Malaria Module - Krafts Flashcards
Where is malaria most prevalent?
Sub-Saharan Africa (90% of deaths)
What causes malaria?
Plasmodium, a Protozoa
What is the cause of the pigmentation in infected malarial cells?
Hemoglobin is broken down to alpha-hematin, which is toxic and pink. Then the parasite converts the hematin to hemozoin.
What mosquito transmits malaria?
Anopheles Mosquito
What are the 3 plasmodium that have a low parasite burden and cause a mild anemia?
Plasmodium vivax (relapse) Plasmodium ovale (relapse) Plasmodium malariae
What is the plasmodium that has a high parasite burden, causes severe anemia, and has a high fatality rate?
Plasmodium falciparum (causes cerebral and multi-organ symptoms)
What are the most common plasmodium?
Plasmodium falciparum
Plasmodium vivax
What is the infectious stage of the plasmodium?
Sporozoites that infect the liver to form hepatic schizonts
What is a trophozoite?
After the ring form, the trophozoite begins to reproduce the protozoan particles.
What is a merozoite?
The infectious particles that can go on to infect other cells.
What plasmodium are Schuffner’s dots found in?
P. ovale and P. vivax
What plasmodium are enlarged red cells found in?
P. ovale and P. vivax
Why is malaria from Plasmodium falciparum worse?
Red cells of any age can be infected
Characteristics of Plasmodium falciparum red cell pathology
Rosettes
Abnormal binding to endothelium
Blood flow impeded
What is the main cause of death in children from Plasmodium falciparum?
Cerebral ischemia
What are some of the symptoms caused by Plasmodium falciparum that are attributed to TNF, INF-y, IL-1?
Suppress red cell production
Causes fever
Tissue damage
Red cell binding to endothelium
How does the spleen become enlarged in a malarial patient?
Super-active spleen macrophages eat the red cells infected with parasites
Causes fibrosis, grayish color
How do the brain vessels become plugged up in a malarial patient?
Red cell rosettes
Hypoxia around vessels
Ischemia
What happens to the liver in a malarial patient?
Enlarged and Pigmented liver
What is the time frame for infection?
Incubation 1-2 weeks
Prodrome: flu-like illness
Paroxysms with fever, chills, sweating, myalgia
Describe Quotidian fevers and what causes it.
Fevers daily with P. falciparum
Describe Tertian fevers and what causes it.
Fevers every 48 hours with P. vivax and P. ovale
Describe Quartan fevers and what causes it?
Fevers every 72 hours with P. malariae
What are some inherited red cell alterations that can help in resistance to malaria?
Hemoglobinopathies (sickle cell)
Thalassemias
G6PD deficiency
RBC antigens (ABO, Duffy)
How can partial immune mediated resistance help in resistance to malaria?
Develops over time in patients in endemic areas
Reduces severity of disease
P. falciparum uses antigenic variation
How is malaria diagnosed?
1) Clinical symptoms with appropriate history
2) Identify plasmodia in RBC on regularly-stained blood smear (gold standard)
3) Rapid immunochromatographic tests (quicker, but less accurate)
