C3. Plasmodium and Malaria Flashcards
What is the most important tropical disease?
Malaria
Who mainly dies from malaria?
Children under 5
True or false?
Malaria is preventable and treatable if diagnosed earlier
True
What is the meaning of an endemic area ?
Where malaria is commonly found
Who should be assessed with malaria ?
Any body who has recently traveled to an endemic country or has been in an international airport, presenting with a fever
Who is at risk of developing malaria ?
Anybody regardless of age, gender, ethnicity or country of brith
How long after travel can malaria be made apparent ?
Up to one year
Should malaria be reported to the local authorities ?
Yes
What are the causative agents of malaria ?
Plasmodium falciparum
Plasmodium ovale
Plasmodium viva
Plasmodium Malariae
Plasmodium Knowlesi
What causative agents of malaria is zoonotic ?
Plasmodium Knowlesi
What genus of mosquito spreads plasmodium? (Vector)
anopheles
Briefly describe the lifecycle of malaria ?
- A single female mosquito lays 50-200 eggs.
- Eggs lay onto still water and develop into aquatic larvae in 2-3 days
- Over 8-10dyas the larvae go through 4 stages of development called instar
- During the last larval instal. the larvae develop into pupae
- After 1-2 days the adult mosquito emerges from the water
What is the meaning of anthropophilic ?
Mosquitos that have the tendency to bite humans
True or false ?
The saliva contains anti-coagulants that prevents blood clots
True
Who are the two hosts that plasmodium lives in ?
Female mosquito and humans
Briefly describe the lifecycle of a mosquito
- Mosquito takes a blood meal and injects sporozoites
- Sporozoites migrate to and infect our liver cells where they mature into schizonts . These liver cells can rupture and release merozoites
- Merozites infect RBCs
- Rig-form trophozoites mature into schizonts, which rupture and release merazoites
- Some differentiate into gametocyte enables formation of male and female gametocytes which are taken up by mosquitos next meal and allows the propagation of the lifecycle
What are the symptoms of malaria ?
No symptoms accosted with the liver stage
Symptoms occur when red blood cells rupture and release malaria toxins and pyrogens
Common symptoms are:
- Fever
- Anaemia
- Slenomegaly
- Jaundice
- Diarrhea
- Vomiting
Are fever pattens regular ?
They are irregular in the first initial weeks and then turns into a regular patten called tertian, subtertiana and quartan
What are the classical stages of fever
Cold stage
hot stage
sweating stage
True or false?
There can be cases of severe malaria whiteout fever
true
What species of malaria usually causes tertian fever curve?
P.vivax/p.ovale
What species of malaria usually cause quartan fever curve ?
P.malariae
What species of malaria usually causes subtertiana fever curve ?
P.falciparum
What complications can arise with P. falciparum if left untreated ?
Altered consciousness and coma caused by hypoglycaemia, acidosis, seizures or very severe anaemia
What is the main cause of malaria death?
Cerebral malaria
Large number of red blood cells containing mature parasites found in capillaries and venues of brain and other organs
What is the underlining mechanism of hypoglycaemia and malaria ?
Caused by impairment of body to undergo gluconeogenosis that is triggered by cytokines in the body. The parasites are additionally taking up large amounts glucose. Also quinine therapy can induce insulin production resulting in low glucose.
What is the underlining mechanism of amaemia and malaria ?
Direct distruction of RBC when shizonts rupture and immune mediated haemolysis occurs. in addition the cytokines produce affect RBC formation in the bone marrow
What is the underlining mechanism of acidosis and malaria ?
Tissue anoxia (oxygen depletion in tissue)linked with severe anaemia leads to anaerobic metabolism and releases lactic acid. Low blood pressure can also cause anoxia therefore drop in blood pressure can occur
What are the key facts associated with malaria and pregnant women ?
- Risk of abortion
- Can cause anaemia and low birth weight
- Parasitre not normalt transmitted From mother to new born baby in endemic areas
- Not all drugs can be used in pregnant women
What is the meaning of recrudescence ?
Malaria caused by a small number of parasites permitting in RBCs
What is the meaning of reinfection?
Malaria attack caused by new inoculation of parasite from infected vector
What is the meaning of relapse ?
When hypnozoites in liver are reactivated and initiate a new cycle of RBC infection been after elimination of all parasites from blood
Why are some people immune to malaria ?
People who live in endemic area people have protection as they may have parasite-specific IgG. This means that frequent exposure to parasite must be made
What is the link between HIV and malaria ?
T-cell count progressively decrease in HIV-infected individuals this means that people with HIV are more likely to have a high number of parasitaemia than immunocompetent people who are infected
Malaria increases plasma viral load in GIV infected people
Reinforce each other
What os the link between climate change and malaria ?
Most affected by global warming. Temperatures will rise and plasmodium parasite will beagle to survive in other ears that they usually do not survive in
