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81 Cards in this Set
- Front
- Back
What are the normal number of specimens for a stool exam and why?
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3 in a 10 day period that happens every other day because of the irregular shedding of eggs/cysts.
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Why should you never collect from a toilet/bedpan?
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Contamination/destruction or introduction of free living protozoa (horse fly worm).
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When should you collect when doing a barium procedure?
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If it's not possible before, do 7-10 days post barium.
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What are some preservations?
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Refrigeration, PVA, formalin, SAF, and MIF
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Refrigeration
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Eggs, larvae, and amoebic cysts and not so much for trophs. They die off and don't move.
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PVA
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Mercuric chloride fixation and poly-vinyl alcohol which is a resin to increase adhesion. This is good for a permanent stain (amoebic trophs)
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Formalin
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10% sedimentation/flotation procedures for eggs, larvae, and amoebic systs.
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SAF
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Sodium acetic acid formalin. Fixes and is permanent.
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MIF
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Merthiolate-iodine-formalin. It is a wet mount for a quick view that is not permanent (usually within 30 minutes)
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What are different types of examination?
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Macroscopic, gross, consistency, formed, microscopically.
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Consistency
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Liquid or soft will contain motile trophs and done within 30 minutes with MIF. With formed, it will primarily contain cysts within 2-3 hours or 24 hours if refrigerated.
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Microscopically
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Cellophane tape prep for Enterobius vermicularis
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Duodenal aspirate
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Giardiasis or Strongyloidiasis.
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Sigmoidscopy
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Examine immediate because the motile trophs glow.
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Urine/vaginal/urethra specimen
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Schistisoma haematobium, E. vermicularis, or Trichomonas vaginalis (done with wet mount of urethral discharge.)
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What do you do with Blood/tissue?
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Use Giemsa or Wrights'. Babesia, malaria, trypanosoma. May need a biopsy (Trichinella spirals, Leishmania, Pneumocystosis, carinii, Toxoplasma gondii.)
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What can be in spinal fluid?
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Naegleria fowlerri (sleeping sickness)
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What are ways to test and diagnose?
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Immunologic, EIA, Fluorescent, microscopic
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Immunologic technique.
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Immuno assay, fluorescent AB test. Organisms that invades tissue will normally stimulate AB production. The problem of it is that it is limited in diagnostic value.
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EIA
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Detection of AB to intestinal parasite. There is corssreactivity with poor sensation and specificity. C. difficile.
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Fluorescent
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Cryptosporium and giardia
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Microscopic
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Gold standard. Detect motile trophs with little light. Use petroleum jelly to preserve wet mount.
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Concentration techniques
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Sedimentation and flotation
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Sedimentation
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Add 10% formalin to specimen and allow to stand for minutes and strain with gauze. Centrifuge for 10 minutes at 1500 rpm. Decant, resuspend with formalin and ethyl acetate. Shake for 30 seconds to mix, centrifuge again for 10 minutes at 1500. Decant and use sediment.
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Flotation
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Difference in specifici gravity. mix with zinc slufate, centrifuge for 10 minutes at 1500 rpm, decant and refill. Eggs will float to top, touch top of meniscus with slip and examine as soon as possible. There is a lot less fecal debris and the operculated eggs collapse.
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What is PVA?
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Polyvinyl alcohol. 3 drops to 1 drop stool. Use a stick and spread/roll around to remove chunks. Use Gamor trihrome stain, iodine and coverslip.
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What is an ocular micronomer?
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A glass disk that fits into the eyepiece with scaled rule to measure size of magnified objects.
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How do trophozoiles reproduce?
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Binary fission.
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How do cysts reproduce?
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Multiplication of nuclei.
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What are the 7 karyosome types?
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Small and central, large and ecentric, blot like, broken and clumped, chromatid bodies (only in cysts), splintered, and irregular.
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Describe Entamoeba histolytica.
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15-25 um, progressive directional motility, finely granular cytoplasm, may contain RBC's, small central karyosome, and fine, even, chromatin.
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Describe Entamoeba histolytica cyst.
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Round 10-20 um. 4 nuclei in mature with round and elongated chromatid bodies.
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Describe Entamoeba coli troph
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15-50 um with nondirectional motility. It is vasulated and contained ingested bacteria. It has large, eccentric karyosomes, coarse and uneven peripheral chromatin.
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Describe Entamoeba coli cyst.
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15-25 um with 8 nuclei in a mature cell. The chromatid bodies are alongated with splintered ends.
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Describe Entamoeba hortmanni troph
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4-12 um with non directional motility and finely granulated cytoplasm it has a small, central karyosome and fine, evenly distributed chromatid.
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Describe Entamoeba harmanni cyst.
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5-10 um round with 4 nuclei and you may or may not see elongated chromatids with round ends.
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Describe Endolimax nana troph.
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5-12 um, ND, vaculated cytoplasm and may contain ingested bacteria with large, irregular karyosome and no peripheral chromatin.
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Describe Endolimax nana cyst.
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5-12 um (oval) with 4 nuclei and you will not see chromatid bodies.
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Describe Iodamoeba butchlii troph
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6-20 um ND that is vaculated and may contain ingested bacteria that have large karyosome surrounded by achromatic granules and no peripheral chromatin.
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Describe Iodamoeba butchlii cysts
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6-15 oval or irregular with 1 nuclei and no chromatid bodies. ** It has a single defined glycogen vacule **
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How do you distinguish entamoebas?
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Peripheral chromatin and/or chromatin bodies.
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How do you distinguish Iodamoeba
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They do not have peripheral chromatin and/or chromatid bodies.
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how do you distinguish trophs?
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Trophs only have one nuclei.
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How do you distinguish E. histolytica
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RBCs in cytoplasm
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What is the only Entamoeba that has 8 nuclei in the cyst?
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Entamoeba coli.
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What exists as an amoeboid and is thought to cause diarrhea?
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Blastocystis hominis.
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What does Naegleria fowleria cause?
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Mengioencephalitis from warm lakes or muddy waters.
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What are the three life cycles for Naegleria fowleria?
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Free living amoebic troph, transient flagellar, and environmentally resistant cyst.
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What is diagnostic of Naegleria fowleria?
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Trophs in spinal fluid (Broad pseudopods and large karyosomes and amiciterin P.
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How can you get Acathamoeba?
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Soil, water, and homemade saline. It causes chronic granulomas encephalitis and keratitis.
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What are the two life stages of Acathamoeba?
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Resistant cysts and a motile troph.
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What are the symptoms of an infection of Acathamoeba?
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Drowsiness, seizures, headache, stiff neck, and personality disorders
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What will you see in a brain biopsy?
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Cysts (15-20 um) spherical and double walled. 10-45 um trophs. There is a spine like pseudopods.
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Histoprep for Acathamoeba will show what?
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Inflammatory lesions with many seg, eos and trophs.
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What is a Balatidium coli?
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Human pathogen but the host is a hog. it causes self limiting diarrhea with nausea, vomitting, and abdominal tenderness. Very large (40-60 um). it has a kidney shaped macronucleus and a micronucleus.
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What are the flagellate species we talk about?
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Giardia lamblia, Dientamoeba fragilis, Chilomastix mesnilli, Trichomonas hominis, Trichomonas vaginalis
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Blood and tissue flagellate sp.
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Leishmania and Trypanosoma
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What are some characteristics of Giardia lamblia?
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Found in feces and obtained from untreated well water. Excystation that causes diarrhea, severe abdominal pain, lose lots of fluids and electrolytes and can cause malnutrition. Very stinky stools that contain no WBC or RBC
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What does Excystation mean?
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Excystation means that the troph can become a cyst and vice versa.
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What does the troph and cyst of Giardia lamblia look like?
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Troph - Ventral sucking disk, paraboral body, axostyle.
Cyst - 4 nuclei with a septum and dashes below the two lower nuclei. |
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Describe Dientamoeba fragilis.
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Two nuclei in a troph with no peripheral chromatin, broken and clumped nucleus. ** There is no cyst form ** and is primarily found in daycare.
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Describe Chiliomastix mesnilli
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Non pathogenic that looks similar to Giardia lamblia
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Describe troph and cyst of Chiliomastix mesnilli.
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Troph - Ventral groove, cytostone.
Cyst - Lemon shaped |
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Describe Trichomonas hominis
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Non-pathogenic found in stool lacking a cyst stage.
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Describe troph of Trichomonas hominis.
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undulating membrane iwth flagella, cytostome, nucleus, and axostyle.
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Describe Trichomonas vaginalis
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4 anterior flagella, undulating membrane, 1 posterior flagella, prostate problems in men. Resides in vaginal areas, can be found in urine. Cause vaginal inflammation with foul frothy discharge, burning and itching, and creates a bad odor. Has jerky motility.
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What is the human form of Leishmania?
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Amastigote. Obligate intracellular orgnism in macrophages, liver, spleen, or bone marrow.
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What is the human form of Trypanosomas sp?
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Trypomastigote. Flagellated form in the blood, lymph, and CSF patients.
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What are the insect forms?
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Epimastigote and promastigote stages are seen in the insect vectors.
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Describe amastigote?
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Retracted flagellum with a kinetoplast and nucleus. Diagnostic stage that is an obligae intracellular organism within macrophages found in the liver, spleen and bone marrow cells. These are Leishmania.
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Describe Trypomastigote.
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Free flagellum with an undulating membrane attached to posterior muscles. The flagella form is in blood, lymph, or CSF. Trypanosomas.
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Describe promastigote
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`Free flagellum.
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Describe epimastigote.
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Free flagellum with an undulating membrane attached anterior to nucleus.
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What are the Leishmania complexes?
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tropica, braziliensis, mexicana, donovani. Dogs and rodents are primary hosts. The sand fly is the vector for Leishmania. Lutzomyia.
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Describe Leishmania tropicana
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Cutaneous leishmaniasis (oriental sore) found in the orient and north central africa.
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Describe L. braziliensis
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mucocutaneous leishmaniasis with an initial lesion that may increase in size, invading and destroying mucosal surfaces of nose and mouth. Destroys cartilage and causes disfigurement. Found in mexico, south and central americas.
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Describe L. mexicana
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New world Leishmania in South central americas with crusted circolor lesions on any exposed body surface. Especially the face and extremities, there are lesions on the eyes. Self limiting that does not invade the mucosal surfaces. You can get a secondary bacterial invection with complications.
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Describe L. donovani
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most severe leishmania. kala-azar. Visceral leishmania from south america, africa, asia, and southern europe. Enters lymphatic of organs at RTE. Liver, pleen, lymph nodes, bone marrow. The symptoms are malaise, anorexia, headache, fever, hepatomegalia, splenomegaly. If untreated you will die within 2 years.
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Describe Trypanosoma rhodesiense.
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Sleeping sickness from the east africa with a rapid onset and death within a year.
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Describe Trypanosoma gambiense
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Sleeping sickness from west africa that is more mild but more chronic. The insect vector is the tsetse fly with game animals being the host.
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Describe T. cruzi
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Chagus disease found in the rural areas of mexico, south central america. Reduviid bugs/kissing bug. Found in amistogote.
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