At the end of 2014, an estimated 1.1 million adults and adolescents and over 11,000 children under the age of 13 were living with HIV in the United States.88 The CDC divides annual HIV incidence statistics into two distinct categories. HIV infections are the estimated number of new infections (HIV incidence) that occurred in a particular year, regardless of when those infections were diagnosed, whereas HIV diagnoses are the number of people who received a diagnosis of HIV in a given year. This distinction is important because a person may be infected long before the year of HIV diagnosis.In 2014, there were an estimated 37,600 new HIV infections in the United States. Over 40,000 people received an HIV diagnosis in 2014, representing an HIV diagnosis rate of 12.6 per 100,000 population. Of these cases, over 99% were diagnosed among adults and adolescents, and less than 1% were diagnosed among children less than 13 years of age. In 2014, 6,721 deaths were attributed directly to HIV, but over 15,000 people with diagnosed HIV infection died, representing a death rate of 4.7 per 100,000.7(p64)
Time
In 2014, an estimated 40,000 HIV diagnoses represented a 19% decline since 2005 in annual diagnoses nationwide. Currently known modes of HIV transmission include homosexual and heterosexual intercourse, injection with nonsterile needles, transplantation of infected tissue, transfusion of blood and clotting factors, and transmission from an infected mother to child.89(p89) The most marked declines in HIV diag- noses from 2005 to 2014 occurred among people who inject drugs (63%) and heterosexuals (35%). Among women, diagnoses declined 40%, from 12,499 in 2005 to 7,533 in 2014. Among men, diagnoses decreased by 11%
over the 10-year period, from 36,296 to 32,185. This smaller reduction is mainly from diagnoses among men who have sex with men (MSM), which increased by about 6% over the 10-year period (see FIGURE 5-9).90
Place
Data on the global occurrence of HIV come from the WHO. At the end of 2016, some 36.7 million people, including 2.1 million children under the age of 15, were estimated to be living with HIV.91 Worldwide,
Examples: Three Important Causes of Morbidity in the United States 133
an estimated 1.8 million people became newly infected with HIV in 2016, an 18% decline from 2.2 million in 2010. The highest number of people living with HIV was in sub-Saharan Africa as well as South and Southeast Asia, but the highest prevalence of HIV as a percentage of total people in a given region was in sub-Saharan Africa and the Americas (see FIGURE 5-10). Several African countries have a particularly high number of people living with HIV. Adult HIV prevalence exceeds 20% in Swaziland, Lesotho, and Botswana.92
In the United States, there is considerable geographic variation in the annual rate of HIV diagnoses.7(p99) In 2015, the lowest rates were in New Hampshire, Vermont, Montana, and Idaho (1.9 to 2.8 per 100,000). The highest rates were in the District of Columbia (66.1 per 100,000), Louisiana (29.2 per 100,000), and Georgia (28.3 per 100,000) (see FIGURE 5-11). Met- ropolitan areas with 500,000 or more people had the highest rates of diag- nosis. The metropolitan areas with the highest HIV diagnosis rates in the United States were Miami, Florida, and Baton Rouge, Louisiana.7(p109)
HIV diagnosis rates (per 100,000 people) in 2015 were highest in the South (16.8), followed by the Northeast (11.6), the West (9.8), and the Midwest (7.6). Although Southern states are home to 37% of the U.S. population, they accounted for 50% of estimated infections in 2014.
Looking among those living with HIV in the United States, people in the South are also less likely to be aware of their infection than those in other U.S. regions. Nationally, 87% of Americans living with HIV knew their FIGURE 5-9 HIV diagnoses by transmission category, 2005–2014.
30,000 25,000 20,000 15,000 10,000 5,000 0
2005 2006 2007
Year of Diagnosis
Number Diagnosed
2008 2009 2010 2011 2012 2013 2014
PWID: People who inject drugs MSM: Men who have sex with men
MSM PWID
Heterosexuals MSM/PWID
Reprinted from Trends in U.S. HIV Diagnoses, 2005-2014. cdc.gov. https://www.cdc.gov/nchhstp/newsroom/docs/factsheets/HIV-Data-Trends-Fact-Sheet-508.pdf. Accessed October 2017.
FIGURE 5-10 Prevalence of HIV among adults aged 15–49, 2016, by WHO region.
Reprinted from World Health Organization. Global Health Observatory (GHO) data: HIV/AIDS. http://www.who.int/gho/hiv/en/. Accessed October 2017.
Eastern Mediterranean: 0.1
Africa: 4.2 Western Pacific: 0.1
South-East Asia: 0.3
Europe: 0.4
Americas: 0.5 Global prevalence: 0.8%
Prevalence (%) by WHO region
Examples: Three Important Causes of Morbidity in the United States 135
FIGURE 5-11 Rates of diagnoses of HIV infection among adults and adolescents, 2015, United States.
4.0 AK
9.6 HI 7.4
WA
2.8 ID
2.2 MT
3.1 WY
8.2 CO
3.5
ND 6.3
MN
4.8 IA
9.1 MO 10.4 AR
29.2 LA
20.6 MS
11.8 AL
28.3 GA
27.9 FL 16.9
SC 15.9 12.9 NC
TN 9.1 KY 11.5
IN 13.7
IL 4.7
WI 8.7
MI 9.5 OH
10.7 PA 13.6
VA 18.6
NY 3.9 ME 2.0 VT
7.0 RI
13.6 DE 26.7 MD 66.1 DC 15.8 NJ 8.8 CT 1.9 NH 10.3 MA 3.3
SD 5.2 NE 6.1 KS 9.9 OK
20.1 TX 7.8
NM 12.7
AZ 5.0 UT 20.1
NV 6.2 OR
14.5 CA
4.7 WV
Rates of HIV diagnoses per 100,000 people.
<10.0 10.0–19.9 20.0–29.9
≥30.0
Reprinted from Centers for Disease Control and Prevention. HIV in the United States by Geographic Distribution. Statistics Center. https://www.cdc.gov/hiv/statistics/overview/geographicdistribution .html. Accessed October 2017.
HIV status in 2012—but of the 15 states below 85%, one-third were states in the South. Southern states also have much worse outcomes for people living with HIV. One goal of the National HIV/AIDS Strategy for the United States is to reduce the death rate among people living with HIV to 21.7 per 1,000 individuals by 2015. Seven of the 10 states that had not met the goal by 2012 were in the South.90
Person
In the United States, advances in HIV research, prevention, and treat- ment have helped to decrease the number of HIV infections through perinatal transmission by more than 90% since the early 1990s. The risk of a pregnant woman transmitting HIV to her unborn child is 1% or less.93 Therefore, the age distribution of HIV diagnoses reflects the pri- mary modes of HIV transmission in the United States, through anal or vaginal sex or by sharing drug-use equipment with an infected person.
Of about 40,000 people who received an HIV diagnosis in 2015, less than 1% were children under 13 years of age, 4% were age 13–19, 37% were age 20–29, 24% were age 30–39, 17% were age 40–49, 12% were age 50–59, and 5% were age 60 and over.7(p18) Youth and young adults 13 to 24 years old are a particularly vulnerable group. They account for 22% of all new HIV diagnoses in the United States, yet they are the least likely age group to be linked to care and have a suppressed viral load (low level of virus in the body).88
Across all racial and ethnic groups, Black people continue to be the most disproportionately affected by HIV in the United States. Although Black men and women represent approximately 12% of the total U.S.
population, they accounted for 44% of all HIV diagnoses in 2014. Sim- ilarly, Latinos make up only 17% of the population, yet they accounted for 23% of all new HIV diagnoses. Though Blacks, Whites, and Latinos experienced decreases in diagnoses from 2005 to 2014, declines have stalled over the latter half of that period for Latinos.90
Gay, bisexual, and other MSM are the group most affected by HIV in the United States. MSM accounted for nearly 67% of HIV diagnoses in 2014 but make up approximately 2% of the U.S. population. Though diagnoses among MSM overall increased slightly from 2005–2014, trends over the decade varied considerably by race and ethnicity. Diagnoses rose 24% for Latino MSM, increased 22% for Black MSM, and declined 18%
for White MSM. Although the number of diagnoses has been rather small among Asian American MSM, there were concerning increases over the same time period (see FIGURE 5-12).
Across these various subgroups, the steepest increases occurred among young Black and Latino MSM age 13–24, who both experienced increases of about 87% from 2005–2014.HIV testing remained stable or increased among the groups experiencing declines in diagnoses, and HIV testing remained stable among Latino gay and bisexual men during this period. Researchers therefore believe the decreases in diagnoses also
reflect a decline in new infections and the increases in HIV diagnoses among Latino MSM suggest infections are likely increasing in this group.90
Discussion
HIV surveillance data are used to track the spread of the epidemic and to plan and evaluate prevention and treatment programs.7 For example, several areas of the United States have implemented needle-exchange programs among people who inject drugs (PWID) in which possibly infected needles are exchanged for new ones. An analysis found that PWID who participated in New York City syringe-exchange programs were about 70% less likely to become infected with HIV than PWID who did not participate.94 Although HIV infections fell from 2005–2014 among PWID, this progress may be threatened by the nation’s opioid epidemic.
As another example, the use of antiretroviral therapy as primary prevention among high-risk uninfected individuals and as treatment of HIV-infected individuals (which has the added benefit of making them less infectious) has been found to be highly effective in reduc- ing HIV transmission. Several studies (including tens of thousands of
FIGURE 5-12 HIV diagnoses among men who have sex with men by race/ethnicity, 2005–2014, United States.
Examples: Three Important Causes of Morbidity in the United States 137
American Indian/Alaska Native Black/African American
Native Hawaiian/Other Pacific Islander Multiple races
Asian American Hispanic/Latino White
10,000 12,000
Number Diagnosed
Year of Diagnosis 8,000
6,000
4,000
2,000
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 0
Reprinted from Trends in U.S. HIV Diagnoses, 2005-2014. https://www.cdc.gov/nchhstp/newsroom/docs/factsheets/HIV-Data-Trends-Fact-Sheet-508.pdf. Accessed October 2017.
sexual encounters) have found no HIV transmissions to an HIV-negative partner occurred when the HIV-positive person was virally suppressed.
These were both heterosexual and homosexual sexual encounters with- out the use of condoms or pre-exposure prophylaxis (PrEP), a drug that people at high risk for HIV take daily to lower their chances of getting infected.95-98 The CDC has therefore stated that people who take ART daily as prescribed and are able to maintain a suppressed viral load “have effectively no risk” of transmitting HIV to their sexual partner.99