Parasitology Flashcards
Microfilariae: sheath, no nuclei in tip of tail
Wucheria Bancrofti
transmission: mosquitos
Lymphedema, elephantiasis involving LE, scrotum
pulmonary tropical eosinophilia syndrome (nocturnal cough and wheezing, fever, eosinophilia)
Microfilaria: sheath space between terminal and subterminal nuclei
Brugia malayi
transmission: mosquitos
Lymphedema but not involving scrotum
Microfilaria: sheath, continuous row of nuclei in the tail
Loa Loa
transmission: mango fly (chysops)
calabrar swellings (episodic angioedema)
subconjunctival migration of adult worms
Microfilaria: no sheath, continous row of nuclei in tail
Mansonella perstans
transmission biting midge (culicoides)
angioedema, pruritis, fever, HA, athralgias, neurologic sx
Microfilaria: unsheathed, nuclei do not extend to tip of tail
Onchocerca volvulus
Transmission: black fly
pruritis, dermatitis, onchocercomata (subQ nodules), LAD
River blindness (ocular lesions)
Dirofilaria immitis
transmitted by mosquitos. infects dogs and humans.
causes pulm dx in humans esp. coin shaped infarcts from dead microfilaria
micro: cuticle, musculature and lateral cords
How many stool specimens for O&P should be submitted?
3 samples on 3 seprate days
10% formula as stool preservative
oAll purpose, easy preparation, long shelf life
oUsed to prepare concentrated wet mount
oGood for helminth eggs and larvae, protozoan cysts, Coccidia oocysts, and Microsporidium spores
oCompatible with immunoassays (e.g. Giardia and Cryptosporidium EIA)
oCons: not good for trichrome, interferes with PCR
Polyvinyl alcohol (PVA) as stool preservative
oLong shelf life (months to years), allows specimens to be shipped to any lab for subsequent evaluation
oUsed to prepare permanent trichrome stain
oGood for preservation of protozoan trophozoite/cyst morphology
oCons: not good for helminth eggs and larvae, Coccidia, and Microsporidia; cannot be used with immunoassay
What does the cellophane tape test detect? how many negatives to r/o infection
Detects pinworm/enterobius vermicularis
How to differentiate babesia from plasmodium
babesia may be extracellular and has maltese cross
Describe the plasmodium life cycle
Plasmodium sporozoites are inoculated into humans by the Anopheles mosquito. The sporozoites infect liver cells and mature into schizonts, which rupture and release merozoites into the blood stream. The merozoites then infect red blood cells, and can either multiply asexually (progressing through trophozoite and schizont stages), or can form gametocytes which are ingested by mosquitos and then reproduce sexually to form more sporozoites.
What bug transmits babesia
deer tick (ixodes)
Give the variable sizes of cryptosporidium, cyclospora,, cytoisospora, and microsporidium
Largest cytoisospora (20-30 uM “eye of sauron”)
cyclospora 8-10 um
cryptosporidium 4-6 uM
microsporidium 1.5-5 uM
*all are detected with auramine-O and modified acid fast except microsporidium is detected by calcofluour white and modified trichrome
Which Helminths can cause Loeffler’s syndrome
soil-skin penetrators: strongyloides hookworms (necator and ancylostoma) Oro-fecal transmission of eggs: Ascaris (-->eggs hatch in gut, larvae penetrate gut then make way to lungs, cough and swallow)
