gather and process information to trace the historical development of our understanding of the cause and prevention of malaria
Background on malaria
Malaria is a disease caused by a protozoan of the genus Plasmodium. It has a complicated life cycle requiring a mosquito of the Anopheles genus to carry the Plasmodium to its host. The disease is common in tropical areas where the Anopheles mosquito lives. The female mosquito requires a blood meal to complete the reproduction cycle of the mosquito. During the blood meal the Plasmodium (sporozoites) are transferred from the mosquito salivary glands into the blood system of the host. The sporozoites travel to the liver via the blood system and enter cells in the liver. After 12 days a new form of the protozoan called merozoites are released and these enter blood cells. At the same time toxins are released. This causes the sweats and fever that are associated with the disease. Some of the merozoites develop into gametocytes and may be sucked up by another mosquito in another blood meal. In the gut of the female mosquito the gametocytes become gametes and are fertilised. This forms sporozoites which will travel to the salivary glands of the female mosquito and await the next blood meal to enter another host.
The disease was known from the start of recorded history but it took many researchers to uncover the complicated life cycle above. Sir Ronald Ross (1857 – 1932) was a British medical officer working in India. For thousands of years, people had been puzzled about the way in which malaria spread but they knew that malaria was common in areas close to swampy land. In the late 1800s, people were beginning to wonder if mosquitoes could spread malaria. Ross collected mosquitoes and painstakingly dissected them under a microscope. He discovered the micro-organism that was known to cause malaria, inside the bodies of Anopheles mosquitoes. This led to the realisation that insects could carry pathogens, that is, they can be vectors of disease.
A useful Internet site:
History of Malaria Division of Laboratory Medicine at Royal Perth Hospital
Date | Development |
---|---|
18 BC | The disease malaria was described by the Romans. Malaria was thought to come from swamps so the name means ‘bad air’ |
1820 | Quinine used to prevent the disease |
1880 | Charles Laveran a French army doctor observed the malarial parasite |
1886 | Golgi observed asexual reproduction in the protozoan Plasmodium and identified two species |
1898 | Giovanni Grassi named the Anopheles mosquito as the carrier of the malarial parasite |
1897 | Ronald Ross discovered that Plasmodium was the protozoan that caused the disease malaria. |
1940 | Chloroquinine the first synthetic anti-malarial drug was used |