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70 Cards in this Set
- Front
- Back
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How is the protozoan disease Leishmaniasis trasmitted to humans?
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Female sandfly vector bite
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What is the lifestyle of this protozoan?
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Leishmania are ingested by macrophages and live within the phagolysosome and are released during cell lysis
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What 2 types of strains of Leishmania exist?
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Dermatotrophic and Viscerotropic
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What are the 3 clinical syndromes that Leishmania infection presents with?
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Cutaneous, Mucocutaneous, and Visceral
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Describe the Cutaneous syndrome caused by Leishmania
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localized painless ulcerative lesions that leaves hypo-pigmented, depressed scar when healed
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Describe the Mucocutaneous syndrome
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after the cutaneous syndrome, the parasites disseminate to mucous membranes and cause destruction years later (L. braziliensis only)
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Describe the visceral syndrome
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Parasites disseminate to liver, spleen, bone marrow causing: fever, cachexia, splenomegaly, pancytopenia, hypergammaglobulinemia
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What are 2 risk factors for clinical disease caused by Leishmania?
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Malnutrition and immunocompromised status
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How do you diagnose Leishmaniasis?
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A good travel history, tissue biopsy, tissue scrape (only cutaneous), or tissue aspirate (except visceral). Giemsa stain samples, culture parasite, or do PCR. Also serology for visceral type
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How do you treat Leishmaniasis?
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Antimonials (containing Antimony) like Pentostam or glucantine).
Pentamidine or amphotericin B for serious disease |
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How can you prevent Leishmaniasis?
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Insecticide and avoiding outside in the evening when the sandflies are out (sounds like the sandpeople from starwars)
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What 2 clinical syndromes are caused by Schistosomiasis?
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1) Liver/large intestine/rectal
2) Urinary/Kidney |
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What animal transmits schistosomiasis to humans?
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Acquatic snails (mainly in Africa)
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Do the infectious Cercariae enter humans and cause schistosomiasis have tails?
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yessir
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Where do these waterborne flukes live in humans?
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venules of the organ where they are causing pathology
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Which of the 2 syndromes do S. mansoni and japonicum cause?
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The liver/intestinal one
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Which of the 2 syndromes do S. haematobium cause?
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The renal one
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When eggs from the Schistosomes fail to be released from the human, what happens?
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They form granulomas and scarring in the liver or bladder
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What is swimmer's itch?
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the initial schistosomiasis infection that causes an itchy rash when the parasite enters the human skin
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What is Katayama Fever?
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the acute schistosomiasis disease when they migrate to the lung (immune-complex to eggs reaction) causing fever, hives, hepatosplenomegaly, bronchospasm
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During chronic schistosomiasis what causes pathology?
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granulomas from inflammation can obstruct urine and blood flow. this blood loss and inflammation causes growth retardation, malnutrition, and cognitive problems
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What are 2 complications caused by the urinary form of schistosomiasis (S. haematobium)?
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hydronephrosis (urine blockage) and a rare bladder cancer
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What are 2 complications of the liver/intestinal form of schistosomiasis (S. mansoni/japonicum)?
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Cirrhosis and esophageal varices
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How do you diagnose Schistosomiasis?
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Eggs (in urine for haematobium and in stool for mansoni/japonicum)
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How do you treat schistosomiasis?
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Praziquantel
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What is the vector and primary host for Toxoplasma gondii?
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Cats and other felines
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What are 4 ways for humans to acquire Toxoplasma?
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Ingesting oocysts from fecal contamination, eating tissue cysts from undercooked meat, vertical (placental), or blood transfusion
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Is T. gondii an intracellular pathogen?
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Yes
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What are some symptoms of toxoplasmosis?
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symmetrical, non-tender cervical ymphadenopathy with fevers, aches
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what is the most common parasitic CNS opportunistic infection in HIV/AIDS patients?
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Toxoplasmosis
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What are some serious manifestations of reactivated Toxoplasma in AIDS patients?
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chorioretinitis, pneumonitis, ring-enhancing edematous brain lesions
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Although congenital Toxoplasmosis is only in 10% of cases, list the 3 serious complications
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chorioretinitis, hydrocephalus, and intracranial calcifications
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How do you diagnose Toxoplasmosis?
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serology, PCR, or direct tissue examination
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How do you treat Toxoplasmosis?
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Bactrim (sulfa drugs)
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What types of Trypanosomiasis are there are what diseases do each cause?
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1) American (Chagas disease)
2) African (sleeping sickness) |
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What 2 subspecies of Trypanosomes cause the African type?
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Trypanosoma brucei gambiense (W. Africa) and rhodesiense (E. Africa)
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Which organism is transmitted by the river vector Glossinia palpalis?
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the West Africa gambiense type
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Which organism is transmitted by the savannah vector Glossinia morsitans?
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The East Africa rhodesiense type
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What are these Glossinia vectors?
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The tsetse fly
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What is the first clinical sign of African trypanosomiasis?
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a chancre at the bite site that progresses to lymphadenopathy
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What is winterbottom's sign?
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A soft, painless mobile posterior cervical llymph node that indicates trypanosomiasis (African type)
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What are some other early signs of african trypanosomiasis?
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wasting, fever, organomegaly, carditis
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What are some symptoms as the disease progresses into the CSF?
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lethargy, insomnia, seizures, coma, hemorrhage (cerebral), multifocal white matter demyelination, cachexia, malnutrition
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Does the East or West African variant progress slower?
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West African gambiense from the palpalis tsetse fly occurs much slower
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How does trypanosome avoid the host immune system?
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the parasite surrounds itself with a coat of variant surface glycoprotein
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How do you diagnose trypanosomiasis?
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microscopy of blood smear or an LP
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How do you treat African sleeping sickness?
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Early (pentamidine)
Late (arsenic containing melarsoprol) or (eflornithine) |
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What are some sign's of American trypanosomiasis?
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fever, blood parasites, pericardial effusion, myocarditis, and Romano's sign
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What is Romano's sign?
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palpebral edema
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What are some chronic disease effects of American trypanosomiasis?
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cardiomyopathy, mega-colon, mega-esophagus
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Waht is the organism that causes American trypanosomiasis?
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Trypanosoma cruzi
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What is T. cruzi's lifecycle like?
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invades phagolysosome of macrophages or muscle cells
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How do you diagnose T. cruzi infection?
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microscopy, IF, PCR
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How do you treat T. cruzi?
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Benznidazole or nifurtimox
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What is the most common parasitic disease?
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Malaria (5 species)
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How is malaria transmitted to humans?
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bite from female anopheline mosquito
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What is the lifecycle like for Plasmodium?
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obligate intracellular that invades RBC's then ruptures them and moves on
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What are the 2 important Plasmodium species?
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P. falciparum (Africa) and P. vivax (elsewhere)
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What cells does P. vivax invade?
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Reticulocytes
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What cells does P. falciparum invade?
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All stages of RBC's
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Why do antimalarials not usually cure P. vivax?
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it has dormant stages in the liver (hypnozoites)
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What does malaria look like clinically?
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asymptomatic until red cells are lysed to release new merozites which causes shaking chills and very high fever (every 3 days)
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What are some severe effects of malaria?
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coma, seizure, anemia, renal failure, low birth weight (antigens that adhere to placenta)
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Which Plasmodium species is the most dangerous and drug-resistant?
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P. falciparum
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What genetic variations in humans are advantageous and make the RBC inhospitable to Plasmodium?
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Sickle cell trait, thalassemia, and G6PDH deficiency
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What are some genetic variations that prevent invasion of Plasmodium into the RBC?
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Ovalocytosis (rigid membrane) and absence of Duffy antigen (needed by P. vivax)
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How do you diagnose malaria?
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Giemsa stain, PCR, rapid diagnostic tests
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How can you help prevent malaria?
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insecticide bed nets, spraying with DDT
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What is the standard malaria treatment?
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ACT (Artemisinin Combination Therapy - Artemisinin+antimalarial)
Chloroquine (P. vivax) + primaquine for latent hypnozoites |
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Why can you not treat pts with G6PDH deficiency with primaquine?
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Causes hemolytic anemia
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