Updated: 10/24/2018

Vibrio cholerae

Topic
Review Topic
0
0
Questions
2
0
0
Evidence
2
0
0
Snapshot
  • A 40-year-old man presents to a local emergency room. He is currently on a medical mission in India. He reports sudden-onset nausea, vomiting, and copious amounts of watery diarrhea. His blood pressure is 93/65 mmHg and pulse is 114/min. On physical exam, he has sunken eyes, decreased skin turgor, and dry mucous membranes. He is given intravenous rehydration with the goal of rapid rehydration.
Introduction
  • Classification
    • Vibrio cholerae
      • a comma-shaped, flagellated, and gram - rod
      • oxidase + and produces cholera toxin
    • transmission
      • fecal-oral via water or uncooked food
  • Epidemiology
    • incidence
      • rare in the United States
    • demographics
      • endemic in developing countries
      • most severe in children
    • risk factors
      • raw seafood
      • contaminated water
      • travel
  • Pathogenesis
    • acid-labile enterotoxin activates Gs and overactivates adenylate cyclase, causing ↑ cAMP 
      • requires large inoculum or decreased acidity in the host’s stomach
      • causes ↑ chloride secretion, resulting in secretory diarrhea and water efflux
      • this results in loss of potassium and bicarbonate
  • Prevention
    • live-attenuated oral cholera vaccine
      • indication
        • adults traveling to endemic areas
        • > 10 days prior to travel
  • Prognosis
    • if untreated, mortality is > 50%
    • if treated, mortality is < 1%
Presentation
  • Symptoms
    • may be asymptomatic
    • acute onset
      • painless rice-water secretory diarrhea
      • nausea
      • vomiting
  • Physical exam
    • dehydration
      • sunken eyes
      • dry mucous membranes
      • decreased skin turgor
Studies
  • Labs
    • stool culture in alkaline media
      • definitive diagnosis but not always necessary
      • no white blood cells in stool
    • electrolyte abnormalities
      • hypokalemia
      • hyponatremia
      • metabolic acidosis
  • Making the diagnosis
    • most cases are clinically diagnosed
Differential
  • Norovirus diarrhea
    • distinguishing factors
      • often associated with cruise ships, child care centers, or other crowded condition
      • typically self-limited
      • no association with geographic endemic locations
  • Campylobacter jejuni-associated diarrhea
    • distinguishing factors
      • bloody diarrhea
      • comma-shaped, but does not grow in alkaline media
      • white blood cells in stool
Treatment
  • Management approach
    • management is centered around rapid rehydration
  • Conservative
    • oral rehydration
      • indication
        • all patients
    • intravenous hydration
      • indication
        • severe dehyration
  • Medical
    • antibiotics
      • indication
        • severe dehydration
      • drugs
        • doxycycline
        • tetracycline
        • ciprofloxacin
Complications
  • Rapid dehydration
  • Hypovolemic shock
  • Death
 

Please rate topic.

Average 5.0 of 3 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Questions (2)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Volume  
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Urine  
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2
Calculator

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M1.MC.1) A stool sample was taken from a 19-year-old male who presented with profuse watery diarrhea. He recently returned from a trip to Central America. A microbiologist identified the causative agent as a gram-negative, oxidase-positive, comma-shaped bacteria that is able to grow well in a pH > 8. Which of the following is a mechanism of action of the toxin produced by this bacteria? Review Topic

QID: 106331
1

Degradation of cell membranes by hydrolysis of the phosphilpids

0%

(0/10)

2

Overactivation of adenylate cyclase by activation of Gs subunit by ADP-ribosylation

100%

(10/10)

3

Overactivation of adenylate cyclase by inhibition of Gi subunit by ADP-ribosylation

0%

(0/10)

4

Inactivation of the 60S ribosomal subunit by cleaving an adenine from the 28S rRNA

0%

(0/10)

5

Overactivation of guanylate cyclase

0%

(0/10)

M1

Select Answer to see Preferred Response

PREFERRED RESPONSE 2
ARTICLES (2)
Topic COMMENTS (2)
Private Note