parasites

Question 1

how is infection diff from disease?

Answer 1

if you have prolonged repeated or high burden of infection you can develop disease

Question 2

traits of parasitic disease

Answer 2

many are zoonoses we get them from animals
humans are dead-end hosts (we’re not target of infections)
rarely fatal (exc: plasmodium falciparum)
usually subacute or chronic

Question 3

two types of parasites

Answer 3

protozoa

helminths

Question 4

protozoa parasite traits

Answer 4

one celled eukaryotes (ex. plasmodium, giardia cryptosporidium, leishmania, trypanosomes)
high innoculation
intracellular (in RBC or macrophages)- can’t stand dry environments
extracellular - in GI tract, cause diarrhea, can stand dry environ

Question 5

general protozoa traits

Answer 5

65,000 species
most harmless, free living
few are parasites

Question 6

characteristics of mastigophora

Answer 6

have flagella 
reprod by syngamy
lack mito/ golgi
form cysts and are free-living
solitary
axostyle 
single celled

Question 7

examples of mastigophora

Answer 7

trypanosoma 
leishmania
giardia
cryptosporidium
trichomonas

Question 8

why was it hard for people in milwaukee to rid water of cryptosporidium?

Answer 8

resistant to chlorine

v. small and hard to filter

Question 9

traits of apicomplexa

Answer 9

not fecal oral
not motile
complex life cycles
prod sporozoites after repro
most form oocysts
entire group is parasitic
single celled

Question 10

examples of apicomplexa

Answer 10

plasmodium

toxoplasma gondii

Question 11

traits of helminths

Answer 11

multicellular
roundworms, flatworms
protected by cuticle
larvae dev. into dormant cysts
complex life cycles, environmental and animal reservoirs
animals are intermediate hosts or reservoirs
humans are definitive hosts (don’t multiply in humans and cuticle prevents digestion so they only pass thru when they’re dead)

Question 12

diff btwn reservoir, intermediate and definitive host

Answer 12

definitive host = where it matures
intermediate host = carrier to definitive host
reservoir = where they multiply, source of parasite, don’t participate in direct transmission
vector = something that passes parasite

Question 13

types of helminths

Answer 13

major groups: flatworms and roundworms

flukes are helminths too

Question 14

flatworm traits

Answer 14

phylum platyhelminthes
thin
segmented
subdivistions: 
cestodes (tapeworms)
trematodes (flukes)

Question 15

roundworm traits

Answer 15

phylum aschelminthes
aka nematodes
cylindrical 
unsegmente
can elongate
have copulatory spicule

Question 16

types of parasite vectors

Answer 16

arthropods
female mosquito - malaria
tsetse flies - sleeping sickness
black flies - river blindness
kissing bugs - chagas disease
ticks - babesiosis

Question 17

parasite reservoirs

Answer 17

humans - malaria, amoebae
animals - pigs: trichinosis, pork tapeworm
cattle: beef tapeworm, cryptosporidiosis
environment

Question 18

parasite entry

Answer 18

oral ingestion
penetration of skin
arthropod-borne

Question 19

how do diff parasites survive host?

Answer 19

surface antigen variation - trypanosomes
host plasm protein coating - blood flukes
superoxide dismutase secretion (protects from phagolysosome) - leishmanis

Question 20

locations of infections

Answer 20

strongyloides - intestinal wall
hookworms - intestinal lumen
RBC - malaria (duffy factor antigen dep.)

Question 21

what causes disease/clinical manifestations?

Answer 21

direct tissue damage by parasite
effects of immune response
usually occur after the initial infection

Question 22

traits of chagas disease

Answer 22

skin lesion - starts w/ eye swelling
american trypanosomiasis
host is kissing bug in americas
can cause organ lesions

Question 23

treatment of chagas

Answer 23

chemoprophylasis - preventative drugs
immunization (prob: parasite camoflauges by altering their antigens to look like the host and they display diff prot at diff stages of life cycle)
field control (bug spray)

Question 24

species that can affect RBC’s

Answer 24

different Plasmodiums:
plasmodium falciparum - all ages of RBC
plasmodium vivax - reticulocytes and young RBS
plasmodium ovale - "  "
plasmodium malariae - old RBCs

Question 25

malaria transmission

Answer 25

humans and mosquitos are vectors diff areas of world are affected differently released into human blood by mosquitos as merozoites they invade RBCs and liver and mature into trophozoites after replication cells burst

Question 26

how does duffy blood group or sickle cell anemia help limit infection

Answer 26

malaria can't bind in people w/o duffy antigen | sickle cell anemia cells burst prematurely before trophozoites are mature

Question 27

treatment for malaria

Answer 27

chloroquine - stops parasite from being able to neutralize heme so it's toxic to plasmodium

Question 28

babesia traits

Answer 28

endemic in US destroys RBCs - confused w/ plasmodium falciparum slow onset transmitted by deer tick and white footed mouse

Question 29

babesia life cycle

Answer 29

merozoites injected by ticks invade RBC no intermediate liver stage replicate by binary fission and lyse RBC

Question 30

toxoplasma traits

Answer 30

survive in macrophages 3 syndromes : mono-like congenital infection brain/heart complications (schizophrenia) people w/ toxoplasma are more likely to die in car accident

Question 31

toxoplasmosis is passed to people thru...

Answer 31

inadequate cooked meat (tissue cysts) or food contaminated w/ cat feces (oocysts) they penetrate intestinal wall, and enter bloodstream and disseminate

Question 32

leishmania traits

Answer 32

small protozoans vector: phlebotomus sand flies reservoirs: rodents, dogs, other animals, humans complex life cycle

Question 33

life cycle of leishmania

Answer 33

flagellated promastigote binds to macrophage and makes superoxide dismutase converts to unflagellated amastigote

Question 34

traits of trypanosome cruzi

Answer 34

slow growing causes nerve GI and heart damage causes chagas disease passed thru kissing bug

Question 35

traits of trypanosome brucei

Answer 35

african sleeping sickness transmission - tsetse fly reservoirs - animals and humans slow chronic systemic disease

Question 36

intestinal and vaginal protozoa

Answer 36

giardia lamblia, trichomonas vaginalis - flagellates in US entamoeba histolytica - amoeba in dev. countries cryptosporidium, cyclospora, isospora - foodborne apicomplexans microsporidia - sm obligate intracellular parasites

Question 37

traits of giardia

Answer 37

persistent non- bloody diarrhea resistant to chlorine intestinal protozoa trophozoites attach to duodenum w/ ventral sucking disk

Question 38

traits of trichomonas vaginalis

Answer 38

vaginal flagellate | transmitted sexually

Question 39

traits of entamoeba histolytica

Answer 39

``` amoebiasis destruct host tissue causing colon ulcers cause diarrhea spread thru abscesses into other organs cyst is imp. virulence factor ```

Question 40

entamoeba histolytica traits

Answer 40

adhere to host cells receptors w/ digalactose residues | attach and kill host cells by forming pores

Question 41

non-immune vs. immune hosts for entamoeba histolytica

Answer 41

Immune hosts have cell mediated immunity but amoebas produce cysteine proteases that digest IgA, IgG and proteins non immune hosts have phagocytic cells destroyed by pathogenic amoebas

Question 42

ascaris traits

Answer 42

``` intestinal helminths (worm) eggs are ingested and can travel through body to lungs ```

Question 43

pinworm traits

Answer 43

enterobius eggs resist drying so they can be spread on surfaces don't require maturation stage outside body make your butt itch so you scratch and spread eggs

Question 44

hookworms

Answer 44

nematodes lives in soil that's contaminated penetrate skin/ don't need oral ingestion moves to heart via blood then lungs where they're coughed up and swallowed clears up asthma by repressing immune response but cause chronic anemia

Question 45

strongyloides stercoralis traits

Answer 45

eats thru intestinal wall and cause septicemia does not require external soil phase, passes directly thru skin via feces migration identical to hookworms

Question 46

tapeworms

Answer 46

definitive host: humans attaches to intestinal wall and can penetrate deep tiss and form cystic larvae acquired by eating raw meat / fish

Question 47

trichinella spiralis traits

Answer 47

asymptomatic burrow in striated/cardiac m. from undercooked meat

Question 48

schistosomes traits

Answer 48

``` blood flukes s. haematobium - bladder s. mansoni - lg. intestine s. japonicum - sm. intestines intermediate host = snails burrows thru skin and pases to veins to mature then goes to FI tract ```

Question 49

schistosomiasis traits

Answer 49

camoflage themselves w/ host proteins | induce granulomas that undergo fibrosis

Question 50

filariasis types and traits

Answer 50

onchocerciasis - river blindness (black flies) elephantiasis - mosquitoes (nocturnal) humans aren't reservoirs limited by vectors (so not in US b/c we control vectors well here) microfilariae offspring travel thru lymph or subcutaneous tissue