People contracting HIV are increasingly acquiring strains that are resistant to antiretrovirals (ARVs), in particular non-nucleoside reverse transcriptase inhibitors (non-nukes). Researchers analyzed information about 496 HIV-positive individuals in a San Diego database, looking at the 1996 to 2013 period. Overall, 13.5 percent of the group had transmitted drug resistance (TDR), and the rate of TDR increased over time. The main TDR was to non-nukes, at 8.5 percent of the cohort; this rate saw an upward trend. The rate of TDR to protease inhibitors and nucleoside/nucleotide reverse transcriptase inhibitors was a respective 4.4 percent and 3.8 percent; these rates remained constant over time. The prevalence of TDR did not differ by individuals’ age, sex, race or ethnicity or their risk factors in contracting HIV. The researchers say that their findings underline the importance of conducting resistance testing to help choose an ARV regimen.