HIV, or human immunodeficiency virus, is a viral infection that leads to AIDS and attacks the body’s immune system, eventually weakening it to a point where an infected person can no longer fight off any infection. HIV is carried in several bodily fluids, including blood, vaginal fluid, semen, anal mucus and breast milk. It gets into the body through open cuts or sores or through the body’s mucous membranes, such as inside the vagina or the tip of the penis.
While many wealthy nations, including the United States, have made major strides in fighting HIV and AIDS, about a quarter of people in Africa are living with HIV, but a majority of people who have it are undergoing antiretroviral treatment.
Learn more about what HIV and AIDS are, who is most at risk of contracting the virus and how the picture of HIV has changed over time in the U.S.
What Is HIV?
HIV is a virus that lowers the body’s ability to naturally fight off infections. If the virus is allowed to reproduce and spread throughout the body, it eventually causes an infected person’s immune system to lose so many crucial cells (called CD4 cells, or T-cells) that the virus develops into AIDS, which often can be terminal.
While HIV can’t be completely removed from the body (yet), major recent medical advancements have made it so that at-risk populations can take medicine (pre-exposure prophylaxis, or PrEP) to lower their risk of contracting the virus and those who already have HIV, treatment can reduce or even effectively remove the risk of passing the virus along.
Undiagnosed and untreated, HIV can lead to AIDS within about 10 years, and without medical intervention, AIDS can kill within just a few years. The CDC estimates that about 1.1 million Americans have HIV, and the World Health Organization says that nearly 37 million people across the globe are living with the virus.
Who Is Most Likely to Get HIV?
In the U.S., men are more likely than women to contract HIV, and about two-thirds of new HIV cases in 2017 were in gay and bisexual men, through straight sexual contact accounted for nearly a quarter of new cases.
New HIV cases by transmission type
|Male-to-male sexual contact||66%|
|Injection drug use||6%|
|Male-to-male sexual contact + injection drug use||3%|
People in their 20s have the highest infection rates among all age groups.
HIV infection rates by age group (cases per 100,000 people)
Among ethnic and racial groups, African-Americans, Hispanics/Latinos and whites account for the vast majority of new cases.
HIV infection cases by race or ethnicity
|Native American/Alaska Native||243|
|Native Hawaiian/other Pacific Islander||54|
HIV Across the U.S. & the World
The rate of new HIV diagnoses in the United States have been on the decline for the past several years, falling by nearly 10% since 2011, but several states have HIV infection rates that are quite a bit higher than the national rate of 12.3 per 100,000 people.
HIV infection rate by state (cases per 100,000 people)
Despite the nation overall seeing its HIV infection rate fall over the past several years, a handful of states have seen their rates go up, some quite dramatically.
Percentage change in HIV infection rates (cases per 100,000 people), 2015-2016
Several cities and metro areas have HIV infection rates that far exceed the national rate of 12.3 per 100,000 people.
HIV rates by metro area, top 50 (cases per 100,000 population)
|Miami–Fort Lauderdale–West Palm Beach, FL||44.1|
|New Orleans–Metairie, LA||38.5|
|Baton Rouge, LA||35.4|
|Atlanta–Sandy Springs–Roswell, GA||32|
|Houston–The Woodlands–Sugar Land, TX||27|
|Las Vegas–Henderson–Paradise, NV||25.8|
|Greensboro–High Point, NC||24.5|
|Little Rock–North Little Rock–Conway, AR||23.7|
|Dallas–Fort Worth–Arlington, TX||23.3|
|Lakeland–Winter Haven, FL||21.4|
|Durham–Chapel Hill, NC||21.1|
|Virginia Beach–Norfolk–Newport News, VA–NC||20.7|
|New York–Newark–Jersey City, NY–NJ–PA||20|
|Los Angeles–Long Beach–Anaheim, CA||19.9|
|Tampa–St. Petersburg–Clearwater, FL||19.9|
|San Antonio–New Braunfels, TX||19.6|
|Augusta–Richmond County, GA–SC||18.6|
|Austin–Round Rock, TX||18.5|
|San Francisco–Oakland–Hayward, CA||18.4|
|Charleston–North Charleston, SC||17.9|
|Louisville/Jefferson County, KY–IN||17.9|
|San Diego–Carlsbad–San Marcos, CA||17.8|
|Deltona–Daytona Beach–Ormond Beach, FL||16.5|
|Cape Coral–Fort Myers,||15.6|
|Riverside–San Bernardino–Ontario, CA||13.9|
|El Paso, TX||13.5|
|Oklahoma City, OK||13.2|
|St. Louis, MO–IL||13|
Across the globe, nearly 70% of those living with HIV are in Africa. A few African countries have adult HIV prevalence rates that exceed 20%.
Percentage of HIV-positive population by global region
Note: Numbers don’t add up to 100% because of rounding
HIV diagnosis rates have fallen in the U.S. by nearly 10% since 2011.
HIV rates by year (cases per 100,000 population)
In much of the world, an HIV diagnosis is still a death sentence, but that’s changing in the U.S., where the availability of modern antiretroviral drugs is extending the lives of those who already have HIV and PrEP is helping at-risk people keep themselves from getting HIV in the first place.
But HIV is still a lifetime concern for those who are at elevated risk and those who become infected. The first step to making sure you stay healthy and avoid passing this potentially deadly disease along is to find out your status by getting tested.
Centers for Disease Control and Prevention, HIV/AIDS, HIV and Youth. (2019). Retrieved from https://www.cdc.gov/hiv/group/age/youth/index.html
Centers for Disease Control and Prevention, HIV/AIDS, Basic Statistics. (2019). Retrieved from https://www.cdc.gov/hiv/basics/statistics.html
Centers for Disease Control and Prevention, HIV Surveillance Report: Diagnoses of HIV Infection in the United States and Dependent Areas, 2016. (2017). Retrieved from https://www.cdc.gov/hiv/pdf/library/reports/surveillance/cdc-hiv-surveillance-report-2016-vol-28.pdf
World Health Organization, HIV/AIDS, Data and statistics. (Undated). Retrieved from https://www.who.int/hiv/data/en/
World Health Organization, Global Health Observatory data repository, Number of people (all ages) living with HIV Estimates by WHO region. (2017). Retrieved from http://apps.who.int/gho/data/view.main.22100WHO?lang=en