Doctor Ciro de Quadros: Epidemiologist who helped eradicate smallpox in the 1970s, and polio and measles in the Western hemisphere

The epidemiologist Ciro de Quadros, who has died of pancreatic cancer, helped eradicate smallpox in the 1970s and later led efforts that eliminated polio and measles in the Western hemisphere, saving or improving the lives of millions. Few people in the past 50 years did more than de Quadros to prevent the spread of infectious diseases.

Beginning in Brazil in the 1960s, he helped arrest smallpox in a remote region of the Amazon. He later led programmes that brought an end to polio and measles, sometimes brokering ceasefires among warring factions in order to vaccinate children in battle zones. "This is one of the greatest public health professionals we've ever had," said DA Henderson, former dean of the Johns Hopkins School of Public Health who was also the director of the World Health Organisation's global project to eliminate smallpox.

He was born in 1940 in Rio Pardo, Brazil. He graduated from medical school in 1966 at the Pontifical Catholic University of Rio Grande do Sul in Porto Alegre. While working for the Brazilian public health service he developed an interest in epidemiology and infectious diseases. He received a master of public health degree in 1968 from the National School of Public Health in Rio de Janeiro.

Working in Brazil in the late 1960s, de Quadros kept meticulous records of the cases he encountered and hired local residents to venture into small settlements. Whenever he found smallpox patients, de Quadros acted quickly to vaccinate anyone who might come in contact with them. The method, known as "surveillance and containment," became the standard in epidemiology.

In less than a year, de Quadros eliminated smallpox from a sprawling Brazilian state of 8 million people. Henderson then asked him to go to Ethiopia in the early 1970s. "You could go walking through those mountains for days and days to find a smallpox case but then you could not vaccinate anybody because nobody wanted the vaccination," de Quadros told The Lancet in 2001. "They would throw stones. They would set dogs on you."

None the less, he won the confidence of the people by hiring local nurses and health workers and quickly brought the disease under control in Ethiopia. The world's last known case of smallpox occurred in Somalia in 1977. That year, de Quadros moved to Washington to work for the Pan American Health Organisation, WHO's regional branch for the Americas. He turned his attention to polio, a disease that often causes paralysis.

Since the discovery of a vaccine in 1955, polio had been largely eliminated with advanced medical care. But it remained a scourge in many poorer nations, where its victims were often reduced to lives as beggars. De Quadros adopted many innovative methods to vaccinate children and bring the disease under control. He obtained investments from Unicef, Rotary International, the Inter-American Development Bank and other organisations and established an international fund to help poorer countries buy vaccines at a discount.

He taught governmental health and finance ministers about the social benefits of preventive medicine. He organised "national immunisation days," in which the vaccination of millions of children was seen as a holiday, with music and sports as a sidelight.

Even more remarkable was de Quadros' diplomatic ability. In several countries where there were wars or rebel insurgencies, he was able to persuade the combatants to lay down their arms in the cause of public health. "Ciro met rebel leaders from El Salvador in a bar in Georgetown," Jon Andrus, deputy director of the Pan American Health Organisation, recalled. "He said if you just stop fighting one day, it will benefit everybody. Ciro was a hero in that sense."

He called the truce "days of tranquility," when public health workers could go into the countryside without fear and vaccinate children against polio. Even the feared Shining Path guerrilla group in Peru agreed to take part. The last known case of polio in the Western Hemisphere was recorded in Peru in 1991.

"I think what Ciro accomplished in the Americas was nothing short of miraculous," Henderson said. "I've never seen anyone else who could do what Ciro did."

He left the Pan American Health Organisation in 2002, after having worked successfully to eradicate measles from the Americas. A year later he joined the Sabin Vaccine Institute, where he was an executive vice president.

De Quadros kept working until about a month ago. He gave hundreds of presentations around the world and was known to heads of state, but he was also likely to show up in remote locations, talking with nurses about local health problems. "My field experience has taught me to listen to fieldworkers," he told The Lancet. "You have to pay attention to everybody, because you cannot predict who will come up with the good idea."

Henderson, who was de Quadros's boss in Ethiopia in the 1970s, estimated that de Quadros helped prevent the deaths of hundreds of thousands of people through his immunisation efforts. "I watched him perform in Ethiopia," Henderson recalled. "The obstacles were unbelievable – the emperor assassinated, two revolutionary groups fighting, nine of his own teams kidnapped, even a helicopter captured and held for ransom. He kept the teams in the field – and that helicopter pilot went out and vaccinated all the rebels."

Ciro Carlos Araujo de Quadros, epidemiologist: born Rio Pardo, Brazil 30 January 1940; married Susana Figueroa (two daughters, and two stepsons); died Washington 28 May 2014.

© The Washington Post