What is the causative agent of malaria? How is it transmitted?
Transmitted by female anopholes (mosquitoes)
Name 4 species of Plamodium that are malarial parsites
Malignant tertian, capable of high density parasitemia progressing rapidly to massive hemolysis
Benign tertian, predominant species of Malarial parasite
Most benign form of malarial parasite
Uncommon form of malarial parasite except in West Africa and isolated areas of South America and Asia
Plasmodium Erythrocyte Cycle: Merozoites from liver or RBCS infect new RBCs by transforming to uninucleat trophozoites
Plasmodium Erythrocyte Cycle: Merozoites from liver or RBCS infect new RBCs by becoming multinucleated schizont or differentiating into gametocytes
Forms a banana-shaped gametocyte
Malaria pathogenesis is related to the _____ cycle
Lysis of infected RBCs is prominent in
Which disease causes RBC Cytoadherence: Infected rBC membranes altered, cells coalesce to form thrombi, stick to capillary endothelium, produce local tissue anoxia.
Which malarial pigment from hemoglobin breakdown is phagocytized in the liver and spleen? It causes organs to enlarge, kidneys to become plugged, brain capillaries to become congested and the brain to become edematous.
What two forms of malaria can cause spleen rupture?
Vivax and Quartan malaria
Vivax and Quartan malaria cause
rupture of spleen
Incubation period of malaria?
What can make incubation period shorter?
What can delay onset?
Transfusion incubation is shorter.
Prophylactic drugs delay onset
4 Symptoms ALL species of malaria cause
Fever, chills, anemia, and splenomegaly
Malarial Paroxysm: Chills - Fever- Sweat
P. vivax, ovale = ___ day cycle
P. malariae- ___ day cycle
Infection with what form of malaria represents a medical emergency?
P. falciparum (severe paroxysm of 12-36 hours with continuous fever)
Parasites in the peripheral blood not completely eradicated, possible with which species?
Recrudescence, possible with all species of plasmodium
Relapsing infection: Involves ______ in liver parenchyma cells that re-infect RBC months/years later. Which two forms of Plasmodium have this commonly?
P. vivax and P. ovale
P. vivax and P. ovale relapsing infection involves hypnozoites in ______________ that re-infect RBC months to years later.
Liver parenchymal cells
Most common complication of malaria
Capillary blockage in brain
Progressively severe heacheache w/o early fever
Sudden high fever (108 F)
Convulsions or delirium
Mistaken for acute alcoholism
Rapid collapse (coma) due to anoxia, cerebral edema, increased spinal fluid pressure
Acute intravascular hemolysis
Hemoglobinuria, hemoglobinemia, and renal insufficiency
Most frequent in which form of plasmodium?
Blackwater Fever (Renal complication)
Most common in P. falciparum (also present in Vivax and Malariae)
Severe P. falciparum or repeated P. malariae infection can cause
Which two plasmodia can cause renal disease?
P. falciparum or P. malariae
Speciation is important in diagnosis or malaria because
it determines tx!
Pimaquine phosphate (Pv and Po relapses)
How to treat Chloroquine resistant Pf and Pv
Take Chloroquine phosphate durg one week before exposure, continue four weeks after return
Causative agent of Babesiosis
Transmission of Babesiosis
Hard ticks, nymph stage
Most Babesiosi US cases are from
Babesia microti, a parasite of rodents
Other cases are from B. divergens and B. duncani
Pleomorphic, ring-like structures in RBCs
Resemble early trophozoite form of P. falciparum (but RBCs are not enlarged or pale)
Clindamycin plus quinine
Atovaquone plus azithromycin
Splenectomized person exposed to ticks has high risk of developing.
Hemoflagellates are in the order ____ and the family ____
A single DNA containing mitochondrial organelle where the flagellum originates
Two parasitic genera in the Trypanosomatidae
Causative agent of Chagas' Disease
Causative agent of East African sleeping sickness
Causative agent of W. African sleeping sickness
3 species in Trypanosoma genera and what they cause
T. cruzi- Chaga's disease
T.b. rhodesiense- E. African sleeping sickness
T.b. gambiense- W. African sleeping sickness
3 species in Leishmania genera
L. donovani- Visceral leishmaniasis
L. tropica/major/mexicana- Cutaneous sores
L. braziliensis- Mucocutaneous sores
Causative agent of visceral leishmaniasis
L. tropica/major/mexicana causes
L. braziliensis causes
How is Chagas disease transmitted?
Reduviid bug feces containing T. cruzi are scratched into bile site or enter via mucous membranes
What is unique about the Trypmastigotes of T. cruzi in the peripheral blood?
They do NOT divide
What form of T. cruzi does NOT divide in the peripheral blood?
A local histiocytoma with fibrous border that blocks lymphatics and causes edema (frequently on face) after infection with T. cruzi
Two disease phases of Chagas
Which form of T. cruzi in Chagas lacks flagella, but has a nucleus?
Intracellular amastigote stage
Only form of T. cruzi present in chronic Chagas
Intracellular amastigote stage
Causes heart problems, CNS problems, thyroid problems, megacolon, and megaesophagus (dysphagia and constipation)
Pt. presents with travel, lymphadenopathy and myocarditis
Pt. presents with travel, cardiomegaly, conduction defects, and dysphagia
Definitive diagnosis of Acute (febrile) phase of Chagas
Demonstration of trypomastigotes in peripheral blood
T. cruzi tx?
Acute Phase: Benznidazole (contraindicated in pregnancy), Nifrutimox
Chronic phase: Benznidazole (drug effectiveness usually limited, but limits progression)
Tramission of Leishmaniasis
(Phlebotomus- Old World)
Leismania amastigoes- mammalian intracellular stage:
1) _______ phagocytized by macrophages of the _____
2) Transform to intracellular amastigotes (note ___ & ___)
3) Proliferate in __________
4) Other cells can be invaded
5) May spread and can remain latent for years
1) Promastigotes, skin
2) nucleus and kinteoplast
3) parasitophorous vacuoles
Characterized by dermal infiltrates of lymphocytes, plasma cells and macrophages filled with Leishmania