Parasitology Final.txt

  1. Hemoflagellates
    • Trypanosomes
    • Leishmania
  2. Hemoflagellates are heteroxenous
    Heteroxenous: part of the life cycle is in blood/tissues (vertebrates) and the other part is in the intestine of the blood sucking invertebrates
  3. Trypanosomes divided into 2 groups:
    • Salivaria: anterior station = via saliva
    • Stercoraria: posterior station = via feces being rubbed into wound, eyes, etc. after blood meal
  4. Morphological types in life cycles of hemoflagellates:
    • Amastigote: tissue form
    • Promastigote: gut of vector
    • Epimastigote: gut of vector
    • Trypomastigote: blood form
  5. Characteristics of morphological types of hemoflagellates:
    • Have a kinetoplast - a conspicuous DNA-containing organelle that is self-replicating and contains genomic material in addition to that which is in the nucleus
    • Single nucleus
    • Single flagellum (amastigote's is short, doesn't protrude past the cell wall)
    • Leaflike or rounded body
  6. Diffuse cutaneous leishmaniasis
    • Restricted to 2 regions: Venezuela and Dominican Republic; Ethiopia and Kenya
    • Result of infection with parasites that cause simple cutaneous leishmaniasis with a lack of immunological response (i.e. macrophages don’t kill amastigotes)
    • Often misdiagnosed as leprosy
    • Lesions are restricted or widespread
    • Raised macules or patches of thin skin
  7. Old World Cutaneous Leishmaniasis from L. tropica symptoms
    • First sign: persistent insect bite
    • Lesion enlarges - Red with no heat or pain
    • Necrosis of surrounding tissue
    • Healing granuloma at base of lesion
    • ‘Dry’ ulcers with lots of amastigotes
    • Slow to form
    • Chronic
    • Cure naturally without treatment
    • Immunity for years
    • Secondary infections
  8. Symptoms for old world cutaneous leishmaniasis for L. major
    • First sign: persistent insect bite
    • Lesion enlarges - Red with no heat or pain
    • Necrosis of surrounding tissue
    • Healing granuloma at base of lesion
    • ‘Wet’ ulcers with few amastigotes
    • Forms quickly
    • Acute
    • Cure naturally without treatment
    • Immunity for years
    • Secondary infections
  9. Visceral leishmaniasis subspecies
    • L. d. donovoni
    • L. d. chagasi
    • L. d. infantum
  10. Visceral Leishmaniasis (“Kala azar”) symptoms
    • Lesion at site of bite
    • Systemic signs develop weeks to years following infection
    • Intermittent medium-grade fever
    • anemia
    • splenomegaly
    • hepatomegaly
    • progressive weight loss and wasting
    • death
  11. Mucocutaneous Leishmaniasis (“Espundia”) symptoms
    • Lesion starts as mild irritation at insect bite or close to mucosal surface
    • Metastatic lesions appear on buccal or nasal mucosa
    • Gradual erosion of tissue and cartilage
  12. Post-kala azar Dermal Leishmaniasis
    • Occurs within 2 years of cure following inadequate treatment
    • Starts with appearance of mottling of skin, like freckles
    • Marked by reddish, depigmented nodules
  13. Visceral Leishmaniasis in Canines
    • Ocular disease
    • Fever
    • Wasting
    • Lymphadenopathy
    • Splenomegaly
    • Anemia
    • Dermatitis, alopecia
    • Ulcers
  14. Trypanosoma cruzi clinical signs: acute phase
    • Asymptomatic
    • Fever
    • anorexia
    • lymphadenopathy
    • mild hepatosplenomegaly
    • myocarditis
    • Romaña's sign or Chagoma at site of innoculation
    • Resolve over a period of a few weeks or months into an asymptomatic chronic form of the disease.
  15. Trypanosoma cruzi clinical signs: symptomatic chronic
    • May not occur for years or even decades after initial infection.
    • Cardiomyopathy
    • Megaesophagus
    • megacolon
    • Weight loss
    • Fatal
  16. Trypanosoma brucei clinical signs: hemolymphatic stage
    • Fever,
    • lymphadenopathy,
    • headache
    • pruritus
  17. T brucei clinical signs: meningoencephalitic stage
    • Headaches,
    • somnolence,
    • abnormal
    • behavior,
    • lead to loss of consciousness and coma.
  18. T brucei clinical signs: cattle
    • Anemia
    • Inflammation and necrosis in parenchymatous organs
    • Enlarged, inflamed lymph nodes
    • Splenomegaly
    • Intermittent high fever
    • Loss of condition
    • Death
  19. Isospora and Eimeria pathogenic factors
    • Pathogenic factors related to coccidial species:
    • ------Number of cells destroyed per oocyst ingested
    • ------Speed of schizogony
    • ------Location of schizogony and gametogony
    • ------Toxin production
    • Pathogenic factors not related to coccidial species:
    • ------Number of oocysts ingested
    • ------Host age, condition and immune status
  20. Eimeria zuernii
    • Both stages in small and large intestine
    • First generation in lamina propria
    • Bloody dysentery with tenesmus
    • “Nervous” and “Winter” coccidiosis
  21. Eimeria bovis
    Asexual in small/large intestine, sexual in cecum/colon.

    Severe enteritis and diarrhea
  22. Eimeria ahsata
    • Small intestine
    • Megaloschizonts
  23. Eimeria stiedae symptoms
    • Hepatomegaly
    • inflammation of bile ducts
    • white nodules on liver
    • Anorexia
    • emaciation
    • diarrhea
  24. Eimeria ninakolyakimovae
    • Asexual in small/large intestine
    • Sexual in cecum/colon
    • Megaloschizonts
  25. Isospora suis
    • Catarrhal enteritis with green, pasty scours (no blood)
    • Die from dehydration
  26. Isospora belli
    • Intestinal epithelium
    • Acute, non-bloody diarrhea with abdominal pain
    • Especially seen in immunocompromised patients
  27. Isospora canis, Isospora felis
    • All stages in small intestine
    • Disease of puppies and kittens
    • Catarrhal to slight hemorrhagicenteritis
    • Diarrhea may be copious, watery, and persistent
    • Eimeria sp. pseudoparasites
  28. Cryptosporidium sp. symptoms: cattle
    • Infection could be inapparent; or,
    • Infection is severe with debilitating diarrhea.
    • Animals usually ~14 days old at onset
    • Yellow, watery diarrhea
    • Lethargic
    • Recovery within a couple of weeks.
  29. Cryptosporidium sp. symptoms: humans
    • Immunocompetent people
    • -----Watery diarrhea
    • -----fever,
    • -----nausea,
    • -----vomiting
    • -----bloating,
    • -----abdominal
    • -----tenderness,
    • -----malaise
    • -----Infection lasts for ~5-10 days.
    • Immunocompromised people
    • -----Diarrhea severe enough for hospitalization
    • -----Possible life threatening due to hyperinfection.
    • -----May involve respiratory tract.
  30. Toxoplasma gondii symptoms: animals
    • Cats rarely have disease.
    • Dogs may have fever, dyspnea, etc.
    • #1 cause of Abortion in sheep.
  31. Toxoplasma gondii symptoms: humans
    • Mild (Acquired)
    • ---Mostly subclinical/undiagnosed,
    • ---mild fever,
    • ---malaise,
    • ---headaches,
    • ---pneumonitis
    • Acute (acquired)
    • ---High fever,
    • ---chills,
    • ---prostration,
    • ---skin rash,
    • ---pneumonitis,
    • ---myocarditis,
    • ---meningoencephalitis,
    • ---chorioretinitis
    • Congenital
    • ---varying degrees depending on stage of pregnancy when infection was acquired
    • ---blindness
    • ---mental impariment
    • ---hearing loss
    • ---chorioretinitis
    • ---hydrocephaly
    • ---convulsions
  32. Sarcocystis cruzi pathogenesis
    • Generalized lymphadenopathy
    • Ulcerations in oral cavity, esophagus, and intestines
    • Jaundice
    • Pallor of mucous membranes
    • Widespread hemorrhages
    • Dark clear fluid in pericardial sac and thoracic/abdominal cavities
  33. Sarcocystis cruzi symptoms in IH
    • Anorexia,
    • weight loss,
    • emaciation,
    • hair loss,
    • anemia,
    • decreased milk yields,
    • abortions,
  34. Sarcocytis neurona sypmtoms
    • Equine
    • Protozoal Myeloencephalitis (EPM)
    • Focal hemorrhages, discoloration, and softening of brain and spinal cord
    • Multifocal myeloencephalitis with necrosis
    • Ataxia, stumbling, disorientation, weakness, lameness, falling and muscle wasting
    • Blindness, torticollis, circling, dysphagia and loss of reflexes
    • Sudden or gradual onset, leads to death
  35. Neospora caninum symptoms
    • Puppies: flaccid hind-limb paralysis
    • Adults: neurological, nodular dermatitis, pneumonia, urine/fecal incontinence, etc.
    • Major cause of bovine abortions.
  36. Fever cycles for malaria
    • Subtertian = fever every 36 hours?
    • Tertian = fever every 48 hours
    • Quartan = fever every 72 hours?
  37. Hemozoin
    Pigment that attracts iron, produced by trophozoites in Plasmodium life cycle
  38. Reproduction in Plasmodium spp. life cycle
    • Shizogony: asexual reproduction, in liver stage
    • Sporogony: sexual reproduction, in erythrocytic and sporogonic cycles
  39. Clinical signs of Plasmodium spp.
    • a cold stage: sensation of cold, shivering
    • a hot stage: fever, headaches, vomiting; seizures in young children
    • a sweating stage: sweats, return to normal temperature, tiredness
    • In P. falciparum malaria, additional findings may include: Mild jaundice, Enlargement of the liver, Increased respiratory rate
  40. Complications of malaria
    • Cerebral malaria
    • Severe anemia
    • Blackwater fever
    • Pulmonary edema or acute respiratory distress syndrome (ARDS)
    • Abnormalities in blood coagulation and thrombocytopenia (decrease in blood platelets)
    • Cardiovascular collapse and shock
    • Acute kidney failure
    • Hyperparasitemia
    • Hypoglycemia (low blood glucose), especially in pregnant women with uncomplicated malaria, or after treatment with quinine.
    • Metabolic acidosis (excessive acidity in the blood and tissue fluids), often in association with hypoglycemia
    • Severe malaria occurs most often in persons who have no immunity to malaria or whose immunity has decreased. These include all residents of areas with low or no malaria transmission, and young children and pregnant women in areas with high transmission.
  41. Anopheles spp. behaviors
    • Anthroprophilic = feed on humans only, Zoophilic = feed on animals
    • Endophagic = bite indoors, Exophagic = bite outdoors
    • Endophilic = rest indoors, Exophilic = rest outdoors
  42. Leucocytozoon spp
    • Parasites of domestic and wild birds
    • Vectors: primarily black flies (Simulium spp.)
  43. Haemoproteus spp.
    • Parasites of birds and reptiles
    • Vectors: hippoboscid flies, biting midges, tabanid flies
  44. Babesia spp. pathogenesis
    • Hemolytic anemia
    • Autoimmune clearance of RBC
    • Increased vascular permeability and vasodilation resulting in circulatory stasis and shock
    • Clogging of small vessels from RBC stickiness
  45. Transovarial vs. transstadial transmission
    • Transovarial: Babesia taken up by adult in blood meal, develops inside egg, is present in the nymph
    • Transstadial: tick picks up parasite in one of the blood feeding stages, parasite will survive through molts from nymph to larvae to adult.
  46. Babesia: spleens vs. no spleens
    • Babesia divergens: with spleens
    • Babesia microti: elderly, immunocompromised, no spleens
  47. Characteristics of Arthropods
    • Chitinous exoskeleton (hard shell)
    • Jointed appendages
    • Segmented body
    • Separate sexes
    • Complete digestive tract
    • Tracheal respiration
    • Malpighian excretory system
    • Open circulatory system
  48. Metamorphosis
    • A change in form during the post-embryonic development.
    • Two types: Incomplete/gradual, Complete
  49. Incomplete Metamorphosis
    • Little difference in form or habitat between instars.
    • Nymphs (immature instars)
    • ------Similar to adults except in size
    • ------No resting stage proceeding the last molt.
  50. Complete Metamorphosis
    • Immature and adult stages are usually quite different in form and habitat.
    • Larvae
    • ------Stages similar in form but not size.
    • ------No compound eyes.
    • ------May or may not have thoracic legs.
    • ------Chewing mouthparts
    • Pupae
    • ------Resting stage
    • ------Covered with protective material
    • ------Final molt occurs at end of pupal phase.
  51. Characteristics of Class Insecta
    • Three body regions: Head, Thorax, Abdomen
    • One pair antennae
    • Three pairs of legs: One per thoracic segment
  52. Characteristics of Order Diptera
    • Single pair of wings or wingless
    • Halteres: small wing-like structure behind the main wings used for balance
    • Mouthparts vary
    • Complete metamorphosis
    • Many are true intermediate hosts or biological vectors.
  53. Myiasis
    • Migration/invasion of living animals by larvae of dipterous flies.
    • Eggs/larvae are deposited in wound or on carcasses.
    • Two types: obligatory, facultative
  54. Types of Myiasis
    • Obligatory (specific): must have a living animal to complete life cycle
    • Facultative (semi-specific): opportunistic
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Parasitology Final.txt
Parasitology Final