Epidemiology

HIV (non-AIDS) first became reportable in Illinois in July 1999 using a coded identifier. On January 1, 2006, Illinois changed to name-based HIV case reporting.

At the end of 2008 in Illinois, there were 17,447 people living with HIV and 14,663 people living with AIDS, with males comprising the majority of each group (76% and 80%, respectively). This represents an increase of 1,802 or 5.9 percent from 2007.

The state reported 1,497 new HIV (non-AIDS) cases and 969 AIDS cases in 2008, representing a 13.3% increase in new HIV (non-AIDS) cases and an 8.4% decrease in AIDS cases compared to 2007 figures.

Among racial/ethnic groups, non-Hispanic blacks represent one-half (51%) of people living with HIV/AIDS in 2008, although non-Hispanic blacks comprise only 15% of the Illinois population. Non-Hispanic blacks remain overrepresented among new HIV (non-AIDS) and new AIDS cases as well, with approximately 53% and 55% of new cases occurring in this group in both 2007 and 2008, respectively. In 2008, 32% of people living with HIV/AIDS were non-Hispanic white and 15% were Hispanic. Among new HIV/AIDS cases, there was a slight decrease in the proportion of cases among non-Hispanic whites. The proportion of HIV/AIDS cases among Hispanics and Asians was unchanged between 2007 and 2008.

Looking at the current ages of people living with HIV/AIDS, the largest proportion of persons are aged 40–49 years (37%); however, there is also a large proportion aged 50 and older (31%). About 18% of people living with HIV are less than 30 years old, compared to just 6% of people living with AIDS. While this age differential most likely represents the fact that HIV infection takes time to progress to AIDS (resulting in an older population living with AIDS), there is some evidence to suggest a shift toward a younger population being infected with HIV: in 2008, persons under the age of 30 years comprised 11% of people living with HIV/AIDS but represented 36% of new case reports of HIV/AIDS.

In regards to exposure categories among people living with HIV/AIDS in 2008, men who have sex with men (MSM) continues to contribute the largest proportion of cases overall (46%), with injection drug users (IDU) the next-largest category, accounting for 16% of cases. The combination category MSM and IDU contributed another 5% of cases. Heterosexual relations accounted for 14% of cases. Newly reported cases attributed to perinatal transmission represent 1% of all cases in 2008. The proportion of newly-reported HIV/AIDS cases with “risk not specified” remains quite high (17%). Some of these cases will likely be re-assigned to other categories upon further investigation by surveillance staff.