Malaria
Biology: Cambridge International A Level, topic 10.1.4
Malaria
Malaria is a disease caused by Protoctista, resulting in cyclical symptoms of fever, chills and ultimately death if left untreated. The parasite can also use birds, bats and other animals as hosts.
Pathogen
- Malaria is caused by several species of the Plasmodium genus.
- P. falciparum causes the most malarial deaths worldwide.
- P. vivax, P. ovale, P. malariae and P. knowlesi are much rarer, but P. vivax can remain in the liver for years without causing symptoms.
- The parasite grows and multiplies in erythrocytes, causing them to burst every 2-3 days, releasing Plasmodium into the bloodstream.
Treatment
- Malaria is treated using antimalarial medication such as Doxycycline and Mefloquine.
- A preventative course of this medication should be taken prior to travel to known high-risk regions - this can reduce the risk of malaria by up to 90%.
- Different antimalarial medication can be used to treat the disease if the preventative course does not work.
Transmission
- Malaria is transmitted by insect vectors, specifically the female Anopheles mosquito when it takes a blood meal from an infected person.
- Malaria is most common in Africa, Asia and South America because the climate is suitably warm for the mosquito to live in and the probability of biting an infected person is higher.
Prevention
- Removing the insect vector is 100% effective in preventing transmission, although this is not always practical on a large scale.
- Sleeping under mosquito nets, applying insect repellent and covering exposed skin help reduce the risk of being bitten in the first place.
- Developing countries are particularly affected by malaria. Funding from governments or charities is often required to provide mosquito nets.
Location
- The mosquito vector for malaria requires warm, damp conditions to survive.
- This limits the disease to hot, humid countries near the equator.
Test yourself on Malaria
Which species of Plasmodium causes the most malarial deaths worldwide?
What happens when someone has malaria?