Food and Waterborne Diseases

Oral Cavity:

  • Dental caries: tooth decay

  • Gingivitis: inflammation of gums

  • Infective endocarditis: inflammation of the inner tissue of the heart

    • Subacute bacterial endocarditis (SBE): due to streptococci w/ slow progression

    • Acute Bacterial endocarditis (ABE): likely due to staphylococcus aureus w/ rapid onset

Classification of water/foodborne diseases

  • intoxication: toxins/poisons ingested

  • infection: LIVE bacteria ingested and grow w/i body

    • toxins produced w/i body

  • incubation: hours-days before sx onset

    • pass from stomach to intestine

  • general sx: diarrhea, abd cramping, vomiting, nausea

  • contamination: improper food prep, water contamination, fecal-oral route, cross-contamination

Non-Inflammatory Gastroenteritis

  1. typically caused by enterotoxin or intoxication

  2. staphylococcal food poisoning

    • enterotoxigenic Staphylococcus aureus

    • produces enterotoxin A-E

      • heat stable (cannot destroy)

  3. Clostridial food poisoning

    • Clostridium perfringens

  4. Bacillus cerus food poisoning

    • enterotoxin

    • emetic syndrome (extreme vomiting)

  5. Botulism

    • Clostridium Botulinum

    • exotoxin, gram positive bacilli

    • type AB neurotoxin

      • prevents release of ACh

      • flacid paralysis

    • sx: flacid paralysis in limbs/facial muscles

    • Variants of botulism:

      1. Infant botulism: contaminated honey

      2. Wound botulism: spores in soil etc. enter wound

    • tx: antitoxin

Gastrointestinal infections

  1. Inflammatory Gastroenteritis: infection of (typically) small bowel

  2. Invasive gastroenteritis: primarily in colon

Inflammatory gastroenteritis

  1. Cholera

    • Vibrio cholera

    • requires large infectious dose to colonize intestines

    • toxin: A-B toxin

      • binding allows A to enter cell

      • increases cAMP lvl in cell

    • Sx: “rice-water” stool, dehydration, hypovolemic shock

  2. Escherichia Coli

    • normal GI flora but some strains can be pathogenic

    • ETEC- Enterotoxigenic E. Coli

      • affects 20% of travelers to endemic area

    • EPEC- enteropathogenic E. Coli

      • fatal in infants

  3. Clostridium difficile

    • associated w/ abx use

    • major cause of pseudomembranous colitis

    • enterotoxin A and cytotoxin B

    • can lead to toxic megacolon

    • tx: fecal transplant (90% effective)

  4. Vibriosis

    • contaminated seafood

    • 1. vibrio parahaemolyticus

    • 2. vibrio vulnificus

      • 50% mortality rate

Invasive Gastroenteritis

  1. Typhoid fever

    • Salmonella enterica serotype typhi

    • blood infection

    • acid resistant

    • sx: diarrhea, hemorrhaging “rose-spots”

    • gallbladder, spleen

    • transmitted by 5 F’s (flies, food, fingers, feces, fomites)

  2. Salmonellosis

    • large dose needed for illness

  3. Shigellosis

    • bacterial dysentery

    • requires only 10-200 bacteria to cause infection

  4. Enterohemorrhagic colitis (EHEC strains)

    • STEC: shiga toxin-producing E. Coli

    • Most common strain: E. coli 0157:H7

    • can advance to hemolytic uremic syndrome (HUS)

  5. Camplyobacteriosis

    • Camplylobacter jejuni

    • Sx: “explosive, bloody diarrhea

  6. Listeriosis

    • Listeria monocytogenes

    • psychrophilic

    • commonly effects newborns and pregnant women

  7. Brucellosis

    • Brucella species

    • undulant fever in humans

    • high fever w/ daytime sweating and nighttime chills