( rhizopoda, sarcodina )

pseudopodal motility 

( mastigophora )

flagellate motility 

( ciliata )

cilia assisted motility 

( sporozoa )

gliding motility 

feeding, motile, replicating ( in human body )

fragile form of parasite in body 

passed in feces, resistant ( can survive harsh env ), infective form 

becomes cyst as poop gets desiccated (encystment)

entamoeba histolytica

amoebiasis

world wide distribution

esp in poor sanitary cond 

modes of transport:

contaminated water / food 

hand mouth

sexual

* usually ingestion

* charac by distinct nuc w/cartwheel appearance (usually 4)

intestinal flagellate

trichimonoas hominis

intestinal flagella

giardia lamblia

giardia intestinalis

giardia duodenalis

ingestion, usually in liquid 

GI pathogen, causing diarrhea

Dx: looking at cysts / trophozoids in feces

cysts in harder stool

trophozoids in watery diarrhea ( looks like a face ) 

oral flagellate

trichmonas tenax

intestinal ciliate

balantidum coli

more common in animals, less in humans 

* but see more in rural areas

ingestion of cyst in food / water

GI pathogen

Dx: cyst in feces

intestinal sporozoa 

isospora belli

cyclospora cayetanensis

cryptosporidium parvum / hominis

ingestion of oocyst 

infects intestinal epi 

2 stage life cycle; sexual ( sporogony ), asexual ( schizogony ) usually seen in 2 diff hosts, but w/this group both stages occur in host

self limiting in immunocompetent 

*w/ cryptsporidium oocysts ingested in contaminated h2o

cause diarrhea ( GI tract )

Dx: look for oocysts in feces (oocysts are acid fast)

urogenital flagellate

trichomonoas vaginalis 

worldwide occurrence

spread sexually only in trophozoid ( no cyst )

infection of UG tract

Dx: diagnose in women w/ vag smear & place slide under microscope, see trophozoid easily

amoeboflagellates

naegleria fowleri

acanthamoeba culbertsoni

balamuthia mandrillaris

have both properties, top 2 most common

primary CNS pathogen

* naegleria enters through olfactory & into CNS in 48 hrs, contracted going swimming in contaminated water, causes primary amebic meningioencephalitis Dx: by looking at CSF

* acanthamoeba enters through lower resp tract or ulcerated, broken skin causes encephalitis & skin infec / granulomas, can also get into eye via contact lenses, effects older & immunosuppressed b/c less virulent Dx: look @ CSF 

haemoflagellates 

trypansoma & leishmania ( 2 genera )

in blood, tissue, lymph, CNS 

insect borne flagellates 

amastigote ( in tissue / cells ) & trypomastigote ( in blood, seen ep in blood smear ) in humans 

other ones...promastigote & epimastigote

T. gambiense ( tsete fly W Africa ) 

T. rhodesiense ( tsete fly E Africa )

above prod african sleeping sickness, into CNS causing edema, encephalitis Dx: in CSF & blood smear

T. cruzi ( reduviid bug Americas ), Chaga's disease / mega disease

acquire by bite of fly, goes to CNS, Dx: w/ blood smear

american trypanosomiasis

chagas disease / mega disease 

vector: reduviid bug 

infec occurs when bug bites & you scratch, you infect yourself w/ scratching causing it to go into the body

found in feces 

spreads to heart & GI causes enlargement of organs

Dx: w/ biopsy ( look for amatigotes ) or done w/ xenodiagnosis ( feed clean bug to pt & look for parasite in bug )

spread by vector: phlebotomine sand fly 

3 forms of disease

1. leishmania tropica ( dermal / cutaneous form )

2. leishmania brasilinesis ( mucocutaneous form )

3. leishmania donovanii ( visceral / tissue form )

tissue sporozoa 

plasmodium spp. ( blood & tissue ) malaria

babesia spp. ( blood ) babesiosis

toxoplasma gondii ( tissue ) toxoplasmosis

sporozoa - two life cycles in two diff hosts

sexual ( sporogony ) definitive host ex malaria mosquito is definitive host

asexual ( schizogony ) int host ex malaria vertbrates 

malaria spreads by mosquito

babesiosis

 ( lyme's disease ) 

easily confused w/ malaria

spreads via tick

babesia microti

babesia divergens

toxoplasmosis

toxoplasma gondii

worldwide prevalance

int hosts: man, cattle, rodent, etc

definitive host: cat family ( domestic or wild )