Companion Text for the Slide Set: Minnesota HIV Surveillance Report, 2006

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Table of Contents

On this page:
Overview
Data Source
Data Limitations
HIV/AIDS in the United States
HIV/AIDS in Minnesota
MDH HIV/AIDS Surveillance: Cumulative cases
Overview of HIV/AIDS in Minnesota, 1990-2006
New HIV Infections in Minnesota
New HIV Infections by Geography
New HIV Infections by Gender
New HIV Infections by Race/Ethnicity
Average Age at HIV Diagnosis, Three-year Averages
New HIV Infections among Adolescents and Young Adults, 1990-2006
New HIV Infections by Mode of Exposure
Mother-to-Child HIV Transmission
Special Populations: New HIV Infections among Foreign-born Persons

Late Testers: Progression to AIDS within one year of HIV diagnosis

Overview

The Minnesota HIV Surveillance Report, 2006 describes the occurrence of reported HIV infections in Minnesota by person, place, and time through December 31, 2006.  Such data provide information about where and among whom HIV transmission is likely occurring.  This knowledge can in turn be used to help educate, target prevention efforts, plan for services, and develop policy. 

Data Source

The data in this report are based on confidential case reports collected through the Minnesota Department of Health (MDH) HIV/AIDS Surveillance System.  In Minnesota, laboratory-confirmed infections of human immunodeficiency virus (HIV) are monitored by the MDH through this active and passive surveillance system.  State rules (Minnesota Rule 4605.7040) requires both physicians and laboratories to report all cases of HIV infection (HIV or AIDS) directly to the MDH (passive surveillance).  Additionally, regular contact is maintained with several clinical sites to help ensure completeness of reporting (active surveillance). 

Data in this report include cases diagnosed with HIV as of December 31, 2006 and reported to the MDH as of April 2007. All data are displayed by earliest date of HIV diagnosis.  Refer to the HIV Surveillance Technical Notes for a more detailed description of data inclusions and exclusions.

Data Limitations

Factors that impact the completeness and accuracy of the available surveillance data on HIV/AIDS include the level of screening and compliance with case reporting.  Thus, any changes in numbers of infections may be due to one of these factors, or due to actual changes in HIV/AIDS occurrence. 

The data presented in this report are not adjusted for reporting delays.  Thus, the case number presented for the most recent reporting year can be viewed as a minimum and will likely increase in the future as further case reports are received.  Changes in past years’ totals are updated in every new annual surveillance report.

HIV/AIDS in the United States

Compared with the rest of the nation, Minnesota is considered to be a low to moderate HIV/AIDS incidence state.  In 2005, state-specific AIDS rates ranged from 1.0 per 100,000 persons in Vermont to 32.7 per 100,000 persons in New York.  Minnesota had the 16th lowest AIDS rate (4.4 AIDS cases reported per 100,000 persons).  Compared with states in the Midwest region, Minnesota had a moderate AIDS rate.  State-specific HIV rates cannot be compared nationally because some states have just begun name-based HIV case surveillance.  At present 47 states have confidential name-based HIV case reporting. 

HIV/AIDS in Minnesota

MDH HIV/AIDS Surveillance: Cumulative Cases

AIDS has been tracked in Minnesota since 1982.  In 1985, AIDS officially became a reportable disease to state and territorial health departments nationwide.  Also in 1985, when the Food and Drug Administration approved the first diagnostic test for HIV, Minnesota became the first state to make HIV infection a reportable condition.  As of December 31, 2006, a cumulative total of 8,149 cases of HIV infection have been reported among Minnesota residents (1). This includes 4,986 AIDS cases and 3,163 HIV, non-AIDS cases. Of these 8,149 HIV/AIDS cases, 2,838 are known to be deceased through correspondence with the reporting source, other health departments, reviews of death certificates, active surveillance, and matches with the National Death Index.

Overview of HIV/AIDS in Minnesota, 1990-2005

The annual number of new AIDS cases increased steadily from the beginning of the epidemic to the early 1990s, reaching a peak of 361 cases in 1992. Beginning in 1996, both the number of newly diagnosed AIDS cases and the number of deaths among AIDS cases declined sharply, primarily due to the success of new antiretroviral therapies including protease inhibitors.  These treatments do not cure, but can delay progression to AIDS among persons with HIV (non-AIDS) infection and improve survival among those with AIDS.  Thus between 2001 and 2004 we saw a slow increase in the number of AIDS cases diagnosed, from 124 in 2001 to 206 in 2004, a 66 percent increase.  The number of AIDS cases diagnosed has again declined in the past two years to 163 in 2006. The number of HIV (non-AIDS) diagnoses has remained fairly constant since the mid 1990s at approximately 200 cases per year. However, over the past 4 years there has been a slight but constant increase from 185 cases in 2003 to 237 cases in 2006, a 28 percent increase.  By the end of 2006, an estimated 5,566 persons with HIV/AIDS were assumed to be living in Minnesota. (2)

New HIV Infections in Minnesota

In this report, the term “new HIV infections” refers to HIV-infected Minnesota residents who were diagnosed in a particular calendar year and reported to the MDH.  This includes persons whose first diagnosis of HIV infection is AIDS (AIDS at first diagnosis).  HIV infection data are displayed by earliest known date of HIV diagnosis.

New HIV Infections by Geography

Historically, about 90% of new HIV infections diagnosed in Minnesota have occurred in Minneapolis, St. Paul and the surrounding seven-county metropolitan area.  This has not changed over time.  Although HIV infection is more common in communities with higher population densities and greater poverty, HIV or AIDS has been diagnosed in over 90% of counties in Minnesota.

New HIV Infections by Gender

Since the beginning of the epidemic, males have accounted for a majority of new HIV infections diagnosed per year.  However, the number and the proportion of cases among females have increased over time.  In 1990, males accounted for 89% of new HIV infections. In 2006, 72% of new infections occurred among males and 28% among females.

New HIV Infections by Race/Ethnicity (3)

Trends in the annual number of new HIV infections diagnosed among males differ by racial/ethnic group.  New cases among White males drove the epidemic in the 1980s and early 1990s.  Although Whites still account for the largest number of new infections among males, this number decreased steadily between 1991 and 2000, but has stayed steady at around 130 since 2001.

In contrast to the overall large decline in the annual number of cases among White males, the decline among African American males was more gradual.  The annual number of cases for African American males peaked in 1992 at 81 and gradually decreased to 33 in 2003. Since 2004 the number of cases among African American males has been stable around 40 with 38 cases diagnosed in 2006. The numbers of new cases in all other racial/ethnic groups during this same time remained stable or increased.  Increases in the annual number of HIV infections diagnosed among Hispanic and African-born males, in particular, have been recorded since the late 1990s. In 2006, the number of cases diagnosed among Hispanic males is the highest ever recorded in Minnesota, doubling the number seen in 2005.   The percentage of new HIV infections diagnosed among men of color as a whole has been increasing over time as the number of cases among White males has dropped.

Similarly, trends in the annual number of HIV infections diagnosed among females differ by racial/ethnic group.  In the beginning of the epidemic, White women accounted for a majority of newly diagnosed cases among females.  Since 1991, the number of new infections among women of color has exceeded the number among White women.  Since 2000, the annual number of new infections diagnosed among African American females had been stable at around 20 cases per year, however in the past two years that number has increased slightly with 28 cases diagnosed in 2006. Between 1999 and 2002 the number of cases among African-born females increased significantly, from 18 to 41 cases. However since 2003 the number has decreased steadily with 18 new infections diagnosed in 2006. The annual number of new infections diagnosed among Hispanic, American Indian, and Asian females continues to be quite small (10 cases or fewer per year for each of these groups).

The most recent data illustrate that men and women of color continue to be disproportionately affected by HIV/AIDS.  Whites make up approximately 88% of the male population in Minnesota and 55% of the new HIV infections diagnosed among men in 2006. Men of color make up approximately 12% of the male population and 45% of the infections diagnosed among men in 2006. Similarly for females, Whites make up approximately 89% of the female population and 32% of new infections among women in 2006 whereas women of color make up approximately 11% of the female population and 68% of the new infections among women. (4)

Note that race is not considered a biological reason for disparities in the occurrence of HIV experienced by persons of color.  Race, however, can be considered a marker for other personal and social characteristics that put a person at greater risk for HIV exposure.  These characteristics may include, but are not limited to, lower socioeconomic status, less education, and greater prevalence of drug use.

Average Age at HIV Diagnosis, Three-year Averages

In recent years, Hispanic (approximate age = 32 years) and African American (approximate age = 34 years) males were slightly younger than White, African-born, American Indian, and Asian males (approximate age = 38 years) at the time of HIV diagnosis.  During the past three years, the average age at HIV diagnosis has been approximately 33 years among African American, African-born and Hispanic females.  American Indian females were slightly younger (approximate age = 29 years), while White (approximate age = 36) females were older. The number of new cases among Asian females over the past three years was to small to calculate average age.  Age at HIV diagnosis can be used as a proxy for age at HIV infection.  However, due to differences in testing behavior (e.g. variable lengths of time between HIV infection and diagnosis) across time and between sociodemographic groups, comparisons of average age at diagnosis are difficult to interpret.

New HIV Infections among Adolescents and Young Adults (5), 1990-2005

Many people are infected with HIV for years before they actually seek testing and become aware of their HIV status.  This phenomenon especially affects the observed case counts for younger age groups.  As a result, the reported number of HIV infections among (5)(with few or no reports of AIDS at first diagnosis) is likely to underestimate the true number of new infections occurring in the population more than the reported number of cases in older age groups does.

In 1990, 10% (45/436) of new HIV infections reported to the MDH were among youth.  In 2006 this percentage was 18% (57/318).  Among young men, the number of new HIV diagnoses peaked in 1991 at 41 cases and then declined through the mid 1990s to a low of 14 cases in 1997.  Since 1997 the annual number of cases diagnosed among young men increased steadily to 32 in 2000, but then dropped to 18 cases in 2002. However, over the past four years that number has increased steadily from 18 cases in 2002 to 35 cases in 2006, close to a hundred percent increase. 

Unlike young men, the annual number of new HIV infections diagnosed among young women has remained relatively consistent over time.  For example, 19 cases of HIV infection were diagnosed among young women in 1992 and 22 cases in 2006.  Females accounted for 38% (22/57) of new HIV infections diagnosed among adolescents and young adults in 2006.  In addition, young women accounted for 25% (22/90) of new infections among females, while young males accounted for 16% (35/228) of new infections among males.

Similar to the adult HIV/AIDS epidemic, persons of color account for a disproportionate number of new HIV infections among adolescents and young adults.  Among young men, Whites accounted for 48% of new HIV infections diagnosed between 2004 and 2006, African Americans accounted for 28%, Hispanics 16%, and African-born 6% of the cases. Among young women, Whites accounted for 18%, African Americans 32%, African-born 31%, and Hispanics 11% of the new infections diagnosed during the same time period.

Starting in 2004, MDH has used a risk re-distribution method to estimate mode of exposure among those cases with unknown risk. For additional details on how this was done please read the HIV Surveillance Technical Notes. All mode of exposure numbers referred to in the text are based on the risk re-distribution.

Men having sex with men (MSM) was the predominant mode of HIV exposure among adolescent and young adult males, accounting for an estimated 89% of the new HIV infections diagnosed between 2004 and 2006. The joint risk of MSM and injecting drug use (IDU) accounted for an estimated 8%, and heterosexual contact accounted for an estimated 3% of the cases in the same time period.

Heterosexual contact accounted for an estimated 87% of new HIV infections diagnosed among adolescent and young adult females between 2004 and 2006, while IDU accounted for an estimated 13% of the cases.

New HIV Infections by Mode of Exposure

Since the beginning, men have driven the HIV/AIDS epidemic in Minnesota and male-to-male sex has been the predominant mode of exposure reported. Though still the majority, both the number and proportion of new HIV infections attributed to MSM have been decreasing since 1991 reaching an apparent plateau in 2000 at just under 130 cases per year.  However in the past two years this number has gone back up with 147 infections attributed to MSM in both 2005 and 2006. On a much smaller scale, the numbers of male cases attributed to IDU and MSM/IDU also have been decreasing over the past decade, while the number of cases attributed to heterosexual contact has been increasing.  The number of cases without a specified risk has also been increasing.

Throughout the epidemic, heterosexual contact has been the predominant mode of HIV exposure reported among females.  IDU is the second most common mode of transmission making up 4% of cases among women in 2006.  Unspecified risk has been designated for a growing percentage of cases for the past several years.  In 1996, 7% of women diagnosed with HIV infection did not have a specified mode of transmission.  This percentage grew to 27% in 2006 with an additional 33% of female cases who would not agree to or could not be interviewed by a Disease Intervention Specialist (6) from the MDH.  Some cases may yet be interviewed, thus, a portion of these women will later have an identified mode of transmission.  This explains part of the higher percentage of cases in recent years with an unspecified mode of exposure.  According to a study conducted by the Centers for Disease Control and Prevention (CDC) (7) it is likely that at least 80% of women with unspecified risk acquired HIV through heterosexual contact.  Heterosexual contact as a mode of HIV transmission is currently only assigned to a female case if she knows that a male sexual partner of hers was HIV-infected or at increased risk for HIV. As mentioned above, in starting in 2004 MDH has used a risk re-distribution method to estimate mode of exposure among those with no risk and the numbers below reflect the risk re-distribution (see HIV Surveillance Technical Notes for further details).

The proportion of cases attributable to a certain mode of exposure differs not only by gender, but also by race.  Of the new HIV infections diagnosed among males between 2004 and 2006, MSM or MSM/IDU accounted for an estimated 96% of cases among White males, 92% of cases among Hispanic males, 67% of cases among African American males, and 8% of cases among African-born males. The latter three also had the highest proportions of cases with unspecified risk (37%, 34%, and 90%, respectively – this includes cases for whom no interview has been obtained; see HIV Surveillance Technical Notes for further information about re-distribution of mode of exposure categories). It is hypothesized that due, in part, to social stigma many of the cases with unspecified risk were unclassified MSM cases and is reflected in the risk re-distribution.  This may not hold as true for African-born cases given that heterosexual contact and contaminated medical equipment have been established modes of HIV exposure in their countries of origin.  IDU was estimated as a risk in 13% of male African American cases, 8% of Hispanic cases and 2% of male White cases diagnosed during 2004-2006.  The number of cases among Asian and American Indian men during the years 2004-2006 was insufficient to make generalizations regarding risk (less than 20 cases in each group), but male-to-male sex appears to be the most prominent mode of exposure among both groups.

Heterosexual contact with a partner who has or is at increased risk for HIV infection accounted for an estimated 78% of cases among African American females, 85% of cases among White females, and 96% of cases among African-born females between 2004 and 2006. More than 40% of cases in each of these groups had no specified risk (including cases for whom no interview has been obtained; see HIV Surveillance Technical Notes for further information about re-distribution of mode of exposure categories). IDU was estimated as a risk for 15% of cases among Whites, 18% among African Americans, and 0% among African-born.  The number of cases among Hispanic, Asian, and American Indian women during the years 2004-2006 were insufficient to make generalizations regarding risk (less than 20 cases in each group).

Mother-to-Child HIV Transmission

The ability to interrupt the transmission of HIV from mother to child via antiretroviral therapy and appropriate perinatal care is an important accomplishment in the history of the HIV/AIDS epidemic.  Newborn HIV infection rates range from 25-30% without antiretroviral therapy, but decrease to 1-2% with appropriate medical intervention.  Unfortunately, these benefits have largely only been realized in the developed world where antiretroviral therapies are more accessible than in undeveloped countries. 

Over the past 10 years the number of births to HIV-infected women has increased steadily from 19 in 1994 to 50 in 2006. During the same time period the rate of transmission has decreased from 15% between 1994 and 1996 to just below 1% in the past three years. However in the same time period the rate of transmission for foreign-born mothers was 1.4%.

The rate of transmission in Minnesota between 1982 and 1994 (before widespread use of zidovudine (8) to prevent mother-to-child HIV transmission) was 25%.  Proper prenatal care, including HIV screening for all pregnant women and appropriate medical intervention for those infected, is a vital element in preventing the spread of HIV.

Special Populations: New HIV Infections among Foreign-born Persons

The number of new HIV infections diagnosed among foreign-born persons in Minnesota has steadily increased from 19 cases in 1990 to 71 cases in 2006.  This increase has been largely driven by the increase of cases among African-born persons from 7 cases in 1990 to 36 cases in 2006, as well as, persons from Mexico, Central and South America from 6 cases in 1990 to 29 cases in 2006.  Among new HIV infections diagnosed in 2006, 22% were among foreign-born persons.  Based on U.S. Census 2000 data, foreign-born persons make up 5% of the total Minnesota population and are, therefore, disproportionately affected by HIV (9).Among African-born this disparity is even more evident, while African-born persons make up less that 1% of the Minnesota population they accounted for 11% of new HIV infections in 2006.

Late Testers: Progression to AIDS within one year of HIV diagnosis

Over the past six years approximately one third of all new HIV infection cases diagnosed in Minnesota have either been AIDS at first diagnosis, or have progressed to an AIDS diagnosis within one year of initial diagnosis with HIV (non-AIDS) infection. As with other characteristics of the HIV epidemic in Minnesota, the proportion of late testers varies by demographic characteristics. The most significant differences occur by race/ethnicity, with the proportion of late testers between 2000 and 2006 among Hispanics (47%) and African-born (35%) being higher than that among Whites (30%) and African Americans (28%). Differences by age are as expected with the percentage of late testers increasing with age at time of diagnosis. In 2006 (10), 8% of those diagnosed between the ages of 13 and 24 were late testers compared to 44% of those 45 years and older. Finally, the percentage of late testers is also significantly higher among foreign-born cases compared to other cases. In 2006, 38% of foreign-born cases were late testers compared to 23% of US-born cases.

(Last Revised: 4/12/2006)


(1) This number includes persons who reported Minnesota as their state of residence at the time of their HIV and/or AIDS diagnosis. It also includes persons who may have been diagnosed in a state that does not have HIV reporting and who subsequently moved to Minnesota and were reported here. HIV-infected persons currently residing in Minnesota, but who resided in another HIV-reporting state at the time of diagnosis are excluded. (return to text)

(2) This number includes persons whose most recently reported state of residence was Minnesota, regardless of residence at time of diagnosis. This estimate does not include persons with undiagnosed HIV infection. (return to text)

(3) Black race was broken down into African-born and African American (Black, not African-born). The numbers exclude 20 persons arriving through the HIV-Positive Refugee Resettlement Program. (return to text)

(4) Population estimates based on U.S. Census 2000 data. (return to text)

(5) In this report, adolescents are defined as 13-19 year-olds and young adults as 20-24 year-olds; these two groups are jointly referred to as “youth.” Analyses are performed for adolescents and young adults combined because case numbers are too small to present meaningful data separately for each. (return to text)

(6) Disease Intervention Specialists attempt to contact all persons recently diagnosed with HIV in order to provide HIV education, partner notification, and connect the person with medical care or other resources. (return to text)

(7) MMWR 2001; 50(RR-6):31-40. (return to text)

(8) A common antiretroviral drug. (return to text)

(9) Based on U.S. Census 2000 data, 260,463 foreign-born persons, including 35,188 African-born persons are living in Minnesota out of a total population of 4,919,479.  Because there are many reasons foreign-born persons may not be included in the census count (e.g. difficulties with verbal or written English), these numbers are likely an underestimate of the actual size of the foreign-born population living in Minnesota. (return to text)

(10) Percentage of late testers for 2006 includes only those progressing to AIDS through March 2007. As such, this percentage is likely through increase as additional reports are made to the MDH.

Updated Tuesday, 23-Apr-2013 09:20:46 CDT