Following a 2009 shift in HIV treatment guidelines that recommended beginning antiretrovirals (ARVs) at higher CD4 counts, young New Yorkers with HIV began treatment earlier in the course of their infection, aidsmap reports. Eighteen percent of them had acquired a drug-resistant strain of the virus.

Publishing their findings in Clinical Infectious Diseases, researchers conducted a multicenter, retrospective cohort study of the New Yorkers ages 13 to 25 who were diagnosed with HIV within one year of their entry into care at one of the clinics included in the study and who entered care between January 2007 and June 2011.

The researchers identified 685 potential subjects and narrowed them down to 331 who met all the criteria for the study. The cohort's average CD4 count upon entering care was 452. A total of 191 of the young people (58 percent) began ARV treatment. Before the 2009 guideline shift, the average CD4 count upon starting ARVs was 261; after the shift, the average CD4 count was 364.

Out of the 212 study participants who had undergone resistance testing before beginning HIV treatment, 38 (18 percent) had a major drug-resistance mutation. The latter period of the study saw a greater likelihood of drug resistance among the participants.

To read the aidsmap story, click here.

To read the study abstract, click here.