Malaria Flashcards
Which species of Plasmodium is associated with an irregular fever pattern and severe malaria complications?
Plasmodium falciparum
Which Plasmodium species are capable of forming hypnozoites in the liver?
Plasmodium vivax and Plasmodium ovale
What is the fever cycle for Plasmodium vivax and Plasmodium ovale?
48-hour fever spikes (tertian malaria)
What is the fever cycle for Plasmodium malariae?
72-hour fever spikes (quartan malaria)
Which Plasmodium species causes daily (24-hour) fever spikes and is carried by macaques?
Plasmodium knowlesi
Which Plasmodium species is most likely to cause cerebral malaria, ARDS, and renal failure?
Plasmodium falciparum
Which Plasmodium species shows banana-shaped gametocytes on blood smear?
Plasmodium falciparum
Which species show Schüffner dots on microscopy?
Plasmodium vivax and Plasmodium ovale
Where is Plasmodium falciparum most commonly found?
Sub-Saharan Africa, Southeast Asia, parts of South America
Where are Plasmodium vivax and ovale endemic?
Southeast Asia, tropical West Africa, and the Americas
Where is Plasmodium knowlesi endemic?
Southeast Asia
What stage is injected by the Anopheles mosquito into humans?
Sporozoites
Where do sporozoites travel after entering the bloodstream?
To the liver (hepatocytes)
What is the name of the structure containing multiple merozoites in hepatocytes?
Schizont
What begins the erythrocytic cycle in malaria?
Merozoites infecting red blood cells
What is the ring form in malaria?
The early intraerythrocytic stage of Plasmodium development
What hematologic findings are seen in malaria?
Anemia, thrombocytopenia, and hemolysis
What complications can occur due to RBC occlusion in P. falciparum?
Cerebral malaria, renal failure, hepatic failure, ARDS
What inherited conditions offer protection against P. falciparum?
Sickle cell trait, alpha/beta thalassemia, G6PD deficiency
What is the gold standard test for malaria diagnosis?
Giemsa-stained thick and thin blood smear
What can be used in resource-poor settings to diagnose malaria?
Rapid diagnostic tests (RDTs)
What is the treatment for severe malaria (e.g., cerebral malaria, high parasitemia)?
IV artesunate
What is the first-line treatment for uncomplicated chloroquine-resistant P. falciparum?
Artemisinin-based combination therapy (ACT)
What drugs can be used in chloroquine-resistant malaria?
Atovaquone-proguanil, quinine + doxycycline, or mefloquine
What is used to eliminate liver hypnozoites in P. vivax and P. ovale infections?
Primaquine or tafenoquine
What must be checked before administering primaquine?
G6PD status (to avoid hemolysis)
What medications can be used for malaria chemoprophylaxis?
Doxycycline, atovaquone-proguanil, or mefloquine
How long should malaria prophylaxis be continued after return from an endemic area?
4 weeks
What physical prevention method is effective against malaria transmission?
Sleeping under insecticide-treated bed nets
How does chloroquine kill Plasmodium parasites?
It accumulates in the parasite’s food vacuole, prevents heme crystallization, and leads to toxic free heme buildup.
What causes chloroquine resistance in Plasmodium falciparum?
Mutations in chloroquine transport proteins prevent the drug from accumulating in the food vacuole.
What is the first-line treatment for chloroquine-resistant Plasmodium falciparum?
Artemisinin-based combination therapy (e.g., artemether-lumefantrine or artesunate-based)
What drug combination is effective for chloroquine-resistant malaria besides artemisinins?
Atovaquone-proguanil, or quinine with doxycycline/tetracycline, or mefloquine
What is cinchonism and which antimalarial drug causes it?
Cinchonism includes tinnitus, hearing loss, and altered mental status; caused by quinine.
What limits the use of mefloquine in malaria treatment?
Neuropsychiatric side effects including sleep disturbances, mood and behavior changes.
What defines severe malaria that requires IV artesunate?
Parasitemia >5%, altered mental status, seizures, or multisystem organ failure.
When should malaria prophylaxis be started before travel and continued after return?
Start 1–2 weeks before travel and continue for 4 weeks after return, depending on the drug.
What Plasmodium life stage infects hepatocytes?
Sporozoites
What do schizonts in hepatocytes release into the bloodstream?
Merozoites
What forms in RBCs after merozoite infection?
Ring forms → trophozoites → schizonts
What happens when schizonts rupture in RBCs?
RBC lysis and release of more merozoites
What forms male and female gametocytes in malaria?
Some merozoites differentiate within RBCs
What organ systems are commonly affected by Plasmodium falciparum?
Brain (cerebral malaria), lungs (ARDS), kidneys (renal failure), and liver (hepatic failure)
What are common systemic symptoms of malaria?
Fatigue, malaise, arthralgias, headache, chills, and high-grade fever
How does malaria lead to jaundice and splenomegaly?
Intravascular hemolysis of parasitized RBCs causes bilirubin buildup and splenic activation.
What lab findings are common in malarial hemolytic anemia?
Decreased haptoglobin, elevated LDH, indirect hyperbilirubinemia, and reticulocytosis
What do P. falciparum gametocytes look like on peripheral smear?
Elongated, banana-shaped gametocytes
What diagnostic findings are associated with P. vivax and P. ovale?
Enlarged RBCs with Schüffner dots on Giemsa stain
Which Plasmodium species produce hypnozoites that lie dormant in the liver?
Plasmodium vivax and Plasmodium ovale
Where is Plasmodium malariae found?
Sub-Saharan Africa, Southeast Asia, Western Pacific, and parts of South America
What causes jaundice and splenomegaly in malaria?
Intravascular hemolysis of parasitized RBCs
What are common systemic symptoms of malaria?
Fatigue, malaise, arthralgias, headache, chills, high-grade fever
What is the fever cycle for P. vivax and P. ovale?
48-hour fever spikes (tertian malaria)
What is the fever cycle for P. malariae?
72-hour fever spikes (quartan malaria)
What is the fever cycle for P. knowlesi?
24-hour fever spikes (quotidian malaria)
What is the fever pattern of P. falciparum?
Irregular fever pattern
What blood smear finding is characteristic of P. falciparum?
Banana-shaped (elongated) gametocytes
What diagnostic findings are associated with P. vivax and P. ovale?
Schüffner dots and enlarged RBCs
What test can be used in resource-poor settings to diagnose malaria?
Rapid diagnostic tests (RDTs)
What is the first-line treatment for chloroquine-resistant P. falciparum?
Artemisinin-based combination therapy (ACT)
What is the treatment for severe malaria?
IV artesunate
What drugs are alternatives for resistant malaria?
Atovaquone-proguanil, quinine + doxycycline, or mefloquine
What is used to kill liver hypnozoites in P. vivax and P. ovale?
Primaquine or tafenoquine
What must be checked before giving primaquine?
G6PD deficiency
What medications are used for malaria chemoprophylaxis?
Doxycycline, atovaquone-proguanil, or mefloquine
How long should malaria prophylaxis continue after return?
4 weeks
What physical method reduces malaria transmission risk?
Sleeping under insecticide-treated bed nets
How does chloroquine kill Plasmodium?
Prevents heme crystallization in food vacuole, leading to toxic free heme
What causes chloroquine resistance in P. falciparum?
Mutations in transport proteins prevent drug accumulation
What is cinchonism and which drug causes it?
Tinnitus, hearing loss, altered mental status caused by quinine
What limits the use of mefloquine?
Neuropsychiatric side effects (e.g., sleep, mood, behavior disturbances)
What are signs of severe malaria requiring hospitalization?
Parasitemia >5%, seizures, decreased consciousness, multiorgan failure
