[04.16a] Malaria (Part 1) V2.1.pdf

Malaria

What is the name of the disease caused by the parasite Plasmodium?

Plasmodium

What is the name of the parasite that causes malaria?

Apicomplexa

To which phylum does the genus Plasmodium belong?

Apical complex

What specialized structure do parasites in the phylum Apicomplexa possess?

Important in pathogenesis of the parasite

Why is the apical complex important in Apicomplexa parasites?

Toxoplasma

Name another parasite that has an apical complex, besides Plasmodium.

Haemosporidia

To which order does Plasmodium belong?

Protozoan

What type of organism is Plasmodium classified as?

5

How many species of Plasmodium can infect humans?

P. falciparum

Which Plasmodium species is the most important one to be concerned about?

P. vivax

Which Plasmodium species is the second most important one in terms of relevance?

P. falciparum, P. vivax, P. ovale, P. malariae, P. knowlesi

Name the five species of Plasmodium that can infect humans.

Gametocyte

What specific stage of P. falciparum is shown in Figure 1?

Basophilic stippling

What RBC finding is noted in Figure 1 (upper left)?

Piroplasmida

What is the order to which the parasite Babesia belongs?

Babesia

Which parasite is similar to Plasmodium, is tick-borne, and is endemic in the U.S.?

Vector-borne disease

What kind of disease is malaria?

Anopheles Mosquitoes

What is the genus of the vector that carries Plasmodium?

Carriers

Anopheles mosquitoes act merely as what to the Plasmodium?

Sporogonic cycle

What cycle happens inside the Anopheles mosquitoes, confirming they are not affected by the parasite?

Warm climate or tropical areas

Where do Anopheles mosquitoes thrive?

Endemic in the Philippines

Malaria is still endemic in what country, according to the source?

30 to 50

Approximately how many species of Anopheles mosquitoes transmit malaria?

An. flavirostris, An. maculatus, An. balabacensis, An. litoralis

Name four specific species of Anopheles mosquitoes mentioned as transmitting malaria.

Elevated rear end

What physical characteristic distinguishes an Anopheles mosquito from an urban mosquito?

Exo-erythrocytic (EE) schizogony

What cycle refers to the life stages found outside the erythrocyte, involved in liver invasion?

Hypnozoites and Merozoites

Name the two Plasmodium life stages involved in the Exo-erythrocytic schizogony.

Erythrocytic (E) schizogony

What is the most important life cycle of Plasmodium, found inside the erythrocyte?

Ring stage, Trophozoites, Schizonts, Merozoites

Name the four Plasmodium life stages involved in the Erythrocytic schizogony.

Immature trophozoites or young trophozoites

What are ring-stage cells also referred to as?

Mature trophozoites

What stage is referred to simply as trophozoites, larger than the ring stage?

Gametogony

What is the production of gametes called?

Microgametocytes

What stage produces male gametes?

Macrogametocytes

What stage produces female gametes?

Sporogonic cycle

What cycle occurs inside the Anopheles mosquito and has no clinical significance to the human host?

Sporozoites

What is the most relevant Plasmodium cycle stage that is transferred from the mosquito into the humans?

Sporozoites, Zygote, Ookinetes, Oocysts

Name the four Plasmodium life stages involved in the Sporogonic cycle.

Low metabolic activity

What characteristic defines the Ring stage, preparing it for development?

DNA, RNA, and protein synthesis, and Hemoglobin digestion

Name the processes that occur during the Mature Trophozoite stage.

DNA replication and Merozoite formation

Name the processes that occur during the Schizont stage.

Schizonts in RBCs

Which type of schizont is typically referred to in exams?

Sporozoites

What stage is contained in the salivary glands of the Anopheles mosquito?

Infective stage of the Plasmodium

What is the clinical relevance of the Sporozoite stage?

Less than a hundred

Approximately how many sporozoites are injected into the bloodstream per bite?

Liver, specifically the hepatocytes

Where do the sporozoites establish a "beachhead" or "command center" after injection?

Schizont

What "carrier ship" houses the asexually dividing sporozoites in the hepatocytes?

Asexual multiplication via mitosis

How do schizonts multiply inside hepatocytes?

Merozoite

What is the daughter cell released when schizonts rupture, responsible for invading RBCs?

Foot soldiers of Plasmodium

What is another informal term used for merozoites?

Erythrocytic phase

What phase does the merozoite infection of RBCs lead to?

Ring stage

Merozoites mature into what stage upon infecting red blood cells?

Food cup

The ring shape of the ring-stage represents what structure used for the parasite's nutrition?

Teenager phase

What informal name is given to the Mature Trophozoite stage?

Schizonts or Gametocytes

A mature trophozoite may differentiate into what two forms?

Adult phase

What informal name is given to the Schizont stage inside the RBC?

Asexual reproduction via mitosis by binary fission

How do schizonts reproduce inside the red blood cell?

Multiple merozoites

What does a schizont contain?

Coordinated attack

How do schizonts rupture, releasing merozoites simultaneously?

Exponential growth

What type of growth characterizes the increase in infected RBCs with each erythrocytic cycle?

Trophozoites

Merozoites must first mature into what stage before they can differentiate into gametocytes?

Gametocytes

What stage, developed from trophozoites, is ingested by the Anopheles mosquito?

Gastrointestinal tract of the mosquito

Where does fertilization of gametocytes occur?

Salivary glands

Where do sporozoites migrate after development in the mosquito gut?

Globin

What is the protein component of hemoglobin that Plasmodium targets for amino acids?

Alpha and beta chains

What two components of hemoglobin are degraded by proteases?

Heme

What toxic byproduct is left after proteases degrade the globin chains?

Hemozoin

What non-toxic metabolite must Plasmodium convert heme into for survival?

Plasmepsin I/II

What aspartate protease is used by Plasmodium to degrade hemoglobin?

Falcipain

What cysteine protease is used by Plasmodium to degrade hemoglobin?

Target hemozoin synthesis (from heme)

What mechanism do most anti-malarial drugs target?

Cytoplasm

Where does Plasmodium store hemozoin?

Autocatalytic process

What possible process is involved in hemozoin synthesis, alongside HRP-1 and HDP?

Histidine-Rich Protein (HRP-1) and Novel Heme Degradation Protein (HDP)

Name two proteins/factors possibly involved in hemozoin synthesis whose mechanisms are still unknown.

Substrate-level phosphorylation

What metabolic process does Plasmodium rely on to generate ATP since RBCs lack mitochondria?

2 ATP

How many ATP are yielded per 1 molecule of glucose via substrate-level phosphorylation?

Pyruvate

Glucose is converted to what molecule during substrate-level phosphorylation?

Lactate

Pyruvate can be converted to what, aiding in the regeneration of pyruvate?

Cytoplasm of the RBC

Where do the reactions of substrate-level phosphorylation occur?

Sticky

What characteristic describes P. falciparum parasitized cells due to variant surface antigens?

Variant surface antigens

What are the "virulence factors" counterpart of the parasite?

Cytoadherence

What is the process of infected RBCs sticking to the endothelium called?

Rosetting

What is the process of infected RBCs attaching to another RBC called?

PfEMP-1

What variant surface antigen is unique to P. falciparum?

Plasmodium falciparum erythrocyte membrane protein-1

What does PfEMP-1 stand for?

Heparan sulfate

What substance does PfEMP-1 bind to?

Cytoadherence

PfEMP-1 is the only surface antigen that facilitates what specific sticking process?

Rosetting

What sticking process is facilitated by all variant surface antigens?

Mature trophozoites and schizonts

What P. falciparum stages express PfEMP-1?

Gametocytes and young trophozoites (immature)

What stages of P. falciparum are usually seen in blood smears?

A-RIFIN/B-RIFIN

What variant surface antigens bind to ABO group A antigen and glycophorin A?

Blood Types A and AB

What blood types are more at risk for complicated malaria?

STEVOR

What variant surface antigen binds to glycophorin C?

Histidine-Rich Protein 2

What does the acronym HRP-2 stand for, and what is it?

Spleen

Where are P. falciparum-infected RBCs prevented from circulating to, allowing them to evade destruction?

Plasmodium lactate dehydrogenase (pLDH)

What important protein is present in all Plasmodium species for energy via glucose metabolism?

Dormant stage

What characteristic describes hypnozoites?

Hypnozoites

What stage is unique to P. vivax and P. ovale?

Malarial relapse

What clinical phenomenon is caused by the reactivation of dormant hypnozoites?

True relapse

Malarial relapse is also known as what?

3 months to 3 years

What is the typical time frame after initial infection for malarial relapse?