Protist Diseases (AQA GCSE Biology): Revision Note

Protists: Basics

• Protists are a diverse group of eukaryotic organisms

• Only a small number of protists are pathogenic, but the diseases they cause can be serious

• Pathogenic protists often need a vector to transfer from one host to the next

Malaria

• The pathogens that cause malaria are protists

• The malarial protist has a life cycle that involves the mosquito as a vector

Transmission

• The mosquito acts as a vector that carries and passes the protist from one person to another

  • A mosquito bites an infected individual

  • Protists are transferred when the same mosquito bites an uninfected individual

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Symptoms

• Recurring episodes of fever

• These episodes can weaken the host so much it can be fatal

Control

• Malaria can be treated with a combination of antimalarial drugs

  • Antibiotics are not effective against protists

• The spread of malaria can be reduced by controlling mosquito populations:

  • Using insecticides

  • Using insecticide-coated nets to kill the mosquito and prevent them biting

  • Preventing the mosquitos from breeding by spraying to kill the larvae, or removing standing water breeding sites

  • Use of antimalarials when travellers visiting infected areas