Brian O. L. Duke, 79; Worked to Combat River Blindness

Brian O. L. Duke, a tropical disease expert and early advocate for free drugs to treat river blindness, a vicious and preventable scourge that afflicts the world’s poor, died June 3 at home in Lancaster, England, after a heart attack. He was 79.

Duke worked with health organizations in Africa, Switzerland and the United States and spent much of his life researching treatments for river blindness, a parasitic disease transmitted to people from black flies.

The flies, living near fast-flowing jungle waters, bite humans and transfer a microscopic, threadlike worm that burrows just beneath the skin. They live and mate in fibrous nodules near joint and muscular tissue and produce larvae that move through the skin.

The worms, which live for many years, cause an itch that can create skin disfigurement. If the worms repeatedly migrate through the cornea, blindness can result. Entire villages, mostly in sub-Saharan Africa and some Latin American countries, have succumbed to blindness.

By the early 1980s, the World Health Organization and the pharmaceutical company Merck & Co. were working closely on the clinical development of an oral drug called ivermectin -- trademarked as Mectizan -- that proved effective in improving and preventing river blindness.

An earlier drug killed parasites in situ, which in vital organs could be fatal. Duke saw Merck’s ivermectin as a breakthrough because it “paralyzed” the worms, “swept” them into the lymphatic system and allowed the body’s immune system to take over from there.

Duke, then a WHO official, was impressed with the Merck drug and told a magazine reporter that the company should donate the vaccine to all those in need. Merck officials reportedly complained to the WHO director-general.

But Duke proved prescient when in 1987 Merck began its Mectizan Donation Program, bringing free treatment to millions in Africa, Latin America and Yemen, a country on the Arabian peninsula.

He became deeply involved in this effort while also serving as medical director of the River Blindness Foundation and then as a consultant to the Atlanta-based Carter Center, which assumed most of the foundation’s duties in 1996.

In 2002, he and a Nigerian health ministry official, Chukwu Okoronkwo, received the first two Merck Mectizan Awards for their contributions to the program.

The WHO estimates that more than 17.7 million people -- 99% in Africa -- remain infected with onchocerciasis, as river blindness is known. Of those, 500,000 are visually impaired and 270,000 are blind.

One of Duke’s enduring concerns was the disruptive socio-economic consequences of entire communities leaving fertile river areas during a black fly scare. Even in recent years, he wrote about the continuing logistical obstacles of getting the drugs to remote African outposts and the need for greater political will to help overcome this problem.

The son of a British tropical medicine doctor, Brian Oliver Lyndhurst Duke was born June 24, 1926, in Kampala, Uganda. He received his undergraduate and medical education at Cambridge University.

He spent more than 20 years in the Colonial Medical Service and the British Medical Research Council, usually at places he called “beyond the end of the road.” To avoid contracting river blindness, he used insect repellents and took other precautions.

While working in Cameroon, Sudan, Nigeria and Guatemala, he persuaded governments to let researchers anesthetize blind patients and extract the worms to create a databank about the worms’ genetic structure. In newly independent African countries, he helped start official pathology and parasitology offices.

After leaving the WHO in 1985, he was invited to the Armed Forces Institute of Pathology in Washington, D.C., as the first “distinguished scientist” in the Department of Infectious and Parasitic Diseases.

In 1991, he retired to England and was an enthusiastic gardener of camellias, clematis and English roses. He requested that his ashes be spread over the botanic gardens in Entebbe, the old Ugandan capital city on Lake Victoria where he grew up.

He is survived by his wife of 20 years, Diane Waters Duke of Lancaster; three children from his first marriage, which ended in divorce; and five grandchildren.