Protist Diseases

Protists are a group of microorganisms that share features with animals, plants and fungi. Some characteristics are common among protists:

  • They are eukaryotic, so they have a nucleus and other membrane-bound organelles
  • Some are parasitic – They can live on or inside of a host organism, extracting nutrients from them at the expense of the hos
  • They prefer moist environments


Malaria is an infectious disease that affects humans and other animals. It is caused by single-celled organisms of the plasmodium family, which enter red blood cells and damage them.

The malaria pathogen is a protist, so it cannot directly spread from one person to another. Instead, it is carried by mosquitoes, which are vectors.


  • Repeated bouts of fever
  • Shivering or shaking chills when the protists burst out of blood cells
  • In severe cases, it can be fatal

How it spreads

1. An infected mosquito bites a person, passing the malaria parasite onto them.

  • The mosquito punctures the skin to feed on blood and the protists enter the human bloodstream through the mosquito’s saliva

2. The malaria parasite travels to the liver through the bloodstream and then reproduces asexually.

3. When the malaria parasites mature, they leave the liver and infect nearby red blood cells.

  • Within 48 to 72 hours, the cells break open, which causes more blood cells to be infected. This releases free haemoglobin into circulation, which can harm other organs.

4. A mosquito bites the infected person, causing the pathogen to enter the mosquito, so it becomes infected.

5. The cycle repeats.

  • The mosquito acts as a vector, passing the malaria pathogen from one person to another

Treatment and prevention

There are two main methods to stop the spread of malaria:

1. Controlling mosquito populations. To prevent mosquitoes from breeding, we can:

  • Draining areas of standing water (the number one breeding spot for mosquitoes)
  • Spraying standing water with insecticides (kills mosquitoes)

2. Reducing the number of mosquito bites and minimising their impact.

  • Using insecticide-coated insect nets while sleeping – The nets kill mosquitoes that land on them, preventing them from biting humans.
  • Travellers visiting infected areas take antimalarial drugs to kill parasites that enter the blood – This helps to stop the infection and the development of symptoms

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