HIV Infection and AIDS, 2000
In 2000, 161 cases of AIDS were diagnosed and reported (3.3 per 100,000 population). This represents a 62% decline in the annual incidence of reported AIDS cases since the peak in 1992 (423 cases) (Figure 3). The recent decline is due in part to the benefits of highly active antiretroviral therapy (HAART). The peak incidence in 1992 likely is due to a change in the AIDS surveillance case definition in 1993 which allowed for retrospective diagnoses; this change incorporated CD4+ T-lymphocyte counts of <200/uL in the absence of other AIDS-indicator diseases.
In addition to AIDS cases diagnosed in 2000, 240 newly diagnosed cases of HIV infection that had not progressed to AIDS by the year’s end were reported in 2000 (4.9 per 100,000 population) (Figure 3). Although this is an 8% increase from 1999, the increase was due mostly to 13 HIV-infected refugees from Africa who immigrated to Minnesota. While newly identified HIV (non-AIDS) case incidence rates have plateaued over the past 6 years, the 2000 incidence rate reflects a 41% decline from the 404 cases reported in 1987. This peak number is not represented in Figure 3 to avoid duplication of reported cases which progressed from an HIV (non-AIDS) diagnosis to AIDS. The plateau in HIV (non-AIDS) cases suggests that the epidemic may be stabilizing in Minnesota, since no changes in surveillance methodology have been made since 1993.
HAART also has led to a marked reduction in mortality. Deaths due to AIDS have declined substantially since 1994, the peak year for deaths (Figure 3). The 67 deaths in persons with a diagnosis of AIDS in 2000 reflects a 75% decline from the 273 deaths in 1994.
Several trends in reported adult/adolescent AIDS cases continue to evolve (Table 3). Male-to-male sex remained the most common exposure category among AIDS cases diagnosed in 2000 (70 cases, 44%), but the proportion of cases with this risk factor has declined steadily over time. In contrast, the proportion of cases related to heterosexual contact has increased. The proportion of female AIDS cases also has increased; females represent 10% of cases diagnosed cumulatively from 1982 to 2000 and 20% of cases diagnosed in 2000. An increasing proportion of AIDS cases continues to be identified in people of color, while the proportion of cases identified in whites is decreasing. In 2000, 41% of AIDS cases were black, 11% were Hispanic, 4% were American Indian, and 1% were Asian/Pacific Islander, compared to 18%, 5%, 2%, and <1%, respectively, from 1982 to 1999. Conversely, in 2000, 42% of AIDS cases were white, compared to 74% of cases from 1982 to 1999.
Trends in cumulative HIV (non-AIDS) infection data are even more pronounced than the trends in AIDS cases described above. For example, male-to-male sex is a risk factor for 60% of reported HIV (non-AIDS) cases and 68% of AIDS cases. Heterosexual transmission accounts for 13% of HIV (non-AIDS) cases and 6% of AIDS cases. Females comprise 19% of HIV (non-AIDS) cases compared to 10% of AIDS cases. Whites comprise 73% of AIDS cases and 62% of HIV (non-AIDS) cases, while blacks and Hispanics comprise 19% and 5% of AIDS cases and 30% and 5% of HIV (non-AIDS) cases, respectively. Injecting drug use as a risk factor accounts for 8% of AIDS cases and 11% of HIV (non-AIDS) cases.
Since 1982, 59 pediatric cases (<13 years of age) have been reported with AIDS/HIV infection in Minnesota. The majority (46 cases, 78%) were born to HIV-infected women and acquired their infection perinatally. Of these, 15 were born outside of Minnesota. With the increased identification of HIV infection in pregnant women and the increased use of antiretroviral therapy during pregnancy, perinatal transmission has declined. No children born in Minnesota in 1999 or 2000 have been identified with HIV infection.
As new treatments become available and the occurrence of AIDS is being delayed, using AIDS diagnoses as a marker for the epidemic is becoming less useful. Assessing trends based on recent HIV infections provides a better mechanism to evaluate current risk of transmission and effectiveness of prevention efforts. In addition, because of increased survival, a growing number of persons are living with HIV infection (Figure 4). These data emphasize the continued importance of monitoring the epidemic to direct policy and prevention efforts.