full_flashcards (3)
(120 cards)
1
Q
Vector
A
An organism that transmits a pathogen; carries the parasite to the subsequent step(s)
2
Q
Phoresis Definition and Example
A
Traveling together; an organism carries another without dependence. EX: Bacteria on the legs of flies
3
Q
Mutualism Definition and Example
A
Both organisms benefit, usually obligatory (+/+). EX: Blood-sucking leeches cannot digest blood without certain bacteria in their intestine
4
Q
Commensalism Definition and Example
A
One organism benefits while the other is neither helped nor harmed (+/o). EX: A bird making a nest in a tree
5
Q
Parasitism Definition and Example
A
Harms the host, or lives at the expense of the host (+/-). EX: Fleas living on a dog
6
Q
Platyhelminth
A
Flat Worm: cestode and trematodes
7
Q
Nematode
A
Round Worm, complete digestive system, dioecious
8
Q
Trematode
A
Platyhelminth, fluke, leaflike. Digenean and monogenean
9
Q
Dioecious
A
Separate sexes; separate male and female reproductive parts on different organisms
10
Q
Monoecious
A
The organism itself has both female and male reproductive parts
11
Q
Oviparous
A
Produces offspring in the form of eggs that are hatched OUTSIDE of the parent
12
Q
Ovoviviparous
A
Produces offspring in the form of eggs that are hatched INSIDE of the parent
13
Q
Cestode
A
Tapeworm, indirect life cycle, proglottids, monoecious
14
Q
Ectoparasite
A
Involves arthropods that feed off the host for a blood meal; live on the surface of the host
15
Q
Endoparasite
A
A parasite that resides within the host
16
Q
Protozoan
A
Single-celled organism that can be free-living or parasitic
17
Q
Trophozoite
A
Motile feeding form of a protozoan
18
Q
Cysts
A
Stage in a parasitic life cycle that has a protective membrane or thickened wall allowing survival outside a host
19
Q
Oocyst definition and who creates them?
A
A cyst-like structure containing a zygote formed by apicomplexans
20
Q
Apicomplexan
A
A phylum under protozoa with cellular machinery for host cell entry and replication
21
Q
Anterior
A
Front
22
Q
Posterior
A
Back
23
Q
Indirect Life Cycle
A
Involves more than one host for its life cycle
24
Q
Direct Life Cycle
A
Does not contain any intermediate hosts
25
Definitive Host
The host in which the parasite reaches sexual maturity
26
Intermediate Host
Required host where the parasite develops but does not reach sexual maturity
27
Paratenic Host
No development takes place in this host and is not infectious to this host (big fish, little fish example)
28
Reservoir Host
An animal that harbors an infection that can be transmitted to humans
29
Aberrant Host
A host in which a parasite cannot complete its life cycle, leading to dead-end infections
30
Facultative Parasite
Can live as a free-living organism or become parasitic depending on environmental conditions
31
Obligatory Parasite
An organism that can’t reproduce without a host
32
Giardia form; Helminths form
Cysts; eggs
33
Wucheria spp.
Nematode, causes blockages in the lymphatic system: lymphatic filariasis
34
Incidental/accidental host
Parasitism of a host different than normal; the parasite does not survive but can cause disease
35
Permanent Parasite
Spends entire life in a host
36
Intermittent Parasite
Feeds on host, then leaves (e.g., mosquito)
37
Parasite vs Predator
Parasites keep the host alive and utilize them. Predators kill prey
38
Parasitoid
An organism that lives in or on a host and eventually kills it; usually insects, wasps, or flies
39
Protelean Parasites
Insects in which only the immature stages are parasitic and the adults are free-living
40
Host Specificity
Infects only a specific host
41
Eimeria spp.
COCCIDIA; highly host specific
42
Hyperparasitism and Example
Parasites being a host for another parasite, e.g., tapeworm juvenile in a flea
43
Morphology and characteristics of cestodes
Long and flat, contain proglottids (segmented). Monoecious, and have indirect life cycles
44
Morphology and characteristics of trematodes
Flat, leaf-like. Digenean or monogenean
45
Morphology and characteristics of nematodes
Complete digestive system, can be round or long but UNSEGMENTED, dioecious
46
Blood fluke
Schistosoma; a parasitic Trematode that lives in the bloodstream of its host
47
Lymphatic filariasis
Wucheria, Brugia
48
River Blindness
Onchocerca
49
Guinea worm
Dracunculus
50
Schistosomiasis
Schistosoma
51
Taeniasis
Taenia
52
Echinococcosis
Echinococcus
53
Whipworm
Trichuris
54
Key clinical signs of malaria
Fever, chills, anemia
55
Apicomplexan reproduction
Merogony: asexual multiplication; Gamogony: sexual reproduction; Sporogony: produces sporozoites for infection
56
Provide examples of insects
Mosquitos, fleas, lice
57
Provide examples of arachnids
Mites, ticks, spiders
58
What groups belong to sarcomastigophora?
Amoeba and flagellates
59
What is a mastigont system?
A structure in flagellates that includes the flagella, basal body, and associated organelles for movement and attachment
60
What’s the common name for Eimeria or Cystoisospora?
Coccidia
61
What are the four groups under Protozoa?
Apicomplexa (coccidia), ciliates, flagellates, amoeba
62
Exists only as a trophozoite. What’s common about them?
Trichomonas vaginalis, Trypanosoma; both are flagellates
63
Only exists as cysts
Toxoplasma gondii
64
What’s the purpose of an environmental cyst?
Protects the parasite in harsh conditions, allowing survival and transmission to the next host
65
Blood fluke
Schistosoma; a parasitic Trematode that lives in the bloodstream of its host
66
Tegument
The outer protective covering in platyhelminths (Trematode, Cestode), aids in nutrient absorption
67
Cuticle
Outer protective layer in nematodes
68
Strobila and Proglottids
Strobila is the body portion of a Cestode, and is comprised of individual segments called proglottids
69
Holdfast Organs
Structures used by parasites to attach to their host. e.g., suckers, spines
70
Scolex
The headlock structure of a Cestode, equipped with suckers or hooks for attachment
71
Buccal Cavity
The mouth opening of some parasites used for feeding or attachment
72
Bursa
A specialized structure in male nematodes for mating (not all males have it)
73
How do amoeba move and eat? What do they form?
Uses pseudopodia, phagocytosis. They form cysts
74
Vector Borne Life Cycle
Transmitted via arthropod vectors
75
What are some examples of vector-borne diseases? What vector do they include?
Trypanosoma brucei - tsetse fly; Leishmania spp - Sandfly
76
In Taenia solium, under what circumstances would the human serve as an intermediate vs a definitive host?
IH: ingest eggs, they develop into larval cysts that develop in tissues (cysticercosis); DH: ingest undercooked or raw pork that contains larval cysts
77
Tapeworm lifecycle; in which host do larval tapeworms occur?
Larval stages occur in the intermediate host
78
Larval tapeworms vs adult tapeworms CESTODES
Larval tapeworms are small and focus on transmission in tissues; Adult tapeworms are long and reproduce in the intestine
79
Helminth vs Protozoan Structures
Helminths - large, multicellular; Protozoans - small, unicellular
80
Under what circumstances would the shape of the esophagus be relevant to identifying the organism?
When identifying if it is a nematode or not. Nematodes have a more complex esophagus
81
What are three organism examples of flagellates? Where do they fall taxonomically?
Leishmania, Giardia, Trypanosoma; Under Protozoa
82
What factors contribute to high rates of parasitism in certain populations?
Poverty, lack of sanitation, malnutrition, high population density, climate conditions favorable to vectors
83
In what ways is parasitism underreported in the US?
Misdiagnosis, stigma, lack of routine screening
84
What is a common misconception about parasitism in the US?
We are not free of parasitic infections; many struggle with them, primarily from pinworms
85
Why are we optimistic about controlling NTDs?
Drug donations, technology advances, improvements in medical access
86
Lymphatic filariasis
Wucheria, Brugia
87
River Blindness
Onchocerca
88
Guinea worm
Dracunculus
89
Schistosomiasis
Schistosoma
90
Taeniasis
Taenia
91
Echinococcosis
Echinococcus
92
Whipworm
Trichuris
93
How have news stories and public health campaigns had an impact on parasitic diseases?
Media coverage has increased public awareness, leading to improved sanitation and sales of antiparasitic drugs
94
What are some major challenges in fighting NTDs?
Climate change, drug resistance, travel and movement of humans and pets
95
How does proper sanitation impact parasite life cycles?
Proper sewage can break fecal-oral transmission in soil-transmitted helminths like Ascaris
96
How does water filtration impact parasitic transmission?
In the instance of Guinea worm, infection depends on copepods in drinking water. Filtering prevents infection
97
How can controlling parasitism negatively impact the ecosystem?
It alters biodiversity and impacts natural selection. Reduction of hosts has unknown effects on ecosystems
98
What’s the biggest challenge in eradicating Guinea Worm?
Dogs acting as animal reservoirs has complicated efforts. Dogs need to drink filtered water too, but now they’re passing it to humans
99
What challenges are specific to Guinea worm and the associated countries?
Political unrest in Mali; Outbreaks in Chad and Ethiopia
100
Briefly describe the lifecycle for Guinea worm. Who is the IH and DH?
Humans drink unfiltered water containing copepods. Copepods die and release larvae. Fertilized female migrates to skin and discharges larvae into water. IH: Copepod; DH: Human
101
Briefly describe the lifecycle for schistosomiasis. Who is the IH and DH?
Eggs are secreted in urine and feces. In water, eggs hatch and penetrate snails. They are released from snails and penetrate human skin. IH: Snail; DH: Human
102
How does the life cycle of Onchocerca impact control efforts?
They rely on blackfly vectors. Vector control and treatment are key to elimination
103
What are the control efforts for Guinea worm, schistosomiasis, and onchocerciasis?
Guinea worm: safe drinking water and education; Schistosomiasis: mass drug administration; Onchocerciasis: distribution of ivermectin
104
What are key clinical signs of schistosomiasis?
Hematuria, bladder damage
105
What are key clinical signs of lymphatic filariasis?
Lymphedema
106
What are the key clinical signs of onchocerciasis? What’s the common name?
River Blindness; severe itching and blindness
107
How to identify a parasite’s endosymbiont in hyperparasitism? Provide two examples
The endosymbiont is typically the smaller one. Examples: Plasmodium in a mosquito, Wolbachia in worms
108
Key clinical signs of malaria
Fever, chills, anemia
109
Apicomplexan reproduction
Merogony: asexual multiplication in a host; Gamogony: formation of gametes; Sporogony: produces sporozoites for infection
110
Accidental host example. How does this affect the host?
Humans are usually the definitive host. They ingest cysts that grow into adults and eggs are passed in feces. However, they can also be the intermediate host in that they ingest eggs. The eggs develop into cysts and develop in tissues causing cysticercosis.
111
Provide examples of insects
Mosquitos, fleas, lice
112
Provide examples of arachnids
Mites, ticks, spiders
113
What groups belong to sarcomastigophora?
Amoeba and flagellates
114
What are the common names for sarcodina and mastigophora?
Sarcodina - Amoeba; Mastigophora - flagellates
115
What is a mastigont system?
A structure in flagellates that includes the flagella, basal body, and associated organelles for movement and attachment
116
What are some examples of species that fall under apicomplexa and coccidia?
Plasmodium, Cryptosporidium, Toxoplasma, Eimeria
117
What’s the common name for Eimeria or Cystoisospora?
Coccidia
118
What groups do amoeba fall under?
Protozoa, Sarcomastigophora
119
What group do ciliates fall under?
Protozoa
120
What are the four groups under Protozoa?
Apicomplexa (coccidia), ciliates, flagellates, amoeba
