Parasitology Exam 3: Microfilariae Flashcards
What are microfilaria?
Roundworms (nematodes) that infect blood/tissue in humans
How are microfilaria transmitted?
Blood-sucking arthropod vector (mosquito, midge, fly)
How are microfilaria identified?
Morphology of microfilaria, define circadian rhythm, and location within human host
What are the blood and tissue microfilaria that infect humans?
W. bancrofti
B. malayi
Loa loa
O. volvulus
Mansonella spp.
Dirofilaria spp.
How is Wuchereria bancrofti transmitted?
Via mosquito bite from Anopheles, Aedes, or Culex fatigans
Morphology of Wuchereria bancrofti adult worm
Has a sheath
NO nuclei present in end of tail
What is the most commonly identified species of filarial worms that infects humans?
W. bancrofti
What disease does W. bancrofti cause?
Bancroftian filariasis and elephantiasis including hydrocele, chyluria, tropical pulmonary eosinophilia
What is hydrocele?
Fluid-filled sac within the scrotum
What is chyluria?
Milky white urine due to obstruction of lymphatic vessels
What is an endosymbiont?
Bacteria (Wolbachia) required for larval development of certain microfilaria (W. bancrofti, Brugia spp., and Onchocerca volvulus)
Wolbachi
Endosymbiont, obligate intracellular organism
What is Knott concentration?
Used to recover small numbers of microfilaria in the blood, centrifugation is used to concentrate organisms onto a slide
Describe the morphology of Brugia malayi
Has a sheath that stains BRIGHT PINK
2 terminal nuclei in tail
How is Brugia malayi transmitted?
Mosquito (Anopheles or Mansonia)