Parasitology (Week 6)Blood and tissue Parasites

Leishmania

All ____________________ are transmitted by the sandfly intermediate host, phlebotomus spp. The bite of the sandfly initially results in a self-healing skin lesion at the bite site.

Ticks

Babesia is also a sporozoan, and resembles the ring forms in malaria. ____________ are the definitive host, and the disease is transmitted to humans. Endemic to the Northeastern US, particularly associated with Marthas Vinyard and Nantucket. Also found in California, but with a less severe disease state.

Plasmodium falciparum

Causes malignant malaria. It is the most deadly form of malaria. Causes high fevers, bloody urine, massive hemolysis, brain damage (clumping of red cells that block capillaries) and subsequent rapid death. Infection can result in severe blackwater fever and renal failure.

Plasmodium ovale

Causes ovale malaria. Similar to vivax, invades younger cells and retics. Causes relapses. Malarial parasites do not enlarge RBC's, but do cause irregular cell margins.

intracellularly

Leishmania: The bite of the sandfly initially results in a self-healing skin lesion at the bite site. The lesion may last up to 1 year, and may be wet or dry. The amastigote (LD bodies) form may be found multiplying ________________ in local macrophages or the lesion.

reticulocytes

P. vivax preferentially invades _______________ and immature RBC's.

95%

Plasmodium falciparum: Only two forms present in the peripheral blood. Ring forms. Mature gametocytes (banana shaped) Infects mature RBC's. P falciparum and P vivax combined constitute ______________ of malarial infections.

Trophozoites

Plasmodium malariae: Causes quartan malaria. Causes relapses. Remissions and recurrences which may occur not for many years. Primarily a rural disease, incidence is increasing due to drug resistant malarial strains. P malaria can invade older RBC's. ____________________________ form a band across the RBC. Do not contain Schuffners, but do contain black pigment in the cells.

tertiary

Plasmodium vivax: Causes benign _______________ malaria. The most widely disseminated and most prevalent parasite causing malaria. P vivax can cause relapses, starting again years after the initial infection sequence.

sporozoites

Plasmodium: Sporozoan which causes malaria. Infected mosquito bites a human and injects infective __________________ which enter the blood vessels.

liver

Sporozoites (gametocytes) travel via the blood and invade the _____________ cells. They develop into merozoites which escape from the liver and invade circulating rbc's.

locomotion

The Sporozoans: Obligate endoparasitic protozoa. No apparent organelles of _______________.

trypomastigote

The _________________ form of the flagellate can be found in a human blood smear or in tissues, such as lymph nodes.

arthropod (insect)

The pathogenic trypanosoma and Leishmania flagellates are found multiplying in the blood (hemoflagellates) or tissue of humans. All species require an _________________ vector.

Babesia

The ring forms of ______________ are often referred to as a "Maltese cross."

Plasmodium ovale troph

What picture is this? (On slide)

Plasmodium vivax

Which Plasmodium will the RBC's enlarge with Schuffners dots (red pigment) in the red cell?

Leishmania tropica

_____________________. Cutaneous or Old World Leishmaniasis.

Trypanosome cruzi

________________________. Chagas' disease Carried by the reduviid bug; the bug bites and fecally contaminates the wound and the trypomastigote is scratched into the wound.

Leishmania braziliensis

__________________________. Mucocutaneous or New World Leishmaniasis.

Leishmania donovanii

___________________________. Visceral leishmaniasis, Kala azar, Dum Dum fever.

Trypanosome brucei gambiense

_______________________________________. West African sleeping sickness. It is carried by the Tse Tse fly; the trypanosome is injected into the human when it bites.

Trypanosome brucei rhodesiense

_________________________________________. East African sleeping sickness. It is carried by the Tse Tse fly; the trypanosome is injected into the human when it bites.