blindness and lymphatic filariasis.

Deadly parasites

After decades of limited progress, the discovery of the two new drugs - ivermectin for river blindness and lymphatic filariasis, and artemisinin for malaria - was a game-changer.

Image copyright CDC

Efforts to eradicate malaria had been failing - older drugs were losing their potency - and the disease was on the rise.

Prof Youyou Tu, who in the 1960s had recently graduated from the Pharmacy Department at Beijing Medical University, looked to traditional herbal medicine to find a potential therapy.

She took an extract from the plant called Artemisia annua, or sweet wormwood, and began testing it on malaria parasites.

The component, later called artemisinin, was highly effective at killing them.

Image copyright Reuters Image caption Youyou Tu is Chief Professor at the China Academy of Traditional Chinese Medicine

Today,the drug is used around the world in combination with other malaria medicines. In Africa alone, this is saving more than 100,000 lives every year.

Tu is the 13th woman to win this Nobel Prize.

She shares the award with two men who found a treatment for another parasite - roundworm.

Their research led to the development of a drug called ivermectin, which is so successful that roundworm diseases are on the verge of eradication.

Satoshi Ōmura, a Japanese microbiologist, focused on studying microbes in soil samples. He selected a number of promising candidates that he though might work as a weapon against diseases.

Irish-born William C Campbell, an expert in parasite biology working in the US, then explored these further and found one was remarkably efficient against parasites.

Image copyright Trinity College Dublin