Microfilariae Flashcards Preview

Med Lab Tech Fall 2016 > Microfilariae > Flashcards

Flashcards in Microfilariae Deck (61)
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1

›group of blood/tissue roundworms

›require an arthropod intermediate host/vector for transmission

› mosquito or blood-sucking fly

fertilized adult females live in tissue

Filariae

2

Filariae include

› Wuchereria bancrofti

› Brugia malayi

› Loa loa

› Onchocerca volvulus

› Mansonella spp.

3

›  Embryonic stage

›  Produced in tissues by females

›  Migrate to lymphatics, blood or skin

›  Develop into adults

› maturation can take up to 1 year

Microfilariae

4

›periodicity

When a parasite appears during certain times of the day. 

 

›more prevalent in peripheral blood at specific times of day or evening

›times appear to coincide with the usual feeding patterns of intermediate host

›nocturnal

› nighttime

›diurnal

› daytime

5

›Modified Knott Technique

› mix 1 mL of whole blood w/ 10 ml  of 2% formalin

› spin 1 min @ 500g

› make thick smears from sediment

6

Microfilariae ›Key characteristics for identification

›distribution of nuclei within tip

›presence/absence of a sheath

7

Pathogenesis of Filariae

›Granulomatous lesions

›Eosinophilia

›Fever/chills

›Elephantiasis

› obstruction of lymphatic circulation

› enlargement of legs, breasts, scrotum

›Calabar swellings

› swelling of subcutaneous tissue

8

Pointed tail

sheathed

no nuclei in tip of tail

Wuchereria bancrofti microfilariae

9

Sheathed

2 nuclei in tip of tail

Brugia malayi

10

Sporozoans include

› Plasmodium

› Babesia

› Cryptosporidium

› Pneumocystis

› Toxoplasma

› Isospora

› Sarcocystis

11

›Causative agents for malaria

› P. falciparum (most dangerous)

› P. vivax

› P. ovale

› P. malariae

12

Clinical Presentation

›Intervals between periods of fever caused by release of __________ from RBCs is identical for given species

merozoites

13

_______ ›are mature at night when     mosquitos feed

gametocytes

14

Sporozoan lab diagnosis criteria

›Giemsa-stained peripheral blood smears examined under oil immersion

› thick smears (screening)

› thin smears (differentiation)

›Timing of blood collection is critical

› greatest # in-between paroxyms

15

›Crescent shaped gametocytes

Plasmodium falciparum

16

›Most dangerous form of malaria

Plasmodium falciparum

17

P. falciparum ring-form trophozoites

18

P. falciparum gametocyte

19

Plasmodium falciparum

20

›May contain Schuffner’s dots

› eosinophilic stippling

Plasmodium vivax

21

›Infects young,immature RBCs

› enlarged and distorted

Plasmodium vivax

22

P. vivax trophozoite

23

P. vivax immature schizont

24

P. vivax macrogametocyte

25

P. vivax microgametocyte

26

Plasmodium vivax troph

27

› Infects young, immature RBCs

› oval and enlarged RBCs

› usually contain Schuffner’s dots

Plasmodium ovale

28

›may contain Ziemann’s dots

› fine, dust-like dots

Plasmodium malariae

29

›6-12 merozoites in rosette form

Plasmodium malariae

30

P. malariae schizont