Shane Avery practices family medicine in Scott County, Ind. In December, a patient came to his office who was pregnant, and an injection drug user.
After running some routine tests, Avery found out that she was positive for HIV. She was the second case he had seen in just a few weeks.
"Right then, I kind of realized, 'Wow, are we on the tip of something?' " Avery says. "But you just put it away. ... It's statistically an oddity when you're just one little doctor, you know?"