Jackson Blood Borne Parasites

Front 1

Describe the following for Plasmodium:
1. classification
2. chief characteristics
3. most common clinical presentation

Back 1

1. protozoa, sporozoa
2. complex protozoa, several life stages, mosquito vector
3. nonspecific cycles of shaking chills, fever & sweating, in a person w/history of travel to an endemic zone. anemia, demonstration of organism on blood smear

Front 2

List the four (4) main species of Plasmodia that cause malaria in humans

Back 2

plasmodium vivax, falciparum (95% of fatalities), malariae, ovale & knowlesi

Front 3

Describe the distinguishing characteristics of the most lethal Plasmodium species

Back 3

falciperum
infects all RBCs (reticulocyte -> mature RBC)
causes cerebral disease, RBCs lyse & aggregate in small blood vessels
banana shaped gametocyte

Front 4

describe the following for malaria:
1. epidemiology
2. clinical presentation
3. transmission
4. pathophysiology

Back 4

1. 100-300 million cases/yr, 1 million deaths annually, most severe in Africa. some cases in USA
2. alternating fever, chills, & sweating. splenomegaly, anemia, CNS disturbances. symptoms usually begin 10-20 days after mosquito bite
3. female mosquito
4. plasmodium life cycle

Front 5

describe the pathology of malaria

Back 5

anemia is due to RBC destruction & sequestration
organ dysfunction
-immune mediated damage as well, TNF, IL-1 & IFN-y are elevated
-thrombocytopenia & nephritis
-ischemia due to poor perfusion causes manifestations of cerebral malaria (main cause of death due to malaria in children)

Front 6

what causes the cyclic symptom presentation associated with malaria?

Back 6

due to release of merezoites & toxic substances released from lysed RBC causing an inflammatory response & symptoms. overtime, the RBC lysis syncrhonizes

Front 7

describe the immune response to malaria

Back 7

antibody & T cell response (as well as innate)
- most deaths occur in young children b/c they do not have an immunity developed against the plasmodium yet. each stage of the plasmodium displays diff antigens making it difficult to develop a vaccine

Front 8

Describe the following for Babesia:
1. classification
2. chief characteristics
3. most common clinical presentation

Back 8

1. complex protozoa
2. deer tick vector, parasite invades RBC, causes tetrad formation in RBC
3. malaise, fever, chills sweating, arthralgias, headache, myalgias, fatigue

Front 9

describe the following for babesiosis:
1. epidemiology
2. clinical presentation
3. transmission
4. pathophysiology

Back 9

1. found in northeastern, & west coast US
2. malaise, fever, chills, sweating, arthralgias, headache, myalgias, fatigue
3. deer tick vector
4. potentially fatal, esp in splenectomized & immunocompromised pt.
- tick takes a blood meal -> sporozoites enter blood stream -> trophozoite -> merezoite -> gamete -> tick takes blood meal & ingests gametes -> fertilization in tick gut -> ookinete -> sporogony -> sporozoite (infectious again)

Front 10

Describe the following for Toxoplasma:
1. classification
2. chief characteristics
3. most common clinical presentation

Back 10

1. complex protozoa
2. several forms (trophozoite, bradyzoite cyst, oocyst, sporozoite)
cats are definitive host
immature oocysts shed in cat feces
3.mononucleosis-like syndrome with fever, lymphadenopathy, rash, myalgia, chorioretinitis; usually resolves within weeks
immunocompromised: Potentially fatal encephalitis (CNS problems in 50%) – fever, headache, altered mental status, seizures, impaired cognitive function, ataxia, visual field loss, focal neurologic deficits

Front 11

Explain the significance of Toxoplasma infection for pregnant patients

Back 11

when a pregnant mother becomes infected & has not been exposed to it before, she does not develop specific immunity against it & thus toxoplasma will infect the fetus.
most severe infections occur during 1st trimester & can cause:
-chorioretinitis, hydrocephalus, brain calcifications, & hepatosplenomegaly, jaundice, fever
-children born with mild or subclinical infeciton are still at increased risk for long term sequela (ex chorioretinitis -> vision loss or retinal detachment, esp if don't recieve treatment.)

Front 12

Explain the significance of Toxoplasma infection for immunocompromised patients

Back 12

lack of specific immunity can lead to musculoskeletal & CNS symptoms
-possible association with increased risk taking behavior

Front 13

describe the transmission of toxoplasma gondii to humans

Back 13

via ingestion of uncooked meats (cow ate grass from soil infected w/it from cat feces)
- accidental ingestion of oocysts from cat feces
- in utero transmission
- blood transfusion/organ transplant

Front 14

describe the diagnosis of congenital toxoplasma infection

Back 14

serology, detecting toxoplasma - specific IgM or IgG
PCR for toxoplasma gondii nucleic acid
visualization of parasite in tissue specimen

Front 15

38 y/o HIV+ male presents w/ataxia & muscle weakness. MRI reveals lesion in frontal lobe & cerebellum, but the pt is seronegative for toxoplasma. explain the mechanism for the seronegativity

Back 15

pt has toxoplasma infection, but immune response is not normal in the pt b/c he is HIV+, thus no antibodies are produced against toxoplasma causing the false negative

Front 16

Describe the process of malaria transmission to humans and the pathogenesis of disease

Back 16

infective sporozoite is injected into blood stream which quickly migrate to liver & develop in hepatocytes -> divide & become merozoites which infect RBCs, develop w/in & lyse to infect more RBCs. also differentiate from merozoite -> gametocytes which are taken up in blood meal by female mosquito -> fuse into zygote -> oocyte + infectious sporozoite
-ALSO sporozoites -> Hypnozoites which remain dormant in liver (only w/vivax & ovale), can cause relapse yrs later.
= diff parasite stages display diff antigens
= resistance to malaria occurs w/sickle-cell trait & lack of duffy antigen

Front 17

List the precautions you would advise for someone who plans to travel to an area endemic for malaria transmission

Back 17

prophylactic medicine based on CDC recommendation for area traveling to.