Gary Slutkin: I began to understand how diseases spread—and how to control them—with tuberculosis. From 1981 to 1984, I was an infectious-disease fellow at San Francisco General Hospital and was then made responsible for controlling TB in the whole city. I had to learn all the characteristics of spread and how to find active cases and "contacts"—people who can transmit it invisibly. Later, I worked on cholera and TB in Somalia. And from 1987, I worked at the World Health Organization for seven years on HIV and AIDS epidemics in Africa.
Controlling HIV was almost entirely about changing behavior. I ended up hiring a lot of psychologists and others who understood how to change community norms. In Uganda we ran an education campaign to destigmatize HIV-positive patients, explain how HIV is transmitted, and promote prevention, including using condoms. The dominant message was "stick to one partner."
After 10 years working in Africa, I moved back to the United States in 1994 and was looking for how I could be useful at home. Two incidents from that time had a big impact on me. One was a 12-year-old boy who performed an "execution style" killing under a bridge. The other was another 12-year-old who threw someone, making them fall seven to 10 flights from a housing project, for not giving him some candy.