Typhoid Fever

有遇到病患,看完書先作筆記…

Introduction

1.
Characterized by Fever and Abdominal pain

2.
Samonella typhi or Samonella paratyphi

  1. Intially
    called typhoid fever, because similar clinical similarity to typhus

  2. Assoication
    with enlarged Peyer's patches and mesenteric lymh nodes

  3. Enteric
    fever was proposed according to the anatomic site of infection

Epidermiology

  1. S. typhi and S. paratyphi have no unknown host other than humans

  2. transmitted
    only through close contact

  3. Most
    cases result from ingestion of contaminated food or water.

  4. 13~17
    milioncases worldwide resulting in ~6000,000 deaths per year

  5. Children
    <1 year of age appear to most susceptible

  6. Endemic
    in developing regions

  7. Many
    S. typhi strains contain plasmids encoding resistance to
    chloamphenicol, ampicillin and trimethoprim

Clinical
Course

  1. Fever
    and abdominal pain are variable

  2. Fever>75%
    of cases, abdominal pain:20~40%

  3. Incubation
    period for S. typhi: 3~21days

  4. Prolonged
    fever
    (38.8~40.5) is the most prominent symptom of this systemic
    infection

  5. Prodrome
    nonspecific syndrome: chills, headache, anorexia, cough, weakness,
    sore throat, dizziness and muscle pain

  6. Patient
    can present with wither diarrhea or constipation.

  7. Abdominal
    pain: tenderness(+)

  8. Early
    Physical findings:

    (1)rash(rose
    spot)
    : faint, salmon-colored, blanching, macuopapular rash,
    primarily in trunk and chest. The rash is evident in ~30% of
    patients at the end of the week and resolves after 2 to 5 d.

    (2)hepatmegaly,
    epistaxis

    (3)Relatively
    bradycardia

    (4)Neuropsychiatric
    symptoms: muttering delirium or coma vigil

  9. Late
    complication: 3~4 weeks of infection in untreated adults, include
    intestinal perforation and/or gastrointestinal hemorrhage

  10. 1~5%
    of patients bacome longterm asymtomatic

  11. Chronic
    carrier in either urine or stool > 1year is higher among women
    and biliary abnormalities

Diagnosis

1.Majority
of cases, the white blood cell count is normal. 15~25% of cases,
leukopenia and neutropenia

2.Nonspecific
lab finding: elevated liver function test(GOT/GPT, LDH, alkaline
phosphatase)

3.EKG:
non specific ST and T abnormalities

4.Good
Standard: culture of S. typhi

(1)Blood
culture: 90% positive during the 1st wk–>50% by the
3rd week

(2)Culture
of stool, urine, rose spots, bone marrow, and gastric or intestinal
secretions

(3)Bone
marrow
culture remain highly(90%) sesitive depsite

(4)Stool
culture: 60~70% negative during the 1st week; become
positive in 3rd week in untreated patients

(5)Widal
test

Treatment:

  1. Chloramphenicol,
    ampicilin, trimethoprim, streptomycin, sulfonamides and tetracycline
    have resistance

  2. Plasmid
    resistance: chloramphenicol, ampicilin and trmethoprim

  3. Susceptible
    strains

    1. Ceftriaxone
      (1~1gm IV/IM) for 10~14 days

    2. Chloranphenicol
      IV/PO

  4. Quinolones:
    only available oral antibiotics for the treatment of MDS S. Typhi

    1. Ciprofloxacin(500mg
      PO BID x 10days)

    2. Ofloxacin
      (10~15mg/kg in divided twice daily x 2~3 days)

    3. Resistance
      bacause of encoding DNA gyrase

    4. All
      strains of S. typhi must screend for resistance to nalidix acid
      resitance and tested for sensitivity to a clinically appropriate
      quinolone.

    5. High
      dose for resistance strains

  5. Chronic
    stage: oral amoxicillin, TMP-SMZ, ciprofloxacin ot norfloxacin have
    ~80% effective eradication rate

    1. anatomic
      abnormality: also reauire surgical correction