micropara

• Symbiosis

  Relationship between different organisms
• Types of symbiosis

  • Commensalism - No benefit nor harm (host)
  • Mutualism - Mutual benefit
  • Parasitism - Harm on host
• Classification of parasites based on habitat

  • Ectoparasites - Outside, infestation
  • Endoparasites - Inside, infection
• Classification of parasites based on dependency

  • Obligate - Needs host to complete life cycle
  • Facultative - Can live without a host
• Classification of parasites based on mode of living

  • Permanent - Remain inside from early life to maturity
  • Intermittent - Invades during feeding time
  • Incidental - Unusual host
  • Transitory - Uses host only for development
  • Erratic - Unusual invasion site
• Types of hosts

  • Definitive - Harbors the adult/sexual stage
  • Intermediate - Harbors larval/asexual stage
  • Reservoir - Harbors parasite as carrier, may act as additional source of infection
  • Paratenic - Means of transport
• Source of exposure

  Most common is soil
• Mode of transmission

  Most common Fecal-oral route
• Portal of exit

  Most common is Anus
• Pathogenicity

  Dynamics of disease process
• Classification of parasites

  • Protozoa - Single celled
  • Metazoa (helminths) - Multi celled
• Classification of protozoa based on motility

  • Amoeba - Pseudopods (crawling)
  • Flagellates - Flagella (crawling)
  • Sporozoa - No motility organ (gliding)
  • Ciliates - Cilia
• Classification of helminths based on shape and structure

  • Nematodes (roundworms)
  • Platyhelminthes

  1. Trematodes (Flukes)
  2. Cestodes (Tapeworms)
• ENTAMOEBA HISTOLYTICA

  Classic flask shaped ulcer on Cecum & Colon
• Infective stage (IS) of Entamoeba histolytica

  Cyst
• Pathogenic stage (PS) of Entamoeba histolytica

  Trophozoite
• Mode of transmission (MOT) of Entamoeba histolytica

  Fecal-oral (contaminated water/food), Sexual transmission
• Pathogenesis of Entamoeba histolytica

  • Amoebic Dysentery - Bloody mucoid stool
  • Amoeboma - Mass inside cecum
  • Extraintestinal - Amoebic liver abscess, Amoebic pneumonitis
• Diagnosis of Entamoeba histolytica

  Direct Fecal smear - Loose watery (Trophozoite), Formed (Cyst)
• Treatment of Entamoeba histolytica

  Drug of choice - Metronidazole, Alternative - Tinidazole
• GIARDIA LAMBLIA

  Trophozoite has a Old man facies with sucking disc, Falling leaf motility
• Infective stage (IS) of Giardia lamblia


  Cyst
• Pathogenic stage (PS) of Giardia lamblia

  Trophozoite
• Mode of transmission (MOT) of Giardia lamblia

  Fecal-oral (contaminated water), Sexual transmission
• Pathogenesis of Giardiasis

  Traveler's diarrhea
• Diagnosis of Giardia lamblia

  Direct Fecal Smear - Cyst & Trophozoite, String test - Alternative
• Treatment of Giardia lamblia

  Metronidazole, Tinidazole, Nitazoxanide
• Trichomonas vaginalis


  Only protozoa with no Cyst stage
• Infective/Pathogenic stage (IS/PS) of Trichomonas vaginalis

  Trophozoite
• Mode of transmission (MOT) of Trichomonas vaginalis

  Sexual transmission, Vertical transmission
• Pathogenesis of Trichomoniasis

  Vaginal mucosa in women, Prostate & Urethra in men, Strawberry cervix with watery to foul greenish yellow discharge
• Diagnosis of Trichomonas vaginalis

  Wet mount (Vaginal, urethral, prostatic discharge and/or urine sample)
• Treatment of Trichomonas vaginalis

  Metronidazole
• Balantidium coli

  Largest protozoa, Cytostome - Primitive mouth & with boring motility
• Infective stage (IS) of Balantidium coli

  Cyst
• Pathogenic stage (PS) of Balantidium coli

  Trophozoite
• Reservoir of Balantidium coli

  Pig/monkey
• Mode of transmission (MOT) of Balantidium coli

  Fecal-oral (contaminated water/food)
• Pathogenesis of Balantidiasis

  Same manifestation with E. histolytica but without extraintestinal invasion
• Diagnosis of Balantidium coli

  Direct Fecal Smear