Blood and Tissue Parasites (part II) Flashcards
Babesia species: List four species which are known human pathogens
Theileria (Babesia) microti
Babesia divergens
B.ducani
Babesia spp. MO-1
Most common Babesia specie which is found in the Northeast USA, Nantucket island.
Theileria (Babesia) microti
Babesia species: Distribution
World wide
Babesia divergens (mainly Europe)
B.ducani (western USA)
Babesia spp. MO-1 (Midwerstern USA)
Babesia species: Incidence of _____
babesiosis (US) (most cases in New England, Minnesota, and Wisconsin)
Babesia species: Epidemiology
Ticks bites (deer tick and brown dog tick) transmit the parasite to human or mouse hots
Babesia species: Host in natures
Use white footed mice and ticks as hosts
Babesia species: Transmission
- Transmission has also occurred through blood transfusions!!!!! (2 cases in Indiana-both recipients died)
- Vertical transmission (going from mom to baby)has also occurred
Babesia species: Infectious form
merozoite form; Maltese cross
Babesia species: Symptoms
most asymptomatic; having no spleen makes a person more prone to severe or fatal disease
Babesia species: Diagnosis thorugh microscope
- Examination of a Giemsa or Wright -giemsa stained blood smear
- Presence of ring form and characteristic merozoite in and outside of red cells; multiple rings and merozoites per cell
Babesia species: Two other methods used in diagnosis
IFA-for detection of antibodies to Bebesia species
Molecular method-real time PCR for species which can speciate the organisms
How can we distinguish Bebesia spp. from Plasmodium spp.?
Clinical and travel histories; Bebesia produces racket shaped merozoites; rings and merozoite are only seen in babesiosis; there are extracellular parasites seen in babesiosis
Plasmodium species: causative agents of ____
malaria
Plasmodium species: ____borne protoza
Mosquito
List five different species of Plasmodium that are known to cause malaria in humans
-P.falciparum, P. malariae, P.ovale, P.vivax, P. knowlesi. (first four most common)
Plasmodium species: distribution
Tropical and subtropical regions–mostly in Africa
Plasmodium species: incidence of _____
Malaria
Plasmodium species: complete life cycle requires two hots:_____ & _____
mosquitoes and humans
Plasmodium species: What type of mosquitoes found?
Anopheles species mosquitoes
P.falciparum: Epidemiology and incidence
Widespread, globally; predominant cause
P. malariae: Epidemiology and incidence
Widespread, globally; less frequently seen causes
P. ovale: Epidemiology and incidence
predominately in sub-Saharan Africa, other areas also
P.vivax: Epidemiology and incidence
wide range than P.ovale, and their niches overlap; second most predominant cause
P.knowlesi: Epidemiology and incidence
Southeast Asia; very rare cause
Plasmodium species: two types of cycles
Exo-erythrocytic (occurs in liver
Erythrocytic
Plasmodium species: Important notes about P.ovale and P.vivax in life cycle.
They both can stay dormant in liver—> diseae can relapse weeks or years later.
RMR: with P.ovale and P.vivaz “IT’s not OVer!!
Plasmodium species: symptoms
- Blackwater fever: intravascular hemolysis, dark urine from Hgb; malaria caused by P.faciparum can be very dangerous!!
- (fever, chills, fatigue, muscle aches, joint aches, diarrhea, vomiting, neurologic change)
Plasmodium species: Types of blood smears used for examination
-Examination of a Giemsa or Wright-Giemsa stained blood smears
Plasmodium species: Things to look for when examining the stained blood smears.
- Presence of ring forms, schizonts, gametocytes
- Chuffner’s dots in P.ovale & P.vivax
- Thin and thick smears should be looked at
Plasmodium species: two other methods for diagnosis
Molecular methods-PCR and Antigen detection-lateral flow test
Plasmodium species: microscopic exam can be fixed with _____.
Methanol-RBCs will not lyse
Plasmodium species: microscopic exam- why do we not fixed with methanol?
You need the RBCs to lyse
No Schuffner’s stippling
P.falciparum and P.malariae
Infects normal sized or smaller than uninfected RBCs
P.falciparum
Primarily ring forms seen in RBCs (applique form) and Multiple rings/RBCs, often hanging off the edges.
P.falciparum
Gametocyte appearance of P.falciparum
Banana shaped
infects normal to slightly larger RBCs
P.malariae
May see band form trophozoites which looks like RBC is wearing a belt.
P.malariae
No stippling and may have few Schizonts usually arranged in a rosette. And Gametocytes are round; may have dark brown pigment
P.malariae
Infected RBCs larger than uninfected RBCs and RBCs are enlarged; many are fimbriated or round or oval
P.ovale
Schuffner’s stippling present with granules are much larger and darker
P.ovale
Schizont (RBC in which parasites are undergoing asexual reproduction) contains 6-14 merozoites
P.ovale
Often infects larger sized RBCs than uninfected RBCs and Schuffner’s stippling present
P.vivax
Schizont is larger and contains 12-24 merozoites
P.vivax
Which organisms have growing trophs (rings), and gametocytes?
All plasmodium species
Plasmodium species: Diagnosis through microscope
- Must distinguish plasmodium spp from babesia spp
- p.knowlesi, looks very similar to P.falciparum-PCR can discriminate the two
Plasmodium knowelsi and P.falciparum look very smiliar how can we differentiate?
PCR can discriminate the two
