CHOLERA

Document Sample
CHOLERA Powered By Docstoc
					MICROBIAL DISEASES
 OF THE DIGESTIVE
      SYSTEM
              MOUTH
• Over 300 types of bacteria
• Dental caries
• Periodontal disease
  –Gingivitis
  –Periodontitis
     DENTAL CARIES
• Dental plaque
  –Accumulation of microorganisms
   and their products (dental plaque)
  –Streptococcus mutans
  –Actinomyces spp.
DENTAL CARIES (cont.)
• Attachment
• Colonization
• Sugar (glucose+fructose)
• Glucose > dextran
• Fructose > lactic acid
Enamel
    DENTAL CARIES (cont.)
•   Lactic acid softens enamel
•   Initial, S. mutans
•   Advance, Lactobacillus spp.
•   Pulp infection
DENTAL CARIES (cont.)
• Treatment
  – Root canal therapy
  – Penicillin
• Prevention
  – Fluoride
  – Reduced sucrose in diet
  – Brushing and flossing
  – Professional cleaning
PERIODONTAL DISEASE
• Inflammation of teeth-supporting tissue
• Gingivitis
   – Gums inflammation (bleeding)
       PERIODONTAL
       DISEASE (cont.)
• Streptococci, actinomyces and
  gram-negative bacteria
• Prevented by brushing & flossing
       PERIODONTITIS
•   Chronic gingivitis
•   10% of teeth loss
•   Affects bone
•   Surgery and cleaning
  LOWER DIGESTIVE
     SYSTEM
• Infections
   –Salmonellosis
• Intoxications
   –Staphylococcus aureus
Practice that contributed to food-
   borne disease (1988-1992)
1. Improper holding temperature
2. Poor personal hygiene of food
  handlers
3. Food obtained from an unsafe
  source was the least commonly
  reported factor
          Syndrome
• A group of symptoms that together
  are characteristic of a specific
  disease
Gastrointestinal Syndrome
• Gastroenteritis associated with
  nausea, vomiting and diarrhea
   Dysentery syndrome
• Any infectious disease of
  the large intestine marked
  by ulceration, hemorrhagic
  diarrhea with mucus and
  often blood
  GASTROENTERITIS
• Inflammation of the stomach and
  intestinal mucosa
     GASTROENTERITIS
          (cont.)
•   Abdominal cramps
•   Nausea
•   Vomiting
•   Dehydration
     GASTROENTERITIS
          (cont.)
•   E. coli
•   Shigella spp.
•   Salmonella spp.
•   Campylobacter spp.
•   Staphylococcus aureus
•   Rotavirus
•   Norwalk virus (Noro virus)
    Routes of exposure to
     enteric pathogens
• Fecal contamination (human/animal)
  –Food
  –Water
  –Fomites (doorknobs, telephones)
  –Direct contact
Petting zoos
Non-traditional pets
Pest animals
Population at risk
Occupational risk
   STAPHYLOCOCCAL
    FOOD POISONING
• S. aureus survives 30 min at 60o C
  (140o F)
• High salt concentration
• Skin and nasal mucosa
• Facultative anaerobes
  -Coagulase positive
    STAPHYLOCOCCAL
     FOOD POISONING
          (cont.)
• Temperature abuse
  –Food let to cool slowly
  –Organisms grow producing toxin
  STAPHYLOCOCCAL
   FOOD POISONING
        (cont.)
• High risk foods
  –Custards
  –Cream pies
  –Ham
  STAPHYLOCOCCAL
FOOD POISONING (cont.)
• Toxin affects brain’s vomiting
  reflex
• Abdominal cramps
• Diarrhea
SALMONELLOSIS
  Salmonella spp.
• Gram negative rods
• Facultative anaerobe
• 2000 serovars
SALMONELLOSIS
    (cont.)
•   S. dublin
•   S. enteritidis
•   S. typhimurium
•   S. cholerasuis
    SALMONELLOSIS
        (cont.)
• Domestic animals
  –Poultry
  –Swine
  –Cattle
  –Dogs and cats
    SALMONELLOSIS
        (cont.)
• Wild animals
  –Rodents
  –reptiles
  –Terrapins (turtles)
   SALMONELLOSIS
       (cont.)
• Incubation of 12 - 36 h
• Intestinal mucosa
• Lymphatic and cardiovascular
  systems
SALMONELLOSIS
    (cont.)
•   Fever
•   Nausea
•   Abdominal pain
•   Cramps
•   Diarrhea
    SALMONELLOSIS
        (cont.)
• Mortality among infants and the
  elderly
• Many shed Salmonella for 6
  months
• Many animals are chronic carriers
    SALMONELLOSIS
        (cont.)
• Treatment
  –Rehydration
  –Antibiotics prolong carrier state
    and increase resistance
TYPHOID FEVER
• Salmonella typhi
   –Rare in animals!
• Incubation
   –2 weeks
TYPHOID FEVER (cont.)
  • High fever (104o F)
  • Continual headache
  • Constipation more common
    than diarrhea
  • 10% fatality rate
TYPHOID FEVER (cont.)
• Many recovered patients become
  carriers (Typhoid Mary)
• Obligatory case report in most
  states and countries
• Lifelong immunity
TYPHOID FEVER (cont.)
• Treatment
  –Cephalosporins
  –Chloramphenicol
  –Amoxillin
Shigellosis
       SHIGELLOSIS
     (Bacillary dysentery)
• Shigella spp.
• Gram negative facultative anaerobic
  rod
• Only infects humans
• Low infectious dose
   –Resistant to low stomach pH
    SHIGELLOSIS (cont.)
• S. sonnei
  – Most common in the USA
  – Least severe
• S. dysenteriae
  –Uncommon in the USA
  –Most severe
   SHIGELLOSIS (cont.)
• Shiga toxin
  –Inhibits protein synthesis
  –Diarrhea with blood and mucus
   (dysentery)
    SHIGELLOSIS (cont.)
• 20,000- 25,000 cases/year
• 5 to 15 deaths
• Treatment
  –Rehydration
  –Fluoroquinolones (severe cases)
Cholera
           CHOLERA
•   Vibrio cholerae
•   Aquatic organism
•   Gram-negative rod
•   Non-invasive
    –toxin producing
Cholera epidemic
South America
1991-1994
• 1 million cases
• 9,600 deaths
       CHOLERA (cont.)
•   Enterotoxin
•   Rice-water stools
•   20 liters of liquid lost/day
•   Occasional outbreaks in Gulf coast
    (seafood)
     CHOLERA (cont.)
• 50% mortality if untreated
• 1% mortality if treated
  –Rehydration
  –Tetracycline
      Vibrio gastroenteritis
•   Vibrio parahaemolyticus
•   Salt water estuaries
•   Resembles cholera
•   Often foodborne (seafood)
E. coli
      Escherichia coli
       gastroenteritis
• Enterotoxigenic E. coli
• Enteroinvasive E. coli
• Enterohemorrhagic E. coli
    Enterotoxigenic E. coli
• Specialized fimbriae
  –Attachment
• Not invasive
• Toxins
• Severe diarrhea
   Enteroinvasive E. coli
• Specialized fimbriae
  –Attachment
• Toxins (cholera-like)
• Traveler’s diarrhea (?)
• Penetrate intestinal lining
  –Shigellosis-like dysentery
Enterohemorrhagic E. coli
• O157:H7 strain
• Foodborne (hamburgers, milk,
  apple cider)
• Verotoxins (colon bleeding)
  Enterohemorrhagic E. coli
          (cont.)
• Cattle carrier
• Hemolytic uremic syndrome
  –Blood in urine
  –Kidney failure
   Campylobacter jejuni
     gastroenteritis
• Gram-negative microaerophilic
  spirally curved rods
• Common in (healthy) domestic
  animals
   –May be shed in milk
• Small infectious dose
• Dysentery
        Yersinia spp.
        gastroenteritis
• Common in domestic animals
• Grows at refrigeration temperature
• Acute pain
    Clostridium perfringens
         gastroenteritis
• Gram-positive, spore-forming
  anaerobic rod
• Contaminated-cooked meat
• Temperature abuse
• Mild diarrhea
        Bacillus cereus
        gastroenteritis
• Gram-positive, spore-forming
  anaerobic rod
• Common in soil and vegetation
• Gastroenteritis is similar to Cl.
  perfringens
VIRAL GASTROENTERITIS
          ROTAVIRUS
•   Most common viral gastroenteritis
•   1,000,000 cases/year (USA)
•   100 deaths/hour
•   (developing countries)
    NORWALK VIRUS
• Common among adults
• More resistant to chlorine than
  other viruses
• No animal models or cell culture
  available

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:14
posted:9/23/2012
language:Latin
pages:74