Cholera and other Vibrio Infections

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Cholera and other Vibrio Infections

• Sung Chul Hwang, M.D.
• Dept. of Pulmonary and Critical Care Medicine
• Ajou University School of Medicine

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Vibrios

• Coma shaped gram negative rods with flagella
• The most common organism in the surface water in
  the world
• Halophilic organism
• Grows well in alkaline media
• Main pathogens are cholerae , parahemolyticus,
  vulnificus

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Cholera

• Acute diarrheal disease caused by enterotoxin
  from V. cholerae in small intestine
• Epidemic or endemic in occurrence South
  Central America, Africa, Southeast Asia, Middle
  East
• May produce massive GI fluid loss acidosis shock

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Etiology

• Short , slightly curved, sausage shaped gram
  negative rod
• Rapidly motile with the use of polar flagellum
• More than 140 serotypes determined by O Ag on
  cell surface LPS
• Only Serotype O1 and O139 are responsible for the
  epidemic cholera
• Other non-O1 strains cause sporadic cases

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Microbiology

• V. cholerae is divideed into two biotypes,
  Classical and El Tor based on on biochemical
  traits and susceptibility to specific phages
• Both are subdivided into ogawa( A, B),
  inaba(A,C), Hikojima (A,B, C)
• Major virulence factor for O1 and O 139 serotype
  is cholera toxin, multimeric protein with one A
  subunit and 5 B subunits. (ADP ribosylation
  factor)

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Pathogenesis

• Ingestion of viable organisms 10 11
• Attach to mucosa by the pili(TCP)
• Production of enterotoxin(CTX)
• (A1A2) (5 B) ADP Ribosylation
• CTX stimulates adenyl cyclase in intestinal
  epithelial cells
• Increase in cAMP
• Secretion of isotonic fluids

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Clinical Features

• Increase in peristalsis ( 1st Sx)
• Abd. Fullness
• Loose stool
• Rice water appearance
• Hypotensive within hours
• Death within 18 hours to several days

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Composition of Cholera Stool
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Diagnosis

• History of acute onset with watery diarrhea in
  the absence of fever or abdominal cramp
• Darkfield or phase contrast microscopy most
  effective and rapid diagnostic test
• Cultures from stool or rectal swab (Gelatin, Meat
  extract, MacConkey, TCBS, Monsur)

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V. Cholerae on TCBS
Yellow Smooth Opaque
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Complications

• Altered consciousness or convulsions especially
  due to hypoglycemia in children
• Electrolyte imbalance Hypokalemia ( in
  children)
• Renal failure
• Aspiration in depressed consciousness and
  vomiting

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Treatment (1)

• Water and salt replacement
• 1) oral replacement in most cases three finger
  pinch of salts plus handful scoop of sugar, in
  half liter or one pint of drinking water
• 2) Intravenous replacement therapy in severe
  cases, when the volume exceeds 100 l/kg/24hours
  or 7 L/day in 70 kg person

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Treatment (2)

• Antibiotics ? Shortens the duration of diarrhea
  and reduce fluid loss
• Tetracycline Drug of choice 250 mg q 6 hrs or
  others such as Ampicillin, CM, TMP/SFX,
  Doxycycline

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Prophylaxis

• Cholera vaccines 50 effective
• Primary immunization
• Booster immunization
• Antibiotics prevents transmission in close
  contacts? tetracycline or CM
• Improve standard of living , public health, and
  sanitation

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Oral Rehydration Solution (ORS)

• 3.5 g Sodium Chloride
• 2.9 g Trisodium Citrate or 2.5 g Sodium
  Bicarbonate
• 1.5 g Potassium Chloride
• 20 g Glucose or 40 g Sucrose

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Mortality

• 50 to 70 in untreated patients
• Children mortality is higher ( ten times)
• Pregnant woman 50 chance of fetal death
  during third trimester
• Death may happen in 2-3 hours of illness but
  usually after 18hours to several days

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Vibrio parahemolyticus

• Major cause of acute diarrheal disease in Japan
  and Korea
• Ingestion of contaminated sea food
• Production of enterotoxin and inflammation in
  small bowel mucosa
• Incubation 23 hrs ( 5 to 92 hrs)

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Symptoms and Signs

• Acute onset of explosive diarrhea
• Abdominal pain, low grade fever, mild chills,
  headache, vomiting, and electrolyte loss
• Very high attack rate

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Lab Findings

• Diarrheal fluid Watery, sometimes mucoid, less
  often bloody ( lt 15) with a few leukocytes 10
  20 WBCs/HPF)
• Stool Culture TCBS agar
• Positive Kanagawa test b- hemolysis

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Clinical Course

• Self limited
• Mortality rare
• Prevention Adequately cooking sea food

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Vibrio vulnificus

• vulnificus means wound making
• Gram negative rod in Vibrio family
• Causes serious wound infections and septicemia
• First identified in 1970s
• Common in those with liver disease or chronic
  illnesses such as DM

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Microbiology

• Gram negative curved rods with a polar flagellum
• Grows well in Salt water Halophilic vibrio
• Epidemic when the temperature of the sea water
  rises
• Exponential growth in the presence of free Iron ,
  tranferrin saturation above 70
• Reason for infecting Liver cirrhosis,
  splenectomy, hemochromatosis, ESRD

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Clinical Types of V. vulnificus Infection

• Localized wound infection cellulitis
• Acute gastroenteritis
• Septicemia with bullae and gangrene

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Predisposing Conditions

• Chronic Liver Diseases Liver cirrhosis, chronic
  hepatitis
• Alcohol abuse
• Hemochromatosis
• Gastrectomy
• Splenectomy
• Immune suppressive therapy
• DM, RA, Leukemia, Lymphoma
• TBC, ESRD

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Contaminated foods

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Clinical Features in Septicemia

• Incubation Period 3 14 days
• Invasion to blood stream through gut mucosa ?
  abrupt onset of fever, chills, hypotension?
  metastatic cutaneous lesion ? Bacteremia ?DIC ?
  Shock
• GI bleeding
• High mortality rate

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Clinical Features in Healthy

• Wound Infections
• Open wound contaminations ? Intense cellulitis
  ? necrotizing vasculitis ? ulcer formation ?
  occasional bacteremia

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Treatment

• Antibiotics Tetracycline or ciprofloxacin
• Supportive care for the Sepsis
• Early Surgical debridement and wide excision with
  skin graft
• Prevention avoid eating raw fish

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Non-O1 V. cholerae

• Diarrheal illness from severe watery diarrhea to
  milder travellers diarrhea
• May produce enterotoxin
• Small numbers of leukocytes and RBCs in stool
• Stool culture on TCBS agar
• Usually no treatment required

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V. vulnificus in blood agar
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Antibiotics for Cholera
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Hemorrhagic Bullae
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Necrotic Bullae Gangrene
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Pathology of the Bullae
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Travelers Diarrhea
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Vibrio bacilli
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Vibrio vulnificus
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Vibrio
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Vesicles of V. vulnificus Infection
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Vesicles of V. vulnificus Infection
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Erythema of the V. vulnificus infection
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