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90 Cards in this Set
- Front
- Back
What Order is the pork worm in?
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Trichurida
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What are characteristics of Trichinella spiralis?
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Largest known intracellular parasite
Int. & Def. hosts are same animal Creates a nurse cell Humans are dead ends to lifecycle Normal hosts are rats, pigs, bears, hyenas |
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Define nurse cell (in Trichinella spiralis)
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infected myocyte, devoid of muscle proteins; multinucleated
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How is a T. spiralis nurse cell formed?
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simultaneous differentiation and redifferentiation
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What is the function(s) of a T. spiralis nurse cell?
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to support growth and development
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What is the timeline of nurse cell formation?
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DRAW OR REVIEW NOTES
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Why does T. spiralis produce an anaerobic environment for the nurse cell?
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J1=anaerobic
If host dies, tissues rot and it will be anaerobic |
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Why does the nurse cell create a collagen capsule?
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Prevent O2 diffusion
Prevent immune attack |
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Why induce angiogenesis of venules to the nurse cell?
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Deoxygenated blood
Carry away waste products |
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What is tyvelosylated protein?
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protein with a sugar side chain
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What species makes tyvelosylated protein and why?
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Trichinella spiralis;
Don't know why |
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What are the 2 pathogenic phases of domestic trichinosis?
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1. Enteral phase
2. Parenteral phase |
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What occurs in the enteral phase of trichinosis? What are the symptoms?
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Damage to intestine cause by J1 --> adult;
diarrhea, abd. pain, vomitting |
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What occurs in the parenteral phase of trichinosis? What are the symptoms?
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Myocarditis or meningitis occurs from larvae migrating through circulation and penetrating skeletal muscle;
muscle pain & weakness, heart failure |
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How does one get T. spiralis infection?
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Eating raw meat
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What are diagnostic tools for T. spiralis infection/trichinosis?
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Immunodiagnostic tests
-ELISA -counterelectrophoresis |
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Of what order are the filarial worms?
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Filaroidea
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Of what family are the filarial worms?
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Onchocercidae
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What NTDs are caused by nematodes?
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Lymphatic filariasis
River blindness Loaisis Heart worm |
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What nematode causes Lymphatic filariasis?
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Wuchereria bancrofti
(also Brugia malayi) |
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What are the functions of the lymphatic system?
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1. Recollect lymph
2. Transport lipids to circulatory system 3. Immune function |
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What is the epidemiology of W. bancrofti?
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1. Transmission solely dependent on vector
2. Barriers to infection in mosquito and environment 3. Distributed around equator 4. Prevalence of more than 120M people |
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What stage of W. bancrofti infects people?
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J3
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What are the 3 pathogenic phases of W. bancrofti infection?
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1. Asymptomatic phase
2. Inflammatory phase 3. Obstructive phase |
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What methods of testing are available during the asymptomatic phase of W. bancrofti infection?
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1. Finger prick
2. ELISA 3. ICT card test (immunochromatographic) |
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What is the active part of the ICT card test? What are the benefits and drawbacks?
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Colloidal gold;
expensive, needs cold storage can be done anytime of day; instant; very sensitive |
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What is the most common pathology of the inflammatory phase of W. bancrofti infection?
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lymphadema - adult worms block up lymph channels
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What are the common pathologies of the obstructive phase of W. bancrofti infection?
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Hydrocele (filarial dance sign), lymph varices, chyluria
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What is the secondary pathology of obstructive phase infection with W. bancrofti?
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elephantiasis
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What are the causes of elephantiasis?
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chronic lymphadema
skin thickening granuloma build up |
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What are the treatment(s) for lymphatic filariasis?
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Combination of 2 of 3 drugs:
DEC Albendazole Ivermectin |
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What does DEC stand for and what does it do?
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diethylcarbamazine
-sensitizes microfilariae to phagocytes |
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What does albendazole do to W. bancrofti?
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stops embryonic development
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What does ivermectin do to W. bancrofti?
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induces worm paralysis
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How is bacteria related to W. bancrofti pathologies?
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Wolbachia live symbiotically with the filaria. When the worms die, the bacteria are released and cause immune response
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What is TLR-4? What does it do?
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Toll-like receptor 4; recruits neutrophils to corneal stroma
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What does Guinea worm (Dracunculus medinensis) cause?
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dracunculiasis
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What does the serpent on the pole have to do with D. medinensis?
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The fiery serpent from the staff of Asclepius (greek god of healing)
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What family is D. medinensis in?
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Dracunculidae
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What are characteristics of the Dracunculidae?
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tissue parasites of vertebrates
-reptiles -aquatic birds -mammals |
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What is the basic biology of D. medinensis?
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Like general nematode bio!
-sexual dimorphism -ovoviviparous female (possesses non-functional vulva) -blood feeders |
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What are the epidemiological conditions of dracunculiasis?
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1. Infected person must enter water
2. Water must contain cyclops 3. Water must be consumed |
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What is the distribution of dracunculiasis?
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Equitorial regions
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Pathogenesis of dracunculiasis?
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1. Emergent adult worm-related
2. Secondary bacterial infection 3. Non-emergent worms |
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When emergent D. medinensis is going on, what are the pathologies and symptoms?
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a. migrating female releases metabolic wastes, triggering immune response
b. causes nausea, rash, localized edema |
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What are pathologies/symptoms of non-emergent D. medinensis?
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worms migrated to wrong part of body, e.g:
-scrotum -joints (arthritis) -CNS (paraplegia) |
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What is the immunology of D. medinensis infection?
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NO cellular, humoral, acquired immune responses!
1. Antigenic cloaking 2. Release M6G to suppress immune system |
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What is M6G? What species releases it?
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morphine-6-glucoronide; D. medinensis
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How do you immunodiagnose D. medinensis infection?
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You don't. There are no circulating antigens.
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What is the treatment for dracunculiasis?
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none; aspirin or anti-inflammatories; bactericides; slowly curl the worm
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Can D. medinensis be eradicated? How?
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Maybe. Education (filter or boil water containing cyclops)
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How does D. medinensis cause arthritis?
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Calcification of the worms by the immune system
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Why do only female mosquitos bite?
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They take a blood meal for their eggs
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Characteristics of the phylum Arthropoda
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1. Segmented animals.
2. Heteronomy 3. Tagmosis due to strong heteronomy 4. Hemocoel 5. Ecdysis |
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What is tagmosis?
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regional specialization of body parts
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What are the tagmata of spiders? What joins them?
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prosoma and opisthosoma; pedicel
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What class and order are ticks in?
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Arachnida, Ixodida
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What is a synapomorphy of ticks?
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obligate ectoparasites
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What are 3 characteristics of ticks?
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hypostome; hematophagous; Haller's organ
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What is evidence for the Devonian hypothesis of tick evolution?
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some ticks parasitize amphibians, so they coevolved with the tetrapod lineage
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What is evidence for the Cretaceous hypothesis of tick evolution?
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Most ticks parasitize mammals, so they coevolved with mammals and amphibian/reptile parasitism is secondary
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Why do we care about the evolution of ticks?
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Insight into their evolution and the evolution of the hemostatic system
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What is the function of the hemostatic system? How does it work?
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prevent blood loss
1. Vasoconstriction 2. Platelets 3. Coagulation factors 4. Fibroblasts |
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If ticks evolved during the Devonian, what does that tell us?
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Ticks may have had an effect on the evolution of the HS (arms race); Hematophagy is OLD
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If ticks evolved during the Cretaceous, what does that tell us?
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Ticks had a minor influence on the evolution of the HS (overcame HS quickly); hematophagy is young
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What are pedipalps for in the gnathosoma?
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Chemosensory
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What is the physical anchor in the tick's gnathosoma?
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hypostome
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Ixodes scapularis is also known as...
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blacklegged or deer tick
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How many hosts are in the tick's lifecycle?
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3 (small, medium, largest)
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What is the most likely period for human parasitism by the tick?
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October to January
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Ticks go from being larvae to ___________
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nymphs
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What are some interesting behaviors of ticks?
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Questing
Quiescence |
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What is questing?
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a strategy to search and wait for a host; detect host chemostimuli with Haller's organ
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What does the Haller's organ include and respond to?
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capsule, pit, setae;
CO2, NH3, organic acids |
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What is quiescence?
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a period of movement down the vegetation and into the soil, in order to reabsorb water from the soil
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What do the salivary glands of a tick secrete?
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enzymes, attachment cement
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What is the host response to tick infection?
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1. Neutrophils cause inflammation
2. Platelets move in create plug 3. Clotting factors coagulate blood 4. Other immune cells move in |
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What are the actions during a tick's taking a blood meal?
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1. Parasite penetration
2. Host response 3. Parasite counter-response |
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How does a tick respond to a host's immune response?
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Salivary glands release:
1. prostaglandin E2 2. anti-histamine 3. carboxypeptidase to cleave bradykinin |
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What is cleaved by carboxypeptidase to prevent pain?
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bradykinin
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What are the funtions of PGE2?
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prostaglandin E2:
a. promote vasodilation b. inhibit platelet aggregation c. inhibit mast cell degranulation (stop histamine) d. Inhibit t-lymphocyte activation |
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What are tick adaptations to hematophagy?
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1. SGs excrete excess water
2. Idiosoma is only partially sclerotized 3. Mating only occurs after initial attachment by female |
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What do ticks transmit?
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spirochate Borrelia bugdorgeri
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What is passage of an agent to offspring called?
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trans-ovarial passage
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What are the pathologies and symptoms of Lyme disease?
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Inflammation due to spirochaete invasion;
Erythema migrans (bulls-eye) Fatigue, chills, fever, arthritis, facial palsy |
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How do you diagnose and treat Lyme disease?
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visual, ELISA, Western blot;
oral antibiotics |
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Define zoonosis
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disease resulting from transmission of a parasite from a wild/domestic animal to a human
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What are types of host defense?
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Integumentary
Alimentary Immune |
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What are some challenges to parasitism?
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Digestive environment
Osmotic variation Low O2 tension Host finding |
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What are 4 ways NTDs promote poverty?
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1. Chronic disability
2. Death 3. Flourishing in impoverished conditions 4. Community and political destabilization |