Estimates of the Time from Seroconversion to Antiretroviral Therapy Initiation among People Newly Diagnosed with Human Immunodeficiency Virus from 2006 to 2015, New York City

Background: We estimated the time from human immunodeficiency virus (HIV) seroconversion to antiretroviral therapy (ART) initiation during an era of expanding HIV testing and treatment efforts. Methods: Applying CD4 depletion parameters from seroconverter cohort data to our population-based sample, we related the square root of the first pretreatment CD4 count to time of seroconversion through a linear mixed model and estimated the time from seroconversion. Results: Among 28 162 people diagnosed with HIV during 2006-2015, 89% initiated ART by June 2017. The median CD4 count at diagnosis increased from 326 (interquartile range [IQR], 132-504) cells/μL to 390 (IQR, 216-571) cells/μL from 2006 to 2015. The median time from estimated seroconversion to ART initiation decreased by 42% from 6.4 (IQR, 3.3-11.4) years in 2006 to 3.7 (IQR, 0.5-8.3) years in 2015. The time from estimated seroconversion to diagnosis decreased by 28%, from a median of 4.6 (IQR, 0.5-10.5) years to 3.3 (IQR, 0-8.1) years from 2006 to 2015, and the time from diagnosis to ART initiation reduced by 60%, from a median of 0.5 (IQR, 0.2-2.1) years to 0.2 (IQR, 0.1-0.3) years from 2006 to 2015. Conclusions: The estimated time from seroconversion to ART initiation was reduced in tandem with expanded HIV testing and treatment efforts. While the time from diagnosis to ART initiation decreased to 0.2 years, the time from seroconversion to diagnosis was 3.3 years among people diagnosed in 2015, highlighting the need for more effective strategies for earlier HIV diagnosis.