MALARIA

What four organisms cause malaria?

Plasmodium vivax, Plasmodium ovale, Plasmodium falciparum, Plasmodium malariae

Why are Plasmodium ovale and vivax called tertian malariae

Burst red blood cells and fever every 48 hours

Why is Plasmodium malariae called quartan malariae?

Burst red blood cells and fever every 72 hours

On what cycle does the fever/red cell bursting occur in Plasmodium falciparum?

Every 36-48 hours

What is the most common and deadly form of malaria?

Plasmodium falciparum

What are the symptoms of malaria?

recurrent episodes of SEVERE fever, chills, night sweats, hemolytic anemia and usually jaundice (episodes of fever and chills and sweating last for about 6 hours)

True/False: with malaria the red cells all lyse at the same time

True- this is what releases the Plasmodium into the circulation causing an immune response thus accounting for the fever

Where do Plasmodia undergo sexual division?

In the Anopheles mosquito (specifically in the stomach of the Anopheles mosquito)

Where do Plasmodia undergo asexual division?

In the human liver and red cells

What is the life cycle of the Plasmodium species?

Begin with sporozoites that enter the human blood from the salivary gland of a mosquito. The sporozoites circulate and head to liver. Invade liver cells. Once in liver cell it is known as a tropozoite. The trophozoite udergoes many rounds of nuclear division to form a multinucleated schizont. The multinucleated schizont then separates onto individual merozoites which enter the circulation as the liver cells lyse. Merozoites now in circulation and enter RBCs. Once inside RBCs merozoites are again trophozoites. Trophozoite in the red cell looks like a ring with a nuclear material diamond in the center. Trophozoite multiplies nucleus again to form large multinucleated schizont. Schizont then divides to lyse red cells and form merozoites. Release of merozoites causes fever, chills, night sweats. Some merozoites change into male and female gametocytes which die unless they are taken up by Anopheles again. In the Anopheles stomach the gametocytes combine to form oocysts which grow into sporozoites

What life form is particular to the Plasmodium vivax and Plasmodium ovale?

hypnozoites in liver cells which are dormant and may become reactivated again; this is why you are asked if you ever had malaria when you go for a blood donation

What does the gametocyte of Plasmodium falciparum look like?

a banana

Do Plasmodium vivax, ovale, and malariae cause severe manifestations?

No

What are other symptoms associated with Plasmodium falciparum infection other than fever chills night sweats?

Red cells get sticky and clog the lungs (pulmonary edema), kidneys (renal failure), and brain (coma)

Which of the Plasmodia are sensitive and resistant to chloroquine respectively?

Plasmodium falciparum is mostly INsensitive (except in certain parts in Central America), Plasmodium vivax,ovale, and malariae are SENSITIVE to chloroquine

Is there hepatosplenomegaly in malaria?

Yes it all types as the RES tries to scoop up all of the lysed red cells. the spleen may occassionally rupture

What two red cells features in African and African Americans appear to offer protection against malaria?

Absence of Duffy a and b antigen which the Plasmodium vivax uses for binding to RBCs (this is why P. vivax is virtually absent in West Africa because of evolved resistance); sickle cell trait which appears to offer protection against Plasmodium falciparum

How is malaria diagnosed?

1. Thin and thick smears to reveal trophozoites, schizonts in the erythrocytes, and maybe gametocytes 2. Rapid antigen tests

What is the difference between recrudescence and relapse in malaria?

Relapse- with P. ovale and vivax- reactivation of latent hypnozoites; Recrudescence- with P. malariae and P. falciparum- results from incomplete eradication of infection

What is a newly emerging Plasmodium that has been discovered in the last 3 years that can also cause human disease

Plasmodium knowleri; usually only in monkeys but can get transmitted to humans

Where are each of the different malariae seen geographically?

Worldwide: P. falciparum and malariae, West Africa: P. ovale, outside of West Africa- P. vivax

Which are the two most common malariae?

P. vivax and P. falciparum

What is the double imapct that G6PD deficiency can have on malaria

G6PD deficiency seems to be protective against malaria; however at the same time , if PRIMAQUINE is used to treat latent P. ovale or P. vivax in G6PD deficient person then it can set off a hemolytic episode

How do you treat non-resistant malaria

Chloroquine for P. vivax, malariae, ovale; Primaquine for liver LATENT P. vivax and ovale because chloroquine cannot kill hypnozoites

How do you treat P. falcifarum which is resistant to chloroquine

quinine PLUS doxycycline/clindamycin/pyrimethamine-sulfadoxine; OR mefloquine; OR atovaquone-proguanil