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203 Cards in this Set
- Front
- Back
30 um x 16 um
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Clonorchis sinensis egg
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85 um x 55 um
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Paragoniums westermani egg
-note operculum and terminal shell thickening |
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0.8-1.6 cm x 0.4-0.8 cm
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Paragonimus westermani
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1-2.5cm x 0.3-0.5cm
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Clonorchis sinensis adult
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3cm x 1.5cm
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Fasciola hepatica adult
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What is this a picture of?
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Charcot-Leyden crystals - breakdown products from eosinophils
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114-180um x 45-73um
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Scistosoma mansoni eggs
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55-85x40-60 um
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Schistosoma japonicum egg
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Define: acetabula (sing: acetabelum)
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Muscular suckers found on the oral or ventrical surface of flukes
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Define: metacercaria
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Developmental stage of hermaphroditic flukes when the cercaria has shed the tail, secreted a protective wall and encysted in the intermediate host
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Define: miracidium
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Ciliated first-stage free-swimming larva which emerges from the egg and must penetrate the first intermediate host (snails) to continue life cycle
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Define: redia
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Second/third larval stage of trematodes that develops in a sporocyst in the first intermediate host
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Define: cercaria
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Final trematode developmental stage in the snail host
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Hermaphroditic flukes are found in ______, and unisexual flukes are found in _______
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Intestines or organs; blood vessels
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What happens to trematodes if the first intermediate host is not available?
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Trematodes require the first inter. host and will die if it is not available
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The metacercaria is found in the first intermediate host (T/F)
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False; it is found in the 2nd host or on aquatic plants (water chestnuts or bamboo)
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Two plants where metacercaria of F. buski or F. hepatica may be found
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Water chestnuts, bamboo
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Geographical distribution of Fasciolopsis buski
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Asia/southeast asia
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The infectious form of Fasciolopsis buski is...
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Metacercariae attached to aquatic vegetation
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The diagnostic form of Fasciolopsis buski or Fasciola hepatica is...
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Large elliptical, unembryonated, brown eggs with operculum about
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Symptoms of Fasciolopsis buski infection
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Intestinal in nature:
- inflammation, ulceration and hemorrhage - abdominal pain and diarrhea (profuse amts of eggs in stool) - impaired B12 absorption (anemia) - Edema and ascites - Eosinophilia |
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Treatment for Fasciolopsis buski
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Praziquantel (biltricide) or niclosamide
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The characteristic feature that distignuishes heterophyids among other flukes
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Their small size (<2.5mm)
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Infective form of heterophyids
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Metacercaria in raw/pickled/undercooked freshwater fish
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What distinguishes Clonorchis sinenis eggs from that of heterophyids?
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Clonorchis has more pronounced opercular shoulders and a larger terminal knob
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Clinical symptoms of heterophyids
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Usually asymptomatic unless severe infection; mucoid diarrhea, ab. pain, possible granulomas in heart or brain
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What is the natural definitive host of Fasciola hepatica?
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Sheep
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The cephalic cone is a characteristic of which adult trematode?
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Fasciola hepatica
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In which body site would Fasciola hepatica be located?
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Large biliary passages and gallbladder
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What is the infectious form of Fasciola hepatica?
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Metacercaria from aquatic plants
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Symptoms of Fasciola hepatica
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Jaundice, hepatomegaly, cirrhosis, eosinophilia, 2ndary bacterial infection, biliary obstruction
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Treatment for Fasciola hepatica
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Bithionol
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Geographical distribution of Clonorchis
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China, Japan, Korea, Vietnam
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Common name for Clonorchis sinensis
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Chinese liver fluke
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Why must several O/P exams be required to diagnose Clonorchis?
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It is excreted intermittently
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The infectious form of Clonorchis
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Metacercaria from undercooked freshwater fish
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Treatment for Clonorchis
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Praziquantel
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Geographical distribution of lung flukes
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East and southeast Asia
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Humans are accidental hosts for lung flukes. What is the primary host?
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Cats
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"Oriental lung fluke" common name
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Paragonimus westermani
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How is Paragoniums westermani diagonsed?
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X-ray showing infiltrate in lungs or eggs/"iron filings" from sputum
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Iron filings in sputum are indicative of
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Lung flukes/Paragonums westermani
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The infectious form of Paragonimus westermani is
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Metacercaria from undercooked freshwater crustaceans (crabs/crayfish)
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Symptoms of Paragonimus infection
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Dyspnea, bronchitis, fibrosis; also brain and liver complications can occur
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Treatment for Paragonimus
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Praziquantel
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Schistosoma eggs are recovered from
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Feces (mansoni, japonicum), urine (haematobium)
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Differentiate male and female schistosome adult forms
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Male: 0.6-2.2cm long and cylindrical/curved
Female: 1.2-2.6cm, slender and circular x-section |
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What helps S. mansoni and S. haematobium keep them in place in the blood vessels?
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Lateral (mansoni) and terminal (haemabotium) pines
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What is the infective form of blood flukes?
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Cercariae from the first intermediate host (snail) penetrate human skin *no secondary intermediate host*
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Define: schistosomule
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The immature schistosome in human tissues after the tail has been lost following penetration of skin
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Where do schistosomules mature?
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Mesenteric and vesicular veins
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Geographical distribution of S. mansoni
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South/central America, Africa, middle east
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Diagnostic stage of Schistosoma mansoni
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Large (140x60um), elongated/ovoid eggs with a large lateral spine
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In Schistosomes, the miracidium is (developed/undeveloped)
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Developed
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Compare S. mansoni and S. japonicum eggs
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S. mansoni: large, elongated, large lat. spine
S. japonicum: medium/small, spherical/oval, minute/absent lateral spine |
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Urinary schistomiasis
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Caused by Schistosoma haematobium (more needed)
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Geographical distribution of Schistosoma haematobium
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Middle east and mediterranean
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Schistosomiasis symptoms
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Petechiae or edema @ infection site; toxic and allergic symptoms; fever/malaise
Acute stage: liver tenderness, hives(urticaria), ab. pain - diarrhea/dysentery for S. mansoni/japonicum - hematuria/dysuria for S.haematobium |
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Which trematode egg can be found in urine? what does it look like?
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Schistosoma haematobium; large, elongated with a prominent terminal spine
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A brown hematin pigment in phagocytic cells may be seen in
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Schistosomiasis
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Treatment for Schistosomiasis
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Praziquantel
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Describe the life cycle of an intestinal trematode
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Egg>Miracidium>Sporocyst>Redia>Cercaria>Metacercaria>adult
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Which platyhemlinth infects humans via skin penetration and is associated with bladder cancer?
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Schistosoma haematobium
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The egg of which fluke genus IS developed when passed in feces?
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Schistosoma
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What is the preferred specimen for the diagnosis of paragonimiasis?
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Sputum
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Which flukes are acquired by eating contaminated vegetation?
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Fasciolopsis buski and Fasciola hepaticum
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Fish containing metacercariae may transmit which species of fluke?
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Clonorchis sinensis, Heterophyes heterophyes,
Metagoniums yokogawai |
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Paragonimus westermani is acquired by...
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Eating infected crustaceans, such as crabs and crayfish
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Schistosoma cercariae enter the human body via
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Penetration of skin or in contaminated drinking water
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Bloody urine is a symptom of infection with which species of Digenea
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Schistosoma haematobium
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Differentiate schizogony and sporogony
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Schizogony: asexual reproduction (multiple nuclear divions before cytoplasmic division)
Sporogony: Sexual reproduction and production of spores/sporozoites |
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The definitive host of Toxoplasma gondii is...
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Cats
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The infective stage of Toxoplasma gondii (for humans) is
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Oocyst
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Toxoplasma gondii tachyzoites
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There is a high infection rate in the population for Toxoplasma gondii (T/F)
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True; up to 75% of the population is infected, but disease is rare (chronic infection)
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The two infectious species of Cryptosporidium
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C. parvum and C. hominis (hominis only infects humans)
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The life cycle of Cryptosporidium requires more than one host (T/F)
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False; cryptosporidium only requires a single host due to autoinfection
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The most common symptom of cryptosporidiosis
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acute and profuse watery diarrhea
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Cryptosporidium spores (are/are not) immediately infective
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Are
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Routine chlorination/commercial disinfectant (does/does not) eliminate Cryptosporidium oocysts
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Does not; requires full strength bleach or 5-10% ammonia
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Infective stage of Sarcocystis
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Sarcocysts in infected meat (via ingestion)
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Sarcocysts release _____, which go on to undergo ______ to produce more infective oocysts
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Bradyzoites; gametogeny
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The infective stage of Plasmodium spp.
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Sporozoites from the saliva of infected mosquitos
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Mosquitos become infected with Plasmodium after they...
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Consume blood containing Plasomdium gametocytes
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Geographical distribution of Plasodium
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Primarily subsaharan Africa; less: SE Asia and S America
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Symptoms of malaria:
- time to presentation - initial symptoms - severe symptoms |
Time to pres: 7-10 days
Initial: fever, headache, chills, vomiting (mild to severe) Severe: severe anemia, resp. distress, multi-organ dysfunction, death |
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Following innoculation with Plasmodium sporozoites, the organism travels to the _____ to become _______
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Liver; cryptozoites
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Cryptozoites produce many ______ via ______ reproduction
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Cryptozoic merozoites; asexual
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The exoerythrocytic phase of Plasmodium development consists of:
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Sporozoites travelling to the liver, becoming cryptozoites, and reproducing asexually to produce many merozoites which then are released into circulation
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Plasmodium species with a 3-day fever cycle
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P. vivax, P. falciparum, P. ovale
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Plasmodium species with a 4-day fever cycle
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P. malariae
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Describe red cell preferences (more/less mature) of Plasmodium spp.
- P. vivax - P. falciparum - P. ovale - P. malariae |
vivax: less mature (Schuffer's granules)
malariae/ovale: more mature falciparum: no preference (hence falciparum is the worst) |
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genus? stage?
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Plasmodium trophozoites [P. falciparum - double signet troph]
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Double signets in smaller trophozoites is characteristic of which Plasmodium sp?
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P. falciparum
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Schuffner's granules are seen in which Plasmodium spp?
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P vivax and P. ovale
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Dormancy in the liver is seen in which Plasmodium spp?
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P vivax and P. ovale
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Define: schizont
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An RBC containing 12-24 merozoites
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As the _______ matures, it becomes larger and distorted
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trophozoite
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The P. malariae trophozoite tends to do what within the RBC?
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Forms a band during early schizogony
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The small ring trophozoite and banana shaped gametocyte is most commonly seen in which Plasmodium sp?
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P. falciparum; mature trophozoites are usually not seen
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How is the Accole form of P. falciparum distinguished?
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The trophozoite is found at the very perimeter of the RBC
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Which stain is useful for staining thick smears for Plasmodium diagnosis?
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Giemsa staining
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# of merozoites in the schizont for
- P. vivax - P. ovale - P. falciparum - P. malariae |
- P. vivax: 12-24
- P. ovale: 6-12 - P. malariae: 6-12 - P. falciparum: merozoites not usually seen |
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Note Schuffner's dots
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Plasmodium vivax trophozoite
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P. vivax schizont (note 12+ merozoites)
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P. malariae troph (note the band)
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P. malariae schizont
note <12 merozoites like P. ovale, and spherical unlike P. ovale |
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P. falciparum trophozoite
- note double signet and small size of troph |
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Accole form of P. falciparum (troph on perimeter)
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P. falciparum gametocytes
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P. ovale trophozoite (note oval shape)
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Babesia trophozoites (arrow pointing to characteristic "Maltese cross")
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Quartan malaria nephropathy is caused by
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P. malariae
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Blackwater fever is caused by
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P. falciparum
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Relapses and superinfections are caused by
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P. vivax and P. ovale due to latency/sequestration in liver
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Treatment for malaria
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Chloroquinine or other quinines depending on species [multidrug treatment is best]
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Specimen requirements for detection of malaria
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- EDTA or fresh whole blood
- Thin and thick smear - Wright's or Giemsa stained |
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The "ParaSight" test looks for:
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presence of P. falciparum-specific histidine rich protein via immunochromatographic strip
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Vector and geographic distribution of Babesia
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Ticks;Northeast/coastal US (martha's vinyard)
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Babesia trophozoites are similar to trophozoites of which other organism?
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P. falciparum
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Malaria can be acquired via which transmission path other than by being bitten by infected mosquitos?
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-Transfusion/organ transplant
-congenitally -sharing needles |
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Hemoflagellates are dimorphic, meaning:
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Morphology differs between vertebrate and invertebrate host
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Define: amastigote
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Small, ovoid, nonflagellated form found in macrophages containing the nucleus and kinetoplast [Trypanosomes]
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Define: promastigote
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Elongated body with a central nucleus and a flagellum [Trypanosomes]
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Define: epimastigote
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Elongated body with undulating membrane and flagellum [Trypanosomes]
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Define: Trypomastigote
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Mature form of a Trypanosome found in peripheral blood; flagellated, undulating membrane and with refractile granules and organelles [Trypanosomes]
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The tsetse (Glossina) fly transmits which parasite?
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Trypanosoma brucei gambiense/rhodesiense
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West African sleeping sickness is caused by
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Trypanosoma brucei gambiense
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East African sleeping sickness is caused by
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Trypanosoma brucei rhodesiense
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Initial symptom of T. brucei gambiense is ____
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asymptomatic or trypanosomal chancre
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More severe symptoms of T. brucei gambiense infection
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Invasion of lymph nodes/enlargement, fever, anorexia, weakness, nausea, vomitting, night sweats
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Winterbottom's sign
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Lymph node enlargement in the posterior cervical region associated with T. brucei gambiense
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Kerandel's sign
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Pressure on palms of hands is followed by severe pain after pressure is removed - T. brucei gambiense
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Diagnosis of T. brucei gambiense is achieved by:
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Demonstration of trypomastigotes in peripheral blood smear or in lymph/CSF
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IgM levels remain very high in T. brucei infections due to:
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Variable surface glycoproteins due to constant gene rearrangement every 1-2 weeks
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Which is the more acutely virulent sub-species of T. brucei?
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T. brucei rhodesiense
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Which symptom is usually found in T. brucei gambiense but not in T. brucei rhodesiense?
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lymphadenopathy
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Amastigote forms of hemoflagellates are seen in TISSUE in which organisms?
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Leishmania spp and Trypanosoma cruzi
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Disease caused by T. cruzi
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Chagas' disease (American trypanosomiasis)
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Vector for T. cruzi
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Reduviid/Triatomid bug
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Trypanosoma cruzi infection is acquired when...
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Epimastigotes enter bloodstream when:
- Triatomid bug feces enters small wound (ie. scratching) - blood transfusion - lab culture - congenital infection |
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Chagoma caused by T. cruzi (periorbital swelling)
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small, slender "C-" shaped trypomastigotes are associated with which species?
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Trypanosoma cruzi
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T. brucei trypomastigotes are much ____ than T. cruzi
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Larger (30+ um compared to 20um for T. cruzi)
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Romana's sign
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Swelling that begins above and below the eye socket and spreads down the neck
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Symptoms of chagas disease
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- fever, malaise, chills, high fever, exhaustion
- symptoms appear ~7-10 days following infection - pinhead size red spots on chest and abdomen - Acute stage: either death or recovery within weeks -Chronic stage: variable periods of remission with occasional fever |
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Most severe symptom in children with T. cruzi infection
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Meningoencephalitis/CNS involvement with rapid fatality
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What are effective host defenses against T. cruzi infection?
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- Depletion of host's iron stops growth
- Host immunity via IgG and complement |
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When is IFA/EIA testing necessary for diagnosing T. cruzi
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During the chronic stage of infection
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Leishmania is carried by which vector?
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Sandfly (Lutzomyia/Phlebotomus)
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How does protozoa achieve motility?
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Pseudopodia (amoeboid movement), flagella or cilia
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Amebic dysentery and amebiasis is attributed mainly to which pathogenic species?
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Entamoeba histolytica
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Which body sites does E. histolytica invade?
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Primarily intestinal wall, but also lungs, brain, liver and skin
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E. histolytica (can/can not) be sexually transmitted
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can
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A nucleus with a central karyosome and intracellular/engulfed RBC's are characteristic of which protozoa?
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Entamoeba histolytica
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An Entamoeba histolytica cyst can have up to __ nuclei
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4 (1, 2 or 4)
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What is the infective stage of Entamoeba histolyticum?
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Cyst
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What is the diagnostic stage of Entamoeba histolyticum?
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Cysts or trophs in feces
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Why is E. dispar significant?
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Very similar in appearance to E. histolyticum but is nonpathogenic; E. histo will contain ingested RBC's
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E. hartmanni differs from E. histolyticum how?
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E. hartmanni uch smaller than E. histolyticum, especially the trophs.
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How is Entamoeba coli different from E. histolytica?
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- E. coli has a large, eccentric karyosome
- Ingests bacteria but not RBC's - cyst contains up to 8 nuclei |
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How is E. polecki different from E. histolytica?
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E. polecki contains up to 2 nuclei and pointed chromatoid bodies, but is otherwise very similar
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How is E. gingivalis different from E. histolytica?
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- no cyst stage
- able to ingest WBC's - found in sputum |
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Iodamoeba butschlii characteristics
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- single compact nucleus
- large glycogen vacuole that stains brown with iodine |
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How is Endolimax nana different from E. histolytica?
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- very small
- large irregular karyosome - no peripheral chromatin |
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Which intestinal amoeba is a strict anaerobe?
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Blastocystis hominis
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A large central vacuole with nuclei located along the periphery is characterstic of which intestinal amoeba?
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Blastocystis hominis
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What will water do to Blastocystis?
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destroy it, causing a possible false negative
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Granulomatous amoebic encephalitis is caused by which protozoa?
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Acanthamoebia spp.
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What is a common route of infection with Acanthamoebia?
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Contact with broken skin or mucous membrane, especially the eyes.
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Which species of protozoa is characterized by:
10-25 um wide - round outer membrane, wrinkled inner membrane - single nucleus - trophs rare |
Acanthamoebia
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What is the largest protozoan parasite of humans?
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Balantidium coli (>40 um trophs)
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Which animal is a reservoir for Balantidium coli?
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Pigs
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Which structure is very characterstic of Balantidium coli?
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A kidney-shaped macronucleus
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Which condition is caused by Naegleria fowleri?
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Primary amebic meningoencephalitis (PAM)
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How does Naegleria fowleri enter the host?
|
Contaminated water gets into the nose; enters through olfactory lobes
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If untreated, how rapidly will death occur with N. floweri infection?
|
3-6 days
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Most common intestinal protozoa in the US
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Giardia lamblia
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Route of transmission of G. lamblia
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Oral fecal route, food contamination
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Giardia lamblia is an invasive species (T/F)
|
False; G. lamblia does not invade, but may cause malabsorption in the intestine, which is symptomatic
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Visual characteristics:
- 10-20um x 5-15um - bilateral symmetry - central axoneme - 2-4 nuclei (1-2 on each side) - troph has flagellae |
Giardia lamblia
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What amoebic parasite is associated with Enterobius vermicularis (pinworm)?
|
Dientamoeba fragilis
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What nonpathogenic species is similar to Giardia? How is it different?
|
Chilomastix mesnili; C. mesnili has a spiral groove known as a "shepherd's crook"
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Trichomonas vaginalis moves via:
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4 anterior flagellae and an undulating membrane
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Trichomonas vaginalis forms cysts (T/F)
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False; T. vaginalis exists only as a trophozoite
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Trichomoniasis symptoms
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- frothy, yellow, foul-smelling vaginal discharge
- burning on urination - urethrtitis - treatment: metranidazole |
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How is Trichomonas hominis different from pathogenic T. vaginalis?
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Has trailing flagella and undulating membrane along entire length of body
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Leishmania or T. cruzi amastigotes (depending on body site)
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Genus/sepcies/stage
What's the arrow pointing to? |
Entamoeba histolyticum
Arrow: chromatoid body |
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Left: <10 um
Right: <12 um |
Entamoeba hartmanni
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Entamoeba coli (note >4 nuclei with eccentric karyosomes)
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Entamoeba gingivalis troph (note consumed WBC)
|
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(Iodine stain)
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Iodamoeba butschlii
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Acanthamoebia spp cyst
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>40 um
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Balantidium coli (kidney shaped nucleus the giveaway)
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Giardia lamblia troph
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Of Leishmania tropica causes an acute infection (T/F)
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False; L. tropica causes a year-long chronic infection
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This Leishmania species causes an acute infection lasting 3-6 months; lesions occur primarily on the lower limbs with ulceration
|
Leishmania major
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Leishmania mexicana and Leishmania braziliensis cause [disease] in [location] and [location], respectively
|
cutaneous leishmaniasis;
Mexicanis: Texas to Brazil Braziliensis: Peruvial andes |
|
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Visceral leischmaniasis
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Caused by Leischmania donovani
- long incubation period - Spiking fever, chills, sweating, diarrhea, weight loss - Splenomegaly and hepatomegaly from RES infection - Untreated: death within 2 yrs |
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Infective form/stage of Leischmania
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promastigote
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Espundia
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AKA mucocutaneous leishmaniasis
Ulcers on the oral or nasal mucosa; caused by L. braziliensis, L. tropica, L. major |
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Phlebotomus sandflies carry which Leishmania species?
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L. donovani
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