The findings are published in the Sept. 4 edition of Annals of Internal Medicine.

The study included more than 45,000 HIV-infected participants receiving clinical care for HIV. The study population was demographically similar to the U.S. population living with HIV, according to national surveillance data from the Centers for Disease Control and Prevention. Over the study period, the researchers found that the proportion of HIV-infected participants prescribed HAART increased 9 percentage points to 83 percent. During this time, the researchers also observed an increase in viral load suppression among those with HIV, regardless of treatment. Suppression of viral load reduces the likelihood of transmitting HIV to others. Among those taking HAART, the proportion with a suppressed viral load increased from 54 percent to 81 percent.

"This is good news for the HIV epidemic in the U.S., but there is room for improvement," said Keri N. Althoff, PhD, MPH, lead author of the study and assistant professor in the Bloomberg School's Department of Epidemiology. "We need to continue to focus on linking HIV-infected adults into care and effective treatment, not only for the individual's health, but to reduce the likelihood of transmission to others."

The analysis also found an increase in median CD4 count for participants who died from HIV during the study period. Median counts increased at the time of death from 60 cells/mm3 to 209 cells/mm3. A higher CD4 count suggests a healthier immune system. Additional research is planned to investigate trends in the causes of death.

"Our study demonstrates the data from the NA-ACCORD can be used to monitor important health indicators among adults with HIV, which is needed to evaluate the impact of the Affordable Care Act and to measure progress towards the National HIV Strategy goals," said Althoff.

The authors of "U.S. Trends in Antiretroviral Therapy Use, HIV RNA Plasma Viral Loads, and CD4 T-Lymphocyte Cell Counts among HIV-infected Persons, 2000 to 2008" are Keri N. Althoff, PhD, MPH; Kate Buchacz, PhD, MPH; H. Irene Hall, PhD, MPH; Jinbing Zhang, MS; David B. Hanna, MS; Peter Rebeiro, ScM; Stephen J. Gange, PhD; Richard D. Moore, MD, MHS; Mari Kitahata, MD, MPH; Kelly A. Gebo, MD, MPH; Jeffrey Martin, MD; Amy C. Justice, MD, PhD; Michael Horberg, MD; Robert S. Hogg, PhD; Timothy R. Sterling, MD; Angela Cescon, MPH; Marina B. Klein, MD; Jennifer Thorne, MD, PhD; Heidi Crane, MD, MPH; Michael J. Mugavero, MD; Sonia Napravnik, PhD; Gregory D. Kirk, MD, PhD; Lisa P. Jacobson, ScD; and John T. Brooks, MD, for the North American AIDS Cohort Collaboration on Research and Design.

The researchers were supported by grants from the National Institutes of Health, the Canadian Institutes of Health Research, the Canadian HIV Trials Network, the government of British Columbia, and the U.S. Centers for Disease Control and Prevention.

Note: If no author is given, the source is cited instead.

• HIV and AIDS
• Infectious Diseases
• Sexual Health

• Public Health
• Ethics
• Social Issues

• Transmission (medicine)
• Antiretroviral drug
• HIV test
• Antiviral drug
• Sexually transmitted disease
• Trichomoniasis