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The order in nature

Linnaeus and the plants

Linnaeus and the animals

Unknown in Linnaeus’ time

To discover new species

Linné on line arrow Plants and Animals arrow Unknown in Linnaeus’ time arrow Malaria parasites burst blood cells

Malaria parasites burst blood cells

Malaria is a disease causing many problems in the world. 300 – 500 million persons suffer from malaria, 2 millions die each year and more than half of them are children.

The disease is caused by unicellular parasites of the genus Plasmodium. There are different species that cause different types of malaria. The parasites first live inside mosquitoes and are transferred to humans when the mosquitoes suck blood. The parasites live and multiply inside the red blood cells. At last the blood cells burst, which gives the sick person an attack of fever. This is repeated every two or three days. In Sweden the disease was called ‘every second day ague' in the old times.

The parasites can be killed with different medicines. One of the first malaria medicines was quinine, a substance from the yellow bark tree, Cinchona. One problem is that the parasites gradually have become resistant to several of the medicines. Because of this, new medicines have to be found all the time.

Malaria is nowadays mostly found in the tropics. Since the mosquitoes mainly bite during the night, on of the best protections against the disease is to sleep under a mosquito net. However, most people living in those areas can afford neither mosquito nets nor good medicines and many of them get malaria.

Resistant: Medicines against parasites contain substances poisonous to the parasites. It might happen that the parasite DNA is changed so that it suddenly can tolerate the poison. It has then gained resistance to the medicine and a new medicine has to be found. Resistance also appears in bacteria and viruses.