Filarial worms

• Filarial worms are transmitted by?

  arthropod or vector
• sheathed


  with embryonic sheath
• unsheathed


  without embryonic sheath
• viviparous females gives birth to pre-larval microfilaria
• Microfilaria


  motile, snakelike with dark staining nuclei
• 4 types of periodicity

  • nocturnal
  • diurnal
  • aperiodic / non-periodic
  • subperiodic
• Nocturnal


  occurs at night
• Diurnal


  occurs during day
• Non-periodic 


  no specific time
• Subperiodic


  timing of occurrence is not clear-cut

  • subperiodic diurnal
  • subperiodic nocturnal
• Infective stage of filarial worms

  Microfilaria
• ingestion of microfilaria from blood or tissues by blood - sucking insects
• 3rd stage filariform larva


  infective stage for filarial worms
• transfer of infective larva to the skin of new host by insect bite.
• common name of Wuchereria bancrofti

  Bancroft's Filarial worm
• common name of Brugia malaya

  Malayan filarial worm
• common name of Loa loa

  african eye worm
• common name of Onchocerca volvulus

  Convoluted filaria
• common name of Mansonella perstans

  Dipetalonema perstans

  Acanthocheilonema perstans
• common name of Mansonella ozzardi

  Ozzard's filaria
• common name of Angiostrongylus cantonensis

  Rat lungworm
• common name of Toxocara canis

  Dog Ascaris
• Common name of Toxocara cati

  Cat ascaris
• common name for Dracunculus medinensis

  • Guinea worm
  • Dragon worm
  • Fiery serpent worm of the Israelites
• Wuchereria bancrofti


  • sheathed
  • nocturnal
  • no nuclei
• Brugia malayi


  • sheathed
  • nocturnal
  • 2 distinct nuclei
• Loa loa


  • sheathed
  • Diurnal
  • nuclei extending to the tip
• Onchocerca volvulus


  • unsheathed
  • non-periodic periodicity
  • no nuclei
• Mansonella perstans


  • unsheathed
  • non-periodic periodicity
  • nuclei extending to the tip
• Mansonella ozzardi


  • unsheathed
  • non-periodic periodicity
  • no nuclei
• Mansonella streptocerca


  • unsheather
  • non-periodic periodicity
  • nuclei extending to the tip
• Wuchereria bancrofti


  vector: Aedes, Anopheles minismus flavirostris
• Brugia malayi


  vector: Mansonia uniformis
• Loa loa


  vector: chrysops fly (mango fly), deer fly
• Onchocerca volvulus


  vector: simulium flies
• Mansonella spp


  vector: culicoides (biting midges)
• Wuchereria bancrofti


  causes Elephantiasis lower lymphatics
• Diagnosis for W. bancrofti, B. malayi, Loa lo, Mansonella spp.

  blood smear
• Treatment for Wuchereria bancrofti

  diethylcarbamazine
• Brugia malayi


  causes Elephantiasis Upper lymphatics