fall pmmv week 1

significance

cause morbidity and mortality, gi blood tissue infections, immunocomp become susceptible, world travel, immigrants with endemic parasites, climate change

phyla

parasitic agents in single celled org (protozoa, sporozoan), multicelled org (helminth worm)

protozoan parasites

classified according to motility organelles, ameba pseudopodia, flagellates flagella, ciliates cilia, sporozoa nonmotile

prorozoa

unicellular, eularyotic, trophozoite (motile, feeding, multiply), cyst (immotile, protected by cell wall, infective for humans)

helminth cestodes (tape/seg)

elongates segmented ribbon like, hermaphroditic, various larval stages

helminth trematodes (flukes/flat)

non seg, intestines/tissues, hermaphroditic, complex life cycle- snails

helminth nematodes (round)

separate sexes, developed digestive system, humans are host, female produces fertilized eggs or larvae

egg

reproductive cell produced by worms of flukes

larvae

early immature worm stage that hatches from an egg

microfilaria

tiny baby roundworm in blood or skin

sheath

tiny cover found on some microfilaria

hexacanth larva

six hooked embryo inside certain tapeworm eggs

oocyst

cyst after sexual reproduction

scolex

the head of a tape worm with hooks and suckers

rostellum

tiny pointed nose or crown on a tapeworm head

proglottids

repeating egg making body segments of a tapeworm

hermaphrodite

animal with both male and female sex organs

brood capsule

small pocket inside a cyst making baby tapeworm heads

hydatid cyst or sand

large fluid filled cyst containing tiny loose tapeworm heads

uterine branches

egg tubes inside a tapeworm segment used to identify species

rhabditiform

first, non infective feeding stage of certain roundworm larvae

filariform

long slender, infectious second stage of roundworm larvae

miracidium

first swimming baby stage of a trematode fluke

coracidium

free swimming baby stage of specific tapeworms

cercaria

tadpole like swimming stage of a trematode fluke

schizont

cell stage that divides into many little parasites

sporogony

making infectious spores through sexual reproduction

schizogony

making many new parasites through asexual multiple splitting

merozoites

tiny new parasites made during a schizont split

gametocyte

male or female sex cell of a malaria parasite

schuffner’s dots

small brick red uniform dots of protein seen inside rbc infected with specific malaria parasites

maurer’s clefts

large coarse irregular dot structures seen inside rbcs infected with specific malaria parasites

undulating membrane

wavy fin like edge used for swimming by some flagellates

karyosome

dense dot of dna inside a nucleus

peripheral chromatin

dna chunks clustered near the edge of the nucleus

axostyle

a stiff rod running down the middle of certain flagellates

kinetoplast

a special dna mass inside the mitochondrion of specific flagellates

axoneme

core hair like thread inside a flagellum or cilium

flame cell

tiny cup shaped cell used by flatworms to remove waste

parabasal body

golgi like body next to the nucleus in some flagellates

operculum

cover or lid on the end of certain fluke eggs

abopercular knob

small bump or hook like point on the opposute end of the operculum on an egg, hatch point

shoulder

small ridge where the operculum meets the egg shell

corticate/mammilate

rough bumpy outer coating on a roundworm egg

definitive host

org where parasite matures and reproduces sexually

intermediate host

temp org where parasite grows into immuature or larval stage, or reproduces asexually

accidental host

org not normal or preferred host

adult

location of parasite stage in human host

diagnostic stage

how parasite leaves the human (in feces)

risk factors

political/social climate, behavorial patterns, immunocomp (AIDS, transplant, lymohoma, cancers)

fecal collection

series of 3 collections a day or 2 apart eithin 10 days, time cinsuming labor intens

pooling 3 formalin preserved spec yields the same recovery rate, saves time, could miss small number para

exam 2 or 3 if 1st is neg and pt is symptomatic

alt specimen collection

place on waxed paped or newspaper transfer to container (not bedpans or toilet), disposable collection container (hat)

fecal preservatives

3:1 preservative to feces

polyvinyl alc

permanently stained smear, DNA-PCR

10% formalin

formalin-ethyl acetate concentration, direct wet mount, immunoassays

sodium acetate-acetic acid formalin

permanently stained smears and concentration

merthiolate-iodine-formalin

concentration and dorect wet mount

single vial systems

concentration, direct we mount, permanently stained smears, and immunoassays

interfering subs

Barium/Bismuth, Mineral Oil/Castor Oil, Abx- Anti-Diarrheal drugs, Metamucil, pseudoparasites, water, tp, urine

macroscopic exam

unpreserved stool checking for intact worms, proglottids on the surface, blood, mucus; liquid soft formed specimen

liquid stool

examine within 30 min to detect motile trophozoites forms

formed stool

examine within 2-3 hrs if rt, 24hrs if 4 C

sedimentation concentration tech

formalin-ethyl acetate FES method, recover all ova cysts and larvae, not trophozoite forms

zinc sulfate flotation concentration tech

preserves delicate protozoan cysts, distorts them slightly, not heavy eggs

direct wet mount

saline and/or iodine for motility and structure, battlement, note parasitic and artifact forms

ocular micrometer calibration

measures structures aiding in parasite ID

permanent staining techs

wheatleys trichrome stain (fresh fixed stool or PVA preserved, intestinal protozoa) and iron hematoxylin stain (SAF preserved)

cellophane tape prep

pinworms (enterobius vermicularis), tape against butthole before child wakes then place on slide

agar plate culture

strongyloides stercoralis, tiny track

entero test

duodenal aspirates, looks for eggs of fasciola hepatica and clonorchis sinensis, recover oocysts of cryptosporidium and C. belli

urine sediment is screened for

schistosoma haematobium eggs, E. vermicularis eggs, trichomonas vaginalis trophozoites

vaginal wet preps or urethral dischrage screens for

trichomonas vaginalis trophozoites

sputum screens for

Strongyloides stercoralis, Ascaris lumbricoides, Hookworm, Paragonimus westermani

lower resp tract screens for

Entamoeba histolytica, Cryptosporidium oocysts, Microsporidia

calcofluor white staining

Microsporidia, Acanthamoeba, Naegleria, Balamuthia

auramine O

Cryptosporidium, Cystoisospora belli, Toxoplasma

modified acid-fast stain

Cryptosporidium, Cystoisospora, and Cyclospora

giemsa stain

Thick and thin blood smear preparation for malaria parasites

whole blood smears vs buffy coat

finger stick, EDTA, Plasmodium, Babesia, Trypanosoma, some microfilaria

Leishmania, Toxoplasma gondii

blood ID procedure thick film

no fix needed, Giemsa stain (releases hgb by lysing rbcs, visible- wbc plt parasites)

blood ID procedure thin film

methanol fixed, Giemsa stain (treat like a diff), parasitemia (percentage of erythocytes paracited), count 500+ rbcs

parasitemia calculation

# of infected rbcs / total # of rbcs counted x100= % of infected rbcs

CSF tests for

amebic meningitis, sleeping sickness, trypomastigote, naegleria fowleri (culture with e. coli, look for thin tracks)

biopsy

histology area, tissue sections stained and examined, Trichinella spiralis, Toxoplasma gondii

tissue parasites stimulate

ab production

enzyme immunoassays EIA

ag detection kits instead of microscopic, Giardia duodenalis, Cryptosporidium, Entamoeba histolytica, Entamoeba dispar, Plasmodium spp

fluorescent ab techs (direct DFA)

Cryptosporidium, Giardia duodenalis, Malarial organisms – Acridine orange

Toxoplasmosis and Entamoeba histolytica tests

commerically immunoassays

molecular testing

PCR and real time PCR, multiplex PCR, rapid no processing, if neg and symptomatic pt investigate

micrometer calibration

stage micrometer- 0.1 mm line ruled in 0.01-mm units

ocular micrometer- ruled in 100 units but has no values