An undated handout photo released by the China Academy of Chinese Medical Sciences (CACMS) shows Chinese professor Tu Youyou (L) working with a colleague in an undisclosed lab location.

London - Three scientists have won the Nobel Prize in medicine for their work on drugs that fight malaria and other parasitic diseases affecting hundreds of millions of people every year.

Tu Youyou, 84, became the first-ever Chinese medicine laureate for her work on artemisinin, a drug that has helped to cut significantly the mortality rates of malaria patients.

Irish-born William Campbell, 85, and Satoshi Omura, 80, from Japan, were cited for their work on a drug called avermectin, derivatives of which have curbed diseases caused by parasitic worms affecting millions of people in Africa and Asia.

The winners share the £633 000 prize money, with one half going to Dr Campbell and Prof Omura, and the other to Prof Tu.

Daily Mail