Clinical and Health Affairs
The Epidemiology of HIV/AIDS in Minnesota: Current Trends
By Shulamith Bonham, M.D., Ogechika K. Alozie, M.D., M.P.H., and W. Keith Henry, M.D.
Abstract
The epidemic of HIV infection and HIV/AIDS in Minnesota reflects national trends in transmission and progression to disease. Analysis of Minnesota’s data also highlights populations that are at much greater risk for HIV infection and progression to AIDS. Although men who have sex with men continue to comprise the majority of people in Minnesota with HIV, other subpopulations—women, people of color, and foreign-born residents—are seeing a rise in their infection rates as well. Members of these groups tend to be diagnosed later and, thus, are at greater risk for their infection to progress to AIDS. This article discusses some of the nuances of the most recent epidemiologic data on HIV/AIDS in Minnesota and makes the case for continued aggressive strategies for outreach, education, and adequate access to health care services among at-risk populations.
Access to health care and a strong public health infrastructure have shaped the epidemiology of HIV/AIDS in Minnesota and helped maintain a relatively low incidence rate of new HIV infection. Minnesota was the first state in the country to require reporting of HIV infection to the Department of Health, a policy that has allowed for excellent tracking of the full scope of the epidemic and optimizing procurement and distribution of resources for treatment and prevention. This approach has served as a model for other states and now has been adopted nationally.
HIV/AIDS in the United States
The Centers for Disease Control and Prevention (CDC) estimates that more than 1.1 million people in the United States were living with either diagnosed or undiagnosed HIV in 2006, with the number of new cases rising steadily every year since 1977.1,2 This steady increase is in part attributable to the advent of highly active antiretroviral therapy (HAART) and improvements in the long-term care of people with HIV/AIDS. Prevalence rates of HIV infection are notoriously difficult to estimate in part because the stigma associated with the infection discourages some people from self-reporting and because of the long asymptomatic period during which many people do not know they are infected.3
In an analysis of newly diagnosed HIV infections in 22 states in 2006, Hall et al. used assays that differentiate recent versus long-standing HIV infection as a new method for evaluating true rates of new HIV infection; they found that 31% of newly diagnosed cases were actually recent infections. Correlating this to national figures for that year, they estimated 56,300 newly transmitted infections, or 22.8 cases per 100,000 population in the United States for 2006. These data also supported findings by the CDC that new infections in this country continue to be concentrated among men who have sex with men (MSM) and African Americans (Table).4 This type of combined methodology, using both clinical assay techniques and traditional epidemiologic population surveys, may greatly contribute to future understanding of the HIV epidemic and may help identify which populations are at greatest risk for late HIV diagnosis and treatment.
HIV/AIDS in Minnesota
Compared with other states, Minnesota has a moderate incidence of HIV/AIDS. Overall data on new HIV infections show modest increases over the last three years, with 326 new infections being reported in 2008.5 According to CDC data for 2007, state-specific rates of new AIDS diagnoses ranged from 24.9 per 100,000 persons in New York (the highest) to 1.0 per 100,000 persons in Vermont (the lowest). Minnesota ranks 11th lowest, with 3.8 new AIDS cases reported per 100,000 persons. Of the 26,347 new HIV cases diagnosed in 2007 in 47 reporting states and the District of Columbia, 224 (0.9%) were diagnosed in Minnesota.1 The AIDS diagnosis rate trends somewhat higher in Minnesota than in surrounding states. Wisconsin, for example, has a rate of 3.6 new cases per 100,000 population; Iowa, 2.5; South Dakota, 1.9; and North Dakota, 1.3 new cases per 100,000 people.5
The rate of new AIDS cases (persons who are HIV positive and meet the case definition of AIDS) in Minnesota increased from the beginning of the epidemic in 1981 until 1992, when it peaked at 361 new cases. With the advent of HAART, new cases of AIDS and AIDS-related mortality declined sharply both in Minnesota and elsewhere in the country. During the last four years, the number of new AIDS cases has decreased in Minnesota from 229 in 2004 to 175 in 2008 (a 24% decrease). Taking into account those who were diagnosed elsewhere and subsequently moved to Minnesota, approximately 6,220 people in the state are known to be living with HIV, 2,805 of whom are known to carry an AIDS diagnosis. As shown in Figure 1, AIDS deaths have stabilized over the last 10 years, and even declined in the last three years. This means more people are living longer with HIV/AIDS and the number of those living with HIV in Minnesota will continue to rise.
- Geographic Distribution of HIV and AIDS
Most Minnesota residents with HIV/AIDS live in the Minneapolis/St. Paul metropolitan area; 86% of all people with the infection live in Hennepin, Ramsey, Anoka, Dakota, Scott, and Washington counties.5 However, HIV/AIDS is not confined to urban areas. HIV infection has been diagnosed in residents of 90% of Minnesota’s counties, and there are currently people living with HIV or HIV/AIDS in 88% of the state’s counties. Of note, those diagnosed with HIV outside of the metro area are more likely to report transmission through IV drug use or heterosexual contact than those diagnosed in the urban and suburban areas.5
- Gender
Although the proportion of men in Minnesota who have HIV/AIDS has been greater than that of women from the beginning of the epidemic, the relative proportion of women has slowly increased. The rate of new HIV diagnoses (with or without concomitant AIDS) among women has increased over the last decade from 19% of newly reported HIV infections in 1998 to 27% of all new diagnoses in 2008. As the percentage of women infected with HIV increased, so, too, has the percentage of those living with HIV/AIDS. In 2008, women comprised 23% of those known to be living with HIV/AIDS.5 However, these statistics belie the rapidity with which the percentage of women of color who have the infection is catching up with the percentage of men of color who have it.
- Race/Ethnicity and Country of Origin
Men and women of color in Minnesota are disproportionately infected with HIV, and their infection is more likely to progress to AIDS (Figure 2). In general, over the last five to 10 years, the rate of new HIV infection has risen faster among Hispanic, African-born, African-American, and Native American men, and among African-American and African-born women than it has among Caucasians. As of 2008, 62% of men living with HIV/AIDS in Minnesota were white, 19% were African American, 8% Hispanic, 1% American Indian, and 1% Asian/Pacific Islander; nonwhite men comprised 38% of men with HIV/AIDS although they make up only 12% of the state’s population. Caucasians make up 88% of the state’s male population but comprised 61% of new HIV infections in men in 2008.
Similarly, women of color make up approximately 11% of the state’s female population but account for 69% of new infections in women in Minnesota. In an analysis of women currently living with HIV/AIDS in the state, 72% are nonwhite (30% African American, 30% African-born, 6% Hispanic, 3% American Indian, and 2% Asian/Pacific Islander).
It also has been noted that the race/ethnicity classification in reported data is often dependent on physician documentation; therefore, it is quite likely that some patients, in particular Native Americans, may be misclassified as “white.” Thus, the racial/ethnic disparities may actually be greater than described.
Another criticism of current data collection techniques relates to the country-of-origin data collected on African-born people. Because national HIV surveillance methods do not generally take into account an individual’s place of birth, people who were born in Africa are often grouped with African Americans. (The Minnesota Department of Health’s particular methodology does generally include specific country-of-origin data.) These populations may have drastically different lifestyles and be affected by different socioeconomic and underlying health factors that affect HIV transmission and morbidity and mortality associated with HIV/AIDS. According to a recent study by Kerani et al., in areas with large African-born populations such as Minnesota, people who were born in Africa account for a substantial proportion of HIV diagnoses.6 However, as African-born persons accounted for 11% of new HIV infections in Minnesota in 2008, it is important to be aware of the potential for misrepresentation in data reporting and analysis.
Among all foreign-born persons in Minnesota, the incidence of HIV infection has increased from 19 cases in 1990 to 62 cases in 2008. The majority of these cases were in African-born persons (from seven to 37 during that time period). U.S. Census data from 2000 indicated that 5% of Minnesota’s population is foreign-born and that 19% of all new HIV cases were among persons who were foreign-born, indicating that this is a high-risk population that may benefit from targeted public health interventions.5
- Adolescents and Young Adults
Minnesota has seen an increase in newly identified cases of HIV among adolescents and young adults, in particular among males ages 13 to 24 years. This age group accounted for 10% of new infections in 1990 and 18% in 2008. The number of new diagnoses among males in this age group peaked at 41 in 1991, then declined until 1997, when 14 cases were reported. Since then, however, there has been a steady rise in the rate of new HIV diagnoses in younger males to a new peak of 42 cases reported in 2008. Nonwhites make up a disproportionate number of these new cases of HIV infection. Among young men, African Americans, Hispanics, and African-born persons accounted for 31%, 9%, and 4% of cases, respectively. These data support the idea of aiming educational messages and testing initiatives at young people, in particular, those of color.5
Modes of Transmission and Risk Factors
The extent to which people in Minnesota become infected with HIV through various methods of transmission is similar to that in other parts of the country. Early in the epidemic, male-to-male sex was the most common mode of HIV exposure. With educational interventions targeted aggressively at MSM, transmission among that population declined significantly during the 1990s. Since then, new infections diagnosed in Minnesota among MSM have steadily increased. In 2008, MSM sexual transmission alone was attributed to 48% of all new Minnesota HIV diagnoses among men. When broken down further, MSM or males who are both MSM and IV drug users accounted for 86% of new cases in white and Hispanic men between 2006 and 2008. (Intravenous drug use alone was identified in 9% of cases involving African-American males, 9% of those involving Hispanic males, and 3% of cases involving white males.) During the same time period, only 68% of new infections among African-American males and 13% among African-born males were attributed to MSM, although these populations are also thought to be less likely to indicate their status as MSM.7 In support of this hypothesis, African-American and African-born males in Minnesota had the highest proportions (36% and 86%, respectively) of new cases with unspecified exposure risk.5
Among women in Minnesota, as well as nationally and globally, heterosexual contact continues to be the predominant mode of HIV transmission. Heterosexual contact was the primary risk for exposure in 89% of new cases diagnosed among African-American women, 84% among white women, and 97% among African-born women between 2006 and 2008.5 (The exact proportion is difficult to ascertain because these data are dependent on follow-up interviews with Minnesota Department of Health staff and because heterosexual contact is only recorded as the mode of transmission if a woman knows definitively that a male partner had HIV or had certain risk factors for it. In 2008, 32% of new female cases in Minnesota had unspecified modes of transmission.)
In addition, there is too little Minnesota data for both Asian/Pacific Islanders and American Indians as well as for Hispanic women to make further generalizations regarding exposure risks.
- Mother-to-Child Transmission
One of the great successes in the battle against HIV/AIDS in the United States has been prevention of mother-to-child transmission among pregnant women with HIV. Although there is always some risk of transmission, the success of HAART and the reduction in side effects and improved safety profiles of the newer antiretrovirals have allowed HIV-positive women to give birth to healthy HIV-negative children. In Minnesota, the number of live births to HIV-infected women has risen from 19 in 1994 to 50 in 2008, while the rate of mother-to-fetus transmission has declined from 15% to 1% over the same time period (Figure 3).5
Mother-to-child transmission will not be eliminated until all pregnant women are screened for HIV and have access to appropriate treatment. Fetal transmission rates are twice as high (2%) among foreign-born mothers. Although this disparity may be a reflection of the overall HIV rate among Minnesota’s foreign-born populations, it also highlights concerns regarding medical insurance and adequate access to timely medical care among different populations.
The Minnesota Department of Health’s Center for Health Statistics estimates that foreign-born women and women of color access prenatal care later in pregnancy and less frequently compared with white women. Eighty-three percent of white women received adequate prenatal care between 2003 and 2007. (Adequacy of prenatal care was determined by the time at which prenatal care began, the number of prenatal care visits a woman had, and the gestational age of the infant/fetus at the time of birth.) The proportion of women in all other ethic groups was lower: 64% among African Americans, 48.8% among American Indians, 71.6% among Asians, and 62% among Hispanics.8 These data do not delineate foreign-born as a separate group, but other data from the Department of Health show that 77% of foreign-born women began prenatal care in the first trimester, compared with 88% of U.S.-born women.9 In combating the spread of HIV and AIDS in Minnesota and globally, we must also address these issues of disparity in medical care in order to halt needless mother-to-child transmission.
- Late Testers
Late testers are those who live with HIV for years before diagnosis. They are of particular concern because they are often in need of medical care long before their HIV infection is identified. Thus, they are at much greater risk of transmitting the infection to others. Between 2000 and 2008, the proportion of people with new HIV diagnoses identified as late testers was 29% among whites and 29% among African Americans, but 47% among Hispanics and 42% among African-born individuals. Overall, 39% of late testers were foreign-born, compared with only 29% who were U.S.-born. This is a particular concern because from 2000 to 2008, almost a third of newly identified HIV cases had progressed to AIDS at the time of or within one year of diagnosis.5
Conclusion
Minnesota has benefited greatly from its excellent public health infrastructure and continues to excel in many measures of health care quality and disease intervention. Yet, the state’s rates of HIV infection and HIV/AIDS have remained troubling, reflecting many of the national trends as the epidemic spreads across demographic divisions. As we continue to battle HIV/AIDS, it is important to attend to the groups with the greatest need for intervention—MSM, people of color, adolescents and young adults, people who are foreign-born, and women—and also to remember that all Minnesotans need access to testing and care in order to control the virus and prevent further transmission. MM
Shulamith Bonham and Ogechika Alozie are fellows in the department of infectious diseases and international medicine at the University of Minnesota. Keith Henry is a staff physician with the HIV program at Hennepin County Medical Center and a professor in the University of Minnesota’s department of medicine.
The authors thank Luisa Pessoa-Brandão, M.S., and other staff from the STD and HIV Section of the Minnesota Department of Health for providing the epidemiologic data for this article.
References
1. Centers for Disease Control and Prevention. HIV/AIDS Statistics and Surveillance Report. Available at: www.cdc.gov/hiv/topics/surveillance/index.htm. Accessed September 4, 2009.
2. Campsmith M, et al. 16th CROI; Montreal, Canada; February 8-11, 2009. Abst. 1036.
3. United States Agency for International Development. HIV/AIDS Surveillance Database. Available at: www.hivaidssurveillancedb.org/hivdb/. Accessed September 4, 2009.
4. Hall H, Song R, Rhodes P, et al. Estimation of HIV incidence in the United States. JAMA. 2008;300(5):520-9.
5. Minnesota Department of Health. HIV Surveillance Report, 2008. Available at: www.health.state.mn.us/divs/idepc/diseases/hiv/hivsurvrpts.html. Accessed September 4, 2009.
6. Kerani RP, Kent JB, Sides T, et al. HIV among African-born person in the United States: a hidden epidemic. J Acquir Immune Defic Syndr. 2008;49:102-6.
7. Millett GA, Flores SA, Peterson JL, Bakeman R. Explaining disparities in HIV infection among black and white men who have sex with men: a meta-analysis of HIV risk behaviors. AIDS. 2007;21(15): 2083-91.
8. Minnesota Center for Health Statistics. Populations of Color Health Status Report Spring 2009. Available at: www.health.state.mn.us/divs/chs/POC/. Accessed September 4, 2009.
9. Minnesota Department of Health. Epidemiological Profile of HIV/AIDS in Minnesota 2008. Available at: www.health.state.mn.us/divs/idepc/diseases/hiv/stats/epiprofile.html. Accessed September 4, 2009.