L25 (Blood and Tissue Protozoans) - B Flashcards
_____: An acute infectious disease of the blood caused by 1 of 4 species of the protozoal genus, Plasmodium
Malaria
Which two ways can plasmodial parasite be transmitted?
- Bite of female Anopheles mosquito
- Use of blood-contaminated needle
Plasmodium vivax only infects ___ cells while Plasmodium malariae infects only ____ cells
A. Leukocytes; Granulocytes
B. Granulocytes; Reticulocytes
C. Reticulocytes; RBC
C. Reticulocytes; RBC
Benign Tertian Malaria causes a fever every third day due to highly synchronous 48 hr life cycle?
Which microbe is this disease associated with?
A. Plasmodium vivax
B. Plasmodium malariae
C. Plasmodium falciparum
A. Plasmodium vivax
Malignant tertian malaria is associated with fever cycle every 3rd day (similar to: Benign Tertian Malaria) – however, it tends to be less synchronous than other species.
Which microbe is most closely associated with this condition?
A. Plasmodium vivax
B. Plasmodium malariae
C. Plasmodium falciparum
C. Plasmodium falciparum
_____ is the most severe form of malaria and can cause high level of parasitemia because it is able to infect RBC’s of all ages!!!
A. Plasmodium vivax
B. Plasmodium malariae
C. Plasmodium falciparum
C. Plasmodium falciparum
Which of the following causes Quartian malaria (characterized by fever spikes every 4th day due to synchronous life cycle of 72 hrs)?
A. Plasmodium vivax
B. Plasmodium malariae
C. Plasmodium falciparum
B. Plasmodium malariae
The trophozoites of ___ ___are often band-shaped. However, RBC’s are not enlarged and there is no Schuffner dots.
A. Plasmodium vivax
B. Plasmodium malariae
C. Plasmodium falciparum
B. Plasmodium malariae
True or False: Plasmodium falciparum is associated with RBC’s that contain Schuffner dots
False - this is seen in Plasmodium vivax
_____: “Ovale” malaria (characterized by 3rd day cycle – similar to P. vivax, but milder). It is the least common of all species.
Plasmodium Ovale
Schuffner cells are associated with ____ and ____
P. ovale and P. vivax
______: Originally known to infect macaque monkeys of South Pacific – unclear if mosquitos are needed for transmission. Therefore: it is still considered to be a zoonotic malaria.
Only able to identify via: genotyping!!!!!!
A. Plasmodium vivax
B. Plasmodium malariae
C. Plasmodium falciparum
D. P. knowlesi
D. P. knowlesi
True or False: Obligate intracellular protozoan parasites cause malaria
True
Memorize this, ok???
True or False: The male Anopheles mosquito is the vector of malaria
False - the female Anopheles mosquito is the vector of malaria
What is the name to describe the sexual phase of the malaria life cycle? the asexual phase?
sexual = sporogony
asexual = schizogony
Compare and contrast schizogony and sporogony:
Sporogony (sexual phase) occurs in the ___ (definitive host) while
Schizogony occurs in the ____ (intermediate host)
mosquito
human
How do sporozoites form in sporogony?
Union of female and male gametes (infective in humans)
True or False: The sporozoite corresponds to infective stage in malaria
True
What can cause malaria relapse?
Hypnozoite
What does the exo-erythrocytic cycle ( 1 round only! ) of P. Vivax produce?
Schizont
Hypnozoite
Merozoite
Which molecule of P.vivax lifecycle infects RBC?
A. Schizont
B. Hypnozoite
C. Merozoite
C. Merozoite
True or False: Ring stage is the diagnostic stage of malaria
True
Compare the erythrocytic cycle of P. vivax to that of the Erythrocytic cycle:
When a mosquito takes a blood meal it injects _____ and ingests ____
injects = sporozoites
ingests = gameteocytes
True or False: The gametocyte allows for sporogony / sexual stage to begin
True
In the malaria life-cycle, ___ are ingested when mosquito first takes blood meal.
____ are formed within mosquito (sexual stage)
Gametocytes; sporozoites
In the malaria life cycle, sporozoites migrate through blood stream to liver, where they form ____ (differentiates into hepatic ____ with merozoites)
merozoites; schizonts
In the malaria life cycle, infected hepatocytes rupture and release merozoites, which invade RBC. However, ____ remains in the liver.
Hypnozoites
In the malaria lifecycle, the merozoite becomes the ____ (ring form) in RBC
trophozoite
True or False: In malaria life cycle, there are RBC in which trophozoite multiplies, producing new merozoites (differentiates into an erythrocytic schizont with merozoites)
True
In malaria lifecycle, ___ are released when RBC rupture and can infect other RBC’s. In fact, some become gametocytes!
A. tropozoites
B. merozoites
C. sporozoites
B. merozoites
_____ are an infective form for humans found in salavary gland of female anopheline mosquito
A. Trophozoites
B. Merozoites
C. Sporozoites
D. Hypnozoites
C. Sporozoite
Where does the sporozoite seen in malaria quickly home into? What does it become there?
Homes into liver parenchyma
Becomes: hepatic schizont
____: Latent form found in hepatocytes, may persist for months to years before rupturing and releasing merozoites
A. Trophozoites
B. Merozoites
C. Sporozoites
D. Hypnozoites
D. Hypnozoites
Which two species (those that cause relapsing malaria) produce Hypnozoite?
- P. vivax
- P. ovale
____: refers to reactivation of infection by hypnozoites
Relapse
_____: Actively growing amoeboid feeding forms (ring forms) that are found intracellularly in RBC’s and develop into schizonts with more merozoites
A. Trophozoites
B. Merozoites
C. Sporozoites
D. Hypnozoites
_____: Form developed from a trophozoite that has undergone asexual multiplication
A. Trophozoites
B. Merozoites
C. Sporozoites
D. Hypnozoites
E. Schizont
E. Schizont
True or False: Each schizont (erythrocytic) contains a species-determined number of merozoites
True
Hepatic and Erythrocytic ____ are the end products of schizogony (asexual phase)
A. Trophozoites
B. Merozoites
C. Sporozoites
D. Hypnozoites
E. Schizont
B. Merozoites
True or False: Merozoites are the daughter cells of a schizont and are release from liver parenchymal cells or RBC’s
True
_____: Pre-gamete stages which can mature into gametes when acquire by an Anopheles mosquito
Gametocytes
True or False: Microgametes are found in males while macrogametocyes are found in females – together, these continue the sexual cycle
True
____ are the target of vaccine development
Sporozoites
____ and ____ form hyponozoites while ___ and ____ do not
P. vivax/ovale - do
P. falciparum/malariae - do NOT
True or False: Schizonts and mature trophs of P. falciparum are easy to find in peripheral circulation
False - usually only in ring forms, merozoites, immature trophs, gametocytes
What triggers cyclic paroxysms?
Synchronous 1) rupture of infected erythrocytes 2) release of merozoites
____: Sudden recurrence of disease
____: Abatement of fever
Paroxysm
Defervescence
If a patient has non-specific symptoms that may be mistakes for viral syndrome or influenza, which stage of malaria may they be in?
A. Prodrome
B. Paroxysm
A. Prodrome
- Early synchronicity of infection
High fever, chills, and rigor that is caused by synchronous lysis of RBC’s and release of merozoites + metabolic waste products describe which key symptom of malaria?
A. Prodrome
B. Paroxysm
B. Paroxysm
Most of the pathologic findings of malaria result from destruction of ___
RBC’s
What are two ways that RBC’s are destroyed in malaria?
1) Release of merozoites
2) Action of spleen to sequester infected cells + lyse them
How can one develop cerebral malaria from infection by P. falciparum malaria?
Occlusion of capillaries
Why can P. falciparum malaria lead to hemoglinuria?
1) Extensive hemolysis + kidney damage
2) Blackwater fever
3) Acute renal failure
How do you dx malaria?
Thick and thin blood stained with Giemsa stain
True or False: In malaria dx, Thick Blood Smear is used to screen for PRESENCE of organisms while Thin Blood Smear is used for species IDENTIFICATION
Tru
How to provide malaria prophylaxis to travelers?
Vaccine
- Targets induction of Ab against sporozoite surface proteins
___ ____: A sporozoan that can cause Babesiosis.
Babesia microti
How is B. microti similar to malaria? different?
Similar - both intra-erythrocytic protozoan parasites
Differences
- B. microti’s vector is a tick and reservoir is white footed mouse
True or False: B. microti has exoerythrocytic cycles (liver stages) like malaria
False - unlike malaria, B. microti does NOT have exoerythrocytic cycles
___ is accidental and intermediate host of B. microti
Human
How is Babesiosis transmitted?
Bite of infected tick
Clinical manifestations of Babesiosis?
Persistent fever, but not recurrent!!!
What abnormal lab finding would suggest Babesiosis?
-Lysis of RBC by parasite
- Elevated liver tests
- Hemolytic anemia
- Elevated reticulocyte
A “maltese cross” suggests which condition?
Babesia
______: A tissue protozoan (sporozoan) and obligate intracellular parasite causing systemic disease
T. gondii
What are the two trophozoite form of T. gondii that are found in humans?
1) Tachyzoite: Actively proliferating trophozoite that can infect any nucleated cell, but has predilection for MONONUCLEAR PHAGOCYTES
2) Bradyzoite: Cyst or pseudocyts that harbors dormant form (predominately found in brain, skeletal m/cardiac m)
Which animal is the definitive host of T. gondii?
Cat
- Humans are intermediate (dead end host)
If human hosts are infected with T. gondii, they will likely form ___ ___ (skeletal m, brain, eyes, myocardium)
tissue cysts
True or False: In T. gondii, infected macrophages distribute tachyzoites throughout body
True
True or False: In T. gondii, pseudocysts are produced in response to humoral immunity
False - in response to ACQUIRED immunity!
True or False: Asexual cycle occurs in all cell types in T. gondii
True
How to dx Toxoplasmosis?
1) Stain CSF
2) PCR - amniotic fluid
What happens if a healthy person gets toxoplasmosis vs. a baby (congenital)??
Healthy
- asymptomatic
- mild, flu
Congenital
- stillborn
True or False: Retinochoroiditis is a severe eye disease that can arise as a result of Toxoplasmosis infection
True
Three ways that Toxoplasmosis can be transmitted?
1) Foodborne
2) Zoonotic
- cat
- gardening
- water
3) Congenital
Which two patient populations are at risk of exposure to Toxoplasmosis?
- Pregnant women
- Immunocompromised
