BOSTON — The adolescent HIV-1 epidemic as reflected in a multisite cohort of U.S. youth is changing from one of vertically transmitted infection to one where infection is acquired through risk behaviors, posing new challenges for providers and the health care system, said Dr. Allison L. Agwu in a poster session at the 15th Conference on Retroviruses and Opportunistic Infections.
The HIV Research Network, a consortium of 21 clinical sites providing primary HIV care, includes 684 patients aged 12–24 years. Vertical transmission was the source of infection in 227 patients and risk behaviors accounted for 457 cases, said Dr. Agwu of Johns Hopkins University, Baltimore.
Analysis of data from this cohort showed patients infected through risk behaviors are older, with a median age of 22 years, compared with a median age of 15 years in vertical-transmission patients. They are also more likely to be male. Of the risk-behavior patients, 292 (64%) are male, as are 108 (48%) of the vertical-transmission patients.
Risk behaviors comprised men having sex with men (51%), unprotected heterosexual activity (45%), and IV drug use (4%).
The median CD4 count in the risk-behavior group was 492 cells/mm
Despite this worse immune suppression and higher levels of viremia in the risk-behavior patients, they were less likely to be on highly active antiretroviral therapy (HAART) (43% vs. 88%). Those infected through risk behaviors also had significantly fewer outpatient visits, averaging five visits a year, whereas vertical-transmission patients averaged seven visits.
Rates of hospitalization did not differ, at 19/100 patient-years in the risk-behavior group and 17/100 patient-years in the vertical-transmission group, Dr. Agwu reported at the meeting, sponsored by the Foundation for Retrovirology and Human Health and the Centers for Disease Control and Prevention. Other aspects of treatment also did not differ significantly between the two groups. For example, 89% of those meeting the criteria for prophylaxis against Pneumocystis carinii pneumonia in the risk-behavior group received prophylaxis, as did 80% of vertical-transmission patients.
Differences in psychosocial risk factors between the two groups might account for the varying rates of HAART use, Dr. Agwu said in an interview. “[We'll] focus on deciphering patient and provider barriers to HAART initiation in the risk-behavior group to institute appropriate interventions.” She added that the number of risk behavior patients in need of treatment is likely to grow as the Centers for Disease Control and Prevention's recommendation of universal opt-out testing is implemented.