25 - Digestive Infections

  1. Symptoms – Throbbing pain, discoloration, roughness, tooth

    can break while chewing

    Causative Agent – Streptococcus mutans, colonize teeth,
    thrive in acidic conditions, produces glucans, dietary sugars

    Pathogenesis – Adherence of bacteria to receptors on teeth,
    sugar production causes drop in pH

    Epidemiology – Heredity, young more susceptible than old

    Prevention – Cut down dietary glucose

    Treatment – Removal of plaque, drilling out and filling of

    Dental Caries

  2. Symptoms – Bleeding gums, sensitivity, bad breath, Receding

    gums, loose discolored teeth

    Causative Agent – Dental Plaque

    Pathogenesis – Plaque/Tartar forms at gum line, gets into
    gingival crevice, causes inflammation

    Epidemiology – 90% of those over 65, people with underlying immunodeficiency

    Prevention – Brushing, cleaning flossing

    Treatment – Cleaning out inflamed gingival crevice and
    removing plaque

    Periodontal Disease

  3. Symptoms – Bleeding/swollen gums, foul odor, rapid onset, fever

    Causative Agent – Treponema genus, spirochete

    Pathogenesis – Bacterial invasion causes necrosis and

    Epidemiology – Stress, malnutrition, immunodeficiency

    Prevention – Brushing and flossing

    Treatment – antibacterial

    Trench Mouth

  4. Symptoms - Belching, vomiting, abdominal pain, bleeding,


    Causative Agent – Heliobacter pylori, short, spiral, gram
    negative microaerophile with multiple flagella

    Pathogenesis – Able to neutralize acidity of stomach, uses
    flagella to corkscrew through stomach lining

    Epidemiology – fecal-oral route, clusters in families, poor
    people most susceptible

    Prevention – No prevention

    Treatment – Antibiotics


  5. Symptoms – blisters, ulcers in mouth, fever

    Causative Agent – Herpes simplex virus, medium sized, double
    stranded enveloped, type 1 or 2

    Pathogenesis – Blisters contain large numbers of virons,
    stress can precipitate recurrances

    Epidemiology – Wide spread, transmitted by close physical

    Prevention – close physical contact

    Treatment – Antivirals

    Herpes Simplex

  6. Symptoms – fever, headache, swelling of parotid glands,

    spasms, usually disappears within a week, symptoms more severe in people past
    puberty, can effect ovaries, testes, pregnancies often miscarry

    Causative Agent – Mumps virus, paramyxovirus family,
    enveloped, single stranded DNA

    Pathogenesis – respiratory droplets, incubation 15 – 20 days,

    Epidemiology – Humans only natural host, lifetime immunity,
    contagious 1 week before and 2 weeks after symptoms

    Prevention – Immunization

    Treatment – None


  7. Symptoms – Severe diarrhea, can lose 20 liters of fluid a day

    Causative agent – Vibrio cholerae, gram negative, curved bacillus

    Pathogenesis – Large numbers must be present, B fragment no toxicity, A fragment toxic

    Epidemiology – Fecal contamination of water

    Prevention – Clean water

    Treatment – rapid replacement of water


  8. Symptoms – dysentery, headache, stiff neck, vomiting,

    convulsions, joint pain

    Causative Agents - S. flexnuri , S. boydii , S. sonnei , S.

    Pathogenesis – Begins in large intestine, cells multiply at
    high rate, nonmotile, dead cell slough off, lots of blood and pus

    Epidemiology – fecal oral, low infecting dose, day cares and
    gay men

    Prevention – Sanitation

    Treatment – Fluid and electrolyte replacement,


  9. Symptoms – vomiting, loose stools, cramps, diarrhea, blood

    stool, usually lasts 10 days

    Causative Agent – E. coli, 4 types

    Pathogenesis – enterotoxin, adheres to cells in small

    Epidemiology – Person to person, contaminated food and water

    Prevention – hand washing, proper preparation of food and

    Treatment – replace fluids and electrolytes, antibiotics for
    infants, Pepto


  10. Symptoms – diarrhea, abdominal pain, nausea, vomiting, fever

    Causative Agent – Salmonella, motile, gram negative,

    Pathogenesis – large number required for infection, adhere
    to receptors on small intestine

    Epidemiology – Most cases have animal source, bacteria can
    survive a long time in environment, children most often infected

    Prevention – Adequate cooking, tracing outbreak of

    Treatment – vaccine, surgical removal of gall bladder


  11. Symptoms – fever, vomiting, diarrhea, dysentery

    Causative agents – campylobacteria jejuni, motile, gram
    negative, curved bacillus

    Pathogenesis – small infecting dose, causes inflammation,
    guillen barre syndrome

    Epidemiology – food and waterborn outbreaks, usually live in
    animal intestines,

    Prevention – proper treatment of water and food

    Treatment –subside on its own, severe cases, erythromycin


  12. Symptoms – vomiting, diarrhea, profuse water diarrhea,

    generally gone within a week

    Causative agents – Rotovirus, double walled capsid, double
    walled dna

    Pathogenesis – infects cells of upper small intestine,
    decreased production of enzymes

    Epidemiology – fecal oral route, childhood epidemics occur
    in winter

    Prevention – handwashing, disinfectant, attenuated vaccine

    Treatment – none

    Rotoviral Gastroenteritis

  13. Symptoms – nausea, vomiting, diarrhea, symptoms go away 12 –

    60 hours

    Causative agents – Norovirus, small, nonenveloped, single
    stranded RNA

    Pathogenesis – infects upper small intestine

    Epidemiology – fecal/oral route, incubation 12 to 48 hours

    Prevention – handwashing/disinfectants

    Treatment – none


  14. Symptoms – fatigue, fever, loss of appetite, nausea, right

    side abdominal pain, dark urine, clay feces, jaundice, children less than 6
    years asymptomatic

    Causative agent – Hepatitis A virus, small, single stranded

    Pathogenesis – contaminated food or water, reaches liver,
    released into bile

    Epidemiology – fecal oral, restaurants, shell fish, daycare,
    nursing homes, homos

    Prevention – vaccine

    Treatment – Gamma globulin within 2 weeks of exposure

    Hep A

  15. Symtoms – SEVER fatigue, fever, loss of appetite, nausea,

    abdominal pain, dark urine, jaundice, formerly known as serum hepatitis

    Causative agent – hepatitis B virus, enveloped, double
    stranded DNA

    Pathogenesis -
    carried in liver, replicates via reverse transcriptase

    Epidemiology – Needles, toothbrushes, sex

    Prevention – Vaccine, passive immunization

    Treatment – none

    Hep B

  16. Symptoms – milder than hep A and B

    Causative agent – hepatitis C virus, enveloped, single
    stranded RNA, flavivirus family

    Pathogenesis – infected blood, 6 week incubation

    Epidemiology – needles, syringes, tattooing,

    Prevention – no vaccine

    Treatment – avoid alcohol, no treatment

    Hep C

  17. Symptoms – ingestion, nausea, vomiting, explosive diarrhea,

    disappear within 4 weeks

    Causative Agent – Giardia Lambdia, flagellated, pear shaped,
    2 sided nuclei, can exist in 2 forms

    Pathogenesis – cyst responsible for infection, attach to
    epithelium of small intestine and move to large intestine

    Epidemiology – single stool can carry 300 million cysts,
    cysts can live in cold water up to 2 months, chlorination often ineffective,
    fecal oral route, oral/anal sex

    Prevention – Filtration of water

    Treatment - Flagyl

Card Set
25 - Digestive Infections
25 - Digestive Infections