Characteristics of HIV infection in patients fifty years or older in Michigan.

This study analyzed factors associated with human immunodeficiency virus (HIV) infection among persons ages 50 years or older at HIV diagnosis and examined differences in morbidity and survival between them and those ages 13 to 49 years. HIV-infected persons reported to the Michigan HIV/AIDS registry between January 1990 and October 2000 were analyzed. Of 12,614 HIV-infected persons selected, 938 (7.4%) were ages 50 years or older at HIV diagnosis. Persons ages 50 years or older at HIV diagnosis were twice as likely to be male (odds ratio [OR]: 1.9) than female. They were slightly at higher risk of contracting HIV through blood products (OR: 1.53) or heterosexual contact (OR: 1.24) than through injection drug use, but the difference was not statistically significant. They were twice as likely to report unknown HIV risk (OR: 1.8) than injection drug use and were significantly less likely to be men who have sex with men (OR: 0.64) than injection drug users. The prevalence of selected acquired immune deficiency syndrome (AIDS)-defining conditions was similar between the two age groups. However, HIV dementia was more commonly diagnosed among older persons, whereas disseminated Mycobacterium avium was less commonly diagnosed in this age group. The overall mean survival was significantly shorter among persons ages 50 years or older (73.5 months [standard deviation (SD)]: 2.21 compared with their counterparts [112.3 months (SD: 0.77)], even after adjusting for CD4 count at HIV diagnosis. Older persons appeared to have contracted HIV through heterosexual contact, blood products, or injection drug use and to have a short survival. This age group should no longer be overlooked.