a year of truvada costs 13,000. most insurers cover the drug. an estimated 4,000 people who it. >> the doctor is a clinical research director at a clinic serving the gay committee. he said prep's adoption could be epidemic. >> in washington d.c., they have the highest prevalence of h.i.v. in the united states. we are shy of 3% overall of the population, higher than some rates of countries in africa. if you are african american and have sex with men and are between the ages of 20 and 40, your chance of having h.i.v. is one in five. >> gay health advocates centered efforts on promoting condom use and awareness of status. in the 1980s, when contracting h.i.v. was a death sentence, it worked. 30 years later medical professionals are skeptical about promoting prep. >> we may lose the skills if we say we don't have to have the conversations any more. prep may quiet our conversations with each other. our discussions around sex, because why bother if everyone is just h.i.v. positive, and taking their medications as they should, or negative and taking th