Letter to the Editor
To the Editor:
In order to provide insights into trends of HIV infection during the 1990s among youth when trend information about HIV was most limited, we assessed the prevalence of HIV among adolescents and young adults, an often overlooked subgroup, from 1992 through 2000, using sentinel HIV surveillance data drawn from the 2 Baltimore City Health Department STD Clinics. We also examined trends in prevalence among 2 important adolescent and young adult risk groups: men who reported same sex activity (MSM) and females reporting partner injection drug use (IDU). Notably very few men or women in this age group reported IDU. For individuals with multiple positive tests, only the first positive test was counted.
A total number of 19,597 adolescent and young adults were tested between 1992 and 2000. The population was predominantly male (60%) and black (96%). We found a constantly decreasing trend in positive diagnosis among adolescents between 1992 and 2000, with the rate of positivity declining from 2.34% in 1992 to 0.57% in 2000. The prevalence among MSM declined from 31.25% in 1992 to 10.53% in 2000. Over the same time period, HIV prevalence in females reporting partner IDU decreased from 11.54% to 2.70%.
Our results suggest that adolescents and young adults receiving care through the 1990s in 2 Baltimore City STD Clinics had decreasing prevalence of HIV. These results suggest that the true community-level incidence of infection may have been declining in the populations seeking care at the clinic—poorer black men and women. An alternative explanation for these results is that the risk profile of those youth seeking care at the clinic may have changed over time. However, the declining trend in prevalence among patients who were young MSM or young women reporting partner IDU show that even among those young STD Clinic patients at highest risk, prevalence declined.
The likelihood that our findings represented a true decrease in HIV incidence are supported by back-calculation estimates of HIV trends.1,2 In both studies, back-calculation estimates suggest that HIV incidence peaked in 1984–1985 and decreased in the early 1990s.1,2 This decline is also supported by Maryland state data that demonstrates a decreasing trend in AIDS cases between 2000 and 2008 which suggests decreasing incidence of HIV during the 1990s.3
Our analysis of data from 2 public STD clinics located in a East Coast city known for high rates of HIV and IDU add support to the belief that the increases in the last decade of the incidence of HIV observed nationally in MSM and women represent true change in the epidemic.1 Future investigations are warranted that examine whether this observed decline in the prevalence of infection during the 1990s occurred in other cities around the United States and to determine which individual and community level factors were associated with the observed change in trajectory of the epidemic in Baltimore over the past 20 years. Such information is essential in developing effective HIV prevention strategies going forward.
Evelyn P. Simpkins, MD
Renata Arrington-Sanders, MD,MPH
Jonathan M. Ellen, MD
Division of General Pediatrics and Adolescent Medicine
Johns Hopkins School of Medicine
Emily Erbelding, MD, MPH
Division of Infectious Diseases
Johns Hopkins School of Medicine
1. Hall HI, Song R, Rhodes P, et al. Estimation of HIV incidence in the united states. JAMA 2008; 5:520–529.
2. Holtgrave D, Hall HI, Rhodes PH, et al. Update annual HIV transmission rates in the united states, 1977–2006. J Acquir Immun Defic Syndr 2009; 50:236–238.