Malaria has been making humans sick for at least one hundred thousand years. It’s caused by parasites with an astonishing capacity to develop resistance to drug treatments. The parasites are transmitted by mosquitos.
Every year hundreds of millions of people in tropical regions of the developing world become ill with malaria. Recent World Health Organisation figures say upwards of two thousand people a day die of the disease.
The term malaria comes from the Italian mala aria – literally “bad air”. It was once known as ague or marsh fever, due to its association with swamps and marshland. Malaria was once common in North America and Europe – it’s thought to have been a major factor in the fall of the Roman Empire. These days, malaria occurs in or close to the tropics, primarily in developing nations.
There are five known types of malaria parasite and they’re becoming increasingly resistant to current anti-malarial drugs. Good progress reducing the incidence of malaria using repellents and mosquito nets has seen the disease eradicated from some areas. But around the world, researchers continue their urgent work to devise a vaccine and more effective malaria treatments.
During World War Two, malaria was a major problem for troops on both sides in the Asia-Pacific theatre. Researchers commonly infected people with malaria while looking for treatments and cures, particularly here in Cairns. That practice fell out of favour, but is now being used again by the Queensland Institute of Medical Research.
It’s a safer research method these days. Volunteers are injected with parasite-infected human blood, under careful medical supervision. They may experience some minor symptoms, but don’t develop malaria. Professor James McCarthy says this is one of the best ways to find new cures for malaria.
Professor McCarthy is an infectious diseases specialist at the Royal Brisbane and Womens Hospital and leader of a research group at the Queensland Institute of Medical Research. He researches human parasites including worms, scabies and malaria. He says there are some exciting developments in the field of malaria research.
Professor McCarthy spoke in Cairns at the Queensland Tropical Health Alliance.