Focus on pathogens: G' lamblia pathology clinical symptoms

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Focus on pathogens G. lamblia pathology /
clinical symptoms

• Intestinal trophs attach to the mucosa via
  ventral suckers which results in an increased
  turnover of mature intestinal epithelial cells.
  Mature cells are replaced by immature intestinal
  cells. Advanced infection also results in
  covering of the mucosal cells by trophs. The
  result is a reduced ability to digest and absorb
  fats and fat-soluble vitamins. Resulting
  symptoms include foul-smelling, bulky, acute
  explosive diarrhea, steatorrhea (fatty), cramps
  which are severe at times, bloating, fatigue
  weight loss. The lack of mucus and blood (vs
  Entamoeba) in the diarrhea is clinically
  significant. Infection does not seem to be
  invasive.

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Focus on pathogens G. lamblia diagnosis/ID

• Diagnostic features of trophs in wet mounts
  permanent stain
• Motility resembles a falling leaf, but is
  active. Motile via 4 lateral, 2 ventral
  2 caudal flagella (tail).
• Shape pear-shaped from top
• spoon-shaped from side
• Size 10-20uM long x 5-15uM wide
• Nuclei 2 bi-laterally symetrical difficult to
  see in wet prep
• Other
• 2 large anteriorly located suction discs
  can result in a mustache appearance - hard to
  see
• dark supporting transverse rod axostyle
  or axomene
• Overall, a very distinctive appearance

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G. lamblia trophs
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Focus on pathogens G. lamblia diagnosis / ID

• Diagnostic features of cysts in wet mounts
  permanent stain
• Size 8-12uM oval
• Nuclei 2-4 at one end
• Wavy or s shaped fibrils remains of axostyle
• Smooth, well defined cyst wall cytoplasm may
  appear to be retracted from wall

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G. lamblia cysts
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Focus on pathogen Trichomonas vaginalis

• Facts / life-cycle T. vaginalis colonizes the
  genitourinary tract of women and rarely of men
  usually assymptomatic. Infection occurs
  primarily via sexual contact, although other
  means of transmission are possible, especially in
  females (etc. damp wash cloth or other
  potentially life-supporting substrate). Simplest
  possible life-cycle the organism does not encyst
  (the troph is the only form) and divides by
  simple binary fission which is favored by pH gt
  5.9 (normal vaginal pH is 3.5 to 4.5). There is
  no non-human reservoir.

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Focus on pathogen Trichomonas vaginalis

• Epidemiology T. vaginalis has a worldwide
  distribution with 1-2 x 108 cases, mostly in
  urban areas or institutions. As much as 70 of
  female prostitutes and female prison inmates are
  thought to be infected in some areas. Prevalence
  is thought to be 3-5 of all females in N.
  America. It often co-infects with other STDs,
  including HIV, and may synergistically increase
  HIV shedding. Infection is often overlooked due
  its mild clinical presentation, and frequent
  concurrent STD infections giving a mixed clinical
  picture. Underdiagnosis is estimated at 50 or
  more. T. vaginalis may persist in a host for 2
  years if untreated. Both males and females can
  transmit the organism. All of these facts
  exacerbate prevalence of infection.

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Focus on pathogen T. vaginalis pathology /
clinical symptoms

• Trichomoniasis is an STD, rarely affecting men.
  It is often asymptomatic in women, but heavy
  infections in a higher than normal pH environment
  result in vaginitis, with prurity and copious
  foul-smelling, green-yellow, sometimes frothy
  discharge. Numerous small hemorrhagic cervical
  lesions may be present (strawberry cervix).
  Frequency of urination can change and painful
  urination is common. Chronic infection can
  result in infertility. Infection during
  pregnancy greatly increases chances of pre-term
  delivery and other complications. The mechanism
  of pathology is not understood.
• Although rare, severe infections in men can
  result in prostate damage and urethral stricture.

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Focus on pathogen T. vaginalis diagnosis/ID

• Laboratory diagnosis
• Transport to lab within 30 minutes of collection
  because T. vaginalis dies quickly outside the
  body
• Characteristic trophs in wet mounts of specimens
  (vaginal and urethral discharges in females and
  prostatic fluid in males)
• Best chance of collecting cells in vaginal sample
  is during ovulation.
• Can be seen as incidental finding in urine
  sediment
• Does not stain well with usual protozoan stains
  Giemsa is often used