MISC Qualitative Tests - Malaria Flashcards
What is the definition of malaria?
A parasitic infection caused by the introduction of the protozoan organism into the blood by the bite of a female anopheles mosquito
What is the scientific terminology for malaria parasite?
Plasmodium
What is injected into humans when bitten by a female mosquito?
Sporozoites
Where do sporozoites develop?
In the liver
What are the two development cycles of sporozoites in the liver?
- Pre-erythrocytic cycle
- Exoerythrocytic cycle
What female mosquito transfers malaria?
Anopheles mosquito
What is the life cycle of Plasmodium?
1) Female mosquito bites human
2) Sporozoites from bite enter parenchymal cells of liver to become schizonts
3) Schizonts rupture, releasing merozoites
4) Merozoites burst out of liver to invade RBC’s
What do Merozoites develop to form?
Immature (ring stage) trophozoites
What do merozoites/trophozoites feed on?
Hemoglobin inside RBC’s
What is the residue from feed on HGB called and what is it made out of?
- Malaria pigment
- Composed of hematin and protein
Where can all stages of asexual cycle be demonstrated?
In a peripheral blood smear
- With the exception of P. falciparum
What are the four types of malaria found in humans?
- Plasmodium Falciparum
- Plasmodium Vivax
- Plasmodium Ovale
- Plasmodium Malariae
Overview of P. Falciparum
- Erythrocytic cycle (Benign Tertian): fever ever 48hrs/ every 2nd day
- Most danger
- Likely to cause intravascular hemolysis
- Fever is prolonged and intensified
Overview of P. Vivax
- Erythrocytic cycle (Benign Tertian): fever ever 48hrs/ every 2nd day
- Most common
Overview of P. Ovale
- Erythrocytic cycle (Benign Tertian): fever ever 48hrs/ every 2nd day
Overview of P. Malariae
- Erythrocytic cycle (Benign Quartan): fever ever 72hrs/ every 3nd day
How long can you store a venous blood sample when testing for malaria (non-refrigerated)?
- Up to 3 days at 2 degrees Celsius to 30 degrees Celsius
What do you do with a blood sample for malaria testing if the sample has been refrigerated?
Allow it to reach room temperature (15-30 degrees Celsius) prior to performing test
What are the materials for a rapid malaria test kit?
- Rapid malaria test kit cardboard containing test strip
- Reagent A
- Capillary Tubes
- Lancets
- Optional venipuncture kit/lavender tube
What type of buffer is the Reagent A in malaria test kit?
Tris buffer containing detergent and sodium azide
How many microliters of blood is collected for malaria test?
15 microliters
What is a positive T1 for malaria?
Positive for P. Falciparum
What is a positive T2 for malaria?
Positive for P. vivax, malariae, or ovule
What is a positive T1 and T2 for malaria?
Positive for P. Falciparum and other types of malaria in a mixed infection
What are some limitations of rapid malaria kit limitations?
- Sample must be obtained when Pt is febrile
- Will only detect antigens
- Must be confirmed with a thick and thin smear for confirmation, sent to NEPMU
- Cannot be used to monitor treatment progress
What are conditions that can illicit false positives in rapid malaria?
- Rheumatoid arthritis
- Chronic viral infections (HEP C)
- Pt with other blood parasite (babesia)
What are some points to consider for rapid malaria tests?
- Collect specimen immediately after onset of fever spike for best result
- Send unstained smears to NEPMU
- Smears should be done frequently but no more than hourly
