses, ranging from the common cold and epidemic keratoconjunctivitis (pink eye) to infectious diarrhea
Enteric Adenovirus
Two adenovirus serotypes, most frequently associated with infectious diarrhea
Serotype 40 and 41
Characterized by 32 cup-shaped depressions along the surface
Calicivirus
Theese viruses cause an acute, self-limited diarrheal illness associated with vomiting and low- grade fever.
The virus could be transmit- ted by the aerosolization of vomitus.
Norwalk and Sapovirus
Small, 28-nm virus that appears as a five- or six- pointed star is the morphology at alkaline pH; suggest that an osmotic diarrhea may develop from inflammatory infiltrates in the lamina propria and intestinal villus atrophy.
Astrovirus
Most common bacterial cause of gastroenteritis in the world. These organisms are developing significant resistance to antibiotics commonly used to treat diarrheal illnesses
C. jejuni
Life-threatening neurologic disease, and reactive arthritis are complications of infection by C. jejuni.
Guillain-Barré syndrome
often the source of the infection of C. jejuni
Contaminated poultry
Preferred antibiotic for C. jejuni because of the increasing rates of fluoroquinolone resistance
Macrolide antibiotic
caused by nontyphoidal Sal-
monella spp. that can lead to gastroenteritis through the ingestion of contaminated meat, poultry, eggs, dairy products, and aquaculture- farmed fish and shellfish.
Gastroenteritis and Food poisoning
Animal host for nontyphoidal salmonella serotyoes
Birds and reptiles
causes the most severe form of enteric fever, typhoid fever.
Salmonella typhi
Bacteria survive in the host immune cells, and are therefore termed
Intracellular pathogens
Responsible for a diarrheal illness characterized by gross blood and pus.
Shigella spp.
(S. sonnei , S. flexneri, S. dysenteriae, and S. boydii)
Most easily communicable bacterial diarrheal pathogens
Shigella Spp.
Shigella bacteria can produce several toxins, including the _ which can have cytotoxic, enterotoxic and neurotoxic effects
Shiga toxin
Typically used as initial empiric therapy when antibiotics are required for Shigella spp.
Fluoroquinolones
Produce adhesins to bind to intestinal mucosa and enterotoxins, which are heat-stable (ST) or heat-labile (LT)
Enterotoxigenic Escherichia coli (ETEC)
similar to V. cholerae toxin
LT toxin
Binds to guanylate cyclase, leading to increased intracellular cyclic guanosine monophosphate (cGMP) levels and active efflux of water and electrolytes from the intestinal cells
ST toxin
Produce an infection similar to Shigella. Progress to an invasive-type diarrheal syndrome, with fever, abdominal cramping, and bloody stools.
Enteroinvasive Escherichia coli (EIEC)
_atients can develop hemolytic-uremic syndrome (HUS), characterized by hemolytic anemia, low platelet count, and kidney failure.
Enterohemorrhagic Escherichia coli (EHEC)
E. coli strain that is the principal cause of EHEC
O157:H7
Referred to as the enteroadherent E. coli in some classification schemes. These organisms commonly affect children in nurseries and daycare center
Enteropathogenic Escherichia coli (EPEC)
Also adhere to the intestinal surface but in a more clumped or aggregative fashion.
Enteroaggregative E. coli (EAEC)
The causative agent of cholera.
V. cholerae
Subunit of V. cholerae that permit attachment to the small bowel mucosa
B subunits
Subunit of V. cholerae that enters the cell.
A subunits
Serogroup that causes of epidemic cholera
Serogroups O1 and O139
Most common virbrio spp. can have fever and evidence of fecal inflammation, sug- gesting that there is some potential for mucosal invasion
Vibrio parahaemolyticus
Most virulent of all noncholera vibrios, causing an often fulminant illness characterized by sepsis and bullous skin lesions in patients with a recent ingestion of shellfish
V. vulnificus
Responsible for bubonic plague
Yersinia enterocolitica
Causative agent of antibiotic-associated diarrhea
C. difficile
Was initially reported in patients receiving clindamycin
C. difficile–associated disease (CDAD)
Epidemic strain of C. difficile that has increased virulence, which is attributed to the overexpression of toxin-encoding genes producing larger amounts of toxins, which causes a more aggressive form of the disease when compared with the nonepidemic strains.
BI/NAP1/027
Mainstay therapy for C. difficile
Metronidazole and Vancomycin
Best known for causing systemic disease, such as meningitis
L. monocytogenes
Associated with peptic ulcer disease
H. pylori
This testing is based on the organism’s high urease activity. 13C- or 14C-labeled urea will, when ingested, produce labeled CO2 in the patient’s breath if the organism is present.
Breath testing
Has been associated with a watery diarrhea
Aeromonas spp. and P. shigelloides
Associated with fish and shellfish, is a rare cause of gastroenteritis.
Edwardsiella tarda
