William C Campbell, 85, who was born in Ramelton, Co Donegal, and later attended Trinity College Dublin, was awarded the prize at a ceremony in Stockholm, Sweden.
As joint recipient, he won the award alongside Japan’s Satoshi ¯Omura for developing avermectin, a drug which has lowered the incidence of river blindness and lymphatic filariasis across Africa and Asia.
River blindness, a parasitic infection, is caused by microscopic worms and is spread by the bites of infected black flies. It can cause intense itching, skin discolouration, rashes, and eye disease, and often leads to permanent blindness.
Lymphatic filariasis, another parasitic disease, is spread by the bites of infected mosquitoes. In some cases, people who contract the condition experience a large amount of swelling of the arms and legs.
Prof ¯Omura first began his work by collecting soil samples from around Japan and isolating bacteria from it. This research was then taken up by Prof Campbell, who showed a particular strain of bacteria, streptomyces avermitilis, was remarkably effective at killing off parasites in animals. This then became the source for the drug avermectin which, when tested on humans, was found to have killed off parasite larvae.
Prof Campbell and Prof ¯Omura shared the prize with China’s Youyou Tu, who was recognised for work in the fight against malaria.
“The two discoveries have provided humankind with powerful new means to combat these debilitating diseases that affect hundreds of millions of people annually,” the judging committee said.
“The consequences in terms of improved human health and reduced suffering are immeasurable.”
Leo Varadkar, the health minister, said:
“This is a great day for Irish science and I want to congratulate Prof Campbell for jointly receiving the prestigious Nobel prize. It’s a magnificent achievement for him and his colleagues. Prof Campbell’s work on developing the drug avermectin, which combats the roundworm parasite and other organisms, is already bringing benefits to people across the planet.”