Chain of infection
Reservoir
Humans (mammals), anopheles mosquitos
How do plasmodium enter the body and where does it go? What form is it in at this point in the cycle?
Sporozoites enter via mosquito bite and infects hepatocytes (liver cells)
How long is malaria's incubtion period?
10-15 days
How is malaria diagnosed?
How does plasmodium evade the immune system?
1. Being an intracellular parasite allows it to hide from the immune system
2. Merozoites from liver cells wrap themselves in hepatocyte membrane3. P. falciparum produces proteins on surface of red blood cells that cause it to stick to blood vessel walls, decreasing passage through spleen and thus diminishing a chance to be caught by the immune system
Mode of transmission
Indirect––via female anopheles mosquito
Describe the first cycle plasmodium undergo in the body and the name of the form that results
Sporozoites undergo tissue schizogony (grows, replicates nucleus and organelles to make a large multinuclear schizont) before eventually undergoing cytokinesis to create many many merozoites, which are released into the bloodstream when hepatocytes burst
When do/what causes the first signs of malaria occur?
First blood schizogony
Tree bark that kills blood schizonts and gametocytes as well as inhibits biocrystalization of hemozoin
1. Destroying hepatocytes, erythrocytes
2. Thrombosis
Portal of exit/entry
Insect bite
What do merozoites do in the bloodstream? What is the result?
Merozoites infect red blood cells and develop into trophozoites
(Bonus question: What is this cycle called?)
Describe uncomplicated malaria
Paroxysms consisting of cycles of chills followed by fever and sweating occur either every second or third day
Combination of symptoms including fever, chills, sweats, headaches, nausea, vomiting, body aches, malaise
What does chloroquine do?
inhibits biocrystallization of hemozoin––only affects erythrocytic stage
What are three ways that malaria harms the body?
2. Cell debris from synchonized bursting of erythrocytes
3. InflammationName some characteristics of the anopheles mosquito and its habits
Over 400 species, bite between dusk and dawn, lay eggs in aquatic habitats
What do trophozoites do in red blood cells?
Undergo blood schizogony to produce 8-24 more merozoites
Describe complicated malaria
Complication of infection due to organ failure or unusual blood metabolism
Respiratory distress, severe anemia (due to hemolysis), cerebral malaria, enlarged spleen
Almost always caused by p. falciparum
What is artemisinin-combination therapy?
Artemisinin used alongside another drug to prevent resistance
90% effective ein treating uncomplicated malaria
Half the world's population is at risk
COVID increased the number of cases and deaths
95% of cases and deaths are in Africa, where children under five account for 80% of all malarial deaths
1. Mitochondrion
2. Rhoptry (contains proteins involved in invading and modifying host cell)
3. Micronemes (contain proteins required for motility and recognizing and binding to host cell)
4. Dense granule (contains proteins that modify parasitophorous vacuole membrane)
5. Apicoplast
What are the two paths for merozoites in the plasmodium life cycle?
Continuing the cycle or developing into gametocytes that can infect new people
Describe recrudescence, relapse, and reinfection
Recrudescence
- Inadequate or ineffective treatment leaves parasites in the blood, causing symptoms to return after some timeRelapse
- Dormant liver stage parasites cause symptoms months or years laterReinfection
- While parasites from previous infections were successfully removed, new parasites are introduced- Patient usually has some immunity
T/F: Resistance to these anti-malarial drugs is common
T - except for artemisinins (except for some areas)
What are the three types of malaria prevention?
Vaccine (not available in US, only against p. falciparum, requires 4 injections and prevents 75% of cases)
Mosquito control (nets, indoor spraying)
Medications