Generalities of Parasitology

• Parasitology


  Study of parasites, that live on & obtain their nutrients from another organism
• Medical parasitology


  Concerned primarily with parasites of humans & their medical significance, as well as their importance in human communities

  
• Tropical medicine


  Branch of medicine which deals with tropical diseases & other special medical problems of tropical regions
• Tropical disease


  Illness, which is indigenous to or endemic in a tropical area; may also occur in sporadic or endemic proportions in areas that are not tropical
• Biological relationships


  • Symbiosis
  • Commensalism
  • Mutualism
  • Parasitism

  
• Symbiosis


  Living together of unlike organisms; the association of two living organisms, each of a different species : when broken apart life will be impossible

  
• Commensalism


  Two species live together & one species benefits from the relationship without harming or benefiting the other
• Mutualism


  Two organisms mutually benefit from each other :when broken apart, life will still be possible
• Parasitism


  Association of two different species of organisms that is beneficial to one at the other's expense.; one organism (parasite), lives in or on another, depending on the latter for its survival and usually at the expense of the host
• Parasites according to habitat

  • Ectoparasite
  • Endoparasite
  • Erratic
  • Coprophilic
  • Hematozoic
  • Cytozoic
  • Coelozoic
  • Enterozoic
• Ectoparasite


  Living outside the body or invasion on the body ; infestation
• Endoparasite


  Living inside the body or invasion in the body; infection
• Erratic


  When it is found in an organ which is not its usual habitat
• Coprophilic


  Usually protozoans, able to multiply in fecal matter outside human body
• Hematozoic


  Lives inside the red blood cells
• Cytozoic


  Living inside cells or tissues
• Coelozoic


  Living in body cavities
• Enterozoic


  Parasite residing in intestines
• Parasites according to parasite-host relationship

  • Obligate
  • Facultative
  • Intermittent
  • Spurious
  • Opportunistic
  • Accidental/incidental
  • Permanent
  • Temporary
• Obligate


  Need a host at some stage of their life cycle to complete their development & propagate their species; cannot survive without its own host
• Facultative


  Capable of existing independently of a host ; free living
• Intermittent


  Visit host during feeding time only
• Spurious


  Transient stay in the host; free-living organism that passes through the digestive tract without infecting the host
• Opportunistic


  Infects individual with underlying diseases
• Accidental/incidental


  Establishes itself on a host in which it does not normally lives
• Permanent


  Remains on or in the body of the host for its entire life
• Temporary


  Lives on the host only for a short period of time
• Parasites according to pathogenicity

  • Pathogenic
  • Non-pathogenic
• Pathogenic


  Depends upon the host for its nutrients & causes harm to its host
• Non-pathogenic


  Host & parasite live in harmony with each other
• Parasites according to transmission

  • Soil transmitted
  • Arthropod/Vector transmitted
  • Food-borne
  • Water-borne
  • Direct contact
• Food-borne transmission


  • Taenia solium (pork)
  • Taenia saginata (beef)
  • Diphyllobothrium latum (fish)
• Water-borne transmission


  • Entamoeba histolytica
  • Giardia lamblia
• Ingesting raw or improperly cooked freshwater fish

  • Clonorchis, Opistorchis, Haplorchis
• Skin penetration


  • Hookworms & strongyloides (via soil)
  • Schistosomes (via water)
• Insect vectors


  • Malaria, Filariasis, Leishmaniasis, Trypanosomiasis, Babesiosis
• Congenital transmission


  • Toxoplasma
• Mother's milk/transmammary transmission


  • Ancylostoma, Strongyloides
• Airborne transmission


  • Enterobius
• Sexual intercourse transmission


  • Trichomonas vaginalis